clarify when history.channel-length applies (#2323)

Rename the constants only; no functional change

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
       - name: "setup go"
         uses: "actions/setup-go@v3"
         with:
-          go-version: "1.24"
+          go-version: "1.25"
       - name: "install python3-pytest"
         run: "sudo apt install -y python3-pytest"
       - name: "make install"

CHANGELOG.md

@@ -1,6 +1,37 @@
 # Changelog
 All notable changes to Ergo will be documented in this file.
 
+## [2.17.0] - 2025-12-22
+
+We're pleased to be publishing v2.17.0, a new stable release. This release adds support for the [IRCv3 metadata specification](https://ircv3.net/specs/extensions/metadata), thanks to [@thatcher-gaming](https://github.com/thatcher-gaming), as well as bug fixes and minor updates.
+
+This release includes changes to the config file format, all of which are fully backwards-compatible and do not require updating the file before upgrading. It includes no changes to the database file format.
+
+Many thanks to [@branchgrove](https://github.com/branchgrove), [@Brutus5000](https://github.com/Brutus5000), [@progval](https://github.com/progval), [@SarahRoseLives](https://github.com/SarahRoseLives), [@thatcher-gaming](https://github.com/thatcher-gaming), [@ValwareIRC](https://github.com/ValwareIRC), and Xogium for contributing patches, reporting issues, and helping test.
+
+### Config changes
+* Added `accounts.metadata` block to configure the new metadata feature. If this block is absent, metadata is disabled. See `default.yaml` for an example. (#2273)
+* Added `server.idle-timeouts` for configurable idle timeouts; when unset, the previous hardcoded defaults are used (#2292, thanks [@Brutus5000](https://github.com/Brutus5000)!)
+* Added `server.oper-throttle` to configure throttling for failed `OPER` attempts; when unset, this defaults to 1 attempt every 10 seconds (#2296)
+
+### Added
+* Implemented support for the [draft/metadata-2](https://ircv3.net/specs/extensions/metadata) specification, allowing clients to set and retrieve metadata on accounts and channels (#2273, #2277, #2281, #2282, #2301, thanks [@thatcher-gaming](https://github.com/thatcher-gaming)!)
+* Added `/v1/status` and `/v1/account_list` HTTP API endpoints (#2261, thanks [@SarahRoseLives](https://github.com/SarahRoseLives)!)
+* Enhanced `/v1/account_details` API response with additional fields (#2261, thanks [@SarahRoseLives](https://github.com/SarahRoseLives)!)
+
+### Fixed
+* Fixed `REGISTER` command to strip guest format when applicable, matching `NS REGISTER` behavior (#2270, #2271, thanks [@ValwareIRC](https://github.com/ValwareIRC) and [@thatcher-gaming](https://github.com/thatcher-gaming)!)
+* Fixed invalid `FAIL` codes in `REGISTER` command (#2269, thanks [@ValwareIRC](https://github.com/ValwareIRC)!)
+* Fixed validation of web push URLs to reject non-HTTPS URLs (#2295)
+* Fixed inconsistent behavior when `history.enabled` is set but `history.chathistory-maxmessages` is not (#2303, #2304, thanks [@branchgrove](https://github.com/branchgrove)!)
+
+### Changed
+* The `OPER` command now imposes a throttle on all attempts, never disconnects the client on failure, and logs non-sensitive information about failed attempts (#2296, #2298, thanks Xogium!)
+
+### Internal
+* Official release builds use Go 1.25 (#2290)
+* Upgraded the Docker base image from Alpine 3.19 to 3.22 (#2306)
+
 ## [2.16.0] - 2025-05-18
 We're pleased to be publishing v2.16.0, a new stable release. This release contains bug fixes and some minor updates.
 
@@ -9,6 +40,7 @@ This release includes changes to the config file format, all of which are fully
 Many thanks to [@csmith](https://github.com/csmith), [@delthas](https://github.com/delthas), donio, [@emersion](https://github.com/emersion), [@KlaasT](https://github.com/KlaasT), [@knolley](https://github.com/knolley), [@Mailaender](https://github.com/Mailaender), and [@prdes](https://github.com/prdes) for reporting issues and helping test.
 
 ### Config changes
+* Added `api` block for configuring the new HTTP API. If this block is absent, the API is disabled (#2231)
 * Added `server.additional-isupport` for publishing arbitrary ISUPPORT tokens (#2220, #2240)
 * Added `server.command-aliases` to configure aliases for server commands (#2229, #2236)
 * Added options to `roleplay` to customize the NUH's sent for `NPC` and `SCENE`. Roleplay remains deprecated and disabled by default. (#2237)

Dockerfile

@@ -1,5 +1,5 @@
 ## build ergo binary
-FROM docker.io/golang:1.24-alpine AS build-env
+FROM docker.io/golang:1.25-alpine3.22 AS build-env
 
 RUN apk upgrade -U --force-refresh --no-cache && apk add --no-cache --purge --clean-protected -l -u make git
 
@@ -16,7 +16,7 @@ RUN sed -i 's/^\(\s*\)\"127.0.0.1:6667\":.*$/\1":6667":/' /go/src/github.com/erg
 RUN make install
 
 ## build ergo container
-FROM docker.io/alpine:3.19
+FROM docker.io/alpine:3.22
 
 # metadata
 LABEL maintainer="Daniel Oaks <daniel@danieloaks.net>,Daniel Thamdrup <dallemon@protonmail.com>" \

Makefile

@@ -1,5 +1,3 @@
-.PHONY: all install build release capdefs test smoke gofmt irctest
-
 GIT_COMMIT := $(shell git rev-parse HEAD 2> /dev/null)
 GIT_TAG := $(shell git tag --points-at HEAD 2> /dev/null | head -n 1)
 
@@ -9,33 +7,42 @@ export CGO_ENABLED ?= 0
 
 capdef_file = ./irc/caps/defs.go
 
+.PHONY: all
 all: build
 
+.PHONY: install
 install:
 	go install -v -ldflags "-X main.commit=$(GIT_COMMIT) -X main.version=$(GIT_TAG)"
 
+.PHONY: build
 build:
 	go build -v -ldflags "-X main.commit=$(GIT_COMMIT) -X main.version=$(GIT_TAG)"
 
+.PHONY: release
 release:
 	goreleaser --skip=publish --clean
 
+.PHONY: capdefs
 capdefs:
 	python3 ./gencapdefs.py > ${capdef_file}
 
+.PHONY: test
 test:
 	python3 ./gencapdefs.py | diff - ${capdef_file}
 	go test ./...
 	go vet ./...
 	./.check-gofmt.sh
 
+.PHONY: smoke
 smoke: install
 	ergo mkcerts --conf ./default.yaml || true
 	ergo run --conf ./default.yaml --smoke
 
+.PHONY: gofmt
 gofmt:
 	./.check-gofmt.sh --fix
 
+.PHONY: irctest
 irctest: install
 	git submodule update --init
 	cd irctest && make ergo

default.yaml

@@ -180,6 +180,21 @@ server:
     # if this is true, the motd is escaped using formatting codes like $c, $b, and $i
     motd-formatting: true
 
+    # send a configurable notice to clients immediately after they connect,
+    # as a way of detecting open proxies
+    #initial-notice: "*** Welcome to the Ergo IRC server"
+
+    # idle timeouts for inactive clients
+    idle-timeouts:
+        # give the client this long to complete connection registration (i.e. the initial
+        # IRC handshake, including capability negotiation and SASL)
+        registration: 60s
+        # if the client hasn't sent anything for this long, send them a PING
+        ping: 1m30s
+        # if the client hasn't sent anything for this long (including the PONG to the
+        # above PING), disconnect them
+        disconnect: 2m30s
+
     # relaying using the RELAYMSG command
     relaymsg:
         # is relaymsg enabled at all?
@@ -358,6 +373,10 @@ server:
     secure-nets:
         # - "10.0.0.0/8"
 
+    # allow attempts to OPER with a password at most this often. defaults to
+    # 10 seconds when unset.
+    oper-throttle: 10s
+
     # Ergo will write files to disk under certain circumstances, e.g.,
     # CPU profiling or data export. by default, these files will be written
     # to the working directory. set this to customize:
@@ -522,7 +541,7 @@ accounts:
         # 1. these nicknames cannot be registered or reserved
         # 2. if a client is automatically renamed by the server,
         #    this is the template that will be used (e.g., Guest-nccj6rgmt97cg)
-        # 3. if enforce-guest-format (see below) is enabled, clients without
+        # 3. if force-guest-format (see below) is enabled, clients without
         #    a registered account will have this template applied to their
         #    nicknames (e.g., 'katie' will become 'Guest-katie')
         guest-nickname-format: "Guest-*"
@@ -724,6 +743,7 @@ oper-classes:
             - "history"      # modify or delete history messages
             - "defcon"       # use the DEFCON command (restrict server capabilities)
             - "massmessage"  # message all users on the server
+            - "metadata"     # modify arbitrary metadata on channels and users
 
 # ircd operators
 opers:
@@ -987,10 +1007,12 @@ history:
     # in your country and the countries of your users.
     enabled: true
 
-    # how many channel-specific events (messages, joins, parts) should be tracked per channel?
+    # if the in-memory backend is enabled for a channel, how many channel-specific events
+    # (messages, joins, parts) should be retained?
     channel-length: 2048
 
-    # how many direct messages and notices should be tracked per user?
+    # if the in-memory backend is enabled for a user, how many direct messages
+    # and notices should be retained?
     client-length: 256
 
     # how long should we try to preserve messages?
@@ -1087,6 +1109,20 @@ history:
 # e.g., ERGO__SERVER__MAX_SENDQ=128k. see the manual for more details.
 allow-environment-overrides: true
 
+# metadata support for setting key/value data on channels and nicknames.
+metadata:
+    # can clients store metadata?
+    enabled: true
+    # how many keys can a client subscribe to?
+    max-subs: 100
+    # how many keys can be stored per entity?
+    max-keys: 100
+    # rate limiting for client metadata updates, which are expensive to process
+    client-throttle:
+        enabled: true
+        duration: 2m
+        max-attempts: 10
+
 # experimental support for mobile push notifications
 # see the manual for potential security, privacy, and performance implications.
 # DO NOT enable if you are running a Tor or I2P hidden service (i.e. one

docs/API.md

@@ -51,6 +51,8 @@ The response is a JSON object with fields:
 * `success`: whether the account exists or not
 * `accountName`: canonical, case-unfolded version of the account name
 * `email`: email address of the account provided
+* `registeredAt`: string, registration date/time of the account (in ISO8601 format)
+* `channels`: array of strings, list of channels the account is registered on or associated with
 
 `/v1/check_auth`
 ----------------
@@ -86,3 +88,37 @@ The response is a JSON object with fields:
 * `success`: whether the account creation succeeded
 * `errorCode`: string, optional, machine-readable description of the error. Possible values include: `ACCOUNT_EXISTS`, `INVALID_PASSPHRASE`, `UNKNOWN_ERROR`.
 * `error`: string, optional, human-readable description of the failure.
+
+`/v1/account_list`
+-------------------
+
+This endpoint fetches a list of all accounts. The request body is ignored and can be empty.
+
+The response is a JSON object with fields:
+
+* `success`: whether the request succeeded
+* `accounts`: array of objects, each with fields:
+  * `success`: boolean, whether this individual account query succeeded
+  * `accountName`: string, canonical, case-unfolded version of the account name
+* `totalCount`: integer, total number of accounts returned
+
+
+`/v1/status`
+-------------
+
+This endpoint returns status information about the running Ergo server. The request body is ignored and can be empty.
+
+The response is a JSON object with fields:
+
+* `success`: whether the request succeeded
+* `version`: string, Ergo server version string
+* `go_version`: string, version of Go runtime used
+* `start_time`: string, server start time in ISO8601 format
+* `users`: object with fields:
+  * `total`: total number of users connected
+  * `invisible`: number of invisible users
+  * `operators`: number of operators connected
+  * `unknown`: number of users with unknown status
+  * `max`: maximum number of users seen connected at once
+* `channels`: integer, number of channels currently active
+* `servers`: integer, number of servers connected in the network

docs/MANUAL.md

@@ -171,6 +171,7 @@ Rehashing also reloads TLS certificates and the MOTD. Some configuration setting
 
 Ergo can also be configured using environment variables, using the following technique:
 
+1. Ensure that `allow-environment-variables` is set to `true` in the YAML config file itself (see `default.yaml` for an example)
 1. Find the "path" of the config variable you want to override in the YAML file, e.g., `server.websockets.allowed-origins`
 1. Convert each path component from "kebab case" to "screaming snake case", e.g., `SERVER`, `WEBSOCKETS`, and `ALLOWED_ORIGINS`.
 1. Prepend `ERGO` to the components, then join them all together using `__` as the separator, e.g., `ERGO__SERVER__WEBSOCKETS__ALLOWED_ORIGINS`.
@@ -526,7 +527,7 @@ If your client or bot is failing to connect to Ergo, here are some things to che
 
 ## Why can't I oper?
 
-If you try to oper unsuccessfully, Ergo will disconnect you from the network. If you're unable to oper, here are some things to double-check:
+If your `OPER` command fails, check your server logs for more information. Here are some general issues to double-check:
 
 1. Did you correctly generate the hashed password with `ergo genpasswd`?
 1. Did you add the password hash to the correct config file, then save the file?
@@ -1071,9 +1072,12 @@ You can import user and channel registrations from an Anope or Atheme database i
 
 ## Hybrid Open Proxy Monitor (HOPM)
 
-[hopm](https://github.com/ircd-hybrid/hopm) can be used to monitor your server for connections from open proxies, then automatically ban them. To configure hopm to work with Ergo, add operator blocks like this to your Ergo config file, which grant hopm the necessary privileges:
+[hopm](https://github.com/ircd-hybrid/hopm) can be used to monitor your server for connections from open proxies, then automatically ban them. To configure hopm to work with Ergo, configure `server.initial_notice` and add operator blocks like this to your Ergo config file, which grant hopm the necessary privileges:
 
 ````yaml
+server:
+    initial-notice: "Welcome to the Ergo IRC server"
+
 # operator classes
 oper-classes:
     # hopm
@@ -1108,6 +1112,9 @@ opers:
 Then configure hopm like this:
 
 ````
+/* replace with the exact notice your server sends on first connection */
+target_string = ":ergo.test NOTICE * :*** Welcome to the Ergo IRC server"
+
 /* ergo */
 connregex = ".+-.+CONNECT.+-.+ Client Connected \\[([^ ]+)\\] \\[u:([^ ]+)\\] \\[h:([^ ]+)\\] \\[ip:([^ ]+)\\] .+";
 

docs/USERGUIDE.md

@@ -86,7 +86,7 @@ Once you've registered your nickname, you can use it to register channels. By de
 /msg ChanServ register #myChannel
 ```
 
-You must already be an operator (have the `+o` channel mode --- your client may display this as an `@` next to your nickname). If you're not a channel operator in the channel you want to register, ask your server administrator for help.
+The channel must exist (if it doesn't, you can create it with `/join #myChannel`) and you must already be an operator (have the `+o` channel mode --- your client may display this as an `@` next to your nickname). If you're not a channel operator in the channel you want to register, ask your server administrator for help.
 
 # Always-on
 

gencapdefs.py

@@ -237,6 +237,13 @@ CAPDEFS = [
         url="https://github.com/ircv3/ircv3-specifications/pull/471",
         standard="Soju/Goguma vendor",
     ),
+    CapDef(
+        identifier="Metadata",
+        name="draft/metadata-2",
+        url="https://ircv3.net/specs/extensions/metadata",
+        standard="draft IRCv3",
+    ),
+
 ]
 
 def validate_defs():

go.mod

@@ -1,6 +1,6 @@
 module github.com/ergochat/ergo
 
-go 1.24
+go 1.25
 
 require (
 	code.cloudfoundry.org/bytefmt v0.0.0-20200131002437-cf55d5288a48
@@ -9,7 +9,7 @@ require (
 	github.com/ergochat/confusables v0.0.0-20201108231250-4ab98ab61fb1
 	github.com/ergochat/go-ident v0.0.0-20230911071154-8c30606d6881
 	github.com/ergochat/irc-go v0.5.0-rc2
-	github.com/go-sql-driver/mysql v1.7.0
+	github.com/go-sql-driver/mysql v1.9.3
 	github.com/gofrs/flock v0.8.1
 	github.com/gorilla/websocket v1.4.2
 	github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd
@@ -18,19 +18,20 @@ require (
 	github.com/stretchr/testify v1.4.0 // indirect
 	github.com/tidwall/buntdb v1.3.2
 	github.com/xdg-go/scram v1.0.2
-	golang.org/x/crypto v0.32.0
-	golang.org/x/term v0.28.0
-	golang.org/x/text v0.21.0
+	golang.org/x/crypto v0.46.0
+	golang.org/x/term v0.38.0
+	golang.org/x/text v0.32.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
-	github.com/emersion/go-msgauth v0.6.8
+	github.com/emersion/go-msgauth v0.7.0
 	github.com/ergochat/webpush-go/v2 v2.0.0
-	github.com/golang-jwt/jwt/v5 v5.2.2
+	github.com/golang-jwt/jwt/v5 v5.3.0
 )
 
 require (
+	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/tidwall/btree v1.4.2 // indirect
 	github.com/tidwall/gjson v1.14.3 // indirect
 	github.com/tidwall/grect v0.1.4 // indirect
@@ -39,7 +40,7 @@ require (
 	github.com/tidwall/rtred v0.1.2 // indirect
 	github.com/tidwall/tinyqueue v0.1.1 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
-	golang.org/x/sys v0.29.0 // indirect
+	golang.org/x/sys v0.39.0 // indirect
 )
 
 replace github.com/gorilla/websocket => github.com/ergochat/websocket v1.4.2-oragono1

go.sum

@@ -1,13 +1,15 @@
 code.cloudfoundry.org/bytefmt v0.0.0-20200131002437-cf55d5288a48 h1:/EMHruHCFXR9xClkGV/t0rmHrdhX4+trQUcBqjwc9xE=
 code.cloudfoundry.org/bytefmt v0.0.0-20200131002437-cf55d5288a48/go.mod h1:wN/zk7mhREp/oviagqUXY3EwuHhWyOvAdsn5Y4CzOrc=
+filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
+filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
 github.com/GehirnInc/crypt v0.0.0-20200316065508-bb7000b8a962 h1:KeNholpO2xKjgaaSyd+DyQRrsQjhbSeS7qe4nEw8aQw=
 github.com/GehirnInc/crypt v0.0.0-20200316065508-bb7000b8a962/go.mod h1:kC29dT1vFpj7py2OvG1khBdQpo3kInWP+6QipLbdngo=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815 h1:bWDMxwH3px2JBh6AyO7hdCn/PkvCZXii8TGj7sbtEbQ=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
-github.com/emersion/go-msgauth v0.6.8 h1:kW/0E9E8Zx5CdKsERC/WnAvnXvX7q9wTHia1OA4944A=
-github.com/emersion/go-msgauth v0.6.8/go.mod h1:YDwuyTCUHu9xxmAeVj0eW4INnwB6NNZoPdLerpSxRrc=
+github.com/emersion/go-msgauth v0.7.0 h1:vj2hMn6KhFtW41kshIBTXvp6KgYSqpA/ZN9Pv4g1INc=
+github.com/emersion/go-msgauth v0.7.0/go.mod h1:mmS9I6HkSovrNgq0HNXTeu8l3sRAAuQ9RMvbM4KU7Ck=
 github.com/ergochat/confusables v0.0.0-20201108231250-4ab98ab61fb1 h1:WLHTOodthVyv5NvYLIvWl112kSFv5IInKKrRN2qpons=
 github.com/ergochat/confusables v0.0.0-20201108231250-4ab98ab61fb1/go.mod h1:mov+uh1DPWsltdQnOdzn08UO9GsJ3MEvhtu0Ci37fdk=
 github.com/ergochat/go-ident v0.0.0-20230911071154-8c30606d6881 h1:+J5m88nvybxB5AnBVGzTXM/yHVytt48rXBGcJGzSbms=
@@ -21,12 +23,12 @@ github.com/ergochat/webpush-go/v2 v2.0.0/go.mod h1:OQlhnq8JeHDzRzAy6bdDObr19uqbH
 github.com/ergochat/websocket v1.4.2-oragono1 h1:plMUunFBM6UoSCIYCKKclTdy/TkkHfUslhOfJQzfueM=
 github.com/ergochat/websocket v1.4.2-oragono1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
-github.com/go-sql-driver/mysql v1.7.0 h1:ueSltNNllEqE3qcWBTD0iQd3IpL/6U+mJxLkazJ7YPc=
-github.com/go-sql-driver/mysql v1.7.0/go.mod h1:OXbVy3sEdcQ2Doequ6Z5BW6fXNQTmx+9S1MCJN5yJMI=
+github.com/go-sql-driver/mysql v1.9.3 h1:U/N249h2WzJ3Ukj8SowVFjdtZKfu9vlLZxjPXV1aweo=
+github.com/go-sql-driver/mysql v1.9.3/go.mod h1:qn46aNg1333BRMNU69Lq93t8du/dwxI64Gl8i5p1WMU=
 github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
-github.com/golang-jwt/jwt/v5 v5.2.2 h1:Rl4B7itRWVtYIHFrSNd7vhTiz9UpLdi6gZhZ3wEeDy8=
-github.com/golang-jwt/jwt/v5 v5.2.2/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
+github.com/golang-jwt/jwt/v5 v5.3.0 h1:pv4AsKCKKZuqlgs5sUmn4x8UlGa0kEVt/puTpKx9vvo=
+github.com/golang-jwt/jwt/v5 v5.3.0/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArsqaEUEa5bE=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
@@ -68,22 +70,22 @@ github.com/xdg-go/pbkdf2 v1.0.0 h1:Su7DPu48wXMwC3bs7MCNG+z4FhcyEuz5dlvchbq0B0c=
 github.com/xdg-go/pbkdf2 v1.0.0/go.mod h1:jrpuAogTd400dnrH08LKmI/xc1MbPOebTwRqcT5RDeI=
 github.com/xdg-go/stringprep v1.0.2 h1:6iq84/ryjjeRmMJwxutI51F2GIPlP5BfTvXHeYjyhBc=
 github.com/xdg-go/stringprep v1.0.2/go.mod h1:8F9zXuvzgwmyT5DUm4GUfZGDdT3W+LCvS6+da4O5kxM=
-golang.org/x/crypto v0.32.0 h1:euUpcYgM8WcP71gNpTqQCn6rC2t6ULUPiOzfWaXVVfc=
-golang.org/x/crypto v0.32.0/go.mod h1:ZnnJkOaASj8g0AjIduWNlq2NRxL0PlBrbKVyZ6V/Ugc=
+golang.org/x/crypto v0.46.0 h1:cKRW/pmt1pKAfetfu+RCEvjvZkA9RimPbh7bhFjGVBU=
+golang.org/x/crypto v0.46.0/go.mod h1:Evb/oLKmMraqjZ2iQTwDwvCtJkczlDuTmdJXoZVzqU0=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
-golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
+golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
+golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
-golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.28.0 h1:/Ts8HFuMR2E6IP/jlo7QVLZHggjKQbhu/7H0LJFr3Gg=
-golang.org/x/term v0.28.0/go.mod h1:Sw/lC2IAUZ92udQNf3WodGtn4k/XoLyZoh8v/8uiwek=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/term v0.38.0 h1:PQ5pkm/rLO6HnxFR7N2lJHOZX6Kez5Y1gDSJla6jo7Q=
+golang.org/x/term v0.38.0/go.mod h1:bSEAKrOT1W+VSu9TSCMtoGEOUcKxOKgl3LE5QEF/xVg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
-golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
+golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

irc/accounts.go

@@ -52,6 +52,7 @@ const (
 	// (not to be confused with their amodes, which a non-always-on client can have):
 	keyAccountChannelToModes    = "account.channeltomodes %s"
 	keyAccountPushSubscriptions = "account.pushsubscriptions %s"
+	keyAccountMetadata          = "account.metadata %s"
 
 	maxCertfpsPerAccount = 5
 )
@@ -137,6 +138,7 @@ func (am *AccountManager) createAlwaysOnClients(config *Config) {
 				am.loadModes(accountName),
 				am.loadRealname(accountName),
 				am.loadPushSubscriptions(accountName),
+				am.loadMetadata(accountName),
 			)
 		}
 	}
@@ -751,6 +753,40 @@ func (am *AccountManager) loadPushSubscriptions(account string) (result []stored
 	}
 }
 
+func (am *AccountManager) saveMetadata(account string, metadata map[string]string) {
+	j, err := json.Marshal(metadata)
+	if err != nil {
+		am.server.logger.Error("internal", "error storing metadata", err.Error())
+		return
+	}
+	val := string(j)
+	key := fmt.Sprintf(keyAccountMetadata, account)
+	am.server.store.Update(func(tx *buntdb.Tx) error {
+		tx.Set(key, val, nil)
+		return nil
+	})
+	return
+}
+
+func (am *AccountManager) loadMetadata(account string) (result map[string]string) {
+	key := fmt.Sprintf(keyAccountMetadata, account)
+	var val string
+	am.server.store.View(func(tx *buntdb.Tx) error {
+		val, _ = tx.Get(key)
+		return nil
+	})
+
+	if val == "" {
+		return nil
+	}
+	if err := json.Unmarshal([]byte(val), &result); err == nil {
+		return result
+	} else {
+		am.server.logger.Error("internal", "error loading metadata", err.Error())
+		return nil
+	}
+}
+
 func (am *AccountManager) addRemoveCertfp(account, certfp string, add bool, hasPrivs bool) (err error) {
 	certfp, err = utils.NormalizeCertfp(certfp)
 	if err != nil {
@@ -1880,6 +1916,7 @@ func (am *AccountManager) Unregister(account string, erase bool) error {
 	pwResetKey := fmt.Sprintf(keyAccountPwReset, casefoldedAccount)
 	emailChangeKey := fmt.Sprintf(keyAccountEmailChange, casefoldedAccount)
 	pushSubscriptionsKey := fmt.Sprintf(keyAccountPushSubscriptions, casefoldedAccount)
+	metadataKey := fmt.Sprintf(keyAccountMetadata, casefoldedAccount)
 
 	var clients []*Client
 	defer func() {
@@ -1939,6 +1976,7 @@ func (am *AccountManager) Unregister(account string, erase bool) error {
 		tx.Delete(pwResetKey)
 		tx.Delete(emailChangeKey)
 		tx.Delete(pushSubscriptionsKey)
+		tx.Delete(metadataKey)
 
 		return nil
 	})
@@ -2299,7 +2337,7 @@ func (ac *AccountCredentials) Serialize() (result string, err error) {
 	return string(credText), nil
 }
 
-func (ac *AccountCredentials) SetPassphrase(passphrase string, bcryptCost uint) (err error) {
+func (ac *AccountCredentials) SetPassphrase(passphrase string, bcryptCost int) (err error) {
 	if passphrase == "" {
 		ac.PassphraseHash = nil
 		ac.SCRAMCreds = SCRAMCreds{}
@@ -2310,7 +2348,7 @@ func (ac *AccountCredentials) SetPassphrase(passphrase string, bcryptCost uint)
 		return errAccountBadPassphrase
 	}
 
-	ac.PassphraseHash, err = passwd.GenerateFromPassword([]byte(passphrase), int(bcryptCost))
+	ac.PassphraseHash, err = passwd.GenerateFromPassword([]byte(passphrase), bcryptCost)
 	if err != nil {
 		return errAccountBadPassphrase
 	}

irc/api.go

@@ -5,7 +5,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"runtime"
 	"strings"
+
+	"github.com/ergochat/ergo/irc/utils"
 )
 
 func newAPIHandler(server *Server) http.Handler {
@@ -18,6 +21,8 @@ func newAPIHandler(server *Server) http.Handler {
 	api.mux.HandleFunc("POST /v1/check_auth", api.handleCheckAuth)
 	api.mux.HandleFunc("POST /v1/saregister", api.handleSaregister)
 	api.mux.HandleFunc("POST /v1/account_details", api.handleAccountDetails)
+	api.mux.HandleFunc("POST /v1/account_list", api.handleAccountList)
+	api.mux.HandleFunc("POST /v1/status", api.handleStatus)
 
 	return api
 }
@@ -29,7 +34,6 @@ type ergoAPI struct {
 
 func (a *ergoAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	defer a.server.HandlePanic(nil)
-
 	defer a.server.logger.Debug("api", r.URL.Path)
 
 	if a.checkBearerAuth(r.Header.Get("Authorization")) {
@@ -117,8 +121,6 @@ func (a *ergoAPI) handleCheckAuth(w http.ResponseWriter, r *http.Request) {
 
 	// try passphrase if present
 	if request.AccountName != "" && request.Passphrase != "" {
-		// TODO this only checks the internal database, not auth-script;
-		// it's a little weird to use both auth-script and the API but we should probably handle it
 		account, err := a.server.accounts.checkPassphrase(request.AccountName, request.Passphrase)
 		switch err {
 		case nil:
@@ -133,7 +135,6 @@ func (a *ergoAPI) handleCheckAuth(w http.ResponseWriter, r *http.Request) {
 			response.Error = err.Error()
 		}
 	}
-
 	// try certfp if present
 	if !response.Success && request.Certfp != "" {
 		// TODO support cerftp
@@ -175,8 +176,10 @@ func (a *ergoAPI) handleSaregister(w http.ResponseWriter, r *http.Request) {
 
 type apiAccountDetailsResponse struct {
 	apiGenericResponse
-	AccountName string `json:"accountName,omitempty"`
-	Email       string `json:"email,omitempty"`
+	AccountName  string   `json:"accountName,omitempty"`
+	Email        string   `json:"email,omitempty"`
+	RegisteredAt string   `json:"registeredAt,omitempty"`
+	Channels     []string `json:"channels,omitempty"`
 }
 
 type apiAccountDetailsRequest struct {
@@ -191,8 +194,6 @@ func (a *ergoAPI) handleAccountDetails(w http.ResponseWriter, r *http.Request) {
 
 	var response apiAccountDetailsResponse
 
-	// TODO could probably use better error handling and more details
-
 	if request.AccountName != "" {
 		accountData, err := a.server.accounts.LoadAccount(request.AccountName)
 		if err == nil {
@@ -207,6 +208,12 @@ func (a *ergoAPI) handleAccountDetails(w http.ResponseWriter, r *http.Request) {
 		case nil:
 			response.AccountName = accountData.Name
 			response.Email = accountData.Settings.Email
+			if !accountData.RegisteredAt.IsZero() {
+				response.RegisteredAt = accountData.RegisteredAt.Format(utils.IRCv3TimestampFormat)
+			}
+
+			// Get channels the account is in
+			response.Channels = a.server.channels.ChannelsForAccount(accountData.NameCasefolded)
 			response.Success = true
 		case errAccountDoesNotExist, errAccountUnverified, errAccountSuspended:
 			response.Success = false
@@ -222,3 +229,83 @@ func (a *ergoAPI) handleAccountDetails(w http.ResponseWriter, r *http.Request) {
 
 	a.writeJSONResponse(response, w, r)
 }
+
+type apiAccountListResponse struct {
+	apiGenericResponse
+	Accounts   []apiAccountDetailsResponse `json:"accounts"`
+	TotalCount int                         `json:"totalCount"`
+}
+
+func (a *ergoAPI) handleAccountList(w http.ResponseWriter, r *http.Request) {
+	var response apiAccountListResponse
+
+	// Get all account names
+	accounts := a.server.accounts.AllNicks()
+	response.TotalCount = len(accounts)
+
+	// Load account details
+	response.Accounts = make([]apiAccountDetailsResponse, len(accounts))
+	for i, account := range accounts {
+		accountData, err := a.server.accounts.LoadAccount(account)
+		if err != nil {
+			response.Accounts[i] = apiAccountDetailsResponse{
+				apiGenericResponse: apiGenericResponse{
+					Success: false,
+					Error:   err.Error(),
+				},
+			}
+			continue
+		}
+
+		response.Accounts[i] = apiAccountDetailsResponse{
+			apiGenericResponse: apiGenericResponse{
+				Success: true,
+			},
+			AccountName: accountData.Name,
+			Email:       accountData.Settings.Email,
+		}
+	}
+
+	response.Success = true
+	a.writeJSONResponse(response, w, r)
+}
+
+type apiStatusResponse struct {
+	apiGenericResponse
+	Version   string `json:"version"`
+	GoVersion string `json:"go_version"`
+	Commit    string `json:"commit,omitempty"`
+	StartTime string `json:"start_time"`
+	Users     struct {
+		Total     int `json:"total"`
+		Invisible int `json:"invisible"`
+		Operators int `json:"operators"`
+		Unknown   int `json:"unknown"`
+		Max       int `json:"max"`
+	} `json:"users"`
+	Channels int `json:"channels"`
+	Servers  int `json:"servers"`
+}
+
+func (a *ergoAPI) handleStatus(w http.ResponseWriter, r *http.Request) {
+	server := a.server
+	stats := server.stats.GetValues()
+
+	response := apiStatusResponse{
+		apiGenericResponse: apiGenericResponse{Success: true},
+		Version:            SemVer,
+		GoVersion:          runtime.Version(),
+		Commit:             Commit,
+		StartTime:          server.ctime.Format(utils.IRCv3TimestampFormat),
+	}
+
+	response.Users.Total = stats.Total
+	response.Users.Invisible = stats.Invisible
+	response.Users.Operators = stats.Operators
+	response.Users.Unknown = stats.Unknown
+	response.Users.Max = stats.Max
+	response.Channels = server.channels.Len()
+	response.Servers = 1
+
+	a.writeJSONResponse(response, w, r)
+}

irc/bunt/bunt_datastore.go

@@ -44,10 +44,11 @@ func (b *buntdbDatastore) GetAll(table datastore.Table) (result []datastore.KV,
 	tablePrefix := fmt.Sprintf("%x ", table)
 	err = b.db.View(func(tx *buntdb.Tx) error {
 		err := tx.AscendGreaterOrEqual("", tablePrefix, func(key, value string) bool {
-			if !strings.HasPrefix(key, tablePrefix) {
+			encUUID, ok := strings.CutPrefix(key, tablePrefix)
+			if !ok {
 				return false
 			}
-			uuid, err := utils.DecodeUUID(strings.TrimPrefix(key, tablePrefix))
+			uuid, err := utils.DecodeUUID(encUUID)
 			if err == nil {
 				result = append(result, datastore.KV{UUID: uuid, Value: []byte(value)})
 			} else {

irc/caps/defs.go

@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 37
+	numCapabs = 38
 	// length of the uint32 array that represents the bitset:
 	bitsetLen = 2
 )
@@ -65,6 +65,10 @@ const (
 	// https://github.com/progval/ircv3-specifications/blob/redaction/extensions/message-redaction.md
 	MessageRedaction Capability = iota
 
+	// Metadata is the draft IRCv3 capability named "draft/metadata-2":
+	// https://ircv3.net/specs/extensions/metadata
+	Metadata Capability = iota
+
 	// Multiline is the proposed IRCv3 capability named "draft/multiline":
 	// https://github.com/ircv3/ircv3-specifications/pull/398
 	Multiline Capability = iota
@@ -178,6 +182,7 @@ var (
 		"draft/extended-isupport",
 		"draft/languages",
 		"draft/message-redaction",
+		"draft/metadata-2",
 		"draft/multiline",
 		"draft/no-implicit-names",
 		"draft/persistence",

irc/channel.go

@@ -7,6 +7,7 @@ package irc
 
 import (
 	"fmt"
+	"iter"
 	"maps"
 	"strconv"
 	"strings"
@@ -55,6 +56,7 @@ type Channel struct {
 	dirtyBits         uint
 	settings          ChannelSettings
 	uuid              utils.UUID
+	metadata          map[string]string
 	// these caches are paired to allow iteration over channel members without holding the lock
 	membersCache    []*Client
 	memberDataCache []*memberData
@@ -126,6 +128,7 @@ func (channel *Channel) applyRegInfo(chanReg RegisteredChannel) {
 	channel.userLimit = chanReg.UserLimit
 	channel.settings = chanReg.Settings
 	channel.forward = chanReg.Forward
+	channel.metadata = chanReg.Metadata
 
 	for _, mode := range chanReg.Modes {
 		channel.flags.SetMode(mode, true)
@@ -163,6 +166,7 @@ func (channel *Channel) ExportRegistration() (info RegisteredChannel) {
 	info.AccountToUMode = maps.Clone(channel.accountToUMode)
 
 	info.Settings = channel.settings
+	info.Metadata = channel.metadata
 
 	return
 }
@@ -726,6 +730,9 @@ func (channel *Channel) AddHistoryItem(item history.Item, account string) (err e
 	status, target, _ := channel.historyStatus(channel.server.Config())
 	if status == HistoryPersistent {
 		err = channel.server.historyDB.AddChannelItem(target, item, account)
+		if err != nil {
+			channel.server.logger.Error("history", "could not add channel message to history", err.Error())
+		}
 	} else if status == HistoryEphemeral {
 		channel.history.Add(item)
 	}
@@ -892,6 +899,10 @@ func (channel *Channel) Join(client *Client, key string, isSajoin bool, rb *Resp
 		rb.Add(nil, client.server.name, "MARKREAD", chname, client.GetReadMarker(chcfname))
 	}
 
+	if rb.session.capabilities.Has(caps.Metadata) {
+		syncChannelMetadata(client.server, rb, channel)
+	}
+
 	if rb.session.client == client {
 		// don't send topic and names for a SAJOIN of a different client
 		channel.SendTopic(client, rb, false)
@@ -1462,8 +1473,8 @@ func (channel *Channel) ShowMaskList(client *Client, mode modes.Mode, rb *Respon
 		rpllist = RPL_EXCEPTLIST
 		rplendoflist = RPL_ENDOFEXCEPTLIST
 	} else if mode == modes.InviteMask {
-		rpllist = RPL_INVITELIST
-		rplendoflist = RPL_ENDOFINVITELIST
+		rpllist = RPL_INVEXLIST
+		rplendoflist = RPL_ENDOFINVEXLIST
 	}
 
 	nick := client.Nick()
@@ -1669,6 +1680,20 @@ func (channel *Channel) auditoriumFriends(client *Client) (friends []*Client) {
 	return
 }
 
+func (channel *Channel) sessionsWithCaps(capabs ...caps.Capability) iter.Seq[*Session] {
+	return func(yield func(*Session) bool) {
+		for _, member := range channel.Members() {
+			for _, sess := range member.Sessions() {
+				if sess.capabilities.HasAll(capabs...) {
+					if !yield(sess) {
+						return
+					}
+				}
+			}
+		}
+	}
+}
+
 // returns whether the client is visible to unprivileged users in the channel
 // (i.e., respecting auditorium mode). note that this assumes that the client
 // is a member; if the client is not, it may return true anyway

irc/channelmanager.go

@@ -206,6 +206,10 @@ func (cm *ChannelManager) Cleanup(channel *Channel) {
 }
 
 func (cm *ChannelManager) SetRegistered(channelName string, account string) (err error) {
+	if account == "" {
+		return errAuthRequired // this is already enforced by ChanServ, but do a final check
+	}
+
 	if cm.server.Defcon() <= 4 {
 		return errFeatureDisabled
 	}

irc/channelreg.go

@@ -63,6 +63,8 @@ type RegisteredChannel struct {
 	Invites map[string]MaskInfo
 	// Settings are the chanserv-modifiable settings
 	Settings ChannelSettings
+	// Metadata set using the METADATA command
+	Metadata map[string]string
 }
 
 func (r *RegisteredChannel) Serialize() ([]byte, error) {

irc/client.go

@@ -41,8 +41,7 @@ const (
 	DefaultMaxLineLen = 512
 
 	// IdentTimeout is how long before our ident (username) check times out.
-	IdentTimeout         = time.Second + 500*time.Millisecond
-	IRCv3TimestampFormat = utils.IRCv3TimestampFormat
+	IdentTimeout = time.Second + 500*time.Millisecond
 	// limit the number of device IDs a client can use, as a DoS mitigation
 	maxDeviceIDsPerClient = 64
 	// maximum total read markers that can be stored
@@ -54,18 +53,16 @@ const (
 	pushQueueLengthPerClient = 16
 )
 
+var (
+	// idle timeouts for client connections, set from the config
+	RegisterTimeout, PingTimeout, DisconnectTimeout time.Duration
+)
+
 const (
-	// RegisterTimeout is how long clients have to register before we disconnect them
-	RegisterTimeout = time.Minute
-	// DefaultIdleTimeout is how long without traffic before we send the client a PING
-	DefaultIdleTimeout = time.Minute + 30*time.Second
 	// For Tor clients, we send a PING at least every 30 seconds, as a workaround for this bug
 	// (single-onion circuits will close unless the client sends data once every 60 seconds):
 	// https://bugs.torproject.org/29665
-	TorIdleTimeout = time.Second * 30
-	// This is how long a client gets without sending any message, including the PONG to our
-	// PING, before we disconnect them:
-	DefaultTotalTimeout = 2*time.Minute + 30*time.Second
+	TorPingTimeout = time.Second * 30
 
 	// round off the ping interval by this much, see below:
 	PingCoalesceThreshold = time.Second
@@ -132,6 +129,8 @@ type Client struct {
 	clearablePushMessages   map[string]time.Time
 	pushSubscriptionsExist  atomic.Uint32 // this is a cache on len(pushSubscriptions) != 0
 	pushQueue               pushQueue
+	metadata                map[string]string
+	metadataThrottle        connection_limits.ThrottleDetails
 }
 
 type saslStatus struct {
@@ -189,6 +188,8 @@ type Session struct {
 	fakelag              Fakelag
 	deferredFakelagCount int
 
+	lastOperAttempt time.Time
+
 	certfp     string
 	peerCerts  []*x509.Certificate
 	sasl       saslStatus
@@ -215,6 +216,9 @@ type Session struct {
 	batch MultilineBatch
 
 	webPushEndpoint string // goroutine-local: web push endpoint registered by the current session
+
+	metadataSubscriptions utils.HashSet[string]
+	metadataPreregVals    map[string]string
 }
 
 // MultilineBatch tracks the state of a client-to-server multiline batch.
@@ -410,6 +414,11 @@ func (server *Server) RunClient(conn IRCConn) {
 		session.certfp, session.peerCerts, _ = utils.GetCertFP(wConn.Conn, RegisterTimeout)
 	}
 
+	if config.Server.InitialNotice != "" {
+		// send initial notice for HOPM to recognize
+		client.Send(nil, client.server.name, "NOTICE", "*", config.Server.InitialNotice)
+	}
+
 	if session.isTor {
 		session.rawHostname = config.Server.TorListeners.Vhost
 		client.rawHostname = session.rawHostname
@@ -424,7 +433,7 @@ func (server *Server) RunClient(conn IRCConn) {
 	client.run(session)
 }
 
-func (server *Server) AddAlwaysOnClient(account ClientAccount, channelToStatus map[string]alwaysOnChannelStatus, lastSeen, readMarkers map[string]time.Time, uModes modes.Modes, realname string, pushSubscriptions []storedPushSubscription) {
+func (server *Server) AddAlwaysOnClient(account ClientAccount, channelToStatus map[string]alwaysOnChannelStatus, lastSeen, readMarkers map[string]time.Time, uModes modes.Modes, realname string, pushSubscriptions []storedPushSubscription, metadata map[string]string) {
 	now := time.Now().UTC()
 	config := server.Config()
 	if lastSeen == nil && account.Settings.AutoreplayMissed {
@@ -509,6 +518,10 @@ func (server *Server) AddAlwaysOnClient(account ClientAccount, channelToStatus m
 		}
 	}
 	client.rebuildPushSubscriptionCache()
+
+	if len(metadata) != 0 {
+		client.metadata = metadata
+	}
 }
 
 func (client *Client) resizeHistory(config *Config) {
@@ -675,7 +688,7 @@ func (client *Client) run(session *Session) {
 	isReattach := client.Registered()
 	if isReattach {
 		client.Touch(session)
-		client.playReattachMessages(session)
+		client.performReattach(session)
 	}
 
 	firstLine := !isReattach
@@ -775,7 +788,9 @@ func (client *Client) run(session *Session) {
 	}
 }
 
-func (client *Client) playReattachMessages(session *Session) {
+func (client *Client) performReattach(session *Session) {
+	client.applyPreregMetadata(session)
+
 	client.server.playRegistrationBurst(session)
 	hasHistoryCaps := session.HasHistoryCaps()
 	for _, channel := range session.client.Channels() {
@@ -799,6 +814,34 @@ func (client *Client) playReattachMessages(session *Session) {
 	session.autoreplayMissedSince = time.Time{}
 }
 
+func (client *Client) applyPreregMetadata(session *Session) {
+	if session.metadataPreregVals == nil {
+		return
+	}
+
+	defer func() {
+		session.metadataPreregVals = nil
+	}()
+
+	updates := client.UpdateMetadataFromPrereg(session.metadataPreregVals, client.server.Config().Metadata.MaxKeys)
+	if len(updates) == 0 {
+		return
+	}
+
+	// TODO this is expensive
+	friends := client.FriendsMonitors(caps.Metadata)
+	for _, s := range client.Sessions() {
+		if s != session {
+			friends.Add(s)
+		}
+	}
+
+	target := client.Nick()
+	for k, v := range updates {
+		broadcastMetadataUpdate(client.server, maps.Keys(friends), session, target, k, v, true)
+	}
+}
+
 //
 // idle, quit, timers and timeouts
 //
@@ -830,19 +873,19 @@ func (client *Client) updateIdleTimer(session *Session, now time.Time) {
 	session.pingSent = false
 
 	if session.idleTimer == nil {
-		pingTimeout := DefaultIdleTimeout
-		if session.isTor {
-			pingTimeout = TorIdleTimeout
+		pingTimeout := PingTimeout
+		if session.isTor && TorPingTimeout < pingTimeout {
+			pingTimeout = TorPingTimeout
 		}
 		session.idleTimer = time.AfterFunc(pingTimeout, session.handleIdleTimeout)
 	}
 }
 
 func (session *Session) handleIdleTimeout() {
-	totalTimeout := DefaultTotalTimeout
-	pingTimeout := DefaultIdleTimeout
-	if session.isTor {
-		pingTimeout = TorIdleTimeout
+	totalTimeout := DisconnectTimeout
+	pingTimeout := PingTimeout
+	if session.isTor && TorPingTimeout < pingTimeout {
+		pingTimeout = TorPingTimeout
 	}
 
 	session.client.stateMutex.Lock()
@@ -1130,6 +1173,7 @@ func (client *Client) SetNick(nick, nickCasefolded, skeleton string) (success bo
 	client.nickCasefolded = nickCasefolded
 	client.skeleton = skeleton
 	client.updateNickMaskNoMutex()
+
 	return true
 }
 
@@ -1363,7 +1407,7 @@ func (client *Client) destroy(session *Session) {
 
 	// alert monitors
 	if registered {
-		client.server.monitorManager.AlertAbout(details.nick, details.nickCasefolded, false)
+		client.server.monitorManager.AlertAbout(details.nick, details.nickCasefolded, false, nil)
 	}
 
 	// clean up channels
@@ -1463,7 +1507,7 @@ func (session *Session) sendFromClientInternal(blocking bool, serverTime time.Ti
 
 func composeMultilineBatch(batchID, fromNickMask, fromAccount string, isBot bool, tags map[string]string, command, target string, message utils.SplitMessage) (result []ircmsg.Message) {
 	batchStart := ircmsg.MakeMessage(tags, fromNickMask, "BATCH", "+"+batchID, caps.MultilineBatchType, target)
-	batchStart.SetTag("time", message.Time.Format(IRCv3TimestampFormat))
+	batchStart.SetTag("time", message.Time.Format(utils.IRCv3TimestampFormat))
 	batchStart.SetTag("msgid", message.Msgid)
 	if fromAccount != "*" {
 		batchStart.SetTag("account", fromAccount)
@@ -1571,7 +1615,7 @@ func (session *Session) setTimeTag(msg *ircmsg.Message, serverTime time.Time) {
 		if serverTime.IsZero() {
 			serverTime = time.Now()
 		}
-		msg.SetTag("time", serverTime.UTC().Format(IRCv3TimestampFormat))
+		msg.SetTag("time", serverTime.UTC().Format(utils.IRCv3TimestampFormat))
 	}
 }
 
@@ -1730,12 +1774,15 @@ func (client *Client) addHistoryItem(target *Client, item history.Item, details,
 	}
 	if cStatus == HistoryPersistent || tStatus == HistoryPersistent {
 		targetedItem.CfCorrespondent = ""
-		client.server.historyDB.AddDirectMessage(details.nickCasefolded, details.account, tDetails.nickCasefolded, tDetails.account, targetedItem)
+		err = client.server.historyDB.AddDirectMessage(details.nickCasefolded, details.account, tDetails.nickCasefolded, tDetails.account, targetedItem)
+		if err != nil {
+			client.server.logger.Error("history", "could not add direct message to history", err.Error())
+		}
 	}
 	return nil
 }
 
-func (client *Client) listTargets(start, end history.Selector, limit int) (results []history.TargetListing, err error) {
+func (client *Client) listTargets(start, end time.Time, limit int) (results []history.TargetListing, err error) {
 	var base, extras []history.TargetListing
 	var chcfnames []string
 	for _, channel := range client.Channels() {
@@ -1756,27 +1803,35 @@ func (client *Client) listTargets(start, end history.Selector, limit int) (resul
 		}
 	}
 	persistentExtras, err := client.server.historyDB.ListChannels(chcfnames)
-	if err == nil && len(persistentExtras) != 0 {
+	if err != nil {
+		client.server.logger.Error("history", "could not list persistent channels", err.Error())
+	} else if len(persistentExtras) != 0 {
 		extras = append(extras, persistentExtras...)
 	}
 
-	_, cSeq, err := client.server.GetHistorySequence(nil, client, "")
-	if err == nil && cSeq != nil {
-		correspondents, err := cSeq.ListCorrespondents(start, end, limit)
-		if err == nil {
-			base = correspondents
-		}
+	// get DM correspondents from the in-memory buffer or the database, as applicable
+	var cErr error
+	status, target := client.historyStatus(client.server.Config())
+	switch status {
+	case HistoryEphemeral:
+		base, cErr = client.history.ListCorrespondents(start, end, limit)
+	case HistoryPersistent:
+		base, cErr = client.server.historyDB.ListCorrespondents(target, start, end, limit)
+	default:
+		// nothing to do
+	}
+	if cErr != nil {
+		base = nil
+		client.server.logger.Error("history", "could not list correspondents", cErr.Error())
 	}
 
-	results = history.MergeTargets(base, extras, start.Time, end.Time, limit)
+	results = history.MergeTargets(base, extras, start, end, limit)
 	return results, nil
 }
 
 // latest PRIVMSG from all DM targets
 func (client *Client) privmsgsBetween(startTime, endTime time.Time, targetLimit, messageLimit int) (results []history.Item, err error) {
-	start := history.Selector{Time: startTime}
-	end := history.Selector{Time: endTime}
-	targets, err := client.listTargets(start, end, targetLimit)
+	targets, err := client.listTargets(startTime, endTime, targetLimit)
 	if err != nil {
 		return
 	}
@@ -1786,7 +1841,7 @@ func (client *Client) privmsgsBetween(startTime, endTime time.Time, targetLimit,
 		}
 		_, seq, err := client.server.GetHistorySequence(nil, client, target.CfName)
 		if err == nil && seq != nil {
-			items, err := seq.Between(start, end, messageLimit)
+			items, err := seq.Between(history.Selector{Time: startTime}, history.Selector{Time: endTime}, messageLimit)
 			if err == nil {
 				results = append(results, items...)
 			} else {
@@ -1815,6 +1870,7 @@ const (
 	IncludeUserModes
 	IncludeRealname
 	IncludePushSubscriptions
+	IncludeMetadata
 )
 
 func (client *Client) markDirty(dirtyBits uint) {
@@ -1896,6 +1952,9 @@ func (client *Client) performWrite(additionalDirtyBits uint) {
 	if (dirtyBits & IncludePushSubscriptions) != 0 {
 		client.server.accounts.savePushSubscriptions(account, client.getPushSubscriptions(true))
 	}
+	if (dirtyBits & IncludeMetadata) != 0 {
+		client.server.accounts.saveMetadata(account, client.ListMetadata())
+	}
 }
 
 // Blocking store; see Channel.Store and Socket.BlockingWrite

irc/commands.go

@@ -209,6 +209,11 @@ func init() {
 			handler:   markReadHandler,
 			minParams: 0, // send FAIL instead of ERR_NEEDMOREPARAMS
 		},
+		"METADATA": {
+			handler:      metadataHandler,
+			minParams:    2,
+			usablePreReg: true,
+		},
 		"MODE": {
 			handler:   modeHandler,
 			minParams: 1,

irc/config.go

@@ -45,6 +45,10 @@ import (
 	"github.com/ergochat/ergo/irc/webpush"
 )
 
+const (
+	defaultProxyDeadline = time.Minute
+)
+
 // here's how this works: exported (capitalized) members of the config structs
 // are defined in the YAML file and deserialized directly from there. They may
 // be postprocessed and overwritten by LoadConfig. Unexported (lowercase) members
@@ -371,7 +375,7 @@ type AccountRegistrationConfig struct {
 		Mailto email.MailtoConfig
 	} `yaml:"callbacks"`
 	VerifyTimeout custime.Duration `yaml:"verify-timeout"`
-	BcryptCost    uint             `yaml:"bcrypt-cost"`
+	BcryptCost    int              `yaml:"bcrypt-cost"`
 }
 
 type VHostConfig struct {
@@ -576,8 +580,14 @@ type Config struct {
 		CoerceIdent             string `yaml:"coerce-ident"`
 		MOTD                    string
 		motdLines               []string
-		MOTDFormatting          bool `yaml:"motd-formatting"`
-		Relaymsg                struct {
+		MOTDFormatting          bool   `yaml:"motd-formatting"`
+		InitialNotice           string `yaml:"initial-notice"`
+		IdleTimeouts            struct {
+			Registration time.Duration
+			Ping         time.Duration
+			Disconnect   time.Duration
+		} `yaml:"idle-timeouts"`
+		Relaymsg struct {
 			Enabled            bool
 			Separators         string
 			AvailableToChanops bool `yaml:"available-to-chanops"`
@@ -599,6 +609,7 @@ type Config struct {
 		Cloaks                   cloaks.CloakConfig              `yaml:"ip-cloaking"`
 		SecureNetDefs            []string                        `yaml:"secure-nets"`
 		secureNets               []net.IPNet
+		OperThrottle             time.Duration `yaml:"oper-throttle"`
 		supportedCaps            *caps.Set
 		supportedCapsWithoutSTS  *caps.Set
 		capValues                caps.Values
@@ -723,6 +734,14 @@ type Config struct {
 		} `yaml:"tagmsg-storage"`
 	}
 
+	Metadata struct {
+		Enabled        bool
+		MaxSubs        int            `yaml:"max-subs"`
+		MaxKeys        int            `yaml:"max-keys"`
+		MaxValueBytes  int            `yaml:"max-value-length"`
+		ClientThrottle ThrottleConfig `yaml:"client-throttle"`
+	}
+
 	WebPush struct {
 		Enabled          bool
 		Timeout          time.Duration
@@ -979,7 +998,7 @@ func (conf *Config) prepareListeners() (err error) {
 	conf.Server.trueListeners = make(map[string]utils.ListenerConfig)
 	for addr, block := range conf.Server.Listeners {
 		var lconf utils.ListenerConfig
-		lconf.ProxyDeadline = RegisterTimeout
+		lconf.ProxyDeadline = defaultProxyDeadline
 		lconf.Tor = block.Tor
 		lconf.STSOnly = block.STSOnly
 		if lconf.STSOnly && !conf.Server.STS.Enabled {
@@ -1229,6 +1248,23 @@ func LoadConfig(filename string) (config *Config, err error) {
 		}
 	}
 
+	if config.Server.IdleTimeouts.Registration <= 0 {
+		config.Server.IdleTimeouts.Registration = time.Minute
+	}
+	if config.Server.IdleTimeouts.Ping <= 0 {
+		config.Server.IdleTimeouts.Ping = time.Minute + 30*time.Second
+	}
+	if config.Server.IdleTimeouts.Disconnect <= 0 {
+		config.Server.IdleTimeouts.Disconnect = 2*time.Minute + 30*time.Second
+	}
+
+	if !(config.Server.IdleTimeouts.Ping < config.Server.IdleTimeouts.Disconnect) {
+		return nil, fmt.Errorf(
+			"ping timeout %v must be strictly less than disconnect timeout %v, to give the client time to respond",
+			config.Server.IdleTimeouts.Ping, config.Server.IdleTimeouts.Disconnect,
+		)
+	}
+
 	if config.Server.CoerceIdent != "" {
 		if config.Server.CheckIdent {
 			return nil, errors.New("Can't configure both check-ident and coerce-ident")
@@ -1473,6 +1509,10 @@ func LoadConfig(filename string) (config *Config, err error) {
 		config.Server.supportedCaps.Disable(caps.SASL)
 	}
 
+	if config.Server.OperThrottle <= 0 {
+		config.Server.OperThrottle = 10 * time.Second
+	}
+
 	if err := config.Accounts.OAuth2.Postprocess(); err != nil {
 		return nil, err
 	}
@@ -1556,6 +1596,12 @@ func LoadConfig(filename string) (config *Config, err error) {
 	if config.Accounts.Registration.BcryptCost == 0 {
 		config.Accounts.Registration.BcryptCost = passwd.DefaultCost
 	}
+	if config.Accounts.Registration.BcryptCost < passwd.MinCost || config.Accounts.Registration.BcryptCost > passwd.MaxCost {
+		return nil, fmt.Errorf(
+			"invalid bcrypt-cost %d (require %d <= cost <= %d)",
+			config.Accounts.Registration.BcryptCost, passwd.MinCost, passwd.MaxCost,
+		)
+	}
 
 	if config.Channels.MaxChannelsPerClient == 0 {
 		config.Channels.MaxChannelsPerClient = 100
@@ -1572,7 +1618,7 @@ func LoadConfig(filename string) (config *Config, err error) {
 	// in the current implementation, we disable history by creating a history buffer
 	// with zero capacity. but the `enabled` config option MUST be respected regardless
 	// of this detail
-	if !config.History.Enabled {
+	if !config.History.Enabled || config.History.ChathistoryMax == 0 {
 		config.History.ChannelLength = 0
 		config.History.ClientLength = 0
 		config.Server.supportedCaps.Disable(caps.Chathistory)
@@ -1637,6 +1683,27 @@ func LoadConfig(filename string) (config *Config, err error) {
 		}
 	}
 
+	if !config.Metadata.Enabled {
+		config.Server.supportedCaps.Disable(caps.Metadata)
+	} else {
+		metadataValues := make([]string, 0, 4)
+		metadataValues = append(metadataValues, "before-connect")
+		// these are required for normal operation, so set sane defaults:
+		if config.Metadata.MaxSubs == 0 {
+			config.Metadata.MaxSubs = 10
+		}
+		metadataValues = append(metadataValues, fmt.Sprintf("max-subs=%d", config.Metadata.MaxSubs))
+		if config.Metadata.MaxKeys == 0 {
+			config.Metadata.MaxKeys = 10
+		}
+		metadataValues = append(metadataValues, fmt.Sprintf("max-keys=%d", config.Metadata.MaxKeys))
+		// this is not required since we enforce a hardcoded upper bound on key+value
+		if config.Metadata.MaxValueBytes > 0 {
+			metadataValues = append(metadataValues, fmt.Sprintf("max-value-bytes=%d", config.Metadata.MaxValueBytes))
+		}
+		config.Server.capValues[caps.Metadata] = strings.Join(metadataValues, ",")
+	}
+
 	err = config.processExtjwt()
 	if err != nil {
 		return nil, err

irc/errors.go

@@ -33,6 +33,7 @@ var (
 	errAccountVerificationInvalidCode = errors.New("Invalid account verification code")
 	errAccountUpdateFailed            = errors.New(`Error while updating your account information`)
 	errAccountMustHoldNick            = errors.New(`You must hold that nickname in order to register it`)
+	errAuthRequired                   = errors.New("You must be logged into an account to do this")
 	errAuthzidAuthcidMismatch         = errors.New(`authcid and authzid must be the same`)
 	errCertfpAlreadyExists            = errors.New(`An account already exists for your certificate fingerprint`)
 	errChannelNotOwnedByAccount       = errors.New("Channel not owned by the specified account")

irc/getters.go

@@ -7,9 +7,11 @@ import (
 	"fmt"
 	"maps"
 	"net"
+	"slices"
 	"time"
 
 	"github.com/ergochat/ergo/irc/caps"
+	"github.com/ergochat/ergo/irc/connection_limits"
 	"github.com/ergochat/ergo/irc/languages"
 	"github.com/ergochat/ergo/irc/modes"
 	"github.com/ergochat/ergo/irc/utils"
@@ -517,7 +519,7 @@ func (client *Client) GetReadMarker(cfname string) (result string) {
 	t, ok := client.readMarkers[cfname]
 	client.stateMutex.RUnlock()
 	if ok {
-		return fmt.Sprintf("timestamp=%s", t.Format(IRCv3TimestampFormat))
+		return fmt.Sprintf("timestamp=%s", t.Format(utils.IRCv3TimestampFormat))
 	}
 	return "*"
 }
@@ -797,10 +799,12 @@ func (channel *Channel) Settings() (result ChannelSettings) {
 }
 
 func (channel *Channel) SetSettings(settings ChannelSettings) {
+	defer channel.MarkDirty(IncludeSettings)
+
 	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+
 	channel.settings = settings
-	channel.stateMutex.Unlock()
-	channel.MarkDirty(IncludeSettings)
 }
 
 func (channel *Channel) setForward(forward string) {
@@ -827,3 +831,262 @@ func (channel *Channel) UUID() utils.UUID {
 	defer channel.stateMutex.RUnlock()
 	return channel.uuid
 }
+
+func (session *Session) isSubscribedTo(key string) bool {
+	session.client.stateMutex.RLock()
+	defer session.client.stateMutex.RUnlock()
+
+	return session.metadataSubscriptions.Has(key)
+}
+
+func (session *Session) SubscribeTo(keys ...string) ([]string, error) {
+	maxSubs := session.client.server.Config().Metadata.MaxSubs
+
+	session.client.stateMutex.Lock()
+	defer session.client.stateMutex.Unlock()
+
+	if session.metadataSubscriptions == nil {
+		session.metadataSubscriptions = make(utils.HashSet[string])
+	}
+
+	var added []string
+
+	for _, k := range keys {
+		if !session.metadataSubscriptions.Has(k) {
+			if len(session.metadataSubscriptions) > maxSubs {
+				return added, errMetadataTooManySubs
+			}
+			added = append(added, k)
+			session.metadataSubscriptions.Add(k)
+		}
+	}
+
+	return added, nil
+}
+
+func (session *Session) UnsubscribeFrom(keys ...string) []string {
+	session.client.stateMutex.Lock()
+	defer session.client.stateMutex.Unlock()
+
+	var removed []string
+
+	for k := range session.metadataSubscriptions {
+		if slices.Contains(keys, k) {
+			removed = append(removed, k)
+			session.metadataSubscriptions.Remove(k)
+		}
+	}
+
+	return removed
+}
+
+func (session *Session) MetadataSubscriptions() utils.HashSet[string] {
+	session.client.stateMutex.Lock()
+	defer session.client.stateMutex.Unlock()
+
+	return maps.Clone(session.metadataSubscriptions)
+}
+
+func (channel *Channel) GetMetadata(key string) (string, bool) {
+	channel.stateMutex.RLock()
+	defer channel.stateMutex.RUnlock()
+
+	val, ok := channel.metadata[key]
+	return val, ok
+}
+
+func (channel *Channel) SetMetadata(key string, value string, limit int) (updated bool, err error) {
+	defer channel.MarkDirty(IncludeAllAttrs)
+
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+
+	if channel.metadata == nil {
+		channel.metadata = make(map[string]string)
+	}
+
+	existing, ok := channel.metadata[key]
+	if !ok && len(channel.metadata) >= limit {
+		return false, errLimitExceeded
+	}
+	updated = !ok || value != existing
+	if updated {
+		channel.metadata[key] = value
+	}
+	return updated, nil
+}
+
+func (channel *Channel) ListMetadata() map[string]string {
+	channel.stateMutex.RLock()
+	defer channel.stateMutex.RUnlock()
+
+	return maps.Clone(channel.metadata)
+}
+
+func (channel *Channel) DeleteMetadata(key string) (updated bool) {
+	defer channel.MarkDirty(IncludeAllAttrs)
+
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+
+	_, updated = channel.metadata[key]
+	if updated {
+		delete(channel.metadata, key)
+	}
+	return updated
+}
+
+func (channel *Channel) ClearMetadata() map[string]string {
+	defer channel.MarkDirty(IncludeAllAttrs)
+	channel.stateMutex.Lock()
+	defer channel.stateMutex.Unlock()
+
+	oldMap := channel.metadata
+	channel.metadata = nil
+
+	return oldMap
+}
+
+func (channel *Channel) CountMetadata() int {
+	channel.stateMutex.RLock()
+	defer channel.stateMutex.RUnlock()
+
+	return len(channel.metadata)
+}
+
+func (client *Client) GetMetadata(key string) (string, bool) {
+	client.stateMutex.RLock()
+	defer client.stateMutex.RUnlock()
+
+	val, ok := client.metadata[key]
+	return val, ok
+}
+
+func (client *Client) SetMetadata(key string, value string, limit int) (updated bool, err error) {
+	var alwaysOn bool
+	defer func() {
+		if alwaysOn && updated {
+			client.markDirty(IncludeMetadata)
+		}
+	}()
+
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+
+	alwaysOn = client.registered && client.alwaysOn
+
+	if client.metadata == nil {
+		client.metadata = make(map[string]string)
+	}
+
+	existing, ok := client.metadata[key]
+	if !ok && len(client.metadata) >= limit {
+		return false, errLimitExceeded
+	}
+	updated = !ok || value != existing
+	if updated {
+		client.metadata[key] = value
+	}
+	return updated, nil
+}
+
+func (client *Client) UpdateMetadataFromPrereg(preregData map[string]string, limit int) (updates map[string]string) {
+	var alwaysOn bool
+	defer func() {
+		if alwaysOn && len(updates) > 0 {
+			client.markDirty(IncludeMetadata)
+		}
+	}()
+
+	updates = make(map[string]string, len(preregData))
+
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+
+	alwaysOn = client.registered && client.alwaysOn
+
+	if client.metadata == nil {
+		client.metadata = make(map[string]string)
+	}
+
+	for k, v := range preregData {
+		// do not overwrite any existing keys
+		_, ok := client.metadata[k]
+		if ok {
+			continue
+		}
+		if len(client.metadata) >= limit {
+			return // we know this is a new key
+		}
+		client.metadata[k] = v
+		updates[k] = v
+	}
+
+	return
+}
+
+func (client *Client) ListMetadata() map[string]string {
+	client.stateMutex.RLock()
+	defer client.stateMutex.RUnlock()
+
+	return maps.Clone(client.metadata)
+}
+
+func (client *Client) DeleteMetadata(key string) (updated bool) {
+	defer func() {
+		if updated {
+			client.markDirty(IncludeMetadata)
+		}
+	}()
+
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+
+	_, updated = client.metadata[key]
+	if updated {
+		delete(client.metadata, key)
+	}
+	return updated
+}
+
+func (client *Client) ClearMetadata() (oldMap map[string]string) {
+	defer func() {
+		if len(oldMap) > 0 {
+			client.markDirty(IncludeMetadata)
+		}
+	}()
+
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+
+	oldMap = client.metadata
+	client.metadata = nil
+
+	return oldMap
+}
+
+func (client *Client) CountMetadata() int {
+	client.stateMutex.RLock()
+	defer client.stateMutex.RUnlock()
+
+	return len(client.metadata)
+}
+
+func (client *Client) checkMetadataThrottle() (throttled bool, remainingTime time.Duration) {
+	config := client.server.Config()
+	if !config.Metadata.ClientThrottle.Enabled {
+		return false, 0
+	}
+
+	client.stateMutex.Lock()
+	defer client.stateMutex.Unlock()
+
+	// copy client.metadataThrottle locally and then back for processing
+	var throttle connection_limits.GenericThrottle
+	throttle.ThrottleDetails = client.metadataThrottle
+	throttle.Duration = config.Metadata.ClientThrottle.Duration
+	throttle.Limit = config.Metadata.ClientThrottle.MaxAttempts
+	throttled, remainingTime = throttle.Touch()
+	client.metadataThrottle = throttle.ThrottleDetails
+	return
+}

irc/handlers.go

@@ -9,11 +9,13 @@ package irc
 import (
 	"bytes"
 	"fmt"
+	"maps"
 	"net"
 	"os"
 	"runtime"
 	"runtime/debug"
 	"runtime/pprof"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -149,11 +151,8 @@ func (server *Server) sendLoginSnomask(nickMask, accountName string) {
 // to indicate that it should be removed from the list
 func acceptHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) bool {
 	for _, tNick := range strings.Split(msg.Params[0], ",") {
-		add := true
-		if strings.HasPrefix(tNick, "-") {
-			add = false
-			tNick = strings.TrimPrefix(tNick, "-")
-		}
+		tNick, negPrefix := strings.CutPrefix(tNick, "-")
+		add := !negPrefix
 
 		target := server.clients.Get(tNick)
 		if target == nil {
@@ -701,11 +700,13 @@ func chathistoryHandler(server *Server, client *Client, msg ircmsg.Message, rb *
 	var channel *Channel
 	var sequence history.Sequence
 	var err error
-	var listTargets bool
+	var disabled, listTargets bool
 	var targets []history.TargetListing
 	defer func() {
 		// errors are sent either without a batch, or in a draft/labeled-response batch as usual
-		if err == utils.ErrInvalidParams {
+		if disabled {
+			rb.Add(nil, server.name, "FAIL", "CHATHISTORY", "MESSAGE_ERROR", msg.Params[0], client.t("That feature is disabled"))
+		} else if err == utils.ErrInvalidParams {
 			rb.Add(nil, server.name, "FAIL", "CHATHISTORY", "INVALID_PARAMS", msg.Params[0], client.t("Invalid parameters"))
 		} else if !listTargets && sequence == nil {
 			rb.Add(nil, server.name, "FAIL", "CHATHISTORY", "INVALID_TARGET", msg.Params[0], utils.SafeErrorParam(target), client.t("Messages could not be retrieved"))
@@ -719,7 +720,7 @@ func chathistoryHandler(server *Server, client *Client, msg ircmsg.Message, rb *
 				for _, target := range targets {
 					name := server.UnfoldName(target.CfName)
 					rb.Add(nil, server.name, "CHATHISTORY", "TARGETS", name,
-						target.Time.Format(IRCv3TimestampFormat))
+						target.Time.Format(utils.IRCv3TimestampFormat))
 				}
 			} else if channel != nil {
 				channel.replayHistoryItems(rb, items, true)
@@ -731,7 +732,8 @@ func chathistoryHandler(server *Server, client *Client, msg ircmsg.Message, rb *
 
 	config := server.Config()
 	maxChathistoryLimit := config.History.ChathistoryMax
-	if maxChathistoryLimit == 0 {
+	if !config.History.Enabled || maxChathistoryLimit == 0 {
+		disabled = true
 		return
 	}
 	preposition := strings.ToLower(msg.Params[0])
@@ -754,7 +756,7 @@ func chathistoryHandler(server *Server, client *Client, msg ircmsg.Message, rb *
 			msgid, err = history.NormalizeMsgid(value), nil
 			return
 		} else if identifier == "timestamp" {
-			timestamp, err = time.Parse(IRCv3TimestampFormat, value)
+			timestamp, err = time.Parse(utils.IRCv3TimestampFormat, value)
 			if err == nil {
 				timestamp = timestamp.UTC()
 				if timestamp.Before(unixEpoch) {
@@ -842,7 +844,12 @@ func chathistoryHandler(server *Server, client *Client, msg ircmsg.Message, rb *
 	}
 
 	if listTargets {
-		targets, err = client.listTargets(start, end, limit)
+		// TARGETS must take time= selectors
+		if start.Time.IsZero() || end.Time.IsZero() {
+			err = utils.ErrInvalidParams
+			return
+		}
+		targets, err = client.listTargets(start.Time, end.Time, limit)
 	} else {
 		channel, sequence, err = server.GetHistorySequence(nil, client, target)
 		if err != nil || sequence == nil {
@@ -2546,8 +2553,19 @@ func operHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 		return false
 	}
 
+	config := server.Config()
+	now := time.Now()
+	nextAllowableAttempt := rb.session.lastOperAttempt.Add(config.Server.OperThrottle)
+	if now.Before(nextAllowableAttempt) {
+		timeLeft := nextAllowableAttempt.Sub(now).Round(time.Millisecond)
+		rb.Add(nil, server.name, ERR_NOOPERHOST, client.Nick(), fmt.Sprintf(client.t("You must wait %v before issuing OPER again"), timeLeft))
+		return false
+	}
+
+	rb.session.lastOperAttempt = now
+
 	// must pass at least one check, and all enabled checks
-	var checkPassed, checkFailed, passwordFailed bool
+	var checkPassed, checkFailed, certFailed, passwordFailed bool
 	oper := server.GetOperator(msg.Params[0])
 	if oper != nil {
 		if oper.Certfp != "" {
@@ -2555,11 +2573,13 @@ func operHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 				checkPassed = true
 			} else {
 				checkFailed = true
+				certFailed = true
 			}
 		}
 		if !checkFailed && oper.Pass != nil {
 			if len(msg.Params) == 1 {
 				checkFailed = true
+				passwordFailed = true
 			} else if bcrypt.CompareHashAndPassword(oper.Pass, []byte(msg.Params[1])) != nil {
 				checkFailed = true
 				passwordFailed = true
@@ -2570,14 +2590,21 @@ func operHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 	}
 
 	if !checkPassed || checkFailed {
-		rb.Add(nil, server.name, ERR_PASSWDMISMATCH, client.Nick(), client.t("Password incorrect"))
-		// #951: only disconnect them if we actually tried to check a password for them
-		if passwordFailed {
-			client.Quit(client.t("Password incorrect"), rb.session)
-			return true
+		rb.Add(nil, server.name, ERR_NOOPERHOST, client.Nick(), client.t("OPER failed; check the server logs for details."))
+
+		// hopefully not too spammy given the throttling:
+		if oper == nil {
+			server.logger.Info("opers", "OPER failed with invalid oper name", msg.Params[0])
+		} else if certFailed {
+			server.logger.Info("opers", "OPER attempt for", msg.Params[0], "failed with invalid certfp")
+		} else if passwordFailed {
+			server.logger.Info("opers", "OPER attempt for", msg.Params[0], "failed with invalid password")
 		} else {
-			return false
+			// should not be possible given config validation
+			server.logger.Info("opers", "OPER attempt for", msg.Params[0], "failed with invalid config")
 		}
+
+		return false
 	}
 
 	if oper != nil {
@@ -2770,8 +2797,10 @@ func redactHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 	targetmsgid := msg.Params[1]
 	//clientOnlyTags := msg.ClientOnlyTags()
 	var reason string
+	var reasonPresent bool
 	if len(msg.Params) > 2 {
 		reason = msg.Params[2]
+		reasonPresent = true
 	}
 	var members []*Client // members of a channel, or both parties of a PM
 	var canDelete CanDelete
@@ -2784,7 +2813,7 @@ func redactHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 	if target[0] == '#' {
 		channel := server.channels.Get(target)
 		if channel == nil {
-			rb.Add(nil, server.name, ERR_NOSUCHCHANNEL, client.Nick(), utils.SafeErrorParam(target), client.t("No such channel"))
+			rb.Add(nil, server.name, "FAIL", "REDACT", "INVALID_TARGET", utils.SafeErrorParam(target), client.t("No such channel"))
 			return false
 		}
 		members = channel.Members()
@@ -2813,10 +2842,16 @@ func redactHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 	}
 
 	err := server.DeleteMessage(target, targetmsgid, accountName)
-	if err == errNoop {
+	switch err {
+	case history.ErrNotFound:
 		rb.Add(nil, server.name, "FAIL", "REDACT", "UNKNOWN_MSGID", utils.SafeErrorParam(target), utils.SafeErrorParam(targetmsgid), client.t("This message does not exist or is too old"))
 		return false
-	} else if err != nil {
+	case history.ErrDisallowed:
+		rb.Add(nil, server.name, "FAIL", "REDACT", "REDACT_FORBIDDEN", utils.SafeErrorParam(target), utils.SafeErrorParam(targetmsgid), client.t("You are not authorized to delete this message"))
+		return false
+	case nil:
+		// OK
+	default:
 		isOper := client.HasRoleCapabs("history")
 		if isOper {
 			rb.Add(nil, server.name, "FAIL", "REDACT", "REDACT_FORBIDDEN", utils.SafeErrorParam(target), utils.SafeErrorParam(targetmsgid), fmt.Sprintf(client.t("Error deleting message: %v"), err))
@@ -2831,7 +2866,8 @@ func redactHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 		// now we have to remove it from the buffer of the client who sent the REDACT command
 		err := server.DeleteMessage(client.Nick(), targetmsgid, accountName)
 
-		if err != nil {
+		// ErrNotFound is expected if both clients are using persistent history
+		if err != nil && err != history.ErrNotFound {
 			client.server.logger.Error("internal", fmt.Sprintf("Private message %s is not deletable by %s from their own buffer's even though we just deleted it from %s's. This is a bug, please report it in details.", targetmsgid, client.Nick(), target), client.Nick())
 			isOper := client.HasRoleCapabs("history")
 			if isOper {
@@ -2845,7 +2881,11 @@ func redactHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 	for _, member := range members {
 		for _, session := range member.Sessions() {
 			if session.capabilities.Has(caps.MessageRedaction) {
-				session.sendFromClientInternal(false, time, msgid, details.nickMask, details.accountName, isBot, nil, "REDACT", target, targetmsgid, reason)
+				if reasonPresent {
+					session.sendFromClientInternal(false, time, msgid, details.nickMask, details.accountName, isBot, nil, "REDACT", target, targetmsgid, reason)
+				} else {
+					session.sendFromClientInternal(false, time, msgid, details.nickMask, details.accountName, isBot, nil, "REDACT", target, targetmsgid)
+				}
 			} else {
 				// If we wanted to send a fallback to clients which do not support
 				// draft/message-redaction, we would do it from here.
@@ -2910,11 +2950,23 @@ func quitHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 
 // REGISTER < account | * > < email | * > <password>
 func registerHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) (exiting bool) {
-	accountName := client.Nick()
-	if accountName == "*" {
+	var accountName string
+	if client.registered {
+		accountName = client.Nick()
+	} else {
 		accountName = client.preregNick
 	}
 
+	config := server.Config()
+	if client.registered && config.Accounts.NickReservation.ForceGuestFormat {
+		matches := config.Accounts.NickReservation.guestRegexp.FindStringSubmatch(accountName)
+		if matches == nil || len(matches) < 2 {
+			rb.Add(nil, server.name, "FAIL", "REGISTER", "INVALID_USERNAME", utils.SafeErrorParam(accountName), client.t("Username invalid or not given"))
+			return
+		}
+		accountName = matches[1]
+	}
+
 	switch msg.Params[0] {
 	case "*", accountName:
 		// ok
@@ -2931,7 +2983,6 @@ func registerHandler(server *Server, client *Client, msg ircmsg.Message, rb *Res
 		return
 	}
 
-	config := server.Config()
 	if !config.Accounts.Registration.Enabled {
 		rb.Add(nil, server.name, "FAIL", "REGISTER", "DISALLOWED", accountName, client.t("Account registration is disabled"))
 		return
@@ -2977,7 +3028,7 @@ func registerHandler(server *Server, client *Client, msg ircmsg.Message, rb *Res
 			announcePendingReg(client, rb, accountName)
 		}
 	case errAccountAlreadyRegistered, errAccountAlreadyUnregistered, errAccountMustHoldNick:
-		rb.Add(nil, server.name, "FAIL", "REGISTER", "USERNAME_EXISTS", accountName, client.t("Username is already registered or otherwise unavailable"))
+		rb.Add(nil, server.name, "FAIL", "REGISTER", "ACCOUNT_EXISTS", accountName, client.t("Username is already registered or otherwise unavailable"))
 	case errAccountBadPassphrase:
 		rb.Add(nil, server.name, "FAIL", "REGISTER", "INVALID_PASSWORD", accountName, client.t("Password was invalid"))
 	default:
@@ -3055,14 +3106,14 @@ func markReadHandler(server *Server, client *Client, msg ircmsg.Message, rb *Res
 
 	// "MARKREAD client set command": MARKREAD <target> <timestamp>
 	readTimestamp := strings.TrimPrefix(msg.Params[1], "timestamp=")
-	readTime, err := time.Parse(IRCv3TimestampFormat, readTimestamp)
+	readTime, err := time.Parse(utils.IRCv3TimestampFormat, readTimestamp)
 	if err != nil {
 		rb.Add(nil, server.name, "FAIL", "MARKREAD", "INVALID_PARAMS", utils.SafeErrorParam(readTimestamp), client.t("Invalid timestamp"))
 		return
 	}
 	readTime = readTime.UTC()
 	result := client.SetReadMarker(cftarget, readTime)
-	readTimestamp = fmt.Sprintf("timestamp=%s", result.Format(IRCv3TimestampFormat))
+	readTimestamp = fmt.Sprintf("timestamp=%s", result.Format(utils.IRCv3TimestampFormat))
 	// inform the originating session whether it was a success or a no-op:
 	rb.Add(nil, server.name, "MARKREAD", unfoldedTarget, readTimestamp)
 	if result.Equal(readTime) {
@@ -3089,6 +3140,287 @@ func markReadHandler(server *Server, client *Client, msg ircmsg.Message, rb *Res
 	return
 }
 
+// METADATA <target> <subcommand> [<and so on>...]
+func metadataHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) (exiting bool) {
+	config := server.Config()
+	if !config.Metadata.Enabled {
+		rb.Add(nil, server.name, "FAIL", "METADATA", "FORBIDDEN", utils.SafeErrorParam(msg.Params[0]), "Metadata is disabled on this server")
+		return
+	}
+
+	subcommand := strings.ToLower(msg.Params[1])
+	needsKey := subcommand == "set" || subcommand == "get" || subcommand == "sub" || subcommand == "unsub"
+	if needsKey && len(msg.Params) < 3 {
+		rb.Add(nil, server.name, ERR_NEEDMOREPARAMS, client.Nick(), msg.Command, client.t("Not enough parameters"))
+		return
+	}
+
+	switch subcommand {
+	case "sub", "unsub", "subs":
+		// these are session-local and function the same whether or not the client is registered
+		return metadataSubsHandler(client, subcommand, msg.Params, rb)
+	case "get", "set", "list", "clear", "sync":
+		if client.registered {
+			return metadataRegisteredHandler(client, config, subcommand, msg.Params, rb)
+		} else {
+			return metadataUnregisteredHandler(client, config, subcommand, msg.Params, rb)
+		}
+	default:
+		rb.Add(nil, server.name, "FAIL", "METADATA", "SUBCOMMAND_INVALID", utils.SafeErrorParam(msg.Params[1]), client.t("Invalid subcommand"))
+		return
+	}
+}
+
+// metadataRegisteredHandler handles metadata-modifying commands from registered clients
+func metadataRegisteredHandler(client *Client, config *Config, subcommand string, params []string, rb *ResponseBuffer) (exiting bool) {
+	server := client.server
+	target := params[0]
+
+	noKeyPerms := func(key string) {
+		rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_NO_PERMISSION", target, key, client.t("You do not have permission to perform this action"))
+	}
+
+	if target == "*" {
+		target = client.Nick()
+	}
+
+	var targetObj MetadataHaver
+	var targetClient *Client
+	var targetChannel *Channel
+	if strings.HasPrefix(target, "#") {
+		targetChannel = server.channels.Get(target)
+		if targetChannel != nil {
+			targetObj = targetChannel
+			target = targetChannel.Name() // canonicalize case
+		}
+	} else {
+		targetClient = server.clients.Get(target)
+		if targetClient != nil {
+			targetObj = targetClient
+			target = targetClient.Nick() // canonicalize case
+		}
+	}
+	if targetObj == nil {
+		rb.Add(nil, server.name, "FAIL", "METADATA", "INVALID_TARGET", target, client.t("Invalid metadata target"))
+		return
+	}
+
+	switch subcommand {
+	case "set":
+		key := params[2]
+		if metadataKeyIsEvil(key) {
+			rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_INVALID", utils.SafeErrorParam(key), client.t("Invalid key name"))
+			return
+		}
+
+		if !metadataCanIEditThisKey(client, targetObj, key) {
+			noKeyPerms(key)
+			return
+		}
+
+		// only rate limit clients changing their own metadata:
+		// channel metadata updates are not any more costly than a PRIVMSG
+		if client == targetClient {
+			if throttled, remainingTime := client.checkMetadataThrottle(); throttled {
+				retryAfter := strconv.Itoa(int(remainingTime.Seconds()) + 1)
+				rb.Add(nil, server.name, "FAIL", "METADATA", "RATE_LIMITED",
+					target, utils.SafeErrorParam(key), retryAfter,
+					fmt.Sprintf(client.t("Please wait at least %v and try again"), remainingTime.Round(time.Millisecond)))
+				return
+			}
+		}
+
+		if len(params) > 3 {
+			value := params[3]
+
+			config := client.server.Config()
+			if failMsg := metadataValueIsEvil(config, key, value); failMsg != "" {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "VALUE_INVALID", client.t(failMsg))
+				return
+			}
+
+			updated, err := targetObj.SetMetadata(key, value, config.Metadata.MaxKeys)
+			if err != nil {
+				// errLimitExceeded is the only possible error
+				rb.Add(nil, server.name, "FAIL", "METADATA", "LIMIT_REACHED", client.t("Too many metadata keys"))
+				return
+			}
+			// echo the value to the client whether or not there was a real update
+			rb.Add(nil, server.name, RPL_KEYVALUE, client.Nick(), target, key, "*", value)
+			if updated {
+				notifySubscribers(server, rb.session, targetObj, target, key, value, true)
+			}
+		} else {
+			if updated := targetObj.DeleteMetadata(key); updated {
+				notifySubscribers(server, rb.session, targetObj, target, key, "", false)
+				rb.Add(nil, server.name, RPL_KEYNOTSET, client.Nick(), target, key, client.t("Key deleted"))
+			} else {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_NOT_SET", utils.SafeErrorParam(key), client.t("Metadata key not set"))
+			}
+		}
+
+	case "get":
+		if !metadataCanISeeThisTarget(client, targetObj) {
+			noKeyPerms("*")
+			return
+		}
+
+		batchId := rb.StartNestedBatch("metadata", target)
+		defer rb.EndNestedBatch(batchId)
+
+		for _, key := range params[2:] {
+			if metadataKeyIsEvil(key) {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_INVALID", utils.SafeErrorParam(key), client.t("Invalid key name"))
+				continue
+			}
+
+			val, ok := targetObj.GetMetadata(key)
+			if !ok {
+				rb.Add(nil, server.name, RPL_KEYNOTSET, client.Nick(), target, key, client.t("Key is not set"))
+				continue
+			}
+
+			visibility := "*"
+			rb.Add(nil, server.name, RPL_KEYVALUE, client.Nick(), target, key, visibility, val)
+		}
+
+	case "list":
+		playMetadataList(rb, client.Nick(), target, targetObj.ListMetadata())
+
+	case "clear":
+		if !metadataCanIEditThisTarget(client, targetObj) {
+			noKeyPerms("*")
+			return
+		}
+
+		values := targetObj.ClearMetadata()
+
+		playMetadataList(rb, client.Nick(), target, values)
+
+	case "sync":
+		if targetChannel != nil {
+			syncChannelMetadata(server, rb, targetChannel)
+		}
+		if targetClient != nil {
+			syncClientMetadata(server, rb, targetClient)
+		}
+	}
+
+	return
+}
+
+// metadataUnregisteredHandler handles metadata-modifying commands for pre-connection-registration
+// clients. these operations act on a session-local buffer; if/when the client completes registration,
+// they are applied to the final Client object (possibly a different client if there was a reattach)
+// on a best-effort basis.
+func metadataUnregisteredHandler(client *Client, config *Config, subcommand string, params []string, rb *ResponseBuffer) (exiting bool) {
+	server := client.server
+	if params[0] != "*" {
+		rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_NO_PERMISSION", utils.SafeErrorParam(params[0]), "*", client.t("You can only modify your own metadata before completing connection registration"))
+		return
+	}
+
+	switch subcommand {
+	case "set":
+		if rb.session.metadataPreregVals == nil {
+			rb.session.metadataPreregVals = make(map[string]string)
+		}
+		key := params[2]
+		if metadataKeyIsEvil(key) {
+			rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_INVALID", utils.SafeErrorParam(key), client.t("Invalid key name"))
+			return
+		}
+		if len(params) >= 4 {
+			value := params[3]
+			// enforce a sane limit on prereg keys. we don't need to enforce the exact limit,
+			// that will be done when applying the buffer after registration
+			if len(rb.session.metadataPreregVals) > config.Metadata.MaxKeys {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "LIMIT_REACHED", client.t("Too many metadata keys"))
+				return
+			}
+			if failMsg := metadataValueIsEvil(config, key, value); failMsg != "" {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "VALUE_INVALID", client.t(failMsg))
+				return
+			}
+			rb.session.metadataPreregVals[key] = value
+			rb.Add(nil, server.name, RPL_KEYVALUE, "*", "*", key, "*", value)
+		} else {
+			// unset
+			_, present := rb.session.metadataPreregVals[key]
+			if present {
+				delete(rb.session.metadataPreregVals, key)
+				rb.Add(nil, server.name, RPL_KEYNOTSET, "*", "*", key, client.t("Key deleted"))
+			} else {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_NOT_SET", utils.SafeErrorParam(key), client.t("Metadata key not set"))
+			}
+		}
+	case "list":
+		playMetadataList(rb, "*", "*", rb.session.metadataPreregVals)
+	case "clear":
+		oldMetadata := rb.session.metadataPreregVals
+		rb.session.metadataPreregVals = nil
+		playMetadataList(rb, "*", "*", oldMetadata)
+	case "sync":
+		rb.Add(nil, server.name, RPL_METADATASYNCLATER, "*", utils.SafeErrorParam(params[1]), "60") // lol
+	}
+	return false
+}
+
+// metadataSubsHandler handles subscription-related commands;
+// these are handled the same whether the client is registered or not
+func metadataSubsHandler(client *Client, subcommand string, params []string, rb *ResponseBuffer) (exiting bool) {
+	server := client.server
+	switch subcommand {
+	case "sub":
+		keys := params[2:]
+		for _, key := range keys {
+			if metadataKeyIsEvil(key) {
+				rb.Add(nil, server.name, "FAIL", "METADATA", "KEY_INVALID", utils.SafeErrorParam(key), client.t("Invalid key name"))
+				return
+			}
+		}
+		added, err := rb.session.SubscribeTo(keys...)
+		if err == errMetadataTooManySubs {
+			bad := keys[len(added)] // get the key that broke the camel's back
+			rb.Add(nil, server.name, "FAIL", "METADATA", "TOO_MANY_SUBS", utils.SafeErrorParam(bad), client.t("Too many subscriptions"))
+		}
+
+		lineLength := MaxLineLen - len(server.name) - len(RPL_METADATASUBOK) - len(client.Nick()) - 10
+
+		chunked := utils.ChunkifyParams(slices.Values(added), lineLength)
+		for _, line := range chunked {
+			params := append([]string{client.Nick()}, line...)
+			rb.Add(nil, server.name, RPL_METADATASUBOK, params...)
+		}
+
+	case "unsub":
+		keys := params[2:]
+		removed := rb.session.UnsubscribeFrom(keys...)
+
+		lineLength := MaxLineLen - len(server.name) - len(RPL_METADATAUNSUBOK) - len(client.Nick()) - 10
+		chunked := utils.ChunkifyParams(slices.Values(removed), lineLength)
+		for _, line := range chunked {
+			params := append([]string{client.Nick()}, line...)
+			rb.Add(nil, server.name, RPL_METADATAUNSUBOK, params...)
+		}
+
+	case "subs":
+		lineLength := MaxLineLen - len(server.name) - len(RPL_METADATASUBS) - len(client.Nick()) - 10
+
+		subs := rb.session.MetadataSubscriptions()
+
+		batchID := rb.StartNestedBatch("metadata-subs")
+		defer rb.EndNestedBatch(batchID)
+
+		chunked := utils.ChunkifyParams(maps.Keys(subs), lineLength)
+		for _, line := range chunked {
+			params := append([]string{client.Nick()}, line...)
+			rb.Add(nil, server.name, RPL_METADATASUBS, params...)
+		}
+	}
+	return false
+}
+
 // REHASH
 func rehashHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) bool {
 	nick := client.Nick()
@@ -3655,6 +3987,7 @@ func webpushHandler(server *Server, client *Client, msg ircmsg.Message, rb *Resp
 
 	if err := webpush.SanityCheckWebPushEndpoint(endpoint); err != nil {
 		rb.Add(nil, server.name, "FAIL", "WEBPUSH", "INVALID_PARAMS", subcommand, client.t("Invalid web push URL"))
+		return false
 	}
 
 	switch subcommand {
@@ -4118,9 +4451,9 @@ func zncHandler(server *Server, client *Client, msg ircmsg.Message, rb *Response
 // fake handler for unknown commands
 func unknownCommandHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) bool {
 	var message string
-	if strings.HasPrefix(msg.Command, "/") {
+	if trimmedCmd, initialSlash := strings.CutPrefix(msg.Command, "/"); initialSlash {
 		message = fmt.Sprintf(client.t("Unknown command; if you are using /QUOTE, the correct syntax is /QUOTE %[1]s, not /QUOTE %[2]s"),
-			strings.TrimPrefix(msg.Command, "/"), msg.Command)
+			trimmedCmd, msg.Command)
 	} else {
 		message = client.t("Unknown command")
 	}

irc/help.go

@@ -238,11 +238,10 @@ Get an explanation of <argument>, or "index" for a list of help topics.`,
 	"history": {
 		text: `HISTORY <target> [limit]
 
-Replay message history. <target> can be a channel name, "me" to replay direct
-message history, or a nickname to replay another client's direct message
-history (they must be logged into the same account as you). [limit] can be
-either an integer (the maximum number of messages to replay), or a time
-duration like 10m or 1h (the time window within which to replay messages).`,
+Replay message history. <target> can be a channel name or a nickname you have
+direct message history with. [limit] can be either an integer (the maximum
+number of messages to replay), or a time duration like 10m or 1h (the time
+window within which to replay messages).`,
 	},
 	"info": {
 		text: `INFO
@@ -339,6 +338,12 @@ command is processed by that server.`,
 MARKREAD updates an IRCv3 read message marker. It is not intended for use by
 end users. For more details, see the latest draft of the read-marker
 specification.`,
+	},
+	"metadata": {
+		text: `METADATA <target> <subcommand> [<everything else>...]
+
+Retrieve and meddle with metadata for the given target.
+Have a look at https://ircv3.net/specs/extensions/metadata for interesting technical information.`,
 	},
 	"mode": {
 		text: `MODE <target> [<modestring> [<mode arguments>...]]

irc/history/database.go

@@ -0,0 +1,126 @@
+// Copyright (c) 2025 Shivaram Lingamneni
+// released under the MIT license
+
+package history
+
+import (
+	"errors"
+	"io"
+	"time"
+)
+
+var (
+	ErrDisallowed = errors.New("disallowed")
+	ErrNotFound   = errors.New("not found")
+)
+
+// Database is an interface for persistent history storage backends.
+type Database interface {
+	// Close closes the database connection and releases resources.
+	io.Closer
+
+	// AddChannelItem adds a history item for a channel.
+	// target is the casefolded channel name.
+	// account is the sender's casefolded account name ("" for no account).
+	AddChannelItem(target string, item Item, account string) error
+
+	// AddDirectMessage adds a history item for a direct message.
+	// All identifiers are casefolded; account identifiers are "" for no account.
+	AddDirectMessage(sender, senderAccount, recipient, recipientAccount string, item Item) error
+
+	// DeleteMsgid deletes a message by its msgid.
+	// accountName is the unfolded account name, or "*" to skip
+	// account validation
+	DeleteMsgid(msgid, accountName string) error
+
+	// MakeSequence creates a Sequence for querying history.
+	// target is the primary target (channel or account), casefolded.
+	// correspondent is the casefolded DM correspondent (empty for channels).
+	// cutoff is the earliest time to include in results.
+	MakeSequence(target, correspondent string, cutoff time.Time) Sequence
+
+	// ListChannels returns the timestamp of the latest message in each
+	// of the given channels (specified as casefolded names).
+	ListChannels(cfchannels []string) (results []TargetListing, err error)
+
+	// ListCorrespondents lists the DM correspondents associated with an account,
+	// in order to implement CHATHISTORY TARGETS.
+	ListCorrespondents(cftarget string, start, end time.Time, limit int) ([]TargetListing, error)
+
+	// these are for theoretical GDPR compliance, not actual chat functionality,
+	// and are not essential:
+
+	// Forget enqueues an account (casefolded) for message deletion.
+	// This is used for GDPR-style "right to be forgotten" requests.
+	// The actual deletion happens asynchronously.
+	Forget(account string)
+
+	// Export exports all messages for an account (casefolded) to the given writer.
+	Export(account string, writer io.Writer)
+}
+
+type noopDatabase struct{}
+
+// NewNoopDatabase returns a Database implementation that does nothing.
+func NewNoopDatabase() Database {
+	return noopDatabase{}
+}
+
+func (n noopDatabase) Close() error {
+	return nil
+}
+
+func (n noopDatabase) AddChannelItem(target string, item Item, account string) error {
+	return nil
+}
+
+func (n noopDatabase) AddDirectMessage(sender, senderAccount, recipient, recipientAccount string, item Item) error {
+	return nil
+}
+
+func (n noopDatabase) DeleteMsgid(msgid, accountName string) error {
+	return nil
+}
+
+func (n noopDatabase) Forget(account string) {
+	// no-op
+}
+
+func (n noopDatabase) Export(account string, writer io.Writer) {
+	// no-op
+}
+
+func (n noopDatabase) ListChannels(cfchannels []string) (results []TargetListing, err error) {
+	return nil, nil
+}
+
+func (n noopDatabase) ListCorrespondents(target string, start, end time.Time, limit int) (results []TargetListing, err error) {
+	return nil, nil
+}
+
+func (n noopDatabase) MakeSequence(target, correspondent string, cutoff time.Time) Sequence {
+	return noopSequence{}
+}
+
+// noopSequence is a no-op implementation of Sequence.
+// XXX: this should never be accessed, because if persistent history is disabled,
+// we should always be working with a bufferSequence instead. But we might as well
+// be defensive in case there's an edge case where (noopDatabase).MakeSequence ends
+// up getting called.
+type noopSequence struct{}
+
+func (n noopSequence) Between(start, end Selector, limit int) (results []Item, err error) {
+	return nil, nil
+}
+
+func (n noopSequence) Around(start Selector, limit int) (results []Item, err error) {
+	return nil, nil
+}
+
+func (n noopSequence) Cutoff() time.Time {
+	return time.Time{}
+}
+
+func (n noopSequence) Ephemeral() bool {
+	return false // we're pretending to be an empty database
+}

irc/history/history.go

@@ -230,10 +230,8 @@ func (list *Buffer) allCorrespondents() (results []TargetListing) {
 }
 
 // list DM correspondents, as one input to CHATHISTORY TARGETS
-func (list *Buffer) listCorrespondents(start, end Selector, cutoff time.Time, limit int) (results []TargetListing, err error) {
-	after := start.Time
-	before := end.Time
-	after, before, ascending := MinMaxAsc(after, before, cutoff)
+func (list *Buffer) ListCorrespondents(start, end time.Time, limit int) (results []TargetListing, err error) {
+	after, before, ascending := MinMaxAsc(start, end, time.Time{})
 
 	correspondents := list.allCorrespondents()
 	if len(correspondents) == 0 {
@@ -300,10 +298,6 @@ func (seq *bufferSequence) Around(start Selector, limit int) (results []Item, er
 	return GenericAround(seq, start, limit)
 }
 
-func (seq *bufferSequence) ListCorrespondents(start, end Selector, limit int) (results []TargetListing, err error) {
-	return seq.list.listCorrespondents(start, end, seq.cutoff, limit)
-}
-
 func (seq *bufferSequence) Cutoff() time.Time {
 	return seq.cutoff
 }

irc/history/queries.go

@@ -21,8 +21,6 @@ type Sequence interface {
 	Between(start, end Selector, limit int) (results []Item, err error)
 	Around(start Selector, limit int) (results []Item, err error)
 
-	ListCorrespondents(start, end Selector, limit int) (results []TargetListing, err error)
-
 	// this are weird hacks that violate the encapsulation of Sequence to some extent;
 	// Cutoff() returns the cutoff time for other code to use (it returns the zero time
 	// if none is set), and Ephemeral() returns whether the backing store is in-memory

irc/history/serialization.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2020 Shivaram Lingamneni
+// released under the MIT license
+
+package history
+
+import (
+	"encoding/json"
+)
+
+// 123 / '{' is the magic number that means JSON;
+// if we want to do a binary encoding later, we just have to add different magic version numbers
+
+func MarshalItem(item *Item) (result []byte, err error) {
+	return json.Marshal(item)
+}
+
+func UnmarshalItem(data []byte, result *Item) (err error) {
+	return json.Unmarshal(data, result)
+}

irc/histserv.go

@@ -164,7 +164,7 @@ func histservExportHandler(service *ircService, server *Server, client *Client,
 
 	config := server.Config()
 	// don't include the account name in the filename because of escaping concerns
-	filename := fmt.Sprintf("%s-%s.json", utils.GenerateSecretToken(), time.Now().UTC().Format(IRCv3TimestampFormat))
+	filename := fmt.Sprintf("%s-%s.json", utils.GenerateSecretToken(), time.Now().UTC().Format(utils.IRCv3TimestampFormat))
 	pathname := config.getOutputPath(filename)
 	outfile, err := os.Create(pathname)
 	if err != nil {

irc/message_cache.go

@@ -45,7 +45,7 @@ type MessageCache struct {
 
 func addAllTags(msg *ircmsg.Message, tags map[string]string, serverTime time.Time, msgid, accountName string, isBot bool) {
 	msg.UpdateTags(tags)
-	msg.SetTag("time", serverTime.Format(IRCv3TimestampFormat))
+	msg.SetTag("time", serverTime.Format(utils.IRCv3TimestampFormat))
 	if accountName != "*" {
 		msg.SetTag("account", accountName)
 	}

irc/metadata.go

@@ -0,0 +1,174 @@
+package irc
+
+import (
+	"errors"
+	"iter"
+	"maps"
+	"regexp"
+	"unicode/utf8"
+
+	"github.com/ergochat/ergo/irc/caps"
+	"github.com/ergochat/ergo/irc/modes"
+)
+
+const (
+	// metadata key + value need to be relayable on a single IRC RPL_KEYVALUE line
+	maxCombinedMetadataLenBytes = 350
+)
+
+var (
+	errMetadataTooManySubs = errors.New("too many subscriptions")
+	errMetadataNotFound    = errors.New("key not found")
+)
+
+type MetadataHaver interface {
+	SetMetadata(key string, value string, limit int) (updated bool, err error)
+	GetMetadata(key string) (string, bool)
+	DeleteMetadata(key string) (updated bool)
+	ListMetadata() map[string]string
+	ClearMetadata() map[string]string
+	CountMetadata() int
+}
+
+func notifySubscribers(server *Server, session *Session, targetObj MetadataHaver, targetName, key, value string, set bool) {
+	var recipientSessions iter.Seq[*Session]
+
+	switch target := targetObj.(type) {
+	case *Client:
+		// TODO this case is expensive and might warrant rate-limiting
+		friends := target.FriendsMonitors(caps.Metadata)
+		// broadcast metadata update to other connected sessions
+		for _, s := range target.Sessions() {
+			friends.Add(s)
+		}
+		recipientSessions = maps.Keys(friends)
+	case *Channel:
+		recipientSessions = target.sessionsWithCaps(caps.Metadata)
+	default:
+		return // impossible
+	}
+
+	broadcastMetadataUpdate(server, recipientSessions, session, targetName, key, value, set)
+}
+
+func broadcastMetadataUpdate(server *Server, sessions iter.Seq[*Session], originator *Session, target, key, value string, set bool) {
+	for s := range sessions {
+		// don't notify the session that made the change
+		if s == originator || !s.isSubscribedTo(key) {
+			continue
+		}
+
+		if set {
+			s.Send(nil, server.name, "METADATA", target, key, "*", value)
+		} else {
+			s.Send(nil, server.name, "METADATA", target, key, "*")
+		}
+	}
+}
+
+func syncClientMetadata(server *Server, rb *ResponseBuffer, target *Client) {
+	batchId := rb.StartNestedBatch("metadata", target.Nick())
+	defer rb.EndNestedBatch(batchId)
+
+	subs := rb.session.MetadataSubscriptions()
+	values := target.ListMetadata()
+	for k, v := range values {
+		if subs.Has(k) {
+			visibility := "*"
+			rb.Add(nil, server.name, "METADATA", target.Nick(), k, visibility, v)
+		}
+	}
+}
+
+func syncChannelMetadata(server *Server, rb *ResponseBuffer, channel *Channel) {
+	batchId := rb.StartNestedBatch("metadata", channel.Name())
+	defer rb.EndNestedBatch(batchId)
+
+	subs := rb.session.MetadataSubscriptions()
+	chname := channel.Name()
+
+	values := channel.ListMetadata()
+	for k, v := range values {
+		if subs.Has(k) {
+			visibility := "*"
+			rb.Add(nil, server.name, "METADATA", chname, k, visibility, v)
+		}
+	}
+
+	for _, client := range channel.Members() {
+		values := client.ListMetadata()
+		for k, v := range values {
+			if subs.Has(k) {
+				visibility := "*"
+				rb.Add(nil, server.name, "METADATA", client.Nick(), k, visibility, v)
+			}
+		}
+	}
+}
+
+func playMetadataList(rb *ResponseBuffer, nick, target string, values map[string]string) {
+	batchId := rb.StartNestedBatch("metadata", target)
+	defer rb.EndNestedBatch(batchId)
+
+	for key, val := range values {
+		visibility := "*"
+		rb.Add(nil, rb.session.client.server.name, RPL_KEYVALUE, nick, target, key, visibility, val)
+	}
+}
+
+func playMetadataVerbBatch(rb *ResponseBuffer, target string, values map[string]string) {
+	batchId := rb.StartNestedBatch("metadata", target)
+	defer rb.EndNestedBatch(batchId)
+
+	for key, val := range values {
+		visibility := "*"
+		rb.Add(nil, rb.session.client.server.name, "METADATA", target, key, visibility, val)
+	}
+}
+
+var validMetadataKeyRegexp = regexp.MustCompile("^[a-z0-9_./-]+$")
+
+func metadataKeyIsEvil(key string) bool {
+	return !validMetadataKeyRegexp.MatchString(key)
+}
+
+func metadataValueIsEvil(config *Config, key, value string) (failMsg string) {
+	if !globalUtf8EnforcementSetting && !utf8.ValidString(value) {
+		return `METADATA values must be UTF-8`
+	}
+
+	if len(key)+len(value) > maxCombinedMetadataLenBytes ||
+		(config.Metadata.MaxValueBytes > 0 && len(value) > config.Metadata.MaxValueBytes) {
+
+		return `Value is too long`
+	}
+
+	return "" // success
+}
+
+func metadataCanIEditThisKey(client *Client, targetObj MetadataHaver, key string) bool {
+	// no key-specific logic as yet
+	return metadataCanIEditThisTarget(client, targetObj)
+}
+
+func metadataCanIEditThisTarget(client *Client, targetObj MetadataHaver) bool {
+	switch target := targetObj.(type) {
+	case *Client:
+		return client == target || client.HasRoleCapabs("metadata")
+	case *Channel:
+		return target.ClientIsAtLeast(client, modes.Operator) || client.HasRoleCapabs("metadata")
+	default:
+		return false // impossible
+	}
+}
+
+func metadataCanISeeThisTarget(client *Client, targetObj MetadataHaver) bool {
+	switch target := targetObj.(type) {
+	case *Client:
+		return true
+	case *Channel:
+		return target.hasClient(client) || client.HasRoleCapabs("metadata")
+	default:
+		return false // impossible
+	}
+}

irc/metadata_test.go

@@ -0,0 +1,25 @@
+package irc
+
+import "testing"
+
+func TestKeyCheck(t *testing.T) {
+	cases := []struct {
+		input  string
+		isEvil bool
+	}{
+		{"ImNormalButIHaveCaps", true},
+		{"imnormalandidonthavecaps", false},
+		{"ergo.chat/vendor-extension", false},
+		{"", true},
+		{":imevil", true},
+		{"im:evil", true},
+		{"key£with$not%allowed^chars", true},
+		{"key.thats_completely/normal-and.fine", false},
+	}
+
+	for _, c := range cases {
+		if metadataKeyIsEvil(c.input) != c.isEvil {
+			t.Errorf("%s should have returned %v. but it didn't. so that's not great", c.input, c.isEvil)
+		}
+	}
+}

irc/modes.go

@@ -251,9 +251,11 @@ func (channel *Channel) ApplyChannelModeChanges(client *Client, isSamode bool, c
 			switch change.Op {
 			case modes.Add:
 				val, err := strconv.Atoi(change.Arg)
-				if err == nil {
+				if err == nil && val > 0 {
 					channel.setUserLimit(val)
 					applied = append(applied, change)
+				} else {
+					rb.Add(nil, client.server.name, ERR_INVALIDMODEPARAM, details.nick, chname, string(change.Mode), utils.SafeErrorParam(change.Arg), client.t("+l user limit value must be an integer between 1 and 2147483647, expressed in base 10"))
 				}
 
 			case modes.Remove:

irc/monitor.go

@@ -28,17 +28,21 @@ func (mm *MonitorManager) Initialize() {
 
 // AddMonitors adds clients using extended-monitor monitoring `client`'s nick to the passed user set.
 func (manager *MonitorManager) AddMonitors(users utils.HashSet[*Session], cfnick string, capabs ...caps.Capability) {
+	// technically, we should check extended-monitor here, but it's not really necessary
+	// since clients will ignore AWAY, ACCOUNT, CHGHOST, and SETNAME for users
+	// they're not tracking
+
 	manager.RLock()
 	defer manager.RUnlock()
 	for session := range manager.watchedby[cfnick] {
-		if session.capabilities.Has(caps.ExtendedMonitor) && session.capabilities.HasAll(capabs...) {
+		if session.capabilities.HasAll(capabs...) {
 			users.Add(session)
 		}
 	}
 }
 
 // AlertAbout alerts everyone monitoring `client`'s nick that `client` is now {on,off}line.
-func (manager *MonitorManager) AlertAbout(nick, cfnick string, online bool) {
+func (manager *MonitorManager) AlertAbout(nick, cfnick string, online bool, client *Client) {
 	var watchers []*Session
 	// safely copy the list of clients watching our nick
 	manager.RLock()
@@ -52,8 +56,21 @@ func (manager *MonitorManager) AlertAbout(nick, cfnick string, online bool) {
 		command = RPL_MONONLINE
 	}
 
+	var metadata map[string]string
+	if online && client != nil {
+		metadata = client.ListMetadata()
+	}
+
 	for _, session := range watchers {
 		session.Send(nil, session.client.server.name, command, session.client.Nick(), nick)
+
+		if metadata != nil && session.capabilities.Has(caps.Metadata) {
+			for key := range session.MetadataSubscriptions() {
+				if val, ok := metadata[key]; ok {
+					session.Send(nil, client.server.name, "METADATA", nick, key, "*", val)
+				}
+			}
+		}
 	}
 }
 

irc/mysql/history.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	"database/sql"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"runtime/debug"
@@ -23,10 +22,6 @@ import (
 	_ "github.com/go-sql-driver/mysql"
 )
 
-var (
-	ErrDisallowed = errors.New("disallowed")
-)
-
 const (
 	// maximum length in bytes of any message target (nickname or channel name) in its
 	// canonicalized (i.e., casefolded) state:
@@ -64,10 +59,16 @@ type MySQL struct {
 	trackAccountMessages atomic.Uint32
 }
 
-func (mysql *MySQL) Initialize(logger *logger.Manager, config Config) {
+var _ history.Database = (*MySQL)(nil)
+
+func NewMySQLDatabase(logger *logger.Manager, config Config) (*MySQL, error) {
+	var mysql MySQL
+
 	mysql.logger = logger
 	mysql.wakeForgetter = make(chan e, 1)
 	mysql.SetConfig(config)
+
+	return &mysql, mysql.open()
 }
 
 func (mysql *MySQL) SetConfig(config Config) {
@@ -89,7 +90,7 @@ func (mysql *MySQL) getExpireTime() (expireTime time.Duration) {
 	return
 }
 
-func (m *MySQL) Open() (err error) {
+func (m *MySQL) open() (err error) {
 	var address string
 	if m.config.SocketPath != "" {
 		address = fmt.Sprintf("unix(%s)", m.config.SocketPath)
@@ -128,7 +129,7 @@ func (m *MySQL) Open() (err error) {
 
 func (mysql *MySQL) fixSchemas() (err error) {
 	_, err = mysql.db.Exec(`CREATE TABLE IF NOT EXISTS metadata (
-		key_name VARCHAR(32) primary key,
+		key_name VARCHAR(32) PRIMARY KEY,
 		value VARCHAR(32) NOT NULL
 	) CHARSET=ascii COLLATE=ascii_bin;`)
 	if err != nil {
@@ -136,17 +137,17 @@ func (mysql *MySQL) fixSchemas() (err error) {
 	}
 
 	var schema string
-	err = mysql.db.QueryRow(`select value from metadata where key_name = ?;`, keySchemaVersion).Scan(&schema)
+	err = mysql.db.QueryRow(`SELECT value FROM metadata WHERE key_name = ?;`, keySchemaVersion).Scan(&schema)
 	if err == sql.ErrNoRows {
 		err = mysql.createTables()
 		if err != nil {
 			return
 		}
-		_, err = mysql.db.Exec(`insert into metadata (key_name, value) values (?, ?);`, keySchemaVersion, latestDbSchema)
+		_, err = mysql.db.Exec(`INSERT INTO metadata (key_name, value) VALUES (?, ?);`, keySchemaVersion, latestDbSchema)
 		if err != nil {
 			return
 		}
-		_, err = mysql.db.Exec(`insert into metadata (key_name, value) values (?, ?);`, keySchemaMinorVersion, latestDbMinorVersion)
+		_, err = mysql.db.Exec(`INSERT INTO metadata (key_name, value) VALUES (?, ?);`, keySchemaMinorVersion, latestDbMinorVersion)
 		if err != nil {
 			return
 		}
@@ -159,7 +160,7 @@ func (mysql *MySQL) fixSchemas() (err error) {
 	}
 
 	var minorVersion string
-	err = mysql.db.QueryRow(`select value from metadata where key_name = ?;`, keySchemaMinorVersion).Scan(&minorVersion)
+	err = mysql.db.QueryRow(`SELECT value FROM metadata WHERE key_name = ?;`, keySchemaMinorVersion).Scan(&minorVersion)
 	if err == sql.ErrNoRows {
 		// XXX for now, the only minor version upgrade is the account tracking tables
 		err = mysql.createComplianceTables()
@@ -170,7 +171,7 @@ func (mysql *MySQL) fixSchemas() (err error) {
 		if err != nil {
 			return
 		}
-		_, err = mysql.db.Exec(`insert into metadata (key_name, value) values (?, ?);`, keySchemaMinorVersion, latestDbMinorVersion)
+		_, err = mysql.db.Exec(`INSERT INTO metadata (key_name, value) VALUES (?, ?);`, keySchemaMinorVersion, latestDbMinorVersion)
 		if err != nil {
 			return
 		}
@@ -180,7 +181,7 @@ func (mysql *MySQL) fixSchemas() (err error) {
 		if err != nil {
 			return
 		}
-		_, err = mysql.db.Exec(`update metadata set value = ? where key_name = ?;`, latestDbMinorVersion, keySchemaMinorVersion)
+		_, err = mysql.db.Exec(`UPDATE metadata SET value = ? WHERE key_name = ?;`, latestDbMinorVersion, keySchemaMinorVersion)
 		if err != nil {
 			return
 		}
@@ -416,7 +417,7 @@ func (mysql *MySQL) deleteCorrespondents(ctx context.Context, threshold int64) {
 	} else {
 		count, err := result.RowsAffected()
 		if !mysql.logError("error deleting correspondents", err) {
-			mysql.logger.Debug(fmt.Sprintf("deleted %d correspondents entries", count))
+			mysql.logger.Debug("mysql", fmt.Sprintf("deleted %d correspondents entries", count))
 		}
 	}
 }
@@ -623,40 +624,46 @@ func (mysql *MySQL) AddChannelItem(target string, item history.Item, account str
 
 func (mysql *MySQL) insertSequenceEntry(ctx context.Context, target string, messageTime int64, id int64) (err error) {
 	_, err = mysql.insertSequence.ExecContext(ctx, target, messageTime, id)
-	mysql.logError("could not insert sequence entry", err)
+	if err != nil {
+		return fmt.Errorf("could not insert sequence entry: %w", err)
+	}
 	return
 }
 
 func (mysql *MySQL) insertConversationEntry(ctx context.Context, target, correspondent string, messageTime int64, id int64) (err error) {
 	_, err = mysql.insertConversation.ExecContext(ctx, target, correspondent, messageTime, id)
-	mysql.logError("could not insert conversations entry", err)
+	if err != nil {
+		return fmt.Errorf("could not insert conversations entry: %w", err)
+	}
 	return
 }
 
 func (mysql *MySQL) insertCorrespondentsEntry(ctx context.Context, target, correspondent string, messageTime int64, historyId int64) (err error) {
 	_, err = mysql.insertCorrespondent.ExecContext(ctx, target, correspondent, messageTime, messageTime)
-	mysql.logError("could not insert conversations entry", err)
+	if err != nil {
+		return fmt.Errorf("could not insert correspondents entry: %w", err)
+	}
 	return
 }
 
 func (mysql *MySQL) insertBase(ctx context.Context, item history.Item) (id int64, err error) {
-	value, err := marshalItem(&item)
-	if mysql.logError("could not marshal item", err) {
-		return
+	value, err := history.MarshalItem(&item)
+	if err != nil {
+		return 0, fmt.Errorf("could not marshal item: %w", err)
 	}
 
-	msgidBytes, err := decodeMsgid(item.Message.Msgid)
-	if mysql.logError("could not decode msgid", err) {
-		return
+	msgidBytes, err := utils.DecodeSecretToken(item.Message.Msgid)
+	if err != nil {
+		return 0, fmt.Errorf("could not decode msgid: %w", err)
 	}
 
 	result, err := mysql.insertHistory.ExecContext(ctx, value, msgidBytes)
-	if mysql.logError("could not insert item", err) {
-		return
+	if err != nil {
+		return 0, fmt.Errorf("could not insert item: %w", err)
 	}
 	id, err = result.LastInsertId()
-	if mysql.logError("could not insert item", err) {
-		return
+	if err != nil {
+		return 0, fmt.Errorf("could not insert item: %w", err)
 	}
 
 	return
@@ -667,7 +674,9 @@ func (mysql *MySQL) insertAccountMessageEntry(ctx context.Context, id int64, acc
 		return
 	}
 	_, err = mysql.insertAccountMessage.ExecContext(ctx, id, account)
-	mysql.logError("could not insert account-message entry", err)
+	if err != nil {
+		return fmt.Errorf("could not insert account-message entry: %w", err)
+	}
 	return
 }
 
@@ -735,20 +744,25 @@ func (mysql *MySQL) DeleteMsgid(msgid, accountName string) (err error) {
 
 	_, id, data, err := mysql.lookupMsgid(ctx, msgid, true)
 	if err != nil {
+		if err == sql.ErrNoRows {
+			return history.ErrNotFound
+		}
 		return
 	}
 
 	if accountName != "*" {
 		var item history.Item
-		err = unmarshalItem(data, &item)
+		err = history.UnmarshalItem(data, &item)
 		// delete if the entry is corrupt
 		if err == nil && item.AccountName != accountName {
-			return ErrDisallowed
+			return history.ErrDisallowed
 		}
 	}
 
 	err = mysql.deleteHistoryIDs(ctx, []uint64{id})
-	mysql.logError("couldn't delete msgid", err)
+	if err != nil {
+		return fmt.Errorf("couldn't delete msgid: %w", err)
+	}
 	return
 }
 
@@ -784,7 +798,7 @@ func (mysql *MySQL) Export(account string, writer io.Writer) {
 				if err != nil {
 					return
 				}
-				err = unmarshalItem(blob, &item)
+				err = history.UnmarshalItem(blob, &item)
 				if err != nil {
 					return
 				}
@@ -812,8 +826,11 @@ func (mysql *MySQL) Export(account string, writer io.Writer) {
 }
 
 func (mysql *MySQL) lookupMsgid(ctx context.Context, msgid string, includeData bool) (result time.Time, id uint64, data []byte, err error) {
-	decoded, err := decodeMsgid(msgid)
+	decoded, err := utils.DecodeSecretToken(msgid)
 	if err != nil {
+		// use sql.ErrNoRows internally for consistency, translate to history.ErrNotFound
+		// at the package boundary if necessary
+		err = sql.ErrNoRows
 		return
 	}
 	cols := `sequence.nanotime, conversations.nanotime`
@@ -831,10 +848,10 @@ func (mysql *MySQL) lookupMsgid(ctx context.Context, msgid string, includeData b
 	} else {
 		err = row.Scan(&nanoSeq, &nanoConv, &id, &data)
 	}
-	if err != sql.ErrNoRows {
-		mysql.logError("could not resolve msgid to time", err)
-	}
 	if err != nil {
+		if err != sql.ErrNoRows {
+			err = fmt.Errorf("could not resolve msgid to time: %w", err)
+		}
 		return
 	}
 	nanotime := extractNanotime(nanoSeq, nanoConv)
@@ -857,8 +874,8 @@ func extractNanotime(seq, conv sql.NullInt64) (result int64) {
 
 func (mysql *MySQL) selectItems(ctx context.Context, query string, args ...interface{}) (results []history.Item, err error) {
 	rows, err := mysql.db.QueryContext(ctx, query, args...)
-	if mysql.logError("could not select history items", err) {
-		return
+	if err != nil {
+		return nil, fmt.Errorf("could not select history items: %w", err)
 	}
 
 	defer rows.Close()
@@ -867,12 +884,12 @@ func (mysql *MySQL) selectItems(ctx context.Context, query string, args ...inter
 		var blob []byte
 		var item history.Item
 		err = rows.Scan(&blob)
-		if mysql.logError("could not scan history item", err) {
-			return
+		if err != nil {
+			return nil, fmt.Errorf("could not scan history item: %w", err)
 		}
-		err = unmarshalItem(blob, &item)
-		if mysql.logError("could not unmarshal history item", err) {
-			return
+		err = history.UnmarshalItem(blob, &item)
+		if err != nil {
+			return nil, fmt.Errorf("could not unmarshal history item: %w", err)
 		}
 		results = append(results, item)
 	}
@@ -949,7 +966,7 @@ func (mysql *MySQL) listCorrespondentsInternal(ctx context.Context, target strin
 
 	rows, err := mysql.db.QueryContext(ctx, query, args...)
 	if err != nil {
-		return
+		return nil, fmt.Errorf("could not query correspondents: %w", err)
 	}
 	defer rows.Close()
 	var correspondent string
@@ -957,7 +974,7 @@ func (mysql *MySQL) listCorrespondentsInternal(ctx context.Context, target strin
 	for rows.Next() {
 		err = rows.Scan(&correspondent, &nanotime)
 		if err != nil {
-			return
+			return nil, fmt.Errorf("could not scan correspondents: %w", err)
 		}
 		results = append(results, history.TargetListing{
 			CfName: correspondent,
@@ -972,6 +989,19 @@ func (mysql *MySQL) listCorrespondentsInternal(ctx context.Context, target strin
 	return
 }
 
+func (mysql *MySQL) ListCorrespondents(cftarget string, start, end time.Time, limit int) (results []history.TargetListing, err error) {
+	ctx, cancel := context.WithTimeout(context.Background(), mysql.getTimeout())
+	defer cancel()
+
+	// TODO accept msgids here?
+
+	results, err = mysql.listCorrespondentsInternal(ctx, cftarget, start, end, time.Time{}, limit)
+	if err != nil {
+		return nil, fmt.Errorf("could not read correspondents: %w", err)
+	}
+	return
+}
+
 func (mysql *MySQL) ListChannels(cfchannels []string) (results []history.TargetListing, err error) {
 	if mysql.db == nil {
 		return
@@ -1000,8 +1030,8 @@ func (mysql *MySQL) ListChannels(cfchannels []string) (results []history.TargetL
 	queryBuf.WriteString(") GROUP BY sequence.target;")
 
 	rows, err := mysql.db.QueryContext(ctx, queryBuf.String(), args...)
-	if mysql.logError("could not query channel listings", err) {
-		return
+	if err != nil {
+		return nil, fmt.Errorf("could not query channel listings: %w", err)
 	}
 	defer rows.Close()
 
@@ -1009,8 +1039,8 @@ func (mysql *MySQL) ListChannels(cfchannels []string) (results []history.TargetL
 	var nanotime int64
 	for rows.Next() {
 		err = rows.Scan(&target, &nanotime)
-		if mysql.logError("could not scan channel listings", err) {
-			return
+		if err != nil {
+			return nil, fmt.Errorf("could not scan channel listings: %w", err)
 		}
 		results = append(results, history.TargetListing{
 			CfName: target,
@@ -1020,12 +1050,13 @@ func (mysql *MySQL) ListChannels(cfchannels []string) (results []history.TargetL
 	return
 }
 
-func (mysql *MySQL) Close() {
+func (mysql *MySQL) Close() (err error) {
 	// closing the database will close our prepared statements as well
 	if mysql.db != nil {
-		mysql.db.Close()
+		err = mysql.db.Close()
 	}
 	mysql.db = nil
+	return
 }
 
 // implements history.Sequence, emulating a single history buffer (for a channel,
@@ -1072,19 +1103,6 @@ func (s *mySQLHistorySequence) Around(start history.Selector, limit int) (result
 	return history.GenericAround(s, start, limit)
 }
 
-func (seq *mySQLHistorySequence) ListCorrespondents(start, end history.Selector, limit int) (results []history.TargetListing, err error) {
-	ctx, cancel := context.WithTimeout(context.Background(), seq.mysql.getTimeout())
-	defer cancel()
-
-	// TODO accept msgids here?
-	startTime := start.Time
-	endTime := end.Time
-
-	results, err = seq.mysql.listCorrespondentsInternal(ctx, seq.target, startTime, endTime, seq.cutoff, limit)
-	seq.mysql.logError("could not read correspondents", err)
-	return
-}
-
 func (seq *mySQLHistorySequence) Cutoff() time.Time {
 	return seq.cutoff
 }

irc/mysql/serialization.go

@@ -1,23 +0,0 @@
-package mysql
-
-import (
-	"encoding/json"
-
-	"github.com/ergochat/ergo/irc/history"
-	"github.com/ergochat/ergo/irc/utils"
-)
-
-// 123 / '{' is the magic number that means JSON;
-// if we want to do a binary encoding later, we just have to add different magic version numbers
-
-func marshalItem(item *history.Item) (result []byte, err error) {
-	return json.Marshal(item)
-}
-
-func unmarshalItem(data []byte, result *history.Item) (err error) {
-	return json.Unmarshal(data, result)
-}
-
-func decodeMsgid(msgid string) ([]byte, error) {
-	return utils.B32Encoder.DecodeString(msgid)
-}

irc/nickname.go

@@ -128,9 +128,11 @@ func performNickChange(server *Server, client *Client, target *Client, session *
 	}
 
 	newCfnick := target.NickCasefolded()
-	if newCfnick != details.nickCasefolded {
-		client.server.monitorManager.AlertAbout(details.nick, details.nickCasefolded, false)
-		client.server.monitorManager.AlertAbout(assignedNickname, newCfnick, true)
+	// send MONITOR updates only for nick changes, not for new connection registration;
+	// defer MONITOR for new connection registration until pre-registration metadata is applied
+	if hadNick && newCfnick != details.nickCasefolded {
+		client.server.monitorManager.AlertAbout(details.nick, details.nickCasefolded, false, nil)
+		client.server.monitorManager.AlertAbout(assignedNickname, newCfnick, true, target)
 	}
 	return nil
 }

irc/nickserv.go

@@ -1055,10 +1055,10 @@ func nsSaregisterHandler(service *ircService, server *Server, client *Client, co
 		var failCode string
 		if err == errAccountAlreadyRegistered || err == errAccountAlreadyVerified {
 			errMsg = client.t("Account already exists")
-			failCode = "USERNAME_EXISTS"
+			failCode = "ACCOUNT_EXISTS"
 		} else if err == errNameReserved {
 			errMsg = client.t(err.Error())
-			failCode = "USERNAME_EXISTS"
+			failCode = "ACCOUNT_EXISTS"
 		} else if err == errAccountBadPassphrase {
 			errMsg = client.t("Passphrase contains forbidden characters or is otherwise invalid")
 			failCode = "INVALID_PASSWORD"

irc/numerics.go

@@ -79,8 +79,8 @@ const (
 	RPL_WHOISACTUALLY      = "338"
 	RPL_INVITING           = "341"
 	RPL_SUMMONING          = "342"
-	RPL_INVITELIST         = "346"
-	RPL_ENDOFINVITELIST    = "347"
+	RPL_INVEXLIST          = "346"
+	RPL_ENDOFINVEXLIST     = "347"
 	RPL_EXCEPTLIST         = "348"
 	RPL_ENDOFEXCEPTLIST    = "349"
 	RPL_VERSION            = "351"
@@ -183,6 +183,13 @@ const (
 	RPL_MONLIST            = "732"
 	RPL_ENDOFMONLIST       = "733"
 	ERR_MONLISTFULL        = "734"
+	RPL_WHOISKEYVALUE      = "760" // metadata numerics
+	RPL_KEYVALUE           = "761"
+	RPL_KEYNOTSET          = "766"
+	RPL_METADATASUBOK      = "770"
+	RPL_METADATAUNSUBOK    = "771"
+	RPL_METADATASUBS       = "772"
+	RPL_METADATASYNCLATER  = "774" // end metadata numerics
 	RPL_LOGGEDIN           = "900"
 	RPL_LOGGEDOUT          = "901"
 	ERR_NICKLOCKED         = "902"

irc/passwd/bcrypt.go

@@ -11,6 +11,7 @@ import (
 
 const (
 	MinCost     = bcrypt.MinCost
+	MaxCost     = bcrypt.MaxCost
 	DefaultCost = 12 // ballpark: 250 msec on a modern Intel CPU
 )
 

irc/server.go

@@ -90,7 +90,8 @@ type Server struct {
 	snomasks          SnoManager
 	store             *buntdb.DB
 	dstore            datastore.Datastore
-	historyDB         mysql.MySQL
+	mysqlHistoryDB    *mysql.MySQL
+	historyDB         history.Database
 	torLimiter        connection_limits.TorLimiter
 	whoWas            WhoWasList
 	stats             Stats
@@ -153,7 +154,6 @@ func (server *Server) Shutdown() {
 	sdnotify.Stopping()
 	server.logger.Info("server", "Stopping server")
 
-	//TODO(dan): Make sure we disallow new nicks
 	for _, client := range server.clients.AllClients() {
 		client.Notice("Server is shutting down")
 	}
@@ -162,10 +162,12 @@ func (server *Server) Shutdown() {
 	server.performAlwaysOnMaintenance(false, true)
 
 	if err := server.store.Close(); err != nil {
-		server.logger.Error("shutdown", fmt.Sprintln("Could not close datastore:", err))
+		server.logger.Error("shutdown", "Could not close datastore", err.Error())
 	}
 
-	server.historyDB.Close()
+	if err := server.historyDB.Close(); err != nil {
+		server.logger.Error("shutdown", "Could not close history database", err.Error())
+	}
 	server.logger.Info("server", fmt.Sprintf("%s exiting", Ver))
 }
 
@@ -428,6 +430,10 @@ func (server *Server) tryRegister(c *Client, session *Session) (exiting bool) {
 		c.SetMode(defaultMode, true)
 	}
 
+	c.applyPreregMetadata(session)
+
+	c.server.monitorManager.AlertAbout(c.Nick(), c.NickCasefolded(), true, c)
+
 	// this is not a reattach, so if the client is always-on, this is the first time
 	// the Client object was created during the current server uptime. mark dirty in
 	// order to persist the realname and the user modes:
@@ -496,6 +502,9 @@ func (server *Server) playRegistrationBurst(session *Session) {
 	if !(rb.session.capabilities.Has(caps.ExtendedISupport) && rb.session.isupportSentPrereg) {
 		server.RplISupport(c, rb)
 	}
+	if session.capabilities.Has(caps.Metadata) {
+		playMetadataVerbBatch(rb, d.nick, c.ListMetadata())
+	}
 	if d.account != "" && session.capabilities.Has(caps.Persistence) {
 		reportPersistenceStatus(c, rb, false)
 	}
@@ -630,7 +639,6 @@ func (client *Client) getWhoisOf(target *Client, hasPrivs bool, rb *ResponseBuff
 	if target.HasMode(modes.Bot) {
 		rb.Add(nil, client.server.name, RPL_WHOISBOT, cnick, tnick, fmt.Sprintf(ircfmt.Unescape(client.t("is a $bBot$b on %s")), client.server.Config().Network.Name))
 	}
-
 	if client == target || oper.HasRoleCapab("ban") {
 		for _, session := range target.Sessions() {
 			if session.certfp != "" {
@@ -642,6 +650,11 @@ func (client *Client) getWhoisOf(target *Client, hasPrivs bool, rb *ResponseBuff
 	if away, awayMessage := target.Away(); away {
 		rb.Add(nil, client.server.name, RPL_AWAY, cnick, tnick, awayMessage)
 	}
+	if rb.session.capabilities.Has(caps.Metadata) {
+		for key, value := range target.ListMetadata() {
+			rb.Add(nil, client.server.name, RPL_WHOISKEYVALUE, cnick, tnick, key, "*", value)
+		}
+	}
 }
 
 // rehash reloads the config and applies the changes from the config file.
@@ -685,6 +698,9 @@ func (server *Server) applyConfig(config *Config) (err error) {
 		globalCasemappingSetting = config.Server.Casemapping
 		globalUtf8EnforcementSetting = config.Server.EnforceUtf8
 		MaxLineLen = config.Server.MaxLineLen
+		RegisterTimeout = config.Server.IdleTimeouts.Registration
+		PingTimeout = config.Server.IdleTimeouts.Ping
+		DisconnectTimeout = config.Server.IdleTimeouts.Disconnect
 	} else {
 		// enforce configs that can't be changed after launch:
 		if server.name != config.Server.Name {
@@ -710,6 +726,8 @@ func (server *Server) applyConfig(config *Config) (err error) {
 			return fmt.Errorf("Cannot enable MySQL after launching the server, rehash aborted")
 		} else if oldConfig.Server.MaxLineLen != config.Server.MaxLineLen {
 			return fmt.Errorf("Cannot change max-line-len after launching the server, rehash aborted")
+		} else if oldConfig.Server.IdleTimeouts != config.Server.IdleTimeouts {
+			return fmt.Errorf("Cannot change idle-timeouts after launching the server, rehash aborted")
 		}
 	}
 
@@ -788,8 +806,10 @@ func (server *Server) applyConfig(config *Config) (err error) {
 			return err
 		}
 	} else {
-		if config.Datastore.MySQL.Enabled && config.Datastore.MySQL != oldConfig.Datastore.MySQL {
-			server.historyDB.SetConfig(config.Datastore.MySQL)
+		if config.Datastore.MySQL.Enabled && server.mysqlHistoryDB != nil {
+			if config.Datastore.MySQL != oldConfig.Datastore.MySQL {
+				server.mysqlHistoryDB.SetConfig(config.Datastore.MySQL)
+			}
 		}
 	}
 
@@ -896,6 +916,9 @@ func (server *Server) applyConfig(config *Config) (err error) {
 	if config.Accounts.RequireSasl.Enabled && config.Accounts.Registration.Enabled {
 		server.logger.Warning("server", "Warning: although require-sasl is enabled, users can still register accounts. If your server is not intended to be public, you must set accounts.registration.enabled to false.")
 	}
+	if config.History.Enabled && config.History.ChathistoryMax == 0 {
+		server.logger.Warning("server", "Warning: for history to work correctly, you must set history.chathistory-maxmessages (see default.yaml for a recommendation).")
+	}
 
 	return err
 }
@@ -996,12 +1019,14 @@ func (server *Server) loadFromDatastore(config *Config) (err error) {
 	server.accounts.Initialize(server)
 
 	if config.Datastore.MySQL.Enabled {
-		server.historyDB.Initialize(server.logger, config.Datastore.MySQL)
-		err = server.historyDB.Open()
+		server.mysqlHistoryDB, err = mysql.NewMySQLDatabase(server.logger, config.Datastore.MySQL)
 		if err != nil {
 			server.logger.Error("internal", "could not connect to mysql", err.Error())
 			return err
 		}
+		server.historyDB = server.mysqlHistoryDB
+	} else {
+		server.historyDB = history.NewNoopDatabase()
 	}
 
 	return nil
@@ -1066,10 +1091,6 @@ func (server *Server) setupListeners(config *Config) (err error) {
 // we may already know the channel we're querying, or we may have
 // to look it up via a string query. This function is responsible for
 // privilege checking.
-// XXX: call this with providedChannel==nil and query=="" to get a sequence
-// suitable for ListCorrespondents (i.e., this function is still used to
-// decide whether the ringbuf or mysql is authoritative about the client's
-// message history).
 func (server *Server) GetHistorySequence(providedChannel *Channel, client *Client, query string) (channel *Channel, sequence history.Sequence, err error) {
 	config := server.Config()
 	// 4 cases: {persistent, ephemeral} x {normal, conversation}
@@ -1221,7 +1242,7 @@ func (server *Server) DeleteMessage(target, msgid, accountName string) (err erro
 			return item.Message.Msgid == msgid && (accountName == "*" || item.AccountName == accountName)
 		})
 		if count == 0 {
-			err = errNoop
+			err = history.ErrNotFound
 		}
 	}
 

irc/strings.go

@@ -73,7 +73,7 @@ var globalCasemappingSetting Casemapping = CasemappingPRECIS
 
 // XXX analogous unsynchronized global variable controlling utf8 validation
 // if this is off, you get the traditional IRC behavior (relaying any valid RFC1459
-// octets) and invalid utf8 messages are silently dropped for websocket clients only.
+// octets), and websocket listeners are disabled.
 // if this is on, invalid utf8 inputs get a FAIL reply.
 var globalUtf8EnforcementSetting bool
 

irc/utils/chunks.go

@@ -0,0 +1,28 @@
+package utils
+
+import "iter"
+
+func ChunkifyParams(params iter.Seq[string], maxChars int) [][]string {
+	var chunked [][]string
+
+	var acc []string
+	var length = 0
+
+	for p := range params {
+		length = length + len(p) + 1 // (accounting for the space)
+
+		if length > maxChars {
+			chunked = append(chunked, acc)
+			acc = []string{}
+			length = 0
+		}
+
+		acc = append(acc, p)
+	}
+
+	if len(acc) != 0 {
+		chunked = append(chunked, acc)
+	}
+
+	return chunked
+}

irc/utils/crypto.go

@@ -42,6 +42,11 @@ func GenerateSecretToken() string {
 	return B32Encoder.EncodeToString(buf[:])
 }
 
+// return a compact representation of a token generated by GenerateSecretToken()
+func DecodeSecretToken(t string) ([]byte, error) {
+	return B32Encoder.DecodeString(t)
+}
+
 // securely check if a supplied token matches a stored token
 func SecretTokensMatch(storedToken string, suppliedToken string) bool {
 	// XXX fix a potential gotcha: if the stored token is uninitialized,

irc/version.go

@@ -7,7 +7,7 @@ import "fmt"
 
 const (
 	// SemVer is the semantic version of Ergo.
-	SemVer = "2.16.0"
+	SemVer = "2.18.0-unreleased"
 )
 
 var (

irc/znc.go

@@ -218,7 +218,7 @@ func zncPlayPrivmsgsFromAll(client *Client, rb *ResponseBuffer, start, end time.
 // PRIVMSG *playback :list
 func zncPlaybackListHandler(client *Client, command string, params []string, rb *ResponseBuffer) {
 	limit := client.server.Config().History.ChathistoryMax
-	correspondents, err := client.listTargets(history.Selector{}, history.Selector{}, limit)
+	correspondents, err := client.listTargets(time.Time{}, time.Time{}, limit)
 	if err != nil {
 		client.server.logger.Error("internal", "couldn't get history for ZNC list", err.Error())
 		return

irctest

@@ -1 +1 @@
-Subproject commit e9e37f5438bd5f02656b89dab0cd40ef113edac6
+Subproject commit 219ca65273489193f54df9d5909aee3b4480c1c5

traditional.yaml

@@ -154,6 +154,21 @@ server:
     # if this is true, the motd is escaped using formatting codes like $c, $b, and $i
     motd-formatting: true
 
+    # send a configurable notice to clients immediately after they connect,
+    # as a way of detecting open proxies
+    #initial-notice: "*** Welcome to the Ergo IRC server"
+
+    # idle timeouts for inactive clients
+    idle-timeouts:
+        # give the client this long to complete connection registration (i.e. the initial
+        # IRC handshake, including capability negotiation and SASL)
+        registration: 60s
+        # if the client hasn't sent anything for this long, send them a PING
+        ping: 1m30s
+        # if the client hasn't sent anything for this long (including the PONG to the
+        # above PING), disconnect them
+        disconnect: 2m30s
+
     # relaying using the RELAYMSG command
     relaymsg:
         # is relaymsg enabled at all?
@@ -330,6 +345,10 @@ server:
     secure-nets:
         # - "10.0.0.0/8"
 
+    # allow attempts to OPER with a password at most this often. defaults to
+    # 10 seconds when unset.
+    oper-throttle: 10s
+
     # Ergo will write files to disk under certain circumstances, e.g.,
     # CPU profiling or data export. by default, these files will be written
     # to the working directory. set this to customize:
@@ -494,7 +513,7 @@ accounts:
         # 1. these nicknames cannot be registered or reserved
         # 2. if a client is automatically renamed by the server,
         #    this is the template that will be used (e.g., Guest-nccj6rgmt97cg)
-        # 3. if enforce-guest-format (see below) is enabled, clients without
+        # 3. if force-guest-format (see below) is enabled, clients without
         #    a registered account will have this template applied to their
         #    nicknames (e.g., 'katie' will become 'Guest-katie')
         guest-nickname-format: "Guest-*"
@@ -695,6 +714,7 @@ oper-classes:
             - "history"      # modify or delete history messages
             - "defcon"       # use the DEFCON command (restrict server capabilities)
             - "massmessage"  # message all users on the server
+            - "metadata"     # modify arbitrary metadata on channels and users
 
 # ircd operators
 opers:
@@ -958,10 +978,12 @@ history:
     # in your country and the countries of your users.
     enabled: true
 
-    # how many channel-specific events (messages, joins, parts) should be tracked per channel?
+    # if the in-memory backend is enabled for a channel, how many channel-specific events
+    # (messages, joins, parts) should be retained?
     channel-length: 2048
 
-    # how many direct messages and notices should be tracked per user?
+    # if the in-memory backend is enabled for a user, how many direct messages
+    # and notices should be retained?
     client-length: 256
 
     # how long should we try to preserve messages?
@@ -1058,6 +1080,20 @@ history:
 # e.g., ERGO__SERVER__MAX_SENDQ=128k. see the manual for more details.
 allow-environment-overrides: true
 
+# metadata support for setting key/value data on channels and nicknames.
+metadata:
+    # can clients store metadata?
+    enabled: true
+    # how many keys can a client subscribe to?
+    max-subs: 100
+    # how many keys can be stored per entity?
+    max-keys: 100
+    # rate limiting for client metadata updates, which are expensive to process
+    client-throttle:
+        enabled: true
+        duration: 2m
+        max-attempts: 10
+
 # experimental support for mobile push notifications
 # see the manual for potential security, privacy, and performance implications.
 # DO NOT enable if you are running a Tor or I2P hidden service (i.e. one

vendor/filippo.io/edwards25519/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/filippo.io/edwards25519/README.md

@@ -0,0 +1,14 @@
+# filippo.io/edwards25519
+
+```
+import "filippo.io/edwards25519"
+```
+
+This library implements the edwards25519 elliptic curve, exposing the necessary APIs to build a wide array of higher-level primitives.
+Read the docs at [pkg.go.dev/filippo.io/edwards25519](https://pkg.go.dev/filippo.io/edwards25519).
+
+The code is originally derived from Adam Langley's internal implementation in the Go standard library, and includes George Tankersley's [performance improvements](https://golang.org/cl/71950). It was then further developed by Henry de Valence for use in ristretto255, and was finally [merged back into the Go standard library](https://golang.org/cl/276272) as of Go 1.17. It now tracks the upstream codebase and extends it with additional functionality.
+
+Most users don't need this package, and should instead use `crypto/ed25519` for signatures, `golang.org/x/crypto/curve25519` for Diffie-Hellman, or `github.com/gtank/ristretto255` for prime order group logic. However, for anyone currently using a fork of `crypto/internal/edwards25519`/`crypto/ed25519/internal/edwards25519` or `github.com/agl/edwards25519`, this package should be a safer, faster, and more powerful alternative.
+
+Since this package is meant to curb proliferation of edwards25519 implementations in the Go ecosystem, it welcomes requests for new APIs or reviewable performance improvements.

vendor/filippo.io/edwards25519/doc.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package edwards25519 implements group logic for the twisted Edwards curve
+//
+//	-x^2 + y^2 = 1 + -(121665/121666)*x^2*y^2
+//
+// This is better known as the Edwards curve equivalent to Curve25519, and is
+// the curve used by the Ed25519 signature scheme.
+//
+// Most users don't need this package, and should instead use crypto/ed25519 for
+// signatures, golang.org/x/crypto/curve25519 for Diffie-Hellman, or
+// github.com/gtank/ristretto255 for prime order group logic.
+//
+// However, developers who do need to interact with low-level edwards25519
+// operations can use this package, which is an extended version of
+// crypto/internal/edwards25519 from the standard library repackaged as
+// an importable module.
+package edwards25519

vendor/filippo.io/edwards25519/edwards25519.go

@@ -0,0 +1,427 @@
+// Copyright (c) 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edwards25519
+
+import (
+	"errors"
+
+	"filippo.io/edwards25519/field"
+)
+
+// Point types.
+
+type projP1xP1 struct {
+	X, Y, Z, T field.Element
+}
+
+type projP2 struct {
+	X, Y, Z field.Element
+}
+
+// Point represents a point on the edwards25519 curve.
+//
+// This type works similarly to math/big.Int, and all arguments and receivers
+// are allowed to alias.
+//
+// The zero value is NOT valid, and it may be used only as a receiver.
+type Point struct {
+	// Make the type not comparable (i.e. used with == or as a map key), as
+	// equivalent points can be represented by different Go values.
+	_ incomparable
+
+	// The point is internally represented in extended coordinates (X, Y, Z, T)
+	// where x = X/Z, y = Y/Z, and xy = T/Z per https://eprint.iacr.org/2008/522.
+	x, y, z, t field.Element
+}
+
+type incomparable [0]func()
+
+func checkInitialized(points ...*Point) {
+	for _, p := range points {
+		if p.x == (field.Element{}) && p.y == (field.Element{}) {
+			panic("edwards25519: use of uninitialized Point")
+		}
+	}
+}
+
+type projCached struct {
+	YplusX, YminusX, Z, T2d field.Element
+}
+
+type affineCached struct {
+	YplusX, YminusX, T2d field.Element
+}
+
+// Constructors.
+
+func (v *projP2) Zero() *projP2 {
+	v.X.Zero()
+	v.Y.One()
+	v.Z.One()
+	return v
+}
+
+// identity is the point at infinity.
+var identity, _ = new(Point).SetBytes([]byte{
+	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})
+
+// NewIdentityPoint returns a new Point set to the identity.
+func NewIdentityPoint() *Point {
+	return new(Point).Set(identity)
+}
+
+// generator is the canonical curve basepoint. See TestGenerator for the
+// correspondence of this encoding with the values in RFC 8032.
+var generator, _ = new(Point).SetBytes([]byte{
+	0x58, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66,
+	0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66,
+	0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66,
+	0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66})
+
+// NewGeneratorPoint returns a new Point set to the canonical generator.
+func NewGeneratorPoint() *Point {
+	return new(Point).Set(generator)
+}
+
+func (v *projCached) Zero() *projCached {
+	v.YplusX.One()
+	v.YminusX.One()
+	v.Z.One()
+	v.T2d.Zero()
+	return v
+}
+
+func (v *affineCached) Zero() *affineCached {
+	v.YplusX.One()
+	v.YminusX.One()
+	v.T2d.Zero()
+	return v
+}
+
+// Assignments.
+
+// Set sets v = u, and returns v.
+func (v *Point) Set(u *Point) *Point {
+	*v = *u
+	return v
+}
+
+// Encoding.
+
+// Bytes returns the canonical 32-byte encoding of v, according to RFC 8032,
+// Section 5.1.2.
+func (v *Point) Bytes() []byte {
+	// This function is outlined to make the allocations inline in the caller
+	// rather than happen on the heap.
+	var buf [32]byte
+	return v.bytes(&buf)
+}
+
+func (v *Point) bytes(buf *[32]byte) []byte {
+	checkInitialized(v)
+
+	var zInv, x, y field.Element
+	zInv.Invert(&v.z)       // zInv = 1 / Z
+	x.Multiply(&v.x, &zInv) // x = X / Z
+	y.Multiply(&v.y, &zInv) // y = Y / Z
+
+	out := copyFieldElement(buf, &y)
+	out[31] |= byte(x.IsNegative() << 7)
+	return out
+}
+
+var feOne = new(field.Element).One()
+
+// SetBytes sets v = x, where x is a 32-byte encoding of v. If x does not
+// represent a valid point on the curve, SetBytes returns nil and an error and
+// the receiver is unchanged. Otherwise, SetBytes returns v.
+//
+// Note that SetBytes accepts all non-canonical encodings of valid points.
+// That is, it follows decoding rules that match most implementations in
+// the ecosystem rather than RFC 8032.
+func (v *Point) SetBytes(x []byte) (*Point, error) {
+	// Specifically, the non-canonical encodings that are accepted are
+	//   1) the ones where the field element is not reduced (see the
+	//      (*field.Element).SetBytes docs) and
+	//   2) the ones where the x-coordinate is zero and the sign bit is set.
+	//
+	// Read more at https://hdevalence.ca/blog/2020-10-04-its-25519am,
+	// specifically the "Canonical A, R" section.
+
+	y, err := new(field.Element).SetBytes(x)
+	if err != nil {
+		return nil, errors.New("edwards25519: invalid point encoding length")
+	}
+
+	// -x² + y² = 1 + dx²y²
+	// x² + dx²y² = x²(dy² + 1) = y² - 1
+	// x² = (y² - 1) / (dy² + 1)
+
+	// u = y² - 1
+	y2 := new(field.Element).Square(y)
+	u := new(field.Element).Subtract(y2, feOne)
+
+	// v = dy² + 1
+	vv := new(field.Element).Multiply(y2, d)
+	vv = vv.Add(vv, feOne)
+
+	// x = +√(u/v)
+	xx, wasSquare := new(field.Element).SqrtRatio(u, vv)
+	if wasSquare == 0 {
+		return nil, errors.New("edwards25519: invalid point encoding")
+	}
+
+	// Select the negative square root if the sign bit is set.
+	xxNeg := new(field.Element).Negate(xx)
+	xx = xx.Select(xxNeg, xx, int(x[31]>>7))
+
+	v.x.Set(xx)
+	v.y.Set(y)
+	v.z.One()
+	v.t.Multiply(xx, y) // xy = T / Z
+
+	return v, nil
+}
+
+func copyFieldElement(buf *[32]byte, v *field.Element) []byte {
+	copy(buf[:], v.Bytes())
+	return buf[:]
+}
+
+// Conversions.
+
+func (v *projP2) FromP1xP1(p *projP1xP1) *projP2 {
+	v.X.Multiply(&p.X, &p.T)
+	v.Y.Multiply(&p.Y, &p.Z)
+	v.Z.Multiply(&p.Z, &p.T)
+	return v
+}
+
+func (v *projP2) FromP3(p *Point) *projP2 {
+	v.X.Set(&p.x)
+	v.Y.Set(&p.y)
+	v.Z.Set(&p.z)
+	return v
+}
+
+func (v *Point) fromP1xP1(p *projP1xP1) *Point {
+	v.x.Multiply(&p.X, &p.T)
+	v.y.Multiply(&p.Y, &p.Z)
+	v.z.Multiply(&p.Z, &p.T)
+	v.t.Multiply(&p.X, &p.Y)
+	return v
+}
+
+func (v *Point) fromP2(p *projP2) *Point {
+	v.x.Multiply(&p.X, &p.Z)
+	v.y.Multiply(&p.Y, &p.Z)
+	v.z.Square(&p.Z)
+	v.t.Multiply(&p.X, &p.Y)
+	return v
+}
+
+// d is a constant in the curve equation.
+var d, _ = new(field.Element).SetBytes([]byte{
+	0xa3, 0x78, 0x59, 0x13, 0xca, 0x4d, 0xeb, 0x75,
+	0xab, 0xd8, 0x41, 0x41, 0x4d, 0x0a, 0x70, 0x00,
+	0x98, 0xe8, 0x79, 0x77, 0x79, 0x40, 0xc7, 0x8c,
+	0x73, 0xfe, 0x6f, 0x2b, 0xee, 0x6c, 0x03, 0x52})
+var d2 = new(field.Element).Add(d, d)
+
+func (v *projCached) FromP3(p *Point) *projCached {
+	v.YplusX.Add(&p.y, &p.x)
+	v.YminusX.Subtract(&p.y, &p.x)
+	v.Z.Set(&p.z)
+	v.T2d.Multiply(&p.t, d2)
+	return v
+}
+
+func (v *affineCached) FromP3(p *Point) *affineCached {
+	v.YplusX.Add(&p.y, &p.x)
+	v.YminusX.Subtract(&p.y, &p.x)
+	v.T2d.Multiply(&p.t, d2)
+
+	var invZ field.Element
+	invZ.Invert(&p.z)
+	v.YplusX.Multiply(&v.YplusX, &invZ)
+	v.YminusX.Multiply(&v.YminusX, &invZ)
+	v.T2d.Multiply(&v.T2d, &invZ)
+	return v
+}
+
+// (Re)addition and subtraction.
+
+// Add sets v = p + q, and returns v.
+func (v *Point) Add(p, q *Point) *Point {
+	checkInitialized(p, q)
+	qCached := new(projCached).FromP3(q)
+	result := new(projP1xP1).Add(p, qCached)
+	return v.fromP1xP1(result)
+}
+
+// Subtract sets v = p - q, and returns v.
+func (v *Point) Subtract(p, q *Point) *Point {
+	checkInitialized(p, q)
+	qCached := new(projCached).FromP3(q)
+	result := new(projP1xP1).Sub(p, qCached)
+	return v.fromP1xP1(result)
+}
+
+func (v *projP1xP1) Add(p *Point, q *projCached) *projP1xP1 {
+	var YplusX, YminusX, PP, MM, TT2d, ZZ2 field.Element
+
+	YplusX.Add(&p.y, &p.x)
+	YminusX.Subtract(&p.y, &p.x)
+
+	PP.Multiply(&YplusX, &q.YplusX)
+	MM.Multiply(&YminusX, &q.YminusX)
+	TT2d.Multiply(&p.t, &q.T2d)
+	ZZ2.Multiply(&p.z, &q.Z)
+
+	ZZ2.Add(&ZZ2, &ZZ2)
+
+	v.X.Subtract(&PP, &MM)
+	v.Y.Add(&PP, &MM)
+	v.Z.Add(&ZZ2, &TT2d)
+	v.T.Subtract(&ZZ2, &TT2d)
+	return v
+}
+
+func (v *projP1xP1) Sub(p *Point, q *projCached) *projP1xP1 {
+	var YplusX, YminusX, PP, MM, TT2d, ZZ2 field.Element
+
+	YplusX.Add(&p.y, &p.x)
+	YminusX.Subtract(&p.y, &p.x)
+
+	PP.Multiply(&YplusX, &q.YminusX) // flipped sign
+	MM.Multiply(&YminusX, &q.YplusX) // flipped sign
+	TT2d.Multiply(&p.t, &q.T2d)
+	ZZ2.Multiply(&p.z, &q.Z)
+
+	ZZ2.Add(&ZZ2, &ZZ2)
+
+	v.X.Subtract(&PP, &MM)
+	v.Y.Add(&PP, &MM)
+	v.Z.Subtract(&ZZ2, &TT2d) // flipped sign
+	v.T.Add(&ZZ2, &TT2d)      // flipped sign
+	return v
+}
+
+func (v *projP1xP1) AddAffine(p *Point, q *affineCached) *projP1xP1 {
+	var YplusX, YminusX, PP, MM, TT2d, Z2 field.Element
+
+	YplusX.Add(&p.y, &p.x)
+	YminusX.Subtract(&p.y, &p.x)
+
+	PP.Multiply(&YplusX, &q.YplusX)
+	MM.Multiply(&YminusX, &q.YminusX)
+	TT2d.Multiply(&p.t, &q.T2d)
+
+	Z2.Add(&p.z, &p.z)
+
+	v.X.Subtract(&PP, &MM)
+	v.Y.Add(&PP, &MM)
+	v.Z.Add(&Z2, &TT2d)
+	v.T.Subtract(&Z2, &TT2d)
+	return v
+}
+
+func (v *projP1xP1) SubAffine(p *Point, q *affineCached) *projP1xP1 {
+	var YplusX, YminusX, PP, MM, TT2d, Z2 field.Element
+
+	YplusX.Add(&p.y, &p.x)
+	YminusX.Subtract(&p.y, &p.x)
+
+	PP.Multiply(&YplusX, &q.YminusX) // flipped sign
+	MM.Multiply(&YminusX, &q.YplusX) // flipped sign
+	TT2d.Multiply(&p.t, &q.T2d)
+
+	Z2.Add(&p.z, &p.z)
+
+	v.X.Subtract(&PP, &MM)
+	v.Y.Add(&PP, &MM)
+	v.Z.Subtract(&Z2, &TT2d) // flipped sign
+	v.T.Add(&Z2, &TT2d)      // flipped sign
+	return v
+}
+
+// Doubling.
+
+func (v *projP1xP1) Double(p *projP2) *projP1xP1 {
+	var XX, YY, ZZ2, XplusYsq field.Element
+
+	XX.Square(&p.X)
+	YY.Square(&p.Y)
+	ZZ2.Square(&p.Z)
+	ZZ2.Add(&ZZ2, &ZZ2)
+	XplusYsq.Add(&p.X, &p.Y)
+	XplusYsq.Square(&XplusYsq)
+
+	v.Y.Add(&YY, &XX)
+	v.Z.Subtract(&YY, &XX)
+
+	v.X.Subtract(&XplusYsq, &v.Y)
+	v.T.Subtract(&ZZ2, &v.Z)
+	return v
+}
+
+// Negation.
+
+// Negate sets v = -p, and returns v.
+func (v *Point) Negate(p *Point) *Point {
+	checkInitialized(p)
+	v.x.Negate(&p.x)
+	v.y.Set(&p.y)
+	v.z.Set(&p.z)
+	v.t.Negate(&p.t)
+	return v
+}
+
+// Equal returns 1 if v is equivalent to u, and 0 otherwise.
+func (v *Point) Equal(u *Point) int {
+	checkInitialized(v, u)
+
+	var t1, t2, t3, t4 field.Element
+	t1.Multiply(&v.x, &u.z)
+	t2.Multiply(&u.x, &v.z)
+	t3.Multiply(&v.y, &u.z)
+	t4.Multiply(&u.y, &v.z)
+
+	return t1.Equal(&t2) & t3.Equal(&t4)
+}
+
+// Constant-time operations
+
+// Select sets v to a if cond == 1 and to b if cond == 0.
+func (v *projCached) Select(a, b *projCached, cond int) *projCached {
+	v.YplusX.Select(&a.YplusX, &b.YplusX, cond)
+	v.YminusX.Select(&a.YminusX, &b.YminusX, cond)
+	v.Z.Select(&a.Z, &b.Z, cond)
+	v.T2d.Select(&a.T2d, &b.T2d, cond)
+	return v
+}
+
+// Select sets v to a if cond == 1 and to b if cond == 0.
+func (v *affineCached) Select(a, b *affineCached, cond int) *affineCached {
+	v.YplusX.Select(&a.YplusX, &b.YplusX, cond)
+	v.YminusX.Select(&a.YminusX, &b.YminusX, cond)
+	v.T2d.Select(&a.T2d, &b.T2d, cond)
+	return v
+}
+
+// CondNeg negates v if cond == 1 and leaves it unchanged if cond == 0.
+func (v *projCached) CondNeg(cond int) *projCached {
+	v.YplusX.Swap(&v.YminusX, cond)
+	v.T2d.Select(new(field.Element).Negate(&v.T2d), &v.T2d, cond)
+	return v
+}
+
+// CondNeg negates v if cond == 1 and leaves it unchanged if cond == 0.
+func (v *affineCached) CondNeg(cond int) *affineCached {
+	v.YplusX.Swap(&v.YminusX, cond)
+	v.T2d.Select(new(field.Element).Negate(&v.T2d), &v.T2d, cond)
+	return v
+}

vendor/filippo.io/edwards25519/extra.go

@@ -0,0 +1,349 @@
+// Copyright (c) 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edwards25519
+
+// This file contains additional functionality that is not included in the
+// upstream crypto/internal/edwards25519 package.
+
+import (
+	"errors"
+
+	"filippo.io/edwards25519/field"
+)
+
+// ExtendedCoordinates returns v in extended coordinates (X:Y:Z:T) where
+// x = X/Z, y = Y/Z, and xy = T/Z as in https://eprint.iacr.org/2008/522.
+func (v *Point) ExtendedCoordinates() (X, Y, Z, T *field.Element) {
+	// This function is outlined to make the allocations inline in the caller
+	// rather than happen on the heap. Don't change the style without making
+	// sure it doesn't increase the inliner cost.
+	var e [4]field.Element
+	X, Y, Z, T = v.extendedCoordinates(&e)
+	return
+}
+
+func (v *Point) extendedCoordinates(e *[4]field.Element) (X, Y, Z, T *field.Element) {
+	checkInitialized(v)
+	X = e[0].Set(&v.x)
+	Y = e[1].Set(&v.y)
+	Z = e[2].Set(&v.z)
+	T = e[3].Set(&v.t)
+	return
+}
+
+// SetExtendedCoordinates sets v = (X:Y:Z:T) in extended coordinates where
+// x = X/Z, y = Y/Z, and xy = T/Z as in https://eprint.iacr.org/2008/522.
+//
+// If the coordinates are invalid or don't represent a valid point on the curve,
+// SetExtendedCoordinates returns nil and an error and the receiver is
+// unchanged. Otherwise, SetExtendedCoordinates returns v.
+func (v *Point) SetExtendedCoordinates(X, Y, Z, T *field.Element) (*Point, error) {
+	if !isOnCurve(X, Y, Z, T) {
+		return nil, errors.New("edwards25519: invalid point coordinates")
+	}
+	v.x.Set(X)
+	v.y.Set(Y)
+	v.z.Set(Z)
+	v.t.Set(T)
+	return v, nil
+}
+
+func isOnCurve(X, Y, Z, T *field.Element) bool {
+	var lhs, rhs field.Element
+	XX := new(field.Element).Square(X)
+	YY := new(field.Element).Square(Y)
+	ZZ := new(field.Element).Square(Z)
+	TT := new(field.Element).Square(T)
+	// -x² + y² = 1 + dx²y²
+	// -(X/Z)² + (Y/Z)² = 1 + d(T/Z)²
+	// -X² + Y² = Z² + dT²
+	lhs.Subtract(YY, XX)
+	rhs.Multiply(d, TT).Add(&rhs, ZZ)
+	if lhs.Equal(&rhs) != 1 {
+		return false
+	}
+	// xy = T/Z
+	// XY/Z² = T/Z
+	// XY = TZ
+	lhs.Multiply(X, Y)
+	rhs.Multiply(T, Z)
+	return lhs.Equal(&rhs) == 1
+}
+
+// BytesMontgomery converts v to a point on the birationally-equivalent
+// Curve25519 Montgomery curve, and returns its canonical 32 bytes encoding
+// according to RFC 7748.
+//
+// Note that BytesMontgomery only encodes the u-coordinate, so v and -v encode
+// to the same value. If v is the identity point, BytesMontgomery returns 32
+// zero bytes, analogously to the X25519 function.
+//
+// The lack of an inverse operation (such as SetMontgomeryBytes) is deliberate:
+// while every valid edwards25519 point has a unique u-coordinate Montgomery
+// encoding, X25519 accepts inputs on the quadratic twist, which don't correspond
+// to any edwards25519 point, and every other X25519 input corresponds to two
+// edwards25519 points.
+func (v *Point) BytesMontgomery() []byte {
+	// This function is outlined to make the allocations inline in the caller
+	// rather than happen on the heap.
+	var buf [32]byte
+	return v.bytesMontgomery(&buf)
+}
+
+func (v *Point) bytesMontgomery(buf *[32]byte) []byte {
+	checkInitialized(v)
+
+	// RFC 7748, Section 4.1 provides the bilinear map to calculate the
+	// Montgomery u-coordinate
+	//
+	//              u = (1 + y) / (1 - y)
+	//
+	// where y = Y / Z.
+
+	var y, recip, u field.Element
+
+	y.Multiply(&v.y, y.Invert(&v.z))        // y = Y / Z
+	recip.Invert(recip.Subtract(feOne, &y)) // r = 1/(1 - y)
+	u.Multiply(u.Add(feOne, &y), &recip)    // u = (1 + y)*r
+
+	return copyFieldElement(buf, &u)
+}
+
+// MultByCofactor sets v = 8 * p, and returns v.
+func (v *Point) MultByCofactor(p *Point) *Point {
+	checkInitialized(p)
+	result := projP1xP1{}
+	pp := (&projP2{}).FromP3(p)
+	result.Double(pp)
+	pp.FromP1xP1(&result)
+	result.Double(pp)
+	pp.FromP1xP1(&result)
+	result.Double(pp)
+	return v.fromP1xP1(&result)
+}
+
+// Given k > 0, set s = s**(2*i).
+func (s *Scalar) pow2k(k int) {
+	for i := 0; i < k; i++ {
+		s.Multiply(s, s)
+	}
+}
+
+// Invert sets s to the inverse of a nonzero scalar v, and returns s.
+//
+// If t is zero, Invert returns zero.
+func (s *Scalar) Invert(t *Scalar) *Scalar {
+	// Uses a hardcoded sliding window of width 4.
+	var table [8]Scalar
+	var tt Scalar
+	tt.Multiply(t, t)
+	table[0] = *t
+	for i := 0; i < 7; i++ {
+		table[i+1].Multiply(&table[i], &tt)
+	}
+	// Now table = [t**1, t**3, t**5, t**7, t**9, t**11, t**13, t**15]
+	// so t**k = t[k/2] for odd k
+
+	// To compute the sliding window digits, use the following Sage script:
+
+	// sage: import itertools
+	// sage: def sliding_window(w,k):
+	// ....:     digits = []
+	// ....:     while k > 0:
+	// ....:         if k % 2 == 1:
+	// ....:             kmod = k % (2**w)
+	// ....:             digits.append(kmod)
+	// ....:             k = k - kmod
+	// ....:         else:
+	// ....:             digits.append(0)
+	// ....:         k = k // 2
+	// ....:     return digits
+
+	// Now we can compute s roughly as follows:
+
+	// sage: s = 1
+	// sage: for coeff in reversed(sliding_window(4,l-2)):
+	// ....:     s = s*s
+	// ....:     if coeff > 0 :
+	// ....:         s = s*t**coeff
+
+	// This works on one bit at a time, with many runs of zeros.
+	// The digits can be collapsed into [(count, coeff)] as follows:
+
+	// sage: [(len(list(group)),d) for d,group in itertools.groupby(sliding_window(4,l-2))]
+
+	// Entries of the form (k, 0) turn into pow2k(k)
+	// Entries of the form (1, coeff) turn into a squaring and then a table lookup.
+	// We can fold the squaring into the previous pow2k(k) as pow2k(k+1).
+
+	*s = table[1/2]
+	s.pow2k(127 + 1)
+	s.Multiply(s, &table[1/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[9/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[11/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[13/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[15/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[7/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[15/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[5/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[1/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[15/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[15/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[7/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[3/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[11/2])
+	s.pow2k(5 + 1)
+	s.Multiply(s, &table[11/2])
+	s.pow2k(9 + 1)
+	s.Multiply(s, &table[9/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[3/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[3/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[3/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[9/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[7/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[3/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[13/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[7/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[9/2])
+	s.pow2k(3 + 1)
+	s.Multiply(s, &table[15/2])
+	s.pow2k(4 + 1)
+	s.Multiply(s, &table[11/2])
+
+	return s
+}
+
+// MultiScalarMult sets v = sum(scalars[i] * points[i]), and returns v.
+//
+// Execution time depends only on the lengths of the two slices, which must match.
+func (v *Point) MultiScalarMult(scalars []*Scalar, points []*Point) *Point {
+	if len(scalars) != len(points) {
+		panic("edwards25519: called MultiScalarMult with different size inputs")
+	}
+	checkInitialized(points...)
+
+	// Proceed as in the single-base case, but share doublings
+	// between each point in the multiscalar equation.
+
+	// Build lookup tables for each point
+	tables := make([]projLookupTable, len(points))
+	for i := range tables {
+		tables[i].FromP3(points[i])
+	}
+	// Compute signed radix-16 digits for each scalar
+	digits := make([][64]int8, len(scalars))
+	for i := range digits {
+		digits[i] = scalars[i].signedRadix16()
+	}
+
+	// Unwrap first loop iteration to save computing 16*identity
+	multiple := &projCached{}
+	tmp1 := &projP1xP1{}
+	tmp2 := &projP2{}
+	// Lookup-and-add the appropriate multiple of each input point
+	for j := range tables {
+		tables[j].SelectInto(multiple, digits[j][63])
+		tmp1.Add(v, multiple) // tmp1 = v + x_(j,63)*Q in P1xP1 coords
+		v.fromP1xP1(tmp1)     // update v
+	}
+	tmp2.FromP3(v) // set up tmp2 = v in P2 coords for next iteration
+	for i := 62; i >= 0; i-- {
+		tmp1.Double(tmp2)    // tmp1 =  2*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  2*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 =  4*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  4*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 =  8*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  8*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 = 16*(prev) in P1xP1 coords
+		v.fromP1xP1(tmp1)    //    v = 16*(prev) in P3 coords
+		// Lookup-and-add the appropriate multiple of each input point
+		for j := range tables {
+			tables[j].SelectInto(multiple, digits[j][i])
+			tmp1.Add(v, multiple) // tmp1 = v + x_(j,i)*Q in P1xP1 coords
+			v.fromP1xP1(tmp1)     // update v
+		}
+		tmp2.FromP3(v) // set up tmp2 = v in P2 coords for next iteration
+	}
+	return v
+}
+
+// VarTimeMultiScalarMult sets v = sum(scalars[i] * points[i]), and returns v.
+//
+// Execution time depends on the inputs.
+func (v *Point) VarTimeMultiScalarMult(scalars []*Scalar, points []*Point) *Point {
+	if len(scalars) != len(points) {
+		panic("edwards25519: called VarTimeMultiScalarMult with different size inputs")
+	}
+	checkInitialized(points...)
+
+	// Generalize double-base NAF computation to arbitrary sizes.
+	// Here all the points are dynamic, so we only use the smaller
+	// tables.
+
+	// Build lookup tables for each point
+	tables := make([]nafLookupTable5, len(points))
+	for i := range tables {
+		tables[i].FromP3(points[i])
+	}
+	// Compute a NAF for each scalar
+	nafs := make([][256]int8, len(scalars))
+	for i := range nafs {
+		nafs[i] = scalars[i].nonAdjacentForm(5)
+	}
+
+	multiple := &projCached{}
+	tmp1 := &projP1xP1{}
+	tmp2 := &projP2{}
+	tmp2.Zero()
+
+	// Move from high to low bits, doubling the accumulator
+	// at each iteration and checking whether there is a nonzero
+	// coefficient to look up a multiple of.
+	//
+	// Skip trying to find the first nonzero coefficent, because
+	// searching might be more work than a few extra doublings.
+	for i := 255; i >= 0; i-- {
+		tmp1.Double(tmp2)
+
+		for j := range nafs {
+			if nafs[j][i] > 0 {
+				v.fromP1xP1(tmp1)
+				tables[j].SelectInto(multiple, nafs[j][i])
+				tmp1.Add(v, multiple)
+			} else if nafs[j][i] < 0 {
+				v.fromP1xP1(tmp1)
+				tables[j].SelectInto(multiple, -nafs[j][i])
+				tmp1.Sub(v, multiple)
+			}
+		}
+
+		tmp2.FromP1xP1(tmp1)
+	}
+
+	v.fromP2(tmp2)
+	return v
+}

vendor/filippo.io/edwards25519/field/fe.go

@@ -0,0 +1,420 @@
+// Copyright (c) 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package field implements fast arithmetic modulo 2^255-19.
+package field
+
+import (
+	"crypto/subtle"
+	"encoding/binary"
+	"errors"
+	"math/bits"
+)
+
+// Element represents an element of the field GF(2^255-19). Note that this
+// is not a cryptographically secure group, and should only be used to interact
+// with edwards25519.Point coordinates.
+//
+// This type works similarly to math/big.Int, and all arguments and receivers
+// are allowed to alias.
+//
+// The zero value is a valid zero element.
+type Element struct {
+	// An element t represents the integer
+	//     t.l0 + t.l1*2^51 + t.l2*2^102 + t.l3*2^153 + t.l4*2^204
+	//
+	// Between operations, all limbs are expected to be lower than 2^52.
+	l0 uint64
+	l1 uint64
+	l2 uint64
+	l3 uint64
+	l4 uint64
+}
+
+const maskLow51Bits uint64 = (1 << 51) - 1
+
+var feZero = &Element{0, 0, 0, 0, 0}
+
+// Zero sets v = 0, and returns v.
+func (v *Element) Zero() *Element {
+	*v = *feZero
+	return v
+}
+
+var feOne = &Element{1, 0, 0, 0, 0}
+
+// One sets v = 1, and returns v.
+func (v *Element) One() *Element {
+	*v = *feOne
+	return v
+}
+
+// reduce reduces v modulo 2^255 - 19 and returns it.
+func (v *Element) reduce() *Element {
+	v.carryPropagate()
+
+	// After the light reduction we now have a field element representation
+	// v < 2^255 + 2^13 * 19, but need v < 2^255 - 19.
+
+	// If v >= 2^255 - 19, then v + 19 >= 2^255, which would overflow 2^255 - 1,
+	// generating a carry. That is, c will be 0 if v < 2^255 - 19, and 1 otherwise.
+	c := (v.l0 + 19) >> 51
+	c = (v.l1 + c) >> 51
+	c = (v.l2 + c) >> 51
+	c = (v.l3 + c) >> 51
+	c = (v.l4 + c) >> 51
+
+	// If v < 2^255 - 19 and c = 0, this will be a no-op. Otherwise, it's
+	// effectively applying the reduction identity to the carry.
+	v.l0 += 19 * c
+
+	v.l1 += v.l0 >> 51
+	v.l0 = v.l0 & maskLow51Bits
+	v.l2 += v.l1 >> 51
+	v.l1 = v.l1 & maskLow51Bits
+	v.l3 += v.l2 >> 51
+	v.l2 = v.l2 & maskLow51Bits
+	v.l4 += v.l3 >> 51
+	v.l3 = v.l3 & maskLow51Bits
+	// no additional carry
+	v.l4 = v.l4 & maskLow51Bits
+
+	return v
+}
+
+// Add sets v = a + b, and returns v.
+func (v *Element) Add(a, b *Element) *Element {
+	v.l0 = a.l0 + b.l0
+	v.l1 = a.l1 + b.l1
+	v.l2 = a.l2 + b.l2
+	v.l3 = a.l3 + b.l3
+	v.l4 = a.l4 + b.l4
+	// Using the generic implementation here is actually faster than the
+	// assembly. Probably because the body of this function is so simple that
+	// the compiler can figure out better optimizations by inlining the carry
+	// propagation.
+	return v.carryPropagateGeneric()
+}
+
+// Subtract sets v = a - b, and returns v.
+func (v *Element) Subtract(a, b *Element) *Element {
+	// We first add 2 * p, to guarantee the subtraction won't underflow, and
+	// then subtract b (which can be up to 2^255 + 2^13 * 19).
+	v.l0 = (a.l0 + 0xFFFFFFFFFFFDA) - b.l0
+	v.l1 = (a.l1 + 0xFFFFFFFFFFFFE) - b.l1
+	v.l2 = (a.l2 + 0xFFFFFFFFFFFFE) - b.l2
+	v.l3 = (a.l3 + 0xFFFFFFFFFFFFE) - b.l3
+	v.l4 = (a.l4 + 0xFFFFFFFFFFFFE) - b.l4
+	return v.carryPropagate()
+}
+
+// Negate sets v = -a, and returns v.
+func (v *Element) Negate(a *Element) *Element {
+	return v.Subtract(feZero, a)
+}
+
+// Invert sets v = 1/z mod p, and returns v.
+//
+// If z == 0, Invert returns v = 0.
+func (v *Element) Invert(z *Element) *Element {
+	// Inversion is implemented as exponentiation with exponent p − 2. It uses the
+	// same sequence of 255 squarings and 11 multiplications as [Curve25519].
+	var z2, z9, z11, z2_5_0, z2_10_0, z2_20_0, z2_50_0, z2_100_0, t Element
+
+	z2.Square(z)             // 2
+	t.Square(&z2)            // 4
+	t.Square(&t)             // 8
+	z9.Multiply(&t, z)       // 9
+	z11.Multiply(&z9, &z2)   // 11
+	t.Square(&z11)           // 22
+	z2_5_0.Multiply(&t, &z9) // 31 = 2^5 - 2^0
+
+	t.Square(&z2_5_0) // 2^6 - 2^1
+	for i := 0; i < 4; i++ {
+		t.Square(&t) // 2^10 - 2^5
+	}
+	z2_10_0.Multiply(&t, &z2_5_0) // 2^10 - 2^0
+
+	t.Square(&z2_10_0) // 2^11 - 2^1
+	for i := 0; i < 9; i++ {
+		t.Square(&t) // 2^20 - 2^10
+	}
+	z2_20_0.Multiply(&t, &z2_10_0) // 2^20 - 2^0
+
+	t.Square(&z2_20_0) // 2^21 - 2^1
+	for i := 0; i < 19; i++ {
+		t.Square(&t) // 2^40 - 2^20
+	}
+	t.Multiply(&t, &z2_20_0) // 2^40 - 2^0
+
+	t.Square(&t) // 2^41 - 2^1
+	for i := 0; i < 9; i++ {
+		t.Square(&t) // 2^50 - 2^10
+	}
+	z2_50_0.Multiply(&t, &z2_10_0) // 2^50 - 2^0
+
+	t.Square(&z2_50_0) // 2^51 - 2^1
+	for i := 0; i < 49; i++ {
+		t.Square(&t) // 2^100 - 2^50
+	}
+	z2_100_0.Multiply(&t, &z2_50_0) // 2^100 - 2^0
+
+	t.Square(&z2_100_0) // 2^101 - 2^1
+	for i := 0; i < 99; i++ {
+		t.Square(&t) // 2^200 - 2^100
+	}
+	t.Multiply(&t, &z2_100_0) // 2^200 - 2^0
+
+	t.Square(&t) // 2^201 - 2^1
+	for i := 0; i < 49; i++ {
+		t.Square(&t) // 2^250 - 2^50
+	}
+	t.Multiply(&t, &z2_50_0) // 2^250 - 2^0
+
+	t.Square(&t) // 2^251 - 2^1
+	t.Square(&t) // 2^252 - 2^2
+	t.Square(&t) // 2^253 - 2^3
+	t.Square(&t) // 2^254 - 2^4
+	t.Square(&t) // 2^255 - 2^5
+
+	return v.Multiply(&t, &z11) // 2^255 - 21
+}
+
+// Set sets v = a, and returns v.
+func (v *Element) Set(a *Element) *Element {
+	*v = *a
+	return v
+}
+
+// SetBytes sets v to x, where x is a 32-byte little-endian encoding. If x is
+// not of the right length, SetBytes returns nil and an error, and the
+// receiver is unchanged.
+//
+// Consistent with RFC 7748, the most significant bit (the high bit of the
+// last byte) is ignored, and non-canonical values (2^255-19 through 2^255-1)
+// are accepted. Note that this is laxer than specified by RFC 8032, but
+// consistent with most Ed25519 implementations.
+func (v *Element) SetBytes(x []byte) (*Element, error) {
+	if len(x) != 32 {
+		return nil, errors.New("edwards25519: invalid field element input size")
+	}
+
+	// Bits 0:51 (bytes 0:8, bits 0:64, shift 0, mask 51).
+	v.l0 = binary.LittleEndian.Uint64(x[0:8])
+	v.l0 &= maskLow51Bits
+	// Bits 51:102 (bytes 6:14, bits 48:112, shift 3, mask 51).
+	v.l1 = binary.LittleEndian.Uint64(x[6:14]) >> 3
+	v.l1 &= maskLow51Bits
+	// Bits 102:153 (bytes 12:20, bits 96:160, shift 6, mask 51).
+	v.l2 = binary.LittleEndian.Uint64(x[12:20]) >> 6
+	v.l2 &= maskLow51Bits
+	// Bits 153:204 (bytes 19:27, bits 152:216, shift 1, mask 51).
+	v.l3 = binary.LittleEndian.Uint64(x[19:27]) >> 1
+	v.l3 &= maskLow51Bits
+	// Bits 204:255 (bytes 24:32, bits 192:256, shift 12, mask 51).
+	// Note: not bytes 25:33, shift 4, to avoid overread.
+	v.l4 = binary.LittleEndian.Uint64(x[24:32]) >> 12
+	v.l4 &= maskLow51Bits
+
+	return v, nil
+}
+
+// Bytes returns the canonical 32-byte little-endian encoding of v.
+func (v *Element) Bytes() []byte {
+	// This function is outlined to make the allocations inline in the caller
+	// rather than happen on the heap.
+	var out [32]byte
+	return v.bytes(&out)
+}
+
+func (v *Element) bytes(out *[32]byte) []byte {
+	t := *v
+	t.reduce()
+
+	var buf [8]byte
+	for i, l := range [5]uint64{t.l0, t.l1, t.l2, t.l3, t.l4} {
+		bitsOffset := i * 51
+		binary.LittleEndian.PutUint64(buf[:], l<<uint(bitsOffset%8))
+		for i, bb := range buf {
+			off := bitsOffset/8 + i
+			if off >= len(out) {
+				break
+			}
+			out[off] |= bb
+		}
+	}
+
+	return out[:]
+}
+
+// Equal returns 1 if v and u are equal, and 0 otherwise.
+func (v *Element) Equal(u *Element) int {
+	sa, sv := u.Bytes(), v.Bytes()
+	return subtle.ConstantTimeCompare(sa, sv)
+}
+
+// mask64Bits returns 0xffffffff if cond is 1, and 0 otherwise.
+func mask64Bits(cond int) uint64 { return ^(uint64(cond) - 1) }
+
+// Select sets v to a if cond == 1, and to b if cond == 0.
+func (v *Element) Select(a, b *Element, cond int) *Element {
+	m := mask64Bits(cond)
+	v.l0 = (m & a.l0) | (^m & b.l0)
+	v.l1 = (m & a.l1) | (^m & b.l1)
+	v.l2 = (m & a.l2) | (^m & b.l2)
+	v.l3 = (m & a.l3) | (^m & b.l3)
+	v.l4 = (m & a.l4) | (^m & b.l4)
+	return v
+}
+
+// Swap swaps v and u if cond == 1 or leaves them unchanged if cond == 0, and returns v.
+func (v *Element) Swap(u *Element, cond int) {
+	m := mask64Bits(cond)
+	t := m & (v.l0 ^ u.l0)
+	v.l0 ^= t
+	u.l0 ^= t
+	t = m & (v.l1 ^ u.l1)
+	v.l1 ^= t
+	u.l1 ^= t
+	t = m & (v.l2 ^ u.l2)
+	v.l2 ^= t
+	u.l2 ^= t
+	t = m & (v.l3 ^ u.l3)
+	v.l3 ^= t
+	u.l3 ^= t
+	t = m & (v.l4 ^ u.l4)
+	v.l4 ^= t
+	u.l4 ^= t
+}
+
+// IsNegative returns 1 if v is negative, and 0 otherwise.
+func (v *Element) IsNegative() int {
+	return int(v.Bytes()[0] & 1)
+}
+
+// Absolute sets v to |u|, and returns v.
+func (v *Element) Absolute(u *Element) *Element {
+	return v.Select(new(Element).Negate(u), u, u.IsNegative())
+}
+
+// Multiply sets v = x * y, and returns v.
+func (v *Element) Multiply(x, y *Element) *Element {
+	feMul(v, x, y)
+	return v
+}
+
+// Square sets v = x * x, and returns v.
+func (v *Element) Square(x *Element) *Element {
+	feSquare(v, x)
+	return v
+}
+
+// Mult32 sets v = x * y, and returns v.
+func (v *Element) Mult32(x *Element, y uint32) *Element {
+	x0lo, x0hi := mul51(x.l0, y)
+	x1lo, x1hi := mul51(x.l1, y)
+	x2lo, x2hi := mul51(x.l2, y)
+	x3lo, x3hi := mul51(x.l3, y)
+	x4lo, x4hi := mul51(x.l4, y)
+	v.l0 = x0lo + 19*x4hi // carried over per the reduction identity
+	v.l1 = x1lo + x0hi
+	v.l2 = x2lo + x1hi
+	v.l3 = x3lo + x2hi
+	v.l4 = x4lo + x3hi
+	// The hi portions are going to be only 32 bits, plus any previous excess,
+	// so we can skip the carry propagation.
+	return v
+}
+
+// mul51 returns lo + hi * 2⁵¹ = a * b.
+func mul51(a uint64, b uint32) (lo uint64, hi uint64) {
+	mh, ml := bits.Mul64(a, uint64(b))
+	lo = ml & maskLow51Bits
+	hi = (mh << 13) | (ml >> 51)
+	return
+}
+
+// Pow22523 set v = x^((p-5)/8), and returns v. (p-5)/8 is 2^252-3.
+func (v *Element) Pow22523(x *Element) *Element {
+	var t0, t1, t2 Element
+
+	t0.Square(x)             // x^2
+	t1.Square(&t0)           // x^4
+	t1.Square(&t1)           // x^8
+	t1.Multiply(x, &t1)      // x^9
+	t0.Multiply(&t0, &t1)    // x^11
+	t0.Square(&t0)           // x^22
+	t0.Multiply(&t1, &t0)    // x^31
+	t1.Square(&t0)           // x^62
+	for i := 1; i < 5; i++ { // x^992
+		t1.Square(&t1)
+	}
+	t0.Multiply(&t1, &t0)     // x^1023 -> 1023 = 2^10 - 1
+	t1.Square(&t0)            // 2^11 - 2
+	for i := 1; i < 10; i++ { // 2^20 - 2^10
+		t1.Square(&t1)
+	}
+	t1.Multiply(&t1, &t0)     // 2^20 - 1
+	t2.Square(&t1)            // 2^21 - 2
+	for i := 1; i < 20; i++ { // 2^40 - 2^20
+		t2.Square(&t2)
+	}
+	t1.Multiply(&t2, &t1)     // 2^40 - 1
+	t1.Square(&t1)            // 2^41 - 2
+	for i := 1; i < 10; i++ { // 2^50 - 2^10
+		t1.Square(&t1)
+	}
+	t0.Multiply(&t1, &t0)     // 2^50 - 1
+	t1.Square(&t0)            // 2^51 - 2
+	for i := 1; i < 50; i++ { // 2^100 - 2^50
+		t1.Square(&t1)
+	}
+	t1.Multiply(&t1, &t0)      // 2^100 - 1
+	t2.Square(&t1)             // 2^101 - 2
+	for i := 1; i < 100; i++ { // 2^200 - 2^100
+		t2.Square(&t2)
+	}
+	t1.Multiply(&t2, &t1)     // 2^200 - 1
+	t1.Square(&t1)            // 2^201 - 2
+	for i := 1; i < 50; i++ { // 2^250 - 2^50
+		t1.Square(&t1)
+	}
+	t0.Multiply(&t1, &t0)     // 2^250 - 1
+	t0.Square(&t0)            // 2^251 - 2
+	t0.Square(&t0)            // 2^252 - 4
+	return v.Multiply(&t0, x) // 2^252 - 3 -> x^(2^252-3)
+}
+
+// sqrtM1 is 2^((p-1)/4), which squared is equal to -1 by Euler's Criterion.
+var sqrtM1 = &Element{1718705420411056, 234908883556509,
+	2233514472574048, 2117202627021982, 765476049583133}
+
+// SqrtRatio sets r to the non-negative square root of the ratio of u and v.
+//
+// If u/v is square, SqrtRatio returns r and 1. If u/v is not square, SqrtRatio
+// sets r according to Section 4.3 of draft-irtf-cfrg-ristretto255-decaf448-00,
+// and returns r and 0.
+func (r *Element) SqrtRatio(u, v *Element) (R *Element, wasSquare int) {
+	t0 := new(Element)
+
+	// r = (u * v3) * (u * v7)^((p-5)/8)
+	v2 := new(Element).Square(v)
+	uv3 := new(Element).Multiply(u, t0.Multiply(v2, v))
+	uv7 := new(Element).Multiply(uv3, t0.Square(v2))
+	rr := new(Element).Multiply(uv3, t0.Pow22523(uv7))
+
+	check := new(Element).Multiply(v, t0.Square(rr)) // check = v * r^2
+
+	uNeg := new(Element).Negate(u)
+	correctSignSqrt := check.Equal(u)
+	flippedSignSqrt := check.Equal(uNeg)
+	flippedSignSqrtI := check.Equal(t0.Multiply(uNeg, sqrtM1))
+
+	rPrime := new(Element).Multiply(rr, sqrtM1) // r_prime = SQRT_M1 * r
+	// r = CT_SELECT(r_prime IF flipped_sign_sqrt | flipped_sign_sqrt_i ELSE r)
+	rr.Select(rPrime, rr, flippedSignSqrt|flippedSignSqrtI)
+
+	r.Absolute(rr) // Choose the nonnegative square root.
+	return r, correctSignSqrt | flippedSignSqrt
+}

vendor/filippo.io/edwards25519/field/fe_amd64.go

@@ -0,0 +1,16 @@
+// Code generated by command: go run fe_amd64_asm.go -out ../fe_amd64.s -stubs ../fe_amd64.go -pkg field. DO NOT EDIT.
+
+//go:build amd64 && gc && !purego
+// +build amd64,gc,!purego
+
+package field
+
+// feMul sets out = a * b. It works like feMulGeneric.
+//
+//go:noescape
+func feMul(out *Element, a *Element, b *Element)
+
+// feSquare sets out = a * a. It works like feSquareGeneric.
+//
+//go:noescape
+func feSquare(out *Element, a *Element)

vendor/filippo.io/edwards25519/field/fe_amd64.s

@@ -0,0 +1,379 @@
+// Code generated by command: go run fe_amd64_asm.go -out ../fe_amd64.s -stubs ../fe_amd64.go -pkg field. DO NOT EDIT.
+
+//go:build amd64 && gc && !purego
+// +build amd64,gc,!purego
+
+#include "textflag.h"
+
+// func feMul(out *Element, a *Element, b *Element)
+TEXT ·feMul(SB), NOSPLIT, $0-24
+	MOVQ a+8(FP), CX
+	MOVQ b+16(FP), BX
+
+	// r0 = a0×b0
+	MOVQ (CX), AX
+	MULQ (BX)
+	MOVQ AX, DI
+	MOVQ DX, SI
+
+	// r0 += 19×a1×b4
+	MOVQ   8(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   32(BX)
+	ADDQ   AX, DI
+	ADCQ   DX, SI
+
+	// r0 += 19×a2×b3
+	MOVQ   16(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   24(BX)
+	ADDQ   AX, DI
+	ADCQ   DX, SI
+
+	// r0 += 19×a3×b2
+	MOVQ   24(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   16(BX)
+	ADDQ   AX, DI
+	ADCQ   DX, SI
+
+	// r0 += 19×a4×b1
+	MOVQ   32(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   8(BX)
+	ADDQ   AX, DI
+	ADCQ   DX, SI
+
+	// r1 = a0×b1
+	MOVQ (CX), AX
+	MULQ 8(BX)
+	MOVQ AX, R9
+	MOVQ DX, R8
+
+	// r1 += a1×b0
+	MOVQ 8(CX), AX
+	MULQ (BX)
+	ADDQ AX, R9
+	ADCQ DX, R8
+
+	// r1 += 19×a2×b4
+	MOVQ   16(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   32(BX)
+	ADDQ   AX, R9
+	ADCQ   DX, R8
+
+	// r1 += 19×a3×b3
+	MOVQ   24(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   24(BX)
+	ADDQ   AX, R9
+	ADCQ   DX, R8
+
+	// r1 += 19×a4×b2
+	MOVQ   32(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   16(BX)
+	ADDQ   AX, R9
+	ADCQ   DX, R8
+
+	// r2 = a0×b2
+	MOVQ (CX), AX
+	MULQ 16(BX)
+	MOVQ AX, R11
+	MOVQ DX, R10
+
+	// r2 += a1×b1
+	MOVQ 8(CX), AX
+	MULQ 8(BX)
+	ADDQ AX, R11
+	ADCQ DX, R10
+
+	// r2 += a2×b0
+	MOVQ 16(CX), AX
+	MULQ (BX)
+	ADDQ AX, R11
+	ADCQ DX, R10
+
+	// r2 += 19×a3×b4
+	MOVQ   24(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   32(BX)
+	ADDQ   AX, R11
+	ADCQ   DX, R10
+
+	// r2 += 19×a4×b3
+	MOVQ   32(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   24(BX)
+	ADDQ   AX, R11
+	ADCQ   DX, R10
+
+	// r3 = a0×b3
+	MOVQ (CX), AX
+	MULQ 24(BX)
+	MOVQ AX, R13
+	MOVQ DX, R12
+
+	// r3 += a1×b2
+	MOVQ 8(CX), AX
+	MULQ 16(BX)
+	ADDQ AX, R13
+	ADCQ DX, R12
+
+	// r3 += a2×b1
+	MOVQ 16(CX), AX
+	MULQ 8(BX)
+	ADDQ AX, R13
+	ADCQ DX, R12
+
+	// r3 += a3×b0
+	MOVQ 24(CX), AX
+	MULQ (BX)
+	ADDQ AX, R13
+	ADCQ DX, R12
+
+	// r3 += 19×a4×b4
+	MOVQ   32(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   32(BX)
+	ADDQ   AX, R13
+	ADCQ   DX, R12
+
+	// r4 = a0×b4
+	MOVQ (CX), AX
+	MULQ 32(BX)
+	MOVQ AX, R15
+	MOVQ DX, R14
+
+	// r4 += a1×b3
+	MOVQ 8(CX), AX
+	MULQ 24(BX)
+	ADDQ AX, R15
+	ADCQ DX, R14
+
+	// r4 += a2×b2
+	MOVQ 16(CX), AX
+	MULQ 16(BX)
+	ADDQ AX, R15
+	ADCQ DX, R14
+
+	// r4 += a3×b1
+	MOVQ 24(CX), AX
+	MULQ 8(BX)
+	ADDQ AX, R15
+	ADCQ DX, R14
+
+	// r4 += a4×b0
+	MOVQ 32(CX), AX
+	MULQ (BX)
+	ADDQ AX, R15
+	ADCQ DX, R14
+
+	// First reduction chain
+	MOVQ   $0x0007ffffffffffff, AX
+	SHLQ   $0x0d, DI, SI
+	SHLQ   $0x0d, R9, R8
+	SHLQ   $0x0d, R11, R10
+	SHLQ   $0x0d, R13, R12
+	SHLQ   $0x0d, R15, R14
+	ANDQ   AX, DI
+	IMUL3Q $0x13, R14, R14
+	ADDQ   R14, DI
+	ANDQ   AX, R9
+	ADDQ   SI, R9
+	ANDQ   AX, R11
+	ADDQ   R8, R11
+	ANDQ   AX, R13
+	ADDQ   R10, R13
+	ANDQ   AX, R15
+	ADDQ   R12, R15
+
+	// Second reduction chain (carryPropagate)
+	MOVQ   DI, SI
+	SHRQ   $0x33, SI
+	MOVQ   R9, R8
+	SHRQ   $0x33, R8
+	MOVQ   R11, R10
+	SHRQ   $0x33, R10
+	MOVQ   R13, R12
+	SHRQ   $0x33, R12
+	MOVQ   R15, R14
+	SHRQ   $0x33, R14
+	ANDQ   AX, DI
+	IMUL3Q $0x13, R14, R14
+	ADDQ   R14, DI
+	ANDQ   AX, R9
+	ADDQ   SI, R9
+	ANDQ   AX, R11
+	ADDQ   R8, R11
+	ANDQ   AX, R13
+	ADDQ   R10, R13
+	ANDQ   AX, R15
+	ADDQ   R12, R15
+
+	// Store output
+	MOVQ out+0(FP), AX
+	MOVQ DI, (AX)
+	MOVQ R9, 8(AX)
+	MOVQ R11, 16(AX)
+	MOVQ R13, 24(AX)
+	MOVQ R15, 32(AX)
+	RET
+
+// func feSquare(out *Element, a *Element)
+TEXT ·feSquare(SB), NOSPLIT, $0-16
+	MOVQ a+8(FP), CX
+
+	// r0 = l0×l0
+	MOVQ (CX), AX
+	MULQ (CX)
+	MOVQ AX, SI
+	MOVQ DX, BX
+
+	// r0 += 38×l1×l4
+	MOVQ   8(CX), AX
+	IMUL3Q $0x26, AX, AX
+	MULQ   32(CX)
+	ADDQ   AX, SI
+	ADCQ   DX, BX
+
+	// r0 += 38×l2×l3
+	MOVQ   16(CX), AX
+	IMUL3Q $0x26, AX, AX
+	MULQ   24(CX)
+	ADDQ   AX, SI
+	ADCQ   DX, BX
+
+	// r1 = 2×l0×l1
+	MOVQ (CX), AX
+	SHLQ $0x01, AX
+	MULQ 8(CX)
+	MOVQ AX, R8
+	MOVQ DX, DI
+
+	// r1 += 38×l2×l4
+	MOVQ   16(CX), AX
+	IMUL3Q $0x26, AX, AX
+	MULQ   32(CX)
+	ADDQ   AX, R8
+	ADCQ   DX, DI
+
+	// r1 += 19×l3×l3
+	MOVQ   24(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   24(CX)
+	ADDQ   AX, R8
+	ADCQ   DX, DI
+
+	// r2 = 2×l0×l2
+	MOVQ (CX), AX
+	SHLQ $0x01, AX
+	MULQ 16(CX)
+	MOVQ AX, R10
+	MOVQ DX, R9
+
+	// r2 += l1×l1
+	MOVQ 8(CX), AX
+	MULQ 8(CX)
+	ADDQ AX, R10
+	ADCQ DX, R9
+
+	// r2 += 38×l3×l4
+	MOVQ   24(CX), AX
+	IMUL3Q $0x26, AX, AX
+	MULQ   32(CX)
+	ADDQ   AX, R10
+	ADCQ   DX, R9
+
+	// r3 = 2×l0×l3
+	MOVQ (CX), AX
+	SHLQ $0x01, AX
+	MULQ 24(CX)
+	MOVQ AX, R12
+	MOVQ DX, R11
+
+	// r3 += 2×l1×l2
+	MOVQ   8(CX), AX
+	IMUL3Q $0x02, AX, AX
+	MULQ   16(CX)
+	ADDQ   AX, R12
+	ADCQ   DX, R11
+
+	// r3 += 19×l4×l4
+	MOVQ   32(CX), AX
+	IMUL3Q $0x13, AX, AX
+	MULQ   32(CX)
+	ADDQ   AX, R12
+	ADCQ   DX, R11
+
+	// r4 = 2×l0×l4
+	MOVQ (CX), AX
+	SHLQ $0x01, AX
+	MULQ 32(CX)
+	MOVQ AX, R14
+	MOVQ DX, R13
+
+	// r4 += 2×l1×l3
+	MOVQ   8(CX), AX
+	IMUL3Q $0x02, AX, AX
+	MULQ   24(CX)
+	ADDQ   AX, R14
+	ADCQ   DX, R13
+
+	// r4 += l2×l2
+	MOVQ 16(CX), AX
+	MULQ 16(CX)
+	ADDQ AX, R14
+	ADCQ DX, R13
+
+	// First reduction chain
+	MOVQ   $0x0007ffffffffffff, AX
+	SHLQ   $0x0d, SI, BX
+	SHLQ   $0x0d, R8, DI
+	SHLQ   $0x0d, R10, R9
+	SHLQ   $0x0d, R12, R11
+	SHLQ   $0x0d, R14, R13
+	ANDQ   AX, SI
+	IMUL3Q $0x13, R13, R13
+	ADDQ   R13, SI
+	ANDQ   AX, R8
+	ADDQ   BX, R8
+	ANDQ   AX, R10
+	ADDQ   DI, R10
+	ANDQ   AX, R12
+	ADDQ   R9, R12
+	ANDQ   AX, R14
+	ADDQ   R11, R14
+
+	// Second reduction chain (carryPropagate)
+	MOVQ   SI, BX
+	SHRQ   $0x33, BX
+	MOVQ   R8, DI
+	SHRQ   $0x33, DI
+	MOVQ   R10, R9
+	SHRQ   $0x33, R9
+	MOVQ   R12, R11
+	SHRQ   $0x33, R11
+	MOVQ   R14, R13
+	SHRQ   $0x33, R13
+	ANDQ   AX, SI
+	IMUL3Q $0x13, R13, R13
+	ADDQ   R13, SI
+	ANDQ   AX, R8
+	ADDQ   BX, R8
+	ANDQ   AX, R10
+	ADDQ   DI, R10
+	ANDQ   AX, R12
+	ADDQ   R9, R12
+	ANDQ   AX, R14
+	ADDQ   R11, R14
+
+	// Store output
+	MOVQ out+0(FP), AX
+	MOVQ SI, (AX)
+	MOVQ R8, 8(AX)
+	MOVQ R10, 16(AX)
+	MOVQ R12, 24(AX)
+	MOVQ R14, 32(AX)
+	RET

vendor/filippo.io/edwards25519/field/fe_amd64_noasm.go

@@ -0,0 +1,12 @@
+// Copyright (c) 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !amd64 || !gc || purego
+// +build !amd64 !gc purego
+
+package field
+
+func feMul(v, x, y *Element) { feMulGeneric(v, x, y) }
+
+func feSquare(v, x *Element) { feSquareGeneric(v, x) }

vendor/filippo.io/edwards25519/field/fe_arm64.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 && gc && !purego
+// +build arm64,gc,!purego
+
+package field
+
+//go:noescape
+func carryPropagate(v *Element)
+
+func (v *Element) carryPropagate() *Element {
+	carryPropagate(v)
+	return v
+}

vendor/filippo.io/edwards25519/field/fe_arm64.s

@@ -0,0 +1,42 @@
+// Copyright (c) 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 && gc && !purego
+
+#include "textflag.h"
+
+// carryPropagate works exactly like carryPropagateGeneric and uses the
+// same AND, ADD, and LSR+MADD instructions emitted by the compiler, but
+// avoids loading R0-R4 twice and uses LDP and STP.
+//
+// See https://golang.org/issues/43145 for the main compiler issue.
+//
+// func carryPropagate(v *Element)
+TEXT ·carryPropagate(SB),NOFRAME|NOSPLIT,$0-8
+	MOVD v+0(FP), R20
+
+	LDP 0(R20), (R0, R1)
+	LDP 16(R20), (R2, R3)
+	MOVD 32(R20), R4
+
+	AND $0x7ffffffffffff, R0, R10
+	AND $0x7ffffffffffff, R1, R11
+	AND $0x7ffffffffffff, R2, R12
+	AND $0x7ffffffffffff, R3, R13
+	AND $0x7ffffffffffff, R4, R14
+
+	ADD R0>>51, R11, R11
+	ADD R1>>51, R12, R12
+	ADD R2>>51, R13, R13
+	ADD R3>>51, R14, R14
+	// R4>>51 * 19 + R10 -> R10
+	LSR $51, R4, R21
+	MOVD $19, R22
+	MADD R22, R10, R21, R10
+
+	STP (R10, R11), 0(R20)
+	STP (R12, R13), 16(R20)
+	MOVD R14, 32(R20)
+
+	RET

vendor/filippo.io/edwards25519/field/fe_arm64_noasm.go

@@ -0,0 +1,12 @@
+// Copyright (c) 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !arm64 || !gc || purego
+// +build !arm64 !gc purego
+
+package field
+
+func (v *Element) carryPropagate() *Element {
+	return v.carryPropagateGeneric()
+}

vendor/filippo.io/edwards25519/field/fe_extra.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package field
+
+import "errors"
+
+// This file contains additional functionality that is not included in the
+// upstream crypto/ed25519/edwards25519/field package.
+
+// SetWideBytes sets v to x, where x is a 64-byte little-endian encoding, which
+// is reduced modulo the field order. If x is not of the right length,
+// SetWideBytes returns nil and an error, and the receiver is unchanged.
+//
+// SetWideBytes is not necessary to select a uniformly distributed value, and is
+// only provided for compatibility: SetBytes can be used instead as the chance
+// of bias is less than 2⁻²⁵⁰.
+func (v *Element) SetWideBytes(x []byte) (*Element, error) {
+	if len(x) != 64 {
+		return nil, errors.New("edwards25519: invalid SetWideBytes input size")
+	}
+
+	// Split the 64 bytes into two elements, and extract the most significant
+	// bit of each, which is ignored by SetBytes.
+	lo, _ := new(Element).SetBytes(x[:32])
+	loMSB := uint64(x[31] >> 7)
+	hi, _ := new(Element).SetBytes(x[32:])
+	hiMSB := uint64(x[63] >> 7)
+
+	// The output we want is
+	//
+	//   v = lo + loMSB * 2²⁵⁵ + hi * 2²⁵⁶ + hiMSB * 2⁵¹¹
+	//
+	// which applying the reduction identity comes out to
+	//
+	//   v = lo + loMSB * 19 + hi * 2 * 19 + hiMSB * 2 * 19²
+	//
+	// l0 will be the sum of a 52 bits value (lo.l0), plus a 5 bits value
+	// (loMSB * 19), a 6 bits value (hi.l0 * 2 * 19), and a 10 bits value
+	// (hiMSB * 2 * 19²), so it fits in a uint64.
+
+	v.l0 = lo.l0 + loMSB*19 + hi.l0*2*19 + hiMSB*2*19*19
+	v.l1 = lo.l1 + hi.l1*2*19
+	v.l2 = lo.l2 + hi.l2*2*19
+	v.l3 = lo.l3 + hi.l3*2*19
+	v.l4 = lo.l4 + hi.l4*2*19
+
+	return v.carryPropagate(), nil
+}

vendor/filippo.io/edwards25519/field/fe_generic.go

@@ -0,0 +1,266 @@
+// Copyright (c) 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package field
+
+import "math/bits"
+
+// uint128 holds a 128-bit number as two 64-bit limbs, for use with the
+// bits.Mul64 and bits.Add64 intrinsics.
+type uint128 struct {
+	lo, hi uint64
+}
+
+// mul64 returns a * b.
+func mul64(a, b uint64) uint128 {
+	hi, lo := bits.Mul64(a, b)
+	return uint128{lo, hi}
+}
+
+// addMul64 returns v + a * b.
+func addMul64(v uint128, a, b uint64) uint128 {
+	hi, lo := bits.Mul64(a, b)
+	lo, c := bits.Add64(lo, v.lo, 0)
+	hi, _ = bits.Add64(hi, v.hi, c)
+	return uint128{lo, hi}
+}
+
+// shiftRightBy51 returns a >> 51. a is assumed to be at most 115 bits.
+func shiftRightBy51(a uint128) uint64 {
+	return (a.hi << (64 - 51)) | (a.lo >> 51)
+}
+
+func feMulGeneric(v, a, b *Element) {
+	a0 := a.l0
+	a1 := a.l1
+	a2 := a.l2
+	a3 := a.l3
+	a4 := a.l4
+
+	b0 := b.l0
+	b1 := b.l1
+	b2 := b.l2
+	b3 := b.l3
+	b4 := b.l4
+
+	// Limb multiplication works like pen-and-paper columnar multiplication, but
+	// with 51-bit limbs instead of digits.
+	//
+	//                          a4   a3   a2   a1   a0  x
+	//                          b4   b3   b2   b1   b0  =
+	//                         ------------------------
+	//                        a4b0 a3b0 a2b0 a1b0 a0b0  +
+	//                   a4b1 a3b1 a2b1 a1b1 a0b1       +
+	//              a4b2 a3b2 a2b2 a1b2 a0b2            +
+	//         a4b3 a3b3 a2b3 a1b3 a0b3                 +
+	//    a4b4 a3b4 a2b4 a1b4 a0b4                      =
+	//   ----------------------------------------------
+	//      r8   r7   r6   r5   r4   r3   r2   r1   r0
+	//
+	// We can then use the reduction identity (a * 2²⁵⁵ + b = a * 19 + b) to
+	// reduce the limbs that would overflow 255 bits. r5 * 2²⁵⁵ becomes 19 * r5,
+	// r6 * 2³⁰⁶ becomes 19 * r6 * 2⁵¹, etc.
+	//
+	// Reduction can be carried out simultaneously to multiplication. For
+	// example, we do not compute r5: whenever the result of a multiplication
+	// belongs to r5, like a1b4, we multiply it by 19 and add the result to r0.
+	//
+	//            a4b0    a3b0    a2b0    a1b0    a0b0  +
+	//            a3b1    a2b1    a1b1    a0b1 19×a4b1  +
+	//            a2b2    a1b2    a0b2 19×a4b2 19×a3b2  +
+	//            a1b3    a0b3 19×a4b3 19×a3b3 19×a2b3  +
+	//            a0b4 19×a4b4 19×a3b4 19×a2b4 19×a1b4  =
+	//           --------------------------------------
+	//              r4      r3      r2      r1      r0
+	//
+	// Finally we add up the columns into wide, overlapping limbs.
+
+	a1_19 := a1 * 19
+	a2_19 := a2 * 19
+	a3_19 := a3 * 19
+	a4_19 := a4 * 19
+
+	// r0 = a0×b0 + 19×(a1×b4 + a2×b3 + a3×b2 + a4×b1)
+	r0 := mul64(a0, b0)
+	r0 = addMul64(r0, a1_19, b4)
+	r0 = addMul64(r0, a2_19, b3)
+	r0 = addMul64(r0, a3_19, b2)
+	r0 = addMul64(r0, a4_19, b1)
+
+	// r1 = a0×b1 + a1×b0 + 19×(a2×b4 + a3×b3 + a4×b2)
+	r1 := mul64(a0, b1)
+	r1 = addMul64(r1, a1, b0)
+	r1 = addMul64(r1, a2_19, b4)
+	r1 = addMul64(r1, a3_19, b3)
+	r1 = addMul64(r1, a4_19, b2)
+
+	// r2 = a0×b2 + a1×b1 + a2×b0 + 19×(a3×b4 + a4×b3)
+	r2 := mul64(a0, b2)
+	r2 = addMul64(r2, a1, b1)
+	r2 = addMul64(r2, a2, b0)
+	r2 = addMul64(r2, a3_19, b4)
+	r2 = addMul64(r2, a4_19, b3)
+
+	// r3 = a0×b3 + a1×b2 + a2×b1 + a3×b0 + 19×a4×b4
+	r3 := mul64(a0, b3)
+	r3 = addMul64(r3, a1, b2)
+	r3 = addMul64(r3, a2, b1)
+	r3 = addMul64(r3, a3, b0)
+	r3 = addMul64(r3, a4_19, b4)
+
+	// r4 = a0×b4 + a1×b3 + a2×b2 + a3×b1 + a4×b0
+	r4 := mul64(a0, b4)
+	r4 = addMul64(r4, a1, b3)
+	r4 = addMul64(r4, a2, b2)
+	r4 = addMul64(r4, a3, b1)
+	r4 = addMul64(r4, a4, b0)
+
+	// After the multiplication, we need to reduce (carry) the five coefficients
+	// to obtain a result with limbs that are at most slightly larger than 2⁵¹,
+	// to respect the Element invariant.
+	//
+	// Overall, the reduction works the same as carryPropagate, except with
+	// wider inputs: we take the carry for each coefficient by shifting it right
+	// by 51, and add it to the limb above it. The top carry is multiplied by 19
+	// according to the reduction identity and added to the lowest limb.
+	//
+	// The largest coefficient (r0) will be at most 111 bits, which guarantees
+	// that all carries are at most 111 - 51 = 60 bits, which fits in a uint64.
+	//
+	//     r0 = a0×b0 + 19×(a1×b4 + a2×b3 + a3×b2 + a4×b1)
+	//     r0 < 2⁵²×2⁵² + 19×(2⁵²×2⁵² + 2⁵²×2⁵² + 2⁵²×2⁵² + 2⁵²×2⁵²)
+	//     r0 < (1 + 19 × 4) × 2⁵² × 2⁵²
+	//     r0 < 2⁷ × 2⁵² × 2⁵²
+	//     r0 < 2¹¹¹
+	//
+	// Moreover, the top coefficient (r4) is at most 107 bits, so c4 is at most
+	// 56 bits, and c4 * 19 is at most 61 bits, which again fits in a uint64 and
+	// allows us to easily apply the reduction identity.
+	//
+	//     r4 = a0×b4 + a1×b3 + a2×b2 + a3×b1 + a4×b0
+	//     r4 < 5 × 2⁵² × 2⁵²
+	//     r4 < 2¹⁰⁷
+	//
+
+	c0 := shiftRightBy51(r0)
+	c1 := shiftRightBy51(r1)
+	c2 := shiftRightBy51(r2)
+	c3 := shiftRightBy51(r3)
+	c4 := shiftRightBy51(r4)
+
+	rr0 := r0.lo&maskLow51Bits + c4*19
+	rr1 := r1.lo&maskLow51Bits + c0
+	rr2 := r2.lo&maskLow51Bits + c1
+	rr3 := r3.lo&maskLow51Bits + c2
+	rr4 := r4.lo&maskLow51Bits + c3
+
+	// Now all coefficients fit into 64-bit registers but are still too large to
+	// be passed around as an Element. We therefore do one last carry chain,
+	// where the carries will be small enough to fit in the wiggle room above 2⁵¹.
+	*v = Element{rr0, rr1, rr2, rr3, rr4}
+	v.carryPropagate()
+}
+
+func feSquareGeneric(v, a *Element) {
+	l0 := a.l0
+	l1 := a.l1
+	l2 := a.l2
+	l3 := a.l3
+	l4 := a.l4
+
+	// Squaring works precisely like multiplication above, but thanks to its
+	// symmetry we get to group a few terms together.
+	//
+	//                          l4   l3   l2   l1   l0  x
+	//                          l4   l3   l2   l1   l0  =
+	//                         ------------------------
+	//                        l4l0 l3l0 l2l0 l1l0 l0l0  +
+	//                   l4l1 l3l1 l2l1 l1l1 l0l1       +
+	//              l4l2 l3l2 l2l2 l1l2 l0l2            +
+	//         l4l3 l3l3 l2l3 l1l3 l0l3                 +
+	//    l4l4 l3l4 l2l4 l1l4 l0l4                      =
+	//   ----------------------------------------------
+	//      r8   r7   r6   r5   r4   r3   r2   r1   r0
+	//
+	//            l4l0    l3l0    l2l0    l1l0    l0l0  +
+	//            l3l1    l2l1    l1l1    l0l1 19×l4l1  +
+	//            l2l2    l1l2    l0l2 19×l4l2 19×l3l2  +
+	//            l1l3    l0l3 19×l4l3 19×l3l3 19×l2l3  +
+	//            l0l4 19×l4l4 19×l3l4 19×l2l4 19×l1l4  =
+	//           --------------------------------------
+	//              r4      r3      r2      r1      r0
+	//
+	// With precomputed 2×, 19×, and 2×19× terms, we can compute each limb with
+	// only three Mul64 and four Add64, instead of five and eight.
+
+	l0_2 := l0 * 2
+	l1_2 := l1 * 2
+
+	l1_38 := l1 * 38
+	l2_38 := l2 * 38
+	l3_38 := l3 * 38
+
+	l3_19 := l3 * 19
+	l4_19 := l4 * 19
+
+	// r0 = l0×l0 + 19×(l1×l4 + l2×l3 + l3×l2 + l4×l1) = l0×l0 + 19×2×(l1×l4 + l2×l3)
+	r0 := mul64(l0, l0)
+	r0 = addMul64(r0, l1_38, l4)
+	r0 = addMul64(r0, l2_38, l3)
+
+	// r1 = l0×l1 + l1×l0 + 19×(l2×l4 + l3×l3 + l4×l2) = 2×l0×l1 + 19×2×l2×l4 + 19×l3×l3
+	r1 := mul64(l0_2, l1)
+	r1 = addMul64(r1, l2_38, l4)
+	r1 = addMul64(r1, l3_19, l3)
+
+	// r2 = l0×l2 + l1×l1 + l2×l0 + 19×(l3×l4 + l4×l3) = 2×l0×l2 + l1×l1 + 19×2×l3×l4
+	r2 := mul64(l0_2, l2)
+	r2 = addMul64(r2, l1, l1)
+	r2 = addMul64(r2, l3_38, l4)
+
+	// r3 = l0×l3 + l1×l2 + l2×l1 + l3×l0 + 19×l4×l4 = 2×l0×l3 + 2×l1×l2 + 19×l4×l4
+	r3 := mul64(l0_2, l3)
+	r3 = addMul64(r3, l1_2, l2)
+	r3 = addMul64(r3, l4_19, l4)
+
+	// r4 = l0×l4 + l1×l3 + l2×l2 + l3×l1 + l4×l0 = 2×l0×l4 + 2×l1×l3 + l2×l2
+	r4 := mul64(l0_2, l4)
+	r4 = addMul64(r4, l1_2, l3)
+	r4 = addMul64(r4, l2, l2)
+
+	c0 := shiftRightBy51(r0)
+	c1 := shiftRightBy51(r1)
+	c2 := shiftRightBy51(r2)
+	c3 := shiftRightBy51(r3)
+	c4 := shiftRightBy51(r4)
+
+	rr0 := r0.lo&maskLow51Bits + c4*19
+	rr1 := r1.lo&maskLow51Bits + c0
+	rr2 := r2.lo&maskLow51Bits + c1
+	rr3 := r3.lo&maskLow51Bits + c2
+	rr4 := r4.lo&maskLow51Bits + c3
+
+	*v = Element{rr0, rr1, rr2, rr3, rr4}
+	v.carryPropagate()
+}
+
+// carryPropagateGeneric brings the limbs below 52 bits by applying the reduction
+// identity (a * 2²⁵⁵ + b = a * 19 + b) to the l4 carry.
+func (v *Element) carryPropagateGeneric() *Element {
+	c0 := v.l0 >> 51
+	c1 := v.l1 >> 51
+	c2 := v.l2 >> 51
+	c3 := v.l3 >> 51
+	c4 := v.l4 >> 51
+
+	// c4 is at most 64 - 51 = 13 bits, so c4*19 is at most 18 bits, and
+	// the final l0 will be at most 52 bits. Similarly for the rest.
+	v.l0 = v.l0&maskLow51Bits + c4*19
+	v.l1 = v.l1&maskLow51Bits + c0
+	v.l2 = v.l2&maskLow51Bits + c1
+	v.l3 = v.l3&maskLow51Bits + c2
+	v.l4 = v.l4&maskLow51Bits + c3
+
+	return v
+}

vendor/filippo.io/edwards25519/scalar.go

@@ -0,0 +1,343 @@
+// Copyright (c) 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edwards25519
+
+import (
+	"encoding/binary"
+	"errors"
+)
+
+// A Scalar is an integer modulo
+//
+//	l = 2^252 + 27742317777372353535851937790883648493
+//
+// which is the prime order of the edwards25519 group.
+//
+// This type works similarly to math/big.Int, and all arguments and
+// receivers are allowed to alias.
+//
+// The zero value is a valid zero element.
+type Scalar struct {
+	// s is the scalar in the Montgomery domain, in the format of the
+	// fiat-crypto implementation.
+	s fiatScalarMontgomeryDomainFieldElement
+}
+
+// The field implementation in scalar_fiat.go is generated by the fiat-crypto
+// project (https://github.com/mit-plv/fiat-crypto) at version v0.0.9 (23d2dbc)
+// from a formally verified model.
+//
+// fiat-crypto code comes under the following license.
+//
+//     Copyright (c) 2015-2020 The fiat-crypto Authors. All rights reserved.
+//
+//     Redistribution and use in source and binary forms, with or without
+//     modification, are permitted provided that the following conditions are
+//     met:
+//
+//         1. Redistributions of source code must retain the above copyright
+//         notice, this list of conditions and the following disclaimer.
+//
+//     THIS SOFTWARE IS PROVIDED BY the fiat-crypto authors "AS IS"
+//     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+//     THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+//     PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design,
+//     Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+//     EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+//     PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+//     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+//     LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+//     NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+//     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+// NewScalar returns a new zero Scalar.
+func NewScalar() *Scalar {
+	return &Scalar{}
+}
+
+// MultiplyAdd sets s = x * y + z mod l, and returns s. It is equivalent to
+// using Multiply and then Add.
+func (s *Scalar) MultiplyAdd(x, y, z *Scalar) *Scalar {
+	// Make a copy of z in case it aliases s.
+	zCopy := new(Scalar).Set(z)
+	return s.Multiply(x, y).Add(s, zCopy)
+}
+
+// Add sets s = x + y mod l, and returns s.
+func (s *Scalar) Add(x, y *Scalar) *Scalar {
+	// s = 1 * x + y mod l
+	fiatScalarAdd(&s.s, &x.s, &y.s)
+	return s
+}
+
+// Subtract sets s = x - y mod l, and returns s.
+func (s *Scalar) Subtract(x, y *Scalar) *Scalar {
+	// s = -1 * y + x mod l
+	fiatScalarSub(&s.s, &x.s, &y.s)
+	return s
+}
+
+// Negate sets s = -x mod l, and returns s.
+func (s *Scalar) Negate(x *Scalar) *Scalar {
+	// s = -1 * x + 0 mod l
+	fiatScalarOpp(&s.s, &x.s)
+	return s
+}
+
+// Multiply sets s = x * y mod l, and returns s.
+func (s *Scalar) Multiply(x, y *Scalar) *Scalar {
+	// s = x * y + 0 mod l
+	fiatScalarMul(&s.s, &x.s, &y.s)
+	return s
+}
+
+// Set sets s = x, and returns s.
+func (s *Scalar) Set(x *Scalar) *Scalar {
+	*s = *x
+	return s
+}
+
+// SetUniformBytes sets s = x mod l, where x is a 64-byte little-endian integer.
+// If x is not of the right length, SetUniformBytes returns nil and an error,
+// and the receiver is unchanged.
+//
+// SetUniformBytes can be used to set s to a uniformly distributed value given
+// 64 uniformly distributed random bytes.
+func (s *Scalar) SetUniformBytes(x []byte) (*Scalar, error) {
+	if len(x) != 64 {
+		return nil, errors.New("edwards25519: invalid SetUniformBytes input length")
+	}
+
+	// We have a value x of 512 bits, but our fiatScalarFromBytes function
+	// expects an input lower than l, which is a little over 252 bits.
+	//
+	// Instead of writing a reduction function that operates on wider inputs, we
+	// can interpret x as the sum of three shorter values a, b, and c.
+	//
+	//    x = a + b * 2^168 + c * 2^336  mod l
+	//
+	// We then precompute 2^168 and 2^336 modulo l, and perform the reduction
+	// with two multiplications and two additions.
+
+	s.setShortBytes(x[:21])
+	t := new(Scalar).setShortBytes(x[21:42])
+	s.Add(s, t.Multiply(t, scalarTwo168))
+	t.setShortBytes(x[42:])
+	s.Add(s, t.Multiply(t, scalarTwo336))
+
+	return s, nil
+}
+
+// scalarTwo168 and scalarTwo336 are 2^168 and 2^336 modulo l, encoded as a
+// fiatScalarMontgomeryDomainFieldElement, which is a little-endian 4-limb value
+// in the 2^256 Montgomery domain.
+var scalarTwo168 = &Scalar{s: [4]uint64{0x5b8ab432eac74798, 0x38afddd6de59d5d7,
+	0xa2c131b399411b7c, 0x6329a7ed9ce5a30}}
+var scalarTwo336 = &Scalar{s: [4]uint64{0xbd3d108e2b35ecc5, 0x5c3a3718bdf9c90b,
+	0x63aa97a331b4f2ee, 0x3d217f5be65cb5c}}
+
+// setShortBytes sets s = x mod l, where x is a little-endian integer shorter
+// than 32 bytes.
+func (s *Scalar) setShortBytes(x []byte) *Scalar {
+	if len(x) >= 32 {
+		panic("edwards25519: internal error: setShortBytes called with a long string")
+	}
+	var buf [32]byte
+	copy(buf[:], x)
+	fiatScalarFromBytes((*[4]uint64)(&s.s), &buf)
+	fiatScalarToMontgomery(&s.s, (*fiatScalarNonMontgomeryDomainFieldElement)(&s.s))
+	return s
+}
+
+// SetCanonicalBytes sets s = x, where x is a 32-byte little-endian encoding of
+// s, and returns s. If x is not a canonical encoding of s, SetCanonicalBytes
+// returns nil and an error, and the receiver is unchanged.
+func (s *Scalar) SetCanonicalBytes(x []byte) (*Scalar, error) {
+	if len(x) != 32 {
+		return nil, errors.New("invalid scalar length")
+	}
+	if !isReduced(x) {
+		return nil, errors.New("invalid scalar encoding")
+	}
+
+	fiatScalarFromBytes((*[4]uint64)(&s.s), (*[32]byte)(x))
+	fiatScalarToMontgomery(&s.s, (*fiatScalarNonMontgomeryDomainFieldElement)(&s.s))
+
+	return s, nil
+}
+
+// scalarMinusOneBytes is l - 1 in little endian.
+var scalarMinusOneBytes = [32]byte{236, 211, 245, 92, 26, 99, 18, 88, 214, 156, 247, 162, 222, 249, 222, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16}
+
+// isReduced returns whether the given scalar in 32-byte little endian encoded
+// form is reduced modulo l.
+func isReduced(s []byte) bool {
+	if len(s) != 32 {
+		return false
+	}
+
+	for i := len(s) - 1; i >= 0; i-- {
+		switch {
+		case s[i] > scalarMinusOneBytes[i]:
+			return false
+		case s[i] < scalarMinusOneBytes[i]:
+			return true
+		}
+	}
+	return true
+}
+
+// SetBytesWithClamping applies the buffer pruning described in RFC 8032,
+// Section 5.1.5 (also known as clamping) and sets s to the result. The input
+// must be 32 bytes, and it is not modified. If x is not of the right length,
+// SetBytesWithClamping returns nil and an error, and the receiver is unchanged.
+//
+// Note that since Scalar values are always reduced modulo the prime order of
+// the curve, the resulting value will not preserve any of the cofactor-clearing
+// properties that clamping is meant to provide. It will however work as
+// expected as long as it is applied to points on the prime order subgroup, like
+// in Ed25519. In fact, it is lost to history why RFC 8032 adopted the
+// irrelevant RFC 7748 clamping, but it is now required for compatibility.
+func (s *Scalar) SetBytesWithClamping(x []byte) (*Scalar, error) {
+	// The description above omits the purpose of the high bits of the clamping
+	// for brevity, but those are also lost to reductions, and are also
+	// irrelevant to edwards25519 as they protect against a specific
+	// implementation bug that was once observed in a generic Montgomery ladder.
+	if len(x) != 32 {
+		return nil, errors.New("edwards25519: invalid SetBytesWithClamping input length")
+	}
+
+	// We need to use the wide reduction from SetUniformBytes, since clamping
+	// sets the 2^254 bit, making the value higher than the order.
+	var wideBytes [64]byte
+	copy(wideBytes[:], x[:])
+	wideBytes[0] &= 248
+	wideBytes[31] &= 63
+	wideBytes[31] |= 64
+	return s.SetUniformBytes(wideBytes[:])
+}
+
+// Bytes returns the canonical 32-byte little-endian encoding of s.
+func (s *Scalar) Bytes() []byte {
+	// This function is outlined to make the allocations inline in the caller
+	// rather than happen on the heap.
+	var encoded [32]byte
+	return s.bytes(&encoded)
+}
+
+func (s *Scalar) bytes(out *[32]byte) []byte {
+	var ss fiatScalarNonMontgomeryDomainFieldElement
+	fiatScalarFromMontgomery(&ss, &s.s)
+	fiatScalarToBytes(out, (*[4]uint64)(&ss))
+	return out[:]
+}
+
+// Equal returns 1 if s and t are equal, and 0 otherwise.
+func (s *Scalar) Equal(t *Scalar) int {
+	var diff fiatScalarMontgomeryDomainFieldElement
+	fiatScalarSub(&diff, &s.s, &t.s)
+	var nonzero uint64
+	fiatScalarNonzero(&nonzero, (*[4]uint64)(&diff))
+	nonzero |= nonzero >> 32
+	nonzero |= nonzero >> 16
+	nonzero |= nonzero >> 8
+	nonzero |= nonzero >> 4
+	nonzero |= nonzero >> 2
+	nonzero |= nonzero >> 1
+	return int(^nonzero) & 1
+}
+
+// nonAdjacentForm computes a width-w non-adjacent form for this scalar.
+//
+// w must be between 2 and 8, or nonAdjacentForm will panic.
+func (s *Scalar) nonAdjacentForm(w uint) [256]int8 {
+	// This implementation is adapted from the one
+	// in curve25519-dalek and is documented there:
+	// https://github.com/dalek-cryptography/curve25519-dalek/blob/f630041af28e9a405255f98a8a93adca18e4315b/src/scalar.rs#L800-L871
+	b := s.Bytes()
+	if b[31] > 127 {
+		panic("scalar has high bit set illegally")
+	}
+	if w < 2 {
+		panic("w must be at least 2 by the definition of NAF")
+	} else if w > 8 {
+		panic("NAF digits must fit in int8")
+	}
+
+	var naf [256]int8
+	var digits [5]uint64
+
+	for i := 0; i < 4; i++ {
+		digits[i] = binary.LittleEndian.Uint64(b[i*8:])
+	}
+
+	width := uint64(1 << w)
+	windowMask := uint64(width - 1)
+
+	pos := uint(0)
+	carry := uint64(0)
+	for pos < 256 {
+		indexU64 := pos / 64
+		indexBit := pos % 64
+		var bitBuf uint64
+		if indexBit < 64-w {
+			// This window's bits are contained in a single u64
+			bitBuf = digits[indexU64] >> indexBit
+		} else {
+			// Combine the current 64 bits with bits from the next 64
+			bitBuf = (digits[indexU64] >> indexBit) | (digits[1+indexU64] << (64 - indexBit))
+		}
+
+		// Add carry into the current window
+		window := carry + (bitBuf & windowMask)
+
+		if window&1 == 0 {
+			// If the window value is even, preserve the carry and continue.
+			// Why is the carry preserved?
+			// If carry == 0 and window & 1 == 0,
+			//    then the next carry should be 0
+			// If carry == 1 and window & 1 == 0,
+			//    then bit_buf & 1 == 1 so the next carry should be 1
+			pos += 1
+			continue
+		}
+
+		if window < width/2 {
+			carry = 0
+			naf[pos] = int8(window)
+		} else {
+			carry = 1
+			naf[pos] = int8(window) - int8(width)
+		}
+
+		pos += w
+	}
+	return naf
+}
+
+func (s *Scalar) signedRadix16() [64]int8 {
+	b := s.Bytes()
+	if b[31] > 127 {
+		panic("scalar has high bit set illegally")
+	}
+
+	var digits [64]int8
+
+	// Compute unsigned radix-16 digits:
+	for i := 0; i < 32; i++ {
+		digits[2*i] = int8(b[i] & 15)
+		digits[2*i+1] = int8((b[i] >> 4) & 15)
+	}
+
+	// Recenter coefficients:
+	for i := 0; i < 63; i++ {
+		carry := (digits[i] + 8) >> 4
+		digits[i] -= carry << 4
+		digits[i+1] += carry
+	}
+
+	return digits
+}

vendor/filippo.io/edwards25519/scalarmult.go

@@ -0,0 +1,214 @@
+// Copyright (c) 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edwards25519
+
+import "sync"
+
+// basepointTable is a set of 32 affineLookupTables, where table i is generated
+// from 256i * basepoint. It is precomputed the first time it's used.
+func basepointTable() *[32]affineLookupTable {
+	basepointTablePrecomp.initOnce.Do(func() {
+		p := NewGeneratorPoint()
+		for i := 0; i < 32; i++ {
+			basepointTablePrecomp.table[i].FromP3(p)
+			for j := 0; j < 8; j++ {
+				p.Add(p, p)
+			}
+		}
+	})
+	return &basepointTablePrecomp.table
+}
+
+var basepointTablePrecomp struct {
+	table    [32]affineLookupTable
+	initOnce sync.Once
+}
+
+// ScalarBaseMult sets v = x * B, where B is the canonical generator, and
+// returns v.
+//
+// The scalar multiplication is done in constant time.
+func (v *Point) ScalarBaseMult(x *Scalar) *Point {
+	basepointTable := basepointTable()
+
+	// Write x = sum(x_i * 16^i) so  x*B = sum( B*x_i*16^i )
+	// as described in the Ed25519 paper
+	//
+	// Group even and odd coefficients
+	// x*B     = x_0*16^0*B + x_2*16^2*B + ... + x_62*16^62*B
+	//         + x_1*16^1*B + x_3*16^3*B + ... + x_63*16^63*B
+	// x*B     = x_0*16^0*B + x_2*16^2*B + ... + x_62*16^62*B
+	//    + 16*( x_1*16^0*B + x_3*16^2*B + ... + x_63*16^62*B)
+	//
+	// We use a lookup table for each i to get x_i*16^(2*i)*B
+	// and do four doublings to multiply by 16.
+	digits := x.signedRadix16()
+
+	multiple := &affineCached{}
+	tmp1 := &projP1xP1{}
+	tmp2 := &projP2{}
+
+	// Accumulate the odd components first
+	v.Set(NewIdentityPoint())
+	for i := 1; i < 64; i += 2 {
+		basepointTable[i/2].SelectInto(multiple, digits[i])
+		tmp1.AddAffine(v, multiple)
+		v.fromP1xP1(tmp1)
+	}
+
+	// Multiply by 16
+	tmp2.FromP3(v)       // tmp2 =    v in P2 coords
+	tmp1.Double(tmp2)    // tmp1 =  2*v in P1xP1 coords
+	tmp2.FromP1xP1(tmp1) // tmp2 =  2*v in P2 coords
+	tmp1.Double(tmp2)    // tmp1 =  4*v in P1xP1 coords
+	tmp2.FromP1xP1(tmp1) // tmp2 =  4*v in P2 coords
+	tmp1.Double(tmp2)    // tmp1 =  8*v in P1xP1 coords
+	tmp2.FromP1xP1(tmp1) // tmp2 =  8*v in P2 coords
+	tmp1.Double(tmp2)    // tmp1 = 16*v in P1xP1 coords
+	v.fromP1xP1(tmp1)    // now v = 16*(odd components)
+
+	// Accumulate the even components
+	for i := 0; i < 64; i += 2 {
+		basepointTable[i/2].SelectInto(multiple, digits[i])
+		tmp1.AddAffine(v, multiple)
+		v.fromP1xP1(tmp1)
+	}
+
+	return v
+}
+
+// ScalarMult sets v = x * q, and returns v.
+//
+// The scalar multiplication is done in constant time.
+func (v *Point) ScalarMult(x *Scalar, q *Point) *Point {
+	checkInitialized(q)
+
+	var table projLookupTable
+	table.FromP3(q)
+
+	// Write x = sum(x_i * 16^i)
+	// so  x*Q = sum( Q*x_i*16^i )
+	//         = Q*x_0 + 16*(Q*x_1 + 16*( ... + Q*x_63) ... )
+	//           <------compute inside out---------
+	//
+	// We use the lookup table to get the x_i*Q values
+	// and do four doublings to compute 16*Q
+	digits := x.signedRadix16()
+
+	// Unwrap first loop iteration to save computing 16*identity
+	multiple := &projCached{}
+	tmp1 := &projP1xP1{}
+	tmp2 := &projP2{}
+	table.SelectInto(multiple, digits[63])
+
+	v.Set(NewIdentityPoint())
+	tmp1.Add(v, multiple) // tmp1 = x_63*Q in P1xP1 coords
+	for i := 62; i >= 0; i-- {
+		tmp2.FromP1xP1(tmp1) // tmp2 =    (prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 =  2*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  2*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 =  4*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  4*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 =  8*(prev) in P1xP1 coords
+		tmp2.FromP1xP1(tmp1) // tmp2 =  8*(prev) in P2 coords
+		tmp1.Double(tmp2)    // tmp1 = 16*(prev) in P1xP1 coords
+		v.fromP1xP1(tmp1)    //    v = 16*(prev) in P3 coords
+		table.SelectInto(multiple, digits[i])
+		tmp1.Add(v, multiple) // tmp1 = x_i*Q + 16*(prev) in P1xP1 coords
+	}
+	v.fromP1xP1(tmp1)
+	return v
+}
+
+// basepointNafTable is the nafLookupTable8 for the basepoint.
+// It is precomputed the first time it's used.
+func basepointNafTable() *nafLookupTable8 {
+	basepointNafTablePrecomp.initOnce.Do(func() {
+		basepointNafTablePrecomp.table.FromP3(NewGeneratorPoint())
+	})
+	return &basepointNafTablePrecomp.table
+}
+
+var basepointNafTablePrecomp struct {
+	table    nafLookupTable8
+	initOnce sync.Once
+}
+
+// VarTimeDoubleScalarBaseMult sets v = a * A + b * B, where B is the canonical
+// generator, and returns v.
+//
+// Execution time depends on the inputs.
+func (v *Point) VarTimeDoubleScalarBaseMult(a *Scalar, A *Point, b *Scalar) *Point {
+	checkInitialized(A)
+
+	// Similarly to the single variable-base approach, we compute
+	// digits and use them with a lookup table.  However, because
+	// we are allowed to do variable-time operations, we don't
+	// need constant-time lookups or constant-time digit
+	// computations.
+	//
+	// So we use a non-adjacent form of some width w instead of
+	// radix 16.  This is like a binary representation (one digit
+	// for each binary place) but we allow the digits to grow in
+	// magnitude up to 2^{w-1} so that the nonzero digits are as
+	// sparse as possible.  Intuitively, this "condenses" the
+	// "mass" of the scalar onto sparse coefficients (meaning
+	// fewer additions).
+
+	basepointNafTable := basepointNafTable()
+	var aTable nafLookupTable5
+	aTable.FromP3(A)
+	// Because the basepoint is fixed, we can use a wider NAF
+	// corresponding to a bigger table.
+	aNaf := a.nonAdjacentForm(5)
+	bNaf := b.nonAdjacentForm(8)
+
+	// Find the first nonzero coefficient.
+	i := 255
+	for j := i; j >= 0; j-- {
+		if aNaf[j] != 0 || bNaf[j] != 0 {
+			break
+		}
+	}
+
+	multA := &projCached{}
+	multB := &affineCached{}
+	tmp1 := &projP1xP1{}
+	tmp2 := &projP2{}
+	tmp2.Zero()
+
+	// Move from high to low bits, doubling the accumulator
+	// at each iteration and checking whether there is a nonzero
+	// coefficient to look up a multiple of.
+	for ; i >= 0; i-- {
+		tmp1.Double(tmp2)
+
+		// Only update v if we have a nonzero coeff to add in.
+		if aNaf[i] > 0 {
+			v.fromP1xP1(tmp1)
+			aTable.SelectInto(multA, aNaf[i])
+			tmp1.Add(v, multA)
+		} else if aNaf[i] < 0 {
+			v.fromP1xP1(tmp1)
+			aTable.SelectInto(multA, -aNaf[i])
+			tmp1.Sub(v, multA)
+		}
+
+		if bNaf[i] > 0 {
+			v.fromP1xP1(tmp1)
+			basepointNafTable.SelectInto(multB, bNaf[i])
+			tmp1.AddAffine(v, multB)
+		} else if bNaf[i] < 0 {
+			v.fromP1xP1(tmp1)
+			basepointNafTable.SelectInto(multB, -bNaf[i])
+			tmp1.SubAffine(v, multB)
+		}
+
+		tmp2.FromP1xP1(tmp1)
+	}
+
+	v.fromP2(tmp2)
+	return v
+}

vendor/filippo.io/edwards25519/tables.go

@@ -0,0 +1,129 @@
+// Copyright (c) 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package edwards25519
+
+import (
+	"crypto/subtle"
+)
+
+// A dynamic lookup table for variable-base, constant-time scalar muls.
+type projLookupTable struct {
+	points [8]projCached
+}
+
+// A precomputed lookup table for fixed-base, constant-time scalar muls.
+type affineLookupTable struct {
+	points [8]affineCached
+}
+
+// A dynamic lookup table for variable-base, variable-time scalar muls.
+type nafLookupTable5 struct {
+	points [8]projCached
+}
+
+// A precomputed lookup table for fixed-base, variable-time scalar muls.
+type nafLookupTable8 struct {
+	points [64]affineCached
+}
+
+// Constructors.
+
+// Builds a lookup table at runtime. Fast.
+func (v *projLookupTable) FromP3(q *Point) {
+	// Goal: v.points[i] = (i+1)*Q, i.e., Q, 2Q, ..., 8Q
+	// This allows lookup of -8Q, ..., -Q, 0, Q, ..., 8Q
+	v.points[0].FromP3(q)
+	tmpP3 := Point{}
+	tmpP1xP1 := projP1xP1{}
+	for i := 0; i < 7; i++ {
+		// Compute (i+1)*Q as Q + i*Q and convert to a projCached
+		// This is needlessly complicated because the API has explicit
+		// receivers instead of creating stack objects and relying on RVO
+		v.points[i+1].FromP3(tmpP3.fromP1xP1(tmpP1xP1.Add(q, &v.points[i])))
+	}
+}
+
+// This is not optimised for speed; fixed-base tables should be precomputed.
+func (v *affineLookupTable) FromP3(q *Point) {
+	// Goal: v.points[i] = (i+1)*Q, i.e., Q, 2Q, ..., 8Q
+	// This allows lookup of -8Q, ..., -Q, 0, Q, ..., 8Q
+	v.points[0].FromP3(q)
+	tmpP3 := Point{}
+	tmpP1xP1 := projP1xP1{}
+	for i := 0; i < 7; i++ {
+		// Compute (i+1)*Q as Q + i*Q and convert to affineCached
+		v.points[i+1].FromP3(tmpP3.fromP1xP1(tmpP1xP1.AddAffine(q, &v.points[i])))
+	}
+}
+
+// Builds a lookup table at runtime. Fast.
+func (v *nafLookupTable5) FromP3(q *Point) {
+	// Goal: v.points[i] = (2*i+1)*Q, i.e., Q, 3Q, 5Q, ..., 15Q
+	// This allows lookup of -15Q, ..., -3Q, -Q, 0, Q, 3Q, ..., 15Q
+	v.points[0].FromP3(q)
+	q2 := Point{}
+	q2.Add(q, q)
+	tmpP3 := Point{}
+	tmpP1xP1 := projP1xP1{}
+	for i := 0; i < 7; i++ {
+		v.points[i+1].FromP3(tmpP3.fromP1xP1(tmpP1xP1.Add(&q2, &v.points[i])))
+	}
+}
+
+// This is not optimised for speed; fixed-base tables should be precomputed.
+func (v *nafLookupTable8) FromP3(q *Point) {
+	v.points[0].FromP3(q)
+	q2 := Point{}
+	q2.Add(q, q)
+	tmpP3 := Point{}
+	tmpP1xP1 := projP1xP1{}
+	for i := 0; i < 63; i++ {
+		v.points[i+1].FromP3(tmpP3.fromP1xP1(tmpP1xP1.AddAffine(&q2, &v.points[i])))
+	}
+}
+
+// Selectors.
+
+// Set dest to x*Q, where -8 <= x <= 8, in constant time.
+func (v *projLookupTable) SelectInto(dest *projCached, x int8) {
+	// Compute xabs = |x|
+	xmask := x >> 7
+	xabs := uint8((x + xmask) ^ xmask)
+
+	dest.Zero()
+	for j := 1; j <= 8; j++ {
+		// Set dest = j*Q if |x| = j
+		cond := subtle.ConstantTimeByteEq(xabs, uint8(j))
+		dest.Select(&v.points[j-1], dest, cond)
+	}
+	// Now dest = |x|*Q, conditionally negate to get x*Q
+	dest.CondNeg(int(xmask & 1))
+}
+
+// Set dest to x*Q, where -8 <= x <= 8, in constant time.
+func (v *affineLookupTable) SelectInto(dest *affineCached, x int8) {
+	// Compute xabs = |x|
+	xmask := x >> 7
+	xabs := uint8((x + xmask) ^ xmask)
+
+	dest.Zero()
+	for j := 1; j <= 8; j++ {
+		// Set dest = j*Q if |x| = j
+		cond := subtle.ConstantTimeByteEq(xabs, uint8(j))
+		dest.Select(&v.points[j-1], dest, cond)
+	}
+	// Now dest = |x|*Q, conditionally negate to get x*Q
+	dest.CondNeg(int(xmask & 1))
+}
+
+// Given odd x with 0 < x < 2^4, return x*Q (in variable time).
+func (v *nafLookupTable5) SelectInto(dest *projCached, x int8) {
+	*dest = v.points[x/2]
+}
+
+// Given odd x with 0 < x < 2^7, return x*Q (in variable time).
+func (v *nafLookupTable8) SelectInto(dest *affineCached, x int8) {
+	*dest = v.points[x/2]
+}

vendor/github.com/emersion/go-msgauth/dkim/header.go

@@ -83,7 +83,12 @@ func parseHeaderParams(s string) (map[string]string, error) {
 			return params, errors.New("dkim: malformed header params")
 		}
 
-		params[strings.TrimSpace(key)] = strings.TrimSpace(value)
+		trimmedKey := strings.TrimSpace(key)
+		_, present := params[trimmedKey]
+		if present {
+			return params, errors.New("dkim: duplicate tag name")
+		}
+		params[trimmedKey] = strings.TrimSpace(value)
 	}
 	return params, nil
 }

vendor/github.com/emersion/go-msgauth/dkim/query.go

@@ -100,7 +100,7 @@ func queryDNSTXT(domain, selector string, txtLookup txtLookupFunc) (*queryResult
 func parsePublicKey(s string) (*queryResult, error) {
 	params, err := parseHeaderParams(s)
 	if err != nil {
-		return nil, permFailError("key syntax error: " + err.Error())
+		return nil, permFailError("key record error: " + err.Error())
 	}
 
 	res := new(queryResult)

vendor/github.com/go-sql-driver/mysql/AUTHORS

@@ -13,29 +13,41 @@
 
 Aaron Hopkins <go-sql-driver at die.net>
 Achille Roussel <achille.roussel at gmail.com>
+Aidan <aidan.liu at pingcap.com>
 Alex Snast <alexsn at fb.com>
 Alexey Palazhchenko <alexey.palazhchenko at gmail.com>
 Andrew Reid <andrew.reid at tixtrack.com>
 Animesh Ray <mail.rayanimesh at gmail.com>
 Arne Hormann <arnehormann at gmail.com>
 Ariel Mashraki <ariel at mashraki.co.il>
+Artur Melanchyk <artur.melanchyk@gmail.com>
 Asta Xie <xiemengjun at gmail.com>
+B Lamarche <blam413 at gmail.com>
+Bes Dollma <bdollma@thousandeyes.com>
+Bogdan Constantinescu <bog.con.bc at gmail.com>
+Brad Higgins <brad at defined.net>
+Brian Hendriks <brian at dolthub.com>
 Bulat Gaifullin <gaifullinbf at gmail.com>
 Caine Jette <jette at alum.mit.edu>
 Carlos Nieto <jose.carlos at menteslibres.net>
 Chris Kirkland <chriskirkland at github.com>
 Chris Moos <chris at tech9computers.com>
 Craig Wilson <craiggwilson at gmail.com>
+Daemonxiao <735462752 at qq.com>
 Daniel Montoya <dsmontoyam at gmail.com>
 Daniel Nichter <nil at codenode.com>
 Daniël van Eeden <git at myname.nl>
 Dave Protasowski <dprotaso at gmail.com>
+Diego Dupin <diego.dupin at gmail.com>
+Dirkjan Bussink <d.bussink at gmail.com>
 DisposaBoy <disposaboy at dby.me>
 Egor Smolyakov <egorsmkv at gmail.com>
 Erwan Martin <hello at erwan.io>
+Evan Elias <evan at skeema.net>
 Evan Shaw <evan at vendhq.com>
 Frederick Mayle <frederickmayle at gmail.com>
 Gustavo Kristic <gkristic at gmail.com>
+Gusted <postmaster at gusted.xyz>
 Hajime Nakagami <nakagami at gmail.com>
 Hanno Braun <mail at hannobraun.com>
 Henri Yandell <flamefew at gmail.com>
@@ -45,13 +57,18 @@ ICHINOSE Shogo <shogo82148 at gmail.com>
 Ilia Cimpoes <ichimpoesh at gmail.com>
 INADA Naoki <songofacandy at gmail.com>
 Jacek Szwec <szwec.jacek at gmail.com>
+Jakub Adamus <kratky at zobak.cz>
 James Harr <james.harr at gmail.com>
 Janek Vedock <janekvedock at comcast.net>
+Jason Ng <oblitorum at gmail.com>
+Jean-Yves Pellé <jy at pelle.link>
 Jeff Hodges <jeff at somethingsimilar.com>
 Jeffrey Charles <jeffreycharles at gmail.com>
+Jennifer Purevsuren <jennifer at dolthub.com>
 Jerome Meyer <jxmeyer at gmail.com>
 Jiajia Zhong <zhong2plus at gmail.com>
 Jian Zhen <zhenjl at gmail.com>
+Joe Mann <contact at joemann.co.uk>
 Joshua Prunier <joshua.prunier at gmail.com>
 Julien Lefevre <julien.lefevr at gmail.com>
 Julien Schmidt <go-sql-driver at julienschmidt.com>
@@ -72,17 +89,23 @@ Lunny Xiao <xiaolunwen at gmail.com>
 Luke Scott <luke at webconnex.com>
 Maciej Zimnoch <maciej.zimnoch at codilime.com>
 Michael Woolnough <michael.woolnough at gmail.com>
+Nao Yokotsuka <yokotukanao at gmail.com>
 Nathanial Murphy <nathanial.murphy at gmail.com>
 Nicola Peduzzi <thenikso at gmail.com>
+Oliver Bone <owbone at github.com>
 Olivier Mengué <dolmen at cpan.org>
 oscarzhao <oscarzhaosl at gmail.com>
 Paul Bonser <misterpib at gmail.com>
+Paulius Lozys <pauliuslozys at gmail.com>
 Peter Schultz <peter.schultz at classmarkets.com>
+Phil Porada <philporada at gmail.com>
+Minh Quang <minhquang4334 at gmail.com>
 Rebecca Chin <rchin at pivotal.io>
 Reed Allman <rdallman10 at gmail.com>
 Richard Wilkes <wilkes at me.com>
 Robert Russell <robert at rrbrussell.com>
 Runrioter Wung <runrioter at gmail.com>
+Samantha Frank <hello at entropy.cat>
 Santhosh Kumar Tekuri <santhosh.tekuri at gmail.com>
 Sho Iizuka <sho.i518 at gmail.com>
 Sho Ikeda <suicaicoca at gmail.com>
@@ -93,6 +116,7 @@ Stan Putrya <root.vagner at gmail.com>
 Stanley Gunawan <gunawan.stanley at gmail.com>
 Steven Hartland <steven.hartland at multiplay.co.uk>
 Tan Jinhua <312841925 at qq.com>
+Tetsuro Aoki <t.aoki1130 at gmail.com>
 Thomas Wodarek <wodarekwebpage at gmail.com>
 Tim Ruffles <timruffles at gmail.com>
 Tom Jenkinson <tom at tjenkinson.me>
@@ -102,6 +126,7 @@ Xiangyu Hu <xiangyu.hu at outlook.com>
 Xiaobing Jiang <s7v7nislands at gmail.com>
 Xiuming Chen <cc at cxm.cc>
 Xuehong Chan <chanxuehong at gmail.com>
+Zhang Xiang <angwerzx at 126.com>
 Zhenye Xie <xiezhenye at gmail.com>
 Zhixin Wen <john.wenzhixin at gmail.com>
 Ziheng Lyu <zihenglv at gmail.com>
@@ -110,15 +135,21 @@ Ziheng Lyu <zihenglv at gmail.com>
 
 Barracuda Networks, Inc.
 Counting Ltd.
+Defined Networking Inc.
 DigitalOcean Inc.
+Dolthub Inc.
 dyves labs AG
 Facebook Inc.
 GitHub Inc.
 Google Inc.
 InfoSum Ltd.
 Keybase Inc.
+Microsoft Corp.
 Multiplay Ltd.
 Percona LLC
+PingCAP Inc.
 Pivotal Inc.
+Shattered Silicon Ltd.
 Stripe Inc.
+ThousandEyes
 Zendesk Inc.

vendor/github.com/go-sql-driver/mysql/CHANGELOG.md

@@ -1,3 +1,110 @@
+# Changelog
+
+## v1.9.3 (2025-06-13)
+
+* `tx.Commit()` and `tx.Rollback()` returned `ErrInvalidConn` always.
+  Now they return cached real error if present. (#1690)
+
+* Optimize reading small resultsets to fix performance regression
+  introduced by compression protocol support. (#1707)
+
+* Fix `db.Ping()` on compressed connection. (#1723)
+
+
+## v1.9.2 (2025-04-07)
+
+v1.9.2 is a re-release of v1.9.1 due to a release process issue; no changes were made to the content.
+
+
+## v1.9.1 (2025-03-21)
+
+### Major Changes
+
+* Add Charset() option. (#1679)
+
+### Bugfixes
+
+* go.mod: fix go version format (#1682)
+* Fix FormatDSN missing ConnectionAttributes (#1619)
+
+## v1.9.0 (2025-02-18)
+
+### Major Changes
+
+- Implement zlib compression. (#1487)
+- Supported Go version is updated to Go 1.21+. (#1639)
+- Add support for VECTOR type introduced in MySQL 9.0. (#1609)
+- Config object can have custom dial function. (#1527)
+
+### Bugfixes
+
+- Fix auth errors when username/password are too long. (#1625)
+- Check if MySQL supports CLIENT_CONNECT_ATTRS before sending client attributes. (#1640)
+- Fix auth switch request handling. (#1666)
+
+### Other changes
+
+- Add "filename:line" prefix to log in go-mysql. Custom loggers now show it. (#1589)
+- Improve error handling. It reduces the "busy buffer" errors. (#1595, #1601, #1641)
+- Use `strconv.Atoi` to parse max_allowed_packet. (#1661)
+- `rejectReadOnly` option now handles ER_READ_ONLY_MODE (1290) error too. (#1660)
+
+
+## Version 1.8.1 (2024-03-26)
+
+Bugfixes:
+
+- fix race condition when context is canceled in [#1562](https://github.com/go-sql-driver/mysql/pull/1562) and [#1570](https://github.com/go-sql-driver/mysql/pull/1570)
+
+## Version 1.8.0 (2024-03-09)
+
+Major Changes:
+
+- Use `SET NAMES charset COLLATE collation`. by @methane in [#1437](https://github.com/go-sql-driver/mysql/pull/1437)
+  - Older go-mysql-driver used `collation_id` in the handshake packet. But it caused collation mismatch in some situation.
+  - If you don't specify charset nor collation, go-mysql-driver sends `SET NAMES utf8mb4` for new connection. This uses server's default collation for utf8mb4.
+  - If you specify charset, go-mysql-driver sends `SET NAMES <charset>`. This uses the server's default collation for `<charset>`.
+  - If you specify collation and/or charset, go-mysql-driver sends `SET NAMES charset COLLATE collation`.
+- PathEscape dbname in DSN. by @methane in [#1432](https://github.com/go-sql-driver/mysql/pull/1432)
+  - This is backward incompatible in rare case. Check your DSN.
+- Drop Go 1.13-17 support by @methane in [#1420](https://github.com/go-sql-driver/mysql/pull/1420)
+  - Use Go 1.18+
+- Parse numbers on text protocol too by @methane in [#1452](https://github.com/go-sql-driver/mysql/pull/1452)
+  - When text protocol is used, go-mysql-driver passed bare `[]byte` to database/sql for avoid unnecessary allocation and conversion.
+  - If user specified `*any` to `Scan()`, database/sql passed the `[]byte` into the target variable.
+  - This confused users because most user doesn't know when text/binary protocol used.
+  - go-mysql-driver 1.8 converts integer/float values into int64/double even in text protocol. This doesn't increase allocation compared to `[]byte` and conversion cost is negatable.
+- New options start using the Functional Option Pattern to avoid increasing technical debt in the Config object. Future version may introduce Functional Option for existing options, but not for now.
+  - Make TimeTruncate functional option by @methane in [1552](https://github.com/go-sql-driver/mysql/pull/1552)
+  - Add BeforeConnect callback to configuration object by @ItalyPaleAle in [#1469](https://github.com/go-sql-driver/mysql/pull/1469)
+
+
+Other changes:
+
+- Adding DeregisterDialContext to prevent memory leaks with dialers we don't need anymore by @jypelle in https://github.com/go-sql-driver/mysql/pull/1422
+- Make logger configurable per connection by @frozenbonito in https://github.com/go-sql-driver/mysql/pull/1408
+- Fix ColumnType.DatabaseTypeName for mediumint unsigned by @evanelias in https://github.com/go-sql-driver/mysql/pull/1428
+- Add connection attributes by @Daemonxiao in https://github.com/go-sql-driver/mysql/pull/1389
+- Stop `ColumnTypeScanType()` from returning `sql.RawBytes` by @methane in https://github.com/go-sql-driver/mysql/pull/1424
+- Exec() now provides access to status of multiple statements. by @mherr-google in https://github.com/go-sql-driver/mysql/pull/1309
+- Allow to change (or disable) the default driver name for registration by @dolmen in https://github.com/go-sql-driver/mysql/pull/1499
+- Add default connection attribute '_server_host' by @oblitorum in https://github.com/go-sql-driver/mysql/pull/1506
+- QueryUnescape DSN ConnectionAttribute value by @zhangyangyu in https://github.com/go-sql-driver/mysql/pull/1470
+- Add client_ed25519 authentication by @Gusted in https://github.com/go-sql-driver/mysql/pull/1518
+
+## Version 1.7.1 (2023-04-25)
+
+Changes:
+
+  - bump actions/checkout@v3 and actions/setup-go@v3 (#1375)
+  - Add go1.20 and mariadb10.11 to the testing matrix (#1403)
+  - Increase default maxAllowedPacket size. (#1411)
+
+Bugfixes:
+
+  - Use SET syntax as specified in the MySQL documentation (#1402)
+
+
 ## Version 1.7 (2022-11-29)
 
 Changes:
@@ -149,7 +256,7 @@ New Features:
 
  - Enable microsecond resolution on TIME, DATETIME and TIMESTAMP (#249)
  - Support for returning table alias on Columns() (#289, #359, #382)
- - Placeholder interpolation, can be actived with the DSN parameter `interpolateParams=true` (#309, #318, #490)
+ - Placeholder interpolation, can be activated with the DSN parameter `interpolateParams=true` (#309, #318, #490)
  - Support for uint64 parameters with high bit set (#332, #345)
  - Cleartext authentication plugin support (#327)
  - Exported ParseDSN function and the Config struct (#403, #419, #429)
@@ -193,7 +300,7 @@ Changes:
  - Also exported the MySQLWarning type
  - mysqlConn.Close returns the first error encountered instead of ignoring all errors
  - writePacket() automatically writes the packet size to the header
- - readPacket() uses an iterative approach instead of the recursive approach to merge splitted packets
+ - readPacket() uses an iterative approach instead of the recursive approach to merge split packets
 
 New Features:
 
@@ -241,7 +348,7 @@ Bugfixes:
 
   - Fixed MySQL 4.1 support: MySQL 4.1 sends packets with lengths which differ from the specification
   - Convert to DB timezone when inserting `time.Time`
-  - Splitted packets (more than 16MB) are now merged correctly
+  - Split packets (more than 16MB) are now merged correctly
   - Fixed false positive `io.EOF` errors when the data was fully read
   - Avoid panics on reuse of closed connections
   - Fixed empty string producing false nil values

vendor/github.com/go-sql-driver/mysql/README.md

@@ -38,17 +38,26 @@ A MySQL-Driver for Go's [database/sql](https://golang.org/pkg/database/sql/) pac
   * Secure `LOAD DATA LOCAL INFILE` support with file allowlisting and `io.Reader` support
   * Optional `time.Time` parsing
   * Optional placeholder interpolation
+  * Supports zlib compression.
 
 ## Requirements
-  * Go 1.13 or higher. We aim to support the 3 latest versions of Go.
-  * MySQL (4.1+), MariaDB, Percona Server, Google CloudSQL or Sphinx (2.2.3+)
+
+* Go 1.21 or higher. We aim to support the 3 latest versions of Go.
+* MySQL (5.7+) and MariaDB (10.5+) are supported.
+* [TiDB](https://github.com/pingcap/tidb) is supported by PingCAP.
+  * Do not ask questions about TiDB in our issue tracker or forum.
+  * [Document](https://docs.pingcap.com/tidb/v6.1/dev-guide-sample-application-golang)
+  * [Forum](https://ask.pingcap.com/)
+* go-mysql would work with Percona Server, Google CloudSQL or Sphinx (2.2.3+).
+  * Maintainers won't support them. Do not expect issues are investigated and resolved by maintainers.
+  * Investigate issues yourself and please send a pull request to fix it.
 
 ---------------------------------------
 
 ## Installation
 Simple install the package to your [$GOPATH](https://github.com/golang/go/wiki/GOPATH "GOPATH") with the [go tool](https://golang.org/cmd/go/ "go command") from shell:
 ```bash
-$ go get -u github.com/go-sql-driver/mysql
+go get -u github.com/go-sql-driver/mysql
 ```
 Make sure [Git is installed](https://git-scm.com/downloads) on your machine and in your system's `PATH`.
 
@@ -114,6 +123,12 @@ This has the same effect as an empty DSN string:
 
 ```
 
+`dbname` is escaped by [PathEscape()](https://pkg.go.dev/net/url#PathEscape) since v1.8.0. If your database name is `dbname/withslash`, it becomes:
+
+```
+/dbname%2Fwithslash
+```
+
 Alternatively, [Config.FormatDSN](https://godoc.org/github.com/go-sql-driver/mysql#Config.FormatDSN) can be used to create a DSN string by filling a struct.
 
 #### Password
@@ -121,7 +136,7 @@ Passwords can consist of any character. Escaping is **not** necessary.
 
 #### Protocol
 See [net.Dial](https://golang.org/pkg/net/#Dial) for more information which networks are available.
-In general you should use an Unix domain socket if available and TCP otherwise for best performance.
+In general you should use a Unix domain socket if available and TCP otherwise for best performance.
 
 #### Address
 For TCP and UDP networks, addresses have the form `host[:port]`.
@@ -145,7 +160,7 @@ Default:        false
 ```
 
 `allowAllFiles=true` disables the file allowlist for `LOAD DATA LOCAL INFILE` and allows *all* files.
-[*Might be insecure!*](http://dev.mysql.com/doc/refman/5.7/en/load-data-local.html)
+[*Might be insecure!*](https://dev.mysql.com/doc/refman/8.0/en/load-data.html#load-data-local)
 
 ##### `allowCleartextPasswords`
 
@@ -194,10 +209,9 @@ Valid Values:   <name>
 Default:        none
 ```
 
-Sets the charset used for client-server interaction (`"SET NAMES <value>"`). If multiple charsets are set (separated by a comma), the following charset is used if setting the charset failes. This enables for example support for `utf8mb4` ([introduced in MySQL 5.5.3](http://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html)) with fallback to `utf8` for older servers (`charset=utf8mb4,utf8`).
+Sets the charset used for client-server interaction (`"SET NAMES <value>"`). If multiple charsets are set (separated by a comma), the following charset is used if setting the charset fails. This enables for example support for `utf8mb4` ([introduced in MySQL 5.5.3](http://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html)) with fallback to `utf8` for older servers (`charset=utf8mb4,utf8`).
 
-Usage of the `charset` parameter is discouraged because it issues additional queries to the server.
-Unless you need the fallback behavior, please use `collation` instead.
+See also [Unicode Support](#unicode-support).
 
 ##### `checkConnLiveness`
 
@@ -226,6 +240,7 @@ The default collation (`utf8mb4_general_ci`) is supported from MySQL 5.5.  You s
 
 Collations for charset "ucs2", "utf16", "utf16le", and "utf32" can not be used ([ref](https://dev.mysql.com/doc/refman/5.7/en/charset-connection.html#charset-connection-impermissible-client-charset)).
 
+See also [Unicode Support](#unicode-support).
 
 ##### `clientFoundRows`
 
@@ -253,6 +268,16 @@ SELECT u.id FROM users as u
 
 will return `u.id` instead of just `id` if `columnsWithAlias=true`.
 
+##### `compress`
+
+```
+Type:           bool
+Valid Values:   true, false
+Default:        false
+```
+
+Toggles zlib compression. false by default.
+
 ##### `interpolateParams`
 
 ```
@@ -279,13 +304,22 @@ Note that this sets the location for time.Time values but does not change MySQL'
 
 Please keep in mind, that param values must be [url.QueryEscape](https://golang.org/pkg/net/url/#QueryEscape)'ed. Alternatively you can manually replace the `/` with `%2F`. For example `US/Pacific` would be `loc=US%2FPacific`.
 
+##### `timeTruncate`
+
+```
+Type:           duration
+Default:        0
+```
+
+[Truncate time values](https://pkg.go.dev/time#Duration.Truncate) to the specified duration. The value must be a decimal number with a unit suffix (*"ms"*, *"s"*, *"m"*, *"h"*), such as *"30s"*, *"0.5m"* or *"1m30s"*.
+
 ##### `maxAllowedPacket`
 ```
 Type:          decimal number
-Default:       4194304
+Default:       64*1024*1024
 ```
 
-Max packet size allowed in bytes. The default value is 4 MiB and should be adjusted to match the server settings. `maxAllowedPacket=0` can be used to automatically fetch the `max_allowed_packet` variable from server *on every connection*.
+Max packet size allowed in bytes. The default value is 64 MiB and should be adjusted to match the server settings. `maxAllowedPacket=0` can be used to automatically fetch the `max_allowed_packet` variable from server *on every connection*.
 
 ##### `multiStatements`
 
@@ -295,9 +329,25 @@ Valid Values:   true, false
 Default:        false
 ```
 
-Allow multiple statements in one query. While this allows batch queries, it also greatly increases the risk of SQL injections. Only the result of the first query is returned, all other results are silently discarded.
+Allow multiple statements in one query. This can be used to bach multiple queries. Use [Rows.NextResultSet()](https://pkg.go.dev/database/sql#Rows.NextResultSet) to get result of the second and subsequent queries.
 
-When `multiStatements` is used, `?` parameters must only be used in the first statement.
+When `multiStatements` is used, `?` parameters must only be used in the first statement. [interpolateParams](#interpolateparams) can be used to avoid this limitation unless prepared statement is used explicitly.
+
+It's possible to access the last inserted ID and number of affected rows for multiple statements by using `sql.Conn.Raw()` and the `mysql.Result`. For example:
+
+```go
+conn, _ := db.Conn(ctx)
+conn.Raw(func(conn any) error {
+  ex := conn.(driver.Execer)
+  res, err := ex.Exec(`
+  UPDATE point SET x = 1 WHERE y = 2;
+  UPDATE point SET x = 2 WHERE y = 3;
+  `, nil)
+  // Both slices have 2 elements.
+  log.Print(res.(mysql.Result).AllRowsAffected())
+  log.Print(res.(mysql.Result).AllLastInsertIds())
+})
+```
 
 ##### `parseTime`
 
@@ -393,6 +443,15 @@ Default:        0
 
 I/O write timeout. The value must be a decimal number with a unit suffix (*"ms"*, *"s"*, *"m"*, *"h"*), such as *"30s"*, *"0.5m"* or *"1m30s"*.
 
+##### `connectionAttributes`
+
+```
+Type:           comma-delimited string of user-defined "key:value" pairs
+Valid Values:   (<name1>:<value1>,<name2>:<value2>,...)
+Default:        none
+```
+
+[Connection attributes](https://dev.mysql.com/doc/refman/8.0/en/performance-schema-connection-attribute-tables.html) are key-value pairs that application programs can pass to the server at connect time.
 
 ##### System Variables
 
@@ -465,12 +524,15 @@ user:password@/
 The connection pool is managed by Go's database/sql package. For details on how to configure the size of the pool and how long connections stay in the pool see `*DB.SetMaxOpenConns`, `*DB.SetMaxIdleConns`, and `*DB.SetConnMaxLifetime` in the [database/sql documentation](https://golang.org/pkg/database/sql/). The read, write, and dial timeouts for each individual connection are configured with the DSN parameters [`readTimeout`](#readtimeout), [`writeTimeout`](#writetimeout), and [`timeout`](#timeout), respectively.
 
 ## `ColumnType` Support
-This driver supports the [`ColumnType` interface](https://golang.org/pkg/database/sql/#ColumnType) introduced in Go 1.8, with the exception of [`ColumnType.Length()`](https://golang.org/pkg/database/sql/#ColumnType.Length), which is currently not supported. All Unsigned database type names will be returned `UNSIGNED ` with `INT`, `TINYINT`, `SMALLINT`, `BIGINT`.
+This driver supports the [`ColumnType` interface](https://golang.org/pkg/database/sql/#ColumnType) introduced in Go 1.8, with the exception of [`ColumnType.Length()`](https://golang.org/pkg/database/sql/#ColumnType.Length), which is currently not supported. All Unsigned database type names will be returned `UNSIGNED ` with `INT`, `TINYINT`, `SMALLINT`, `MEDIUMINT`, `BIGINT`.
 
 ## `context.Context` Support
 Go 1.8 added `database/sql` support for `context.Context`. This driver supports query timeouts and cancellation via contexts.
 See [context support in the database/sql package](https://golang.org/doc/go1.8#database_sql) for more details.
 
+> [!IMPORTANT]
+> The `QueryContext`, `ExecContext`, etc. variants provided by `database/sql` will cause the connection to be closed if the provided context is cancelled or timed out before the result is received by the driver.
+
 
 ### `LOAD DATA LOCAL INFILE` support
 For this feature you need direct access to the package. Therefore you must change the import path (no `_`):
@@ -478,7 +540,7 @@ For this feature you need direct access to the package. Therefore you must chang
 import "github.com/go-sql-driver/mysql"
 ```
 
-Files must be explicitly allowed by registering them with `mysql.RegisterLocalFile(filepath)` (recommended) or the allowlist check must be deactivated by using the DSN parameter `allowAllFiles=true` ([*Might be insecure!*](http://dev.mysql.com/doc/refman/5.7/en/load-data-local.html)).
+Files must be explicitly allowed by registering them with `mysql.RegisterLocalFile(filepath)` (recommended) or the allowlist check must be deactivated by using the DSN parameter `allowAllFiles=true` ([*Might be insecure!*](https://dev.mysql.com/doc/refman/8.0/en/load-data.html#load-data-local)).
 
 To use a `io.Reader` a handler function must be registered with `mysql.RegisterReaderHandler(name, handler)` which returns a `io.Reader` or `io.ReadCloser`. The Reader is available with the filepath `Reader::<name>` then. Choose different names for different handlers and `DeregisterReaderHandler` when you don't need it anymore.
 
@@ -496,9 +558,11 @@ However, many want to scan MySQL `DATE` and `DATETIME` values into `time.Time` v
 ### Unicode support
 Since version 1.5 Go-MySQL-Driver automatically uses the collation ` utf8mb4_general_ci` by default.
 
-Other collations / charsets can be set using the [`collation`](#collation) DSN parameter.
+Other charsets / collations can be set using the [`charset`](#charset) or [`collation`](#collation) DSN parameter.
 
-Version 1.0 of the driver recommended adding `&charset=utf8` (alias for `SET NAMES utf8`) to the DSN to enable proper UTF-8 support. This is not necessary anymore. The [`collation`](#collation) parameter should be preferred to set another collation / charset than the default.
+- When only the `charset` is specified, the `SET NAMES <charset>` query is sent and the server's default collation is used.
+- When both the `charset` and `collation` are specified, the `SET NAMES <charset> COLLATE <collation>` query is sent.
+- When only the `collation` is specified, the collation is specified in the protocol handshake and the `SET NAMES` query is not sent. This can save one roundtrip, but note that the server may ignore the specified collation silently and use the server's default charset/collation instead.
 
 See http://dev.mysql.com/doc/refman/8.0/en/charset-unicode.html for more details on MySQL's Unicode support.
 

vendor/github.com/go-sql-driver/mysql/atomic_bool.go

@@ -1,19 +0,0 @@
-// Go MySQL Driver - A MySQL-Driver for Go's database/sql package.
-//
-// Copyright 2022 The Go-MySQL-Driver Authors. All rights reserved.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
-//go:build go1.19
-// +build go1.19
-
-package mysql
-
-import "sync/atomic"
-
-/******************************************************************************
-*                               Sync utils                                    *
-******************************************************************************/
-
-type atomicBool = atomic.Bool

vendor/github.com/go-sql-driver/mysql/atomic_bool_go118.go

@@ -1,47 +0,0 @@
-// Go MySQL Driver - A MySQL-Driver for Go's database/sql package.
-//
-// Copyright 2022 The Go-MySQL-Driver Authors. All rights reserved.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
-//go:build !go1.19
-// +build !go1.19
-
-package mysql
-
-import "sync/atomic"
-
-/******************************************************************************
-*                               Sync utils                                    *
-******************************************************************************/
-
-// atomicBool is an implementation of atomic.Bool for older version of Go.
-// it is a wrapper around uint32 for usage as a boolean value with
-// atomic access.
-type atomicBool struct {
-	_     noCopy
-	value uint32
-}
-
-// Load returns whether the current boolean value is true
-func (ab *atomicBool) Load() bool {
-	return atomic.LoadUint32(&ab.value) > 0
-}
-
-// Store sets the value of the bool regardless of the previous value
-func (ab *atomicBool) Store(value bool) {
-	if value {
-		atomic.StoreUint32(&ab.value, 1)
-	} else {
-		atomic.StoreUint32(&ab.value, 0)
-	}
-}
-
-// Swap sets the value of the bool and returns the old value.
-func (ab *atomicBool) Swap(value bool) bool {
-	if value {
-		return atomic.SwapUint32(&ab.value, 1) > 0
-	}
-	return atomic.SwapUint32(&ab.value, 0) > 0
-}

vendor/github.com/go-sql-driver/mysql/auth.go

@@ -13,10 +13,13 @@ import (
 	"crypto/rsa"
 	"crypto/sha1"
 	"crypto/sha256"
+	"crypto/sha512"
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
 	"sync"
+
+	"filippo.io/edwards25519"
 )
 
 // server pub keys registry
@@ -33,7 +36,7 @@ var (
 // Note: The provided rsa.PublicKey instance is exclusively owned by the driver
 // after registering it and may not be modified.
 //
-//	data, err := ioutil.ReadFile("mykey.pem")
+//	data, err := os.ReadFile("mykey.pem")
 //	if err != nil {
 //		log.Fatal(err)
 //	}
@@ -225,6 +228,44 @@ func encryptPassword(password string, seed []byte, pub *rsa.PublicKey) ([]byte,
 	return rsa.EncryptOAEP(sha1, rand.Reader, pub, plain, nil)
 }
 
+// authEd25519 does ed25519 authentication used by MariaDB.
+func authEd25519(scramble []byte, password string) ([]byte, error) {
+	// Derived from https://github.com/MariaDB/server/blob/d8e6bb00888b1f82c031938f4c8ac5d97f6874c3/plugin/auth_ed25519/ref10/sign.c
+	// Code style is from https://cs.opensource.google/go/go/+/refs/tags/go1.21.5:src/crypto/ed25519/ed25519.go;l=207
+	h := sha512.Sum512([]byte(password))
+
+	s, err := edwards25519.NewScalar().SetBytesWithClamping(h[:32])
+	if err != nil {
+		return nil, err
+	}
+	A := (&edwards25519.Point{}).ScalarBaseMult(s)
+
+	mh := sha512.New()
+	mh.Write(h[32:])
+	mh.Write(scramble)
+	messageDigest := mh.Sum(nil)
+	r, err := edwards25519.NewScalar().SetUniformBytes(messageDigest)
+	if err != nil {
+		return nil, err
+	}
+
+	R := (&edwards25519.Point{}).ScalarBaseMult(r)
+
+	kh := sha512.New()
+	kh.Write(R.Bytes())
+	kh.Write(A.Bytes())
+	kh.Write(scramble)
+	hramDigest := kh.Sum(nil)
+	k, err := edwards25519.NewScalar().SetUniformBytes(hramDigest)
+	if err != nil {
+		return nil, err
+	}
+
+	S := k.MultiplyAdd(k, s, r)
+
+	return append(R.Bytes(), S.Bytes()...), nil
+}
+
 func (mc *mysqlConn) sendEncryptedPassword(seed []byte, pub *rsa.PublicKey) error {
 	enc, err := encryptPassword(mc.cfg.Passwd, seed, pub)
 	if err != nil {
@@ -290,8 +331,14 @@ func (mc *mysqlConn) auth(authData []byte, plugin string) ([]byte, error) {
 		enc, err := encryptPassword(mc.cfg.Passwd, authData, pubKey)
 		return enc, err
 
+	case "client_ed25519":
+		if len(authData) != 32 {
+			return nil, ErrMalformPkt
+		}
+		return authEd25519(authData, mc.cfg.Passwd)
+
 	default:
-		errLog.Print("unknown auth plugin:", plugin)
+		mc.log("unknown auth plugin:", plugin)
 		return nil, ErrUnknownPlugin
 	}
 }
@@ -338,7 +385,7 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error {
 
 	switch plugin {
 
-	// https://insidemysql.com/preparing-your-community-connector-for-mysql-8-part-2-sha256/
+	// https://dev.mysql.com/blog-archive/preparing-your-community-connector-for-mysql-8-part-2-sha256/
 	case "caching_sha2_password":
 		switch len(authData) {
 		case 0:
@@ -346,7 +393,7 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error {
 		case 1:
 			switch authData[0] {
 			case cachingSha2PasswordFastAuthSuccess:
-				if err = mc.readResultOK(); err == nil {
+				if err = mc.resultUnchanged().readResultOK(); err == nil {
 					return nil // auth successful
 				}
 
@@ -376,13 +423,13 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error {
 						}
 
 						if data[0] != iAuthMoreData {
-							return fmt.Errorf("unexpect resp from server for caching_sha2_password perform full authentication")
+							return fmt.Errorf("unexpected resp from server for caching_sha2_password, perform full authentication")
 						}
 
 						// parse public key
 						block, rest := pem.Decode(data[1:])
 						if block == nil {
-							return fmt.Errorf("No Pem data found, data: %s", rest)
+							return fmt.Errorf("no pem data found, data: %s", rest)
 						}
 						pkix, err := x509.ParsePKIXPublicKey(block.Bytes)
 						if err != nil {
@@ -397,7 +444,7 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error {
 						return err
 					}
 				}
-				return mc.readResultOK()
+				return mc.resultUnchanged().readResultOK()
 
 			default:
 				return ErrMalformPkt
@@ -426,7 +473,7 @@ func (mc *mysqlConn) handleAuthResult(oldAuthData []byte, plugin string) error {
 			if err != nil {
 				return err
 			}
-			return mc.readResultOK()
+			return mc.resultUnchanged().readResultOK()
 		}
 
 	default:

vendor/github.com/go-sql-driver/mysql/buffer.go

@@ -10,54 +10,47 @@ package mysql
 
 import (
 	"io"
-	"net"
-	"time"
 )
 
 const defaultBufSize = 4096
 const maxCachedBufSize = 256 * 1024
 
+// readerFunc is a function that compatible with io.Reader.
+// We use this function type instead of io.Reader because we want to
+// just pass mc.readWithTimeout.
+type readerFunc func([]byte) (int, error)
+
 // A buffer which is used for both reading and writing.
 // This is possible since communication on each connection is synchronous.
 // In other words, we can't write and read simultaneously on the same connection.
 // The buffer is similar to bufio.Reader / Writer but zero-copy-ish
 // Also highly optimized for this particular use case.
-// This buffer is backed by two byte slices in a double-buffering scheme
 type buffer struct {
-	buf     []byte // buf is a byte buffer who's length and capacity are equal.
-	nc      net.Conn
-	idx     int
-	length  int
-	timeout time.Duration
-	dbuf    [2][]byte // dbuf is an array with the two byte slices that back this buffer
-	flipcnt uint      // flipccnt is the current buffer counter for double-buffering
+	buf       []byte // read buffer.
+	cachedBuf []byte // buffer that will be reused. len(cachedBuf) <= maxCachedBufSize.
 }
 
 // newBuffer allocates and returns a new buffer.
-func newBuffer(nc net.Conn) buffer {
-	fg := make([]byte, defaultBufSize)
+func newBuffer() buffer {
 	return buffer{
-		buf:  fg,
-		nc:   nc,
-		dbuf: [2][]byte{fg, nil},
+		cachedBuf: make([]byte, defaultBufSize),
 	}
 }
 
-// flip replaces the active buffer with the background buffer
-// this is a delayed flip that simply increases the buffer counter;
-// the actual flip will be performed the next time we call `buffer.fill`
-func (b *buffer) flip() {
-	b.flipcnt += 1
+// busy returns true if the read buffer is not empty.
+func (b *buffer) busy() bool {
+	return len(b.buf) > 0
 }
 
-// fill reads into the buffer until at least _need_ bytes are in it
-func (b *buffer) fill(need int) error {
-	n := b.length
-	// fill data into its double-buffering target: if we've called
-	// flip on this buffer, we'll be copying to the background buffer,
-	// and then filling it with network data; otherwise we'll just move
-	// the contents of the current buffer to the front before filling it
-	dest := b.dbuf[b.flipcnt&1]
+// len returns how many bytes in the read buffer.
+func (b *buffer) len() int {
+	return len(b.buf)
+}
+
+// fill reads into the read buffer until at least _need_ bytes are in it.
+func (b *buffer) fill(need int, r readerFunc) error {
+	// we'll move the contents of the current buffer to dest before filling it.
+	dest := b.cachedBuf
 
 	// grow buffer if necessary to fit the whole packet.
 	if need > len(dest) {
@@ -67,64 +60,41 @@ func (b *buffer) fill(need int) error {
 		// if the allocated buffer is not too large, move it to backing storage
 		// to prevent extra allocations on applications that perform large reads
 		if len(dest) <= maxCachedBufSize {
-			b.dbuf[b.flipcnt&1] = dest
+			b.cachedBuf = dest
 		}
 	}
 
-	// if we're filling the fg buffer, move the existing data to the start of it.
-	// if we're filling the bg buffer, copy over the data
-	if n > 0 {
-		copy(dest[:n], b.buf[b.idx:])
-	}
-
-	b.buf = dest
-	b.idx = 0
+	// move the existing data to the start of the buffer.
+	n := len(b.buf)
+	copy(dest[:n], b.buf)
 
 	for {
-		if b.timeout > 0 {
-			if err := b.nc.SetReadDeadline(time.Now().Add(b.timeout)); err != nil {
-				return err
-			}
-		}
-
-		nn, err := b.nc.Read(b.buf[n:])
+		nn, err := r(dest[n:])
 		n += nn
 
-		switch err {
-		case nil:
-			if n < need {
-				continue
-			}
-			b.length = n
-			return nil
-
-		case io.EOF:
-			if n >= need {
-				b.length = n
-				return nil
-			}
-			return io.ErrUnexpectedEOF
-
-		default:
-			return err
+		if err == nil && n < need {
+			continue
 		}
+
+		b.buf = dest[:n]
+
+		if err == io.EOF {
+			if n < need {
+				err = io.ErrUnexpectedEOF
+			} else {
+				err = nil
+			}
+		}
+		return err
 	}
 }
 
 // returns next N bytes from buffer.
 // The returned slice is only guaranteed to be valid until the next read
-func (b *buffer) readNext(need int) ([]byte, error) {
-	if b.length < need {
-		// refill
-		if err := b.fill(need); err != nil {
-			return nil, err
-		}
-	}
-
-	offset := b.idx
-	b.idx += need
-	b.length -= need
-	return b.buf[offset:b.idx], nil
+func (b *buffer) readNext(need int) []byte {
+	data := b.buf[:need:need]
+	b.buf = b.buf[need:]
+	return data
 }
 
 // takeBuffer returns a buffer with the requested size.
@@ -132,18 +102,18 @@ func (b *buffer) readNext(need int) ([]byte, error) {
 // Otherwise a bigger buffer is made.
 // Only one buffer (total) can be used at a time.
 func (b *buffer) takeBuffer(length int) ([]byte, error) {
-	if b.length > 0 {
+	if b.busy() {
 		return nil, ErrBusyBuffer
 	}
 
 	// test (cheap) general case first
-	if length <= cap(b.buf) {
-		return b.buf[:length], nil
+	if length <= len(b.cachedBuf) {
+		return b.cachedBuf[:length], nil
 	}
 
-	if length < maxPacketSize {
-		b.buf = make([]byte, length)
-		return b.buf, nil
+	if length < maxCachedBufSize {
+		b.cachedBuf = make([]byte, length)
+		return b.cachedBuf, nil
 	}
 
 	// buffer is larger than we want to store.
@@ -154,10 +124,10 @@ func (b *buffer) takeBuffer(length int) ([]byte, error) {
 // known to be smaller than defaultBufSize.
 // Only one buffer (total) can be used at a time.
 func (b *buffer) takeSmallBuffer(length int) ([]byte, error) {
-	if b.length > 0 {
+	if b.busy() {
 		return nil, ErrBusyBuffer
 	}
-	return b.buf[:length], nil
+	return b.cachedBuf[:length], nil
 }
 
 // takeCompleteBuffer returns the complete existing buffer.
@@ -165,18 +135,15 @@ func (b *buffer) takeSmallBuffer(length int) ([]byte, error) {
 // cap and len of the returned buffer will be equal.
 // Only one buffer (total) can be used at a time.
 func (b *buffer) takeCompleteBuffer() ([]byte, error) {
-	if b.length > 0 {
+	if b.busy() {
 		return nil, ErrBusyBuffer
 	}
-	return b.buf, nil
+	return b.cachedBuf, nil
 }
 
 // store stores buf, an updated buffer, if its suitable to do so.
-func (b *buffer) store(buf []byte) error {
-	if b.length > 0 {
-		return ErrBusyBuffer
-	} else if cap(buf) <= maxPacketSize && cap(buf) > cap(b.buf) {
-		b.buf = buf[:cap(buf)]
+func (b *buffer) store(buf []byte) {
+	if cap(buf) <= maxCachedBufSize && cap(buf) > cap(b.cachedBuf) {
+		b.cachedBuf = buf[:cap(buf)]
 	}
-	return nil
 }

vendor/github.com/go-sql-driver/mysql/collations.go

@@ -8,8 +8,8 @@
 
 package mysql
 
-const defaultCollation = "utf8mb4_general_ci"
-const binaryCollation = "binary"
+const defaultCollationID = 45 // utf8mb4_general_ci
+const binaryCollationID = 63
 
 // A list of available collations mapped to the internal ID.
 // To update this map use the following MySQL query:

vendor/github.com/go-sql-driver/mysql/compress.go

@@ -0,0 +1,213 @@
+// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
+//
+// Copyright 2024 The Go-MySQL-Driver Authors. All rights reserved.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package mysql
+
+import (
+	"bytes"
+	"compress/zlib"
+	"fmt"
+	"io"
+	"sync"
+)
+
+var (
+	zrPool *sync.Pool // Do not use directly. Use zDecompress() instead.
+	zwPool *sync.Pool // Do not use directly. Use zCompress() instead.
+)
+
+func init() {
+	zrPool = &sync.Pool{
+		New: func() any { return nil },
+	}
+	zwPool = &sync.Pool{
+		New: func() any {
+			zw, err := zlib.NewWriterLevel(new(bytes.Buffer), 2)
+			if err != nil {
+				panic(err) // compress/zlib return non-nil error only if level is invalid
+			}
+			return zw
+		},
+	}
+}
+
+func zDecompress(src []byte, dst *bytes.Buffer) (int, error) {
+	br := bytes.NewReader(src)
+	var zr io.ReadCloser
+	var err error
+
+	if a := zrPool.Get(); a == nil {
+		if zr, err = zlib.NewReader(br); err != nil {
+			return 0, err
+		}
+	} else {
+		zr = a.(io.ReadCloser)
+		if err := zr.(zlib.Resetter).Reset(br, nil); err != nil {
+			return 0, err
+		}
+	}
+
+	n, _ := dst.ReadFrom(zr) // ignore err because zr.Close() will return it again.
+	err = zr.Close()         // zr.Close() may return chuecksum error.
+	zrPool.Put(zr)
+	return int(n), err
+}
+
+func zCompress(src []byte, dst io.Writer) error {
+	zw := zwPool.Get().(*zlib.Writer)
+	zw.Reset(dst)
+	if _, err := zw.Write(src); err != nil {
+		return err
+	}
+	err := zw.Close()
+	zwPool.Put(zw)
+	return err
+}
+
+type compIO struct {
+	mc   *mysqlConn
+	buff bytes.Buffer
+}
+
+func newCompIO(mc *mysqlConn) *compIO {
+	return &compIO{
+		mc: mc,
+	}
+}
+
+func (c *compIO) reset() {
+	c.buff.Reset()
+}
+
+func (c *compIO) readNext(need int) ([]byte, error) {
+	for c.buff.Len() < need {
+		if err := c.readCompressedPacket(); err != nil {
+			return nil, err
+		}
+	}
+	data := c.buff.Next(need)
+	return data[:need:need], nil // prevent caller writes into c.buff
+}
+
+func (c *compIO) readCompressedPacket() error {
+	header, err := c.mc.readNext(7)
+	if err != nil {
+		return err
+	}
+	_ = header[6] // bounds check hint to compiler; guaranteed by readNext
+
+	// compressed header structure
+	comprLength := getUint24(header[0:3])
+	compressionSequence := header[3]
+	uncompressedLength := getUint24(header[4:7])
+	if debug {
+		fmt.Printf("uncompress cmplen=%v uncomplen=%v pkt_cmp_seq=%v expected_cmp_seq=%v\n",
+			comprLength, uncompressedLength, compressionSequence, c.mc.sequence)
+	}
+	// Do not return ErrPktSync here.
+	// Server may return error packet (e.g. 1153 Got a packet bigger than 'max_allowed_packet' bytes)
+	// before receiving all packets from client. In this case, seqnr is younger than expected.
+	// NOTE: Both of mariadbclient and mysqlclient do not check seqnr. Only server checks it.
+	if debug && compressionSequence != c.mc.compressSequence {
+		fmt.Printf("WARN: unexpected cmpress seq nr: expected %v, got %v",
+			c.mc.compressSequence, compressionSequence)
+	}
+	c.mc.compressSequence = compressionSequence + 1
+
+	comprData, err := c.mc.readNext(comprLength)
+	if err != nil {
+		return err
+	}
+
+	// if payload is uncompressed, its length will be specified as zero, and its
+	// true length is contained in comprLength
+	if uncompressedLength == 0 {
+		c.buff.Write(comprData)
+		return nil
+	}
+
+	// use existing capacity in bytesBuf if possible
+	c.buff.Grow(uncompressedLength)
+	nread, err := zDecompress(comprData, &c.buff)
+	if err != nil {
+		return err
+	}
+	if nread != uncompressedLength {
+		return fmt.Errorf("invalid compressed packet: uncompressed length in header is %d, actual %d",
+			uncompressedLength, nread)
+	}
+	return nil
+}
+
+const minCompressLength = 150
+const maxPayloadLen = maxPacketSize - 4
+
+// writePackets sends one or some packets with compression.
+// Use this instead of mc.netConn.Write() when mc.compress is true.
+func (c *compIO) writePackets(packets []byte) (int, error) {
+	totalBytes := len(packets)
+	blankHeader := make([]byte, 7)
+	buf := &c.buff
+
+	for len(packets) > 0 {
+		payloadLen := min(maxPayloadLen, len(packets))
+		payload := packets[:payloadLen]
+		uncompressedLen := payloadLen
+
+		buf.Reset()
+		buf.Write(blankHeader) // Buffer.Write() never returns error
+
+		// If payload is less than minCompressLength, don't compress.
+		if uncompressedLen < minCompressLength {
+			buf.Write(payload)
+			uncompressedLen = 0
+		} else {
+			err := zCompress(payload, buf)
+			if debug && err != nil {
+				fmt.Printf("zCompress error: %v", err)
+			}
+			// do not compress if compressed data is larger than uncompressed data
+			// I intentionally miss 7 byte header in the buf; zCompress must compress more than 7 bytes.
+			if err != nil || buf.Len() >= uncompressedLen {
+				buf.Reset()
+				buf.Write(blankHeader)
+				buf.Write(payload)
+				uncompressedLen = 0
+			}
+		}
+
+		if n, err := c.writeCompressedPacket(buf.Bytes(), uncompressedLen); err != nil {
+			// To allow returning ErrBadConn when sending really 0 bytes, we sum
+			// up compressed bytes that is returned by underlying Write().
+			return totalBytes - len(packets) + n, err
+		}
+		packets = packets[payloadLen:]
+	}
+
+	return totalBytes, nil
+}
+
+// writeCompressedPacket writes a compressed packet with header.
+// data should start with 7 size space for header followed by payload.
+func (c *compIO) writeCompressedPacket(data []byte, uncompressedLen int) (int, error) {
+	mc := c.mc
+	comprLength := len(data) - 7
+	if debug {
+		fmt.Printf(
+			"writeCompressedPacket: comprLength=%v, uncompressedLen=%v, seq=%v\n",
+			comprLength, uncompressedLen, mc.compressSequence)
+	}
+
+	// compression header
+	putUint24(data[0:3], comprLength)
+	data[3] = mc.compressSequence
+	putUint24(data[4:7], uncompressedLen)
+
+	mc.compressSequence++
+	return mc.writeWithTimeout(data)
+}

vendor/github.com/go-sql-driver/mysql/connection.go

@@ -13,28 +13,32 @@ import (
 	"database/sql"
 	"database/sql/driver"
 	"encoding/json"
+	"fmt"
 	"io"
 	"net"
+	"runtime"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"time"
 )
 
 type mysqlConn struct {
 	buf              buffer
 	netConn          net.Conn
-	rawConn          net.Conn // underlying connection when netConn is TLS connection.
-	affectedRows     uint64
-	insertId         uint64
+	rawConn          net.Conn    // underlying connection when netConn is TLS connection.
+	result           mysqlResult // managed by clearResult() and handleOkPacket().
+	compIO           *compIO
 	cfg              *Config
+	connector        *connector
 	maxAllowedPacket int
 	maxWriteSize     int
-	writeTimeout     time.Duration
 	flags            clientFlag
 	status           statusFlag
 	sequence         uint8
+	compressSequence uint8
 	parseTime        bool
-	reset            bool // set when the Go SQL package calls ResetSession
+	compress         bool
 
 	// for context support (Go 1.8+)
 	watching bool
@@ -42,61 +46,92 @@ type mysqlConn struct {
 	closech  chan struct{}
 	finished chan<- struct{}
 	canceled atomicError // set non-nil if conn is canceled
-	closed   atomicBool  // set when conn is closed, before closech is closed
+	closed   atomic.Bool // set when conn is closed, before closech is closed
+}
+
+// Helper function to call per-connection logger.
+func (mc *mysqlConn) log(v ...any) {
+	_, filename, lineno, ok := runtime.Caller(1)
+	if ok {
+		pos := strings.LastIndexByte(filename, '/')
+		if pos != -1 {
+			filename = filename[pos+1:]
+		}
+		prefix := fmt.Sprintf("%s:%d ", filename, lineno)
+		v = append([]any{prefix}, v...)
+	}
+
+	mc.cfg.Logger.Print(v...)
+}
+
+func (mc *mysqlConn) readWithTimeout(b []byte) (int, error) {
+	to := mc.cfg.ReadTimeout
+	if to > 0 {
+		if err := mc.netConn.SetReadDeadline(time.Now().Add(to)); err != nil {
+			return 0, err
+		}
+	}
+	return mc.netConn.Read(b)
+}
+
+func (mc *mysqlConn) writeWithTimeout(b []byte) (int, error) {
+	to := mc.cfg.WriteTimeout
+	if to > 0 {
+		if err := mc.netConn.SetWriteDeadline(time.Now().Add(to)); err != nil {
+			return 0, err
+		}
+	}
+	return mc.netConn.Write(b)
+}
+
+func (mc *mysqlConn) resetSequence() {
+	mc.sequence = 0
+	mc.compressSequence = 0
+}
+
+// syncSequence must be called when finished writing some packet and before start reading.
+func (mc *mysqlConn) syncSequence() {
+	// Syncs compressionSequence to sequence.
+	// This is not documented but done in `net_flush()` in MySQL and MariaDB.
+	// https://github.com/mariadb-corporation/mariadb-connector-c/blob/8228164f850b12353da24df1b93a1e53cc5e85e9/libmariadb/ma_net.c#L170-L171
+	// https://github.com/mysql/mysql-server/blob/824e2b4064053f7daf17d7f3f84b7a3ed92e5fb4/sql-common/net_serv.cc#L293
+	if mc.compress {
+		mc.sequence = mc.compressSequence
+		mc.compIO.reset()
+	}
 }
 
 // Handles parameters set in DSN after the connection is established
 func (mc *mysqlConn) handleParams() (err error) {
 	var cmdSet strings.Builder
-	for param, val := range mc.cfg.Params {
-		switch param {
-		// Charset: character_set_connection, character_set_client, character_set_results
-		case "charset":
-			charsets := strings.Split(val, ",")
-			for i := range charsets {
-				// ignore errors here - a charset may not exist
-				err = mc.exec("SET NAMES " + charsets[i])
-				if err == nil {
-					break
-				}
-			}
-			if err != nil {
-				return
-			}
 
-		// Other system vars accumulated in a single SET command
-		default:
-			if cmdSet.Len() == 0 {
-				// Heuristic: 29 chars for each other key=value to reduce reallocations
-				cmdSet.Grow(4 + len(param) + 1 + len(val) + 30*(len(mc.cfg.Params)-1))
-				cmdSet.WriteString("SET ")
-			} else {
-				cmdSet.WriteByte(',')
-			}
-			cmdSet.WriteString(param)
-			cmdSet.WriteByte('=')
-			cmdSet.WriteString(val)
+	for param, val := range mc.cfg.Params {
+		if cmdSet.Len() == 0 {
+			// Heuristic: 29 chars for each other key=value to reduce reallocations
+			cmdSet.Grow(4 + len(param) + 3 + len(val) + 30*(len(mc.cfg.Params)-1))
+			cmdSet.WriteString("SET ")
+		} else {
+			cmdSet.WriteString(", ")
 		}
+		cmdSet.WriteString(param)
+		cmdSet.WriteString(" = ")
+		cmdSet.WriteString(val)
 	}
 
 	if cmdSet.Len() > 0 {
 		err = mc.exec(cmdSet.String())
-		if err != nil {
-			return
-		}
 	}
 
 	return
 }
 
+// markBadConn replaces errBadConnNoWrite with driver.ErrBadConn.
+// This function is used to return driver.ErrBadConn only when safe to retry.
 func (mc *mysqlConn) markBadConn(err error) error {
-	if mc == nil {
-		return err
+	if err == errBadConnNoWrite {
+		return driver.ErrBadConn
 	}
-	if err != errBadConnNoWrite {
-		return err
-	}
-	return driver.ErrBadConn
+	return err
 }
 
 func (mc *mysqlConn) Begin() (driver.Tx, error) {
@@ -105,7 +140,6 @@ func (mc *mysqlConn) Begin() (driver.Tx, error) {
 
 func (mc *mysqlConn) begin(readOnly bool) (driver.Tx, error) {
 	if mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	var q string
@@ -126,12 +160,16 @@ func (mc *mysqlConn) Close() (err error) {
 	if !mc.closed.Load() {
 		err = mc.writeCommandPacket(comQuit)
 	}
-
-	mc.cleanup()
-
+	mc.close()
 	return
 }
 
+// close closes the network connection and clear results without sending COM_QUIT.
+func (mc *mysqlConn) close() {
+	mc.cleanup()
+	mc.clearResult()
+}
+
 // Closes the network connection and unsets internal variables. Do not call this
 // function after successfully authentication, call Close instead. This function
 // is called before auth or on auth failure because MySQL will have already
@@ -143,12 +181,16 @@ func (mc *mysqlConn) cleanup() {
 
 	// Makes cleanup idempotent
 	close(mc.closech)
-	if mc.netConn == nil {
+	conn := mc.rawConn
+	if conn == nil {
 		return
 	}
-	if err := mc.netConn.Close(); err != nil {
-		errLog.Print(err)
+	if err := conn.Close(); err != nil {
+		mc.log("closing connection:", err)
 	}
+	// This function can be called from multiple goroutines.
+	// So we can not mc.clearResult() here.
+	// Caller should do it if they are in safe goroutine.
 }
 
 func (mc *mysqlConn) error() error {
@@ -163,14 +205,13 @@ func (mc *mysqlConn) error() error {
 
 func (mc *mysqlConn) Prepare(query string) (driver.Stmt, error) {
 	if mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	// Send command
 	err := mc.writeCommandPacketStr(comStmtPrepare, query)
 	if err != nil {
 		// STMT_PREPARE is safe to retry.  So we can return ErrBadConn here.
-		errLog.Print(err)
+		mc.log(err)
 		return nil, driver.ErrBadConn
 	}
 
@@ -204,8 +245,10 @@ func (mc *mysqlConn) interpolateParams(query string, args []driver.Value) (strin
 	buf, err := mc.buf.takeCompleteBuffer()
 	if err != nil {
 		// can not take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return "", ErrInvalidConn
+		mc.cleanup()
+		// interpolateParams would be called before sending any query.
+		// So its safe to retry.
+		return "", driver.ErrBadConn
 	}
 	buf = buf[:0]
 	argPos := 0
@@ -246,7 +289,7 @@ func (mc *mysqlConn) interpolateParams(query string, args []driver.Value) (strin
 				buf = append(buf, "'0000-00-00'"...)
 			} else {
 				buf = append(buf, '\'')
-				buf, err = appendDateTime(buf, v.In(mc.cfg.Loc))
+				buf, err = appendDateTime(buf, v.In(mc.cfg.Loc), mc.cfg.timeTruncate)
 				if err != nil {
 					return "", err
 				}
@@ -296,7 +339,6 @@ func (mc *mysqlConn) interpolateParams(query string, args []driver.Value) (strin
 
 func (mc *mysqlConn) Exec(query string, args []driver.Value) (driver.Result, error) {
 	if mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	if len(args) != 0 {
@@ -310,28 +352,25 @@ func (mc *mysqlConn) Exec(query string, args []driver.Value) (driver.Result, err
 		}
 		query = prepared
 	}
-	mc.affectedRows = 0
-	mc.insertId = 0
 
 	err := mc.exec(query)
 	if err == nil {
-		return &mysqlResult{
-			affectedRows: int64(mc.affectedRows),
-			insertId:     int64(mc.insertId),
-		}, err
+		copied := mc.result
+		return &copied, err
 	}
 	return nil, mc.markBadConn(err)
 }
 
 // Internal function to execute commands
 func (mc *mysqlConn) exec(query string) error {
+	handleOk := mc.clearResult()
 	// Send command
 	if err := mc.writeCommandPacketStr(comQuery, query); err != nil {
 		return mc.markBadConn(err)
 	}
 
 	// Read Result
-	resLen, err := mc.readResultSetHeaderPacket()
+	resLen, err := handleOk.readResultSetHeaderPacket()
 	if err != nil {
 		return err
 	}
@@ -348,7 +387,7 @@ func (mc *mysqlConn) exec(query string) error {
 		}
 	}
 
-	return mc.discardResults()
+	return handleOk.discardResults()
 }
 
 func (mc *mysqlConn) Query(query string, args []driver.Value) (driver.Rows, error) {
@@ -356,8 +395,9 @@ func (mc *mysqlConn) Query(query string, args []driver.Value) (driver.Rows, erro
 }
 
 func (mc *mysqlConn) query(query string, args []driver.Value) (*textRows, error) {
+	handleOk := mc.clearResult()
+
 	if mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	if len(args) != 0 {
@@ -373,43 +413,47 @@ func (mc *mysqlConn) query(query string, args []driver.Value) (*textRows, error)
 	}
 	// Send command
 	err := mc.writeCommandPacketStr(comQuery, query)
-	if err == nil {
-		// Read Result
-		var resLen int
-		resLen, err = mc.readResultSetHeaderPacket()
-		if err == nil {
-			rows := new(textRows)
-			rows.mc = mc
+	if err != nil {
+		return nil, mc.markBadConn(err)
+	}
 
-			if resLen == 0 {
-				rows.rs.done = true
+	// Read Result
+	var resLen int
+	resLen, err = handleOk.readResultSetHeaderPacket()
+	if err != nil {
+		return nil, err
+	}
 
-				switch err := rows.NextResultSet(); err {
-				case nil, io.EOF:
-					return rows, nil
-				default:
-					return nil, err
-				}
-			}
+	rows := new(textRows)
+	rows.mc = mc
 
-			// Columns
-			rows.rs.columns, err = mc.readColumns(resLen)
-			return rows, err
+	if resLen == 0 {
+		rows.rs.done = true
+
+		switch err := rows.NextResultSet(); err {
+		case nil, io.EOF:
+			return rows, nil
+		default:
+			return nil, err
 		}
 	}
-	return nil, mc.markBadConn(err)
+
+	// Columns
+	rows.rs.columns, err = mc.readColumns(resLen)
+	return rows, err
 }
 
 // Gets the value of the given MySQL System Variable
 // The returned byte slice is only valid until the next read
 func (mc *mysqlConn) getSystemVar(name string) ([]byte, error) {
 	// Send command
+	handleOk := mc.clearResult()
 	if err := mc.writeCommandPacketStr(comQuery, "SELECT @@"+name); err != nil {
 		return nil, err
 	}
 
 	// Read Result
-	resLen, err := mc.readResultSetHeaderPacket()
+	resLen, err := handleOk.readResultSetHeaderPacket()
 	if err == nil {
 		rows := new(textRows)
 		rows.mc = mc
@@ -430,7 +474,7 @@ func (mc *mysqlConn) getSystemVar(name string) ([]byte, error) {
 	return nil, err
 }
 
-// finish is called when the query has canceled.
+// cancel is called when the query has canceled.
 func (mc *mysqlConn) cancel(err error) {
 	mc.canceled.Set(err)
 	mc.cleanup()
@@ -451,7 +495,6 @@ func (mc *mysqlConn) finish() {
 // Ping implements driver.Pinger interface
 func (mc *mysqlConn) Ping(ctx context.Context) (err error) {
 	if mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return driver.ErrBadConn
 	}
 
@@ -460,11 +503,12 @@ func (mc *mysqlConn) Ping(ctx context.Context) (err error) {
 	}
 	defer mc.finish()
 
+	handleOk := mc.clearResult()
 	if err = mc.writeCommandPacket(comPing); err != nil {
 		return mc.markBadConn(err)
 	}
 
-	return mc.readResultOK()
+	return handleOk.readResultOK()
 }
 
 // BeginTx implements driver.ConnBeginTx interface
@@ -636,15 +680,42 @@ func (mc *mysqlConn) CheckNamedValue(nv *driver.NamedValue) (err error) {
 // ResetSession implements driver.SessionResetter.
 // (From Go 1.10)
 func (mc *mysqlConn) ResetSession(ctx context.Context) error {
-	if mc.closed.Load() {
+	if mc.closed.Load() || mc.buf.busy() {
 		return driver.ErrBadConn
 	}
-	mc.reset = true
+
+	// Perform a stale connection check. We only perform this check for
+	// the first query on a connection that has been checked out of the
+	// connection pool: a fresh connection from the pool is more likely
+	// to be stale, and it has not performed any previous writes that
+	// could cause data corruption, so it's safe to return ErrBadConn
+	// if the check fails.
+	if mc.cfg.CheckConnLiveness {
+		conn := mc.netConn
+		if mc.rawConn != nil {
+			conn = mc.rawConn
+		}
+		var err error
+		if mc.cfg.ReadTimeout != 0 {
+			err = conn.SetReadDeadline(time.Now().Add(mc.cfg.ReadTimeout))
+		}
+		if err == nil {
+			err = connCheck(conn)
+		}
+		if err != nil {
+			mc.log("closing bad idle connection: ", err)
+			return driver.ErrBadConn
+		}
+	}
+
 	return nil
 }
 
 // IsValid implements driver.Validator interface
 // (From Go 1.15)
 func (mc *mysqlConn) IsValid() bool {
-	return !mc.closed.Load()
+	return !mc.closed.Load() && !mc.buf.busy()
 }
+
+var _ driver.SessionResetter = &mysqlConn{}
+var _ driver.Validator = &mysqlConn{}

vendor/github.com/go-sql-driver/mysql/connector.go

@@ -11,11 +11,55 @@ package mysql
 import (
 	"context"
 	"database/sql/driver"
+	"fmt"
 	"net"
+	"os"
+	"strconv"
+	"strings"
 )
 
 type connector struct {
-	cfg *Config // immutable private copy.
+	cfg               *Config // immutable private copy.
+	encodedAttributes string  // Encoded connection attributes.
+}
+
+func encodeConnectionAttributes(cfg *Config) string {
+	connAttrsBuf := make([]byte, 0)
+
+	// default connection attributes
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrClientName)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrClientNameValue)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrOS)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrOSValue)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrPlatform)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrPlatformValue)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrPid)
+	connAttrsBuf = appendLengthEncodedString(connAttrsBuf, strconv.Itoa(os.Getpid()))
+	serverHost, _, _ := net.SplitHostPort(cfg.Addr)
+	if serverHost != "" {
+		connAttrsBuf = appendLengthEncodedString(connAttrsBuf, connAttrServerHost)
+		connAttrsBuf = appendLengthEncodedString(connAttrsBuf, serverHost)
+	}
+
+	// user-defined connection attributes
+	for _, connAttr := range strings.Split(cfg.ConnectionAttributes, ",") {
+		k, v, found := strings.Cut(connAttr, ":")
+		if !found {
+			continue
+		}
+		connAttrsBuf = appendLengthEncodedString(connAttrsBuf, k)
+		connAttrsBuf = appendLengthEncodedString(connAttrsBuf, v)
+	}
+
+	return string(connAttrsBuf)
+}
+
+func newConnector(cfg *Config) *connector {
+	encodedAttributes := encodeConnectionAttributes(cfg)
+	return &connector{
+		cfg:               cfg,
+		encodedAttributes: encodedAttributes,
+	}
 }
 
 // Connect implements driver.Connector interface.
@@ -23,43 +67,56 @@ type connector struct {
 func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 	var err error
 
+	// Invoke beforeConnect if present, with a copy of the configuration
+	cfg := c.cfg
+	if c.cfg.beforeConnect != nil {
+		cfg = c.cfg.Clone()
+		err = c.cfg.beforeConnect(ctx, cfg)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	// New mysqlConn
 	mc := &mysqlConn{
 		maxAllowedPacket: maxPacketSize,
 		maxWriteSize:     maxPacketSize - 1,
 		closech:          make(chan struct{}),
-		cfg:              c.cfg,
+		cfg:              cfg,
+		connector:        c,
 	}
 	mc.parseTime = mc.cfg.ParseTime
 
 	// Connect to Server
-	dialsLock.RLock()
-	dial, ok := dials[mc.cfg.Net]
-	dialsLock.RUnlock()
-	if ok {
-		dctx := ctx
-		if mc.cfg.Timeout > 0 {
-			var cancel context.CancelFunc
-			dctx, cancel = context.WithTimeout(ctx, c.cfg.Timeout)
-			defer cancel()
-		}
-		mc.netConn, err = dial(dctx, mc.cfg.Addr)
-	} else {
-		nd := net.Dialer{Timeout: mc.cfg.Timeout}
-		mc.netConn, err = nd.DialContext(ctx, mc.cfg.Net, mc.cfg.Addr)
+	dctx := ctx
+	if mc.cfg.Timeout > 0 {
+		var cancel context.CancelFunc
+		dctx, cancel = context.WithTimeout(ctx, c.cfg.Timeout)
+		defer cancel()
 	}
 
+	if c.cfg.DialFunc != nil {
+		mc.netConn, err = c.cfg.DialFunc(dctx, mc.cfg.Net, mc.cfg.Addr)
+	} else {
+		dialsLock.RLock()
+		dial, ok := dials[mc.cfg.Net]
+		dialsLock.RUnlock()
+		if ok {
+			mc.netConn, err = dial(dctx, mc.cfg.Addr)
+		} else {
+			nd := net.Dialer{}
+			mc.netConn, err = nd.DialContext(dctx, mc.cfg.Net, mc.cfg.Addr)
+		}
+	}
 	if err != nil {
 		return nil, err
 	}
+	mc.rawConn = mc.netConn
 
 	// Enable TCP Keepalives on TCP connections
 	if tc, ok := mc.netConn.(*net.TCPConn); ok {
 		if err := tc.SetKeepAlive(true); err != nil {
-			// Don't send COM_QUIT before handshake.
-			mc.netConn.Close()
-			mc.netConn = nil
-			return nil, err
+			c.cfg.Logger.Print(err)
 		}
 	}
 
@@ -71,11 +128,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 	}
 	defer mc.finish()
 
-	mc.buf = newBuffer(mc.netConn)
-
-	// Set I/O timeouts
-	mc.buf.timeout = mc.cfg.ReadTimeout
-	mc.writeTimeout = mc.cfg.WriteTimeout
+	mc.buf = newBuffer()
 
 	// Reading Handshake Initialization Packet
 	authData, plugin, err := mc.readHandshakePacket()
@@ -92,7 +145,7 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 	authResp, err := mc.auth(authData, plugin)
 	if err != nil {
 		// try the default auth plugin, if using the requested plugin failed
-		errLog.Print("could not use requested auth plugin '"+plugin+"': ", err.Error())
+		c.cfg.Logger.Print("could not use requested auth plugin '"+plugin+"': ", err.Error())
 		plugin = defaultAuthPlugin
 		authResp, err = mc.auth(authData, plugin)
 		if err != nil {
@@ -114,6 +167,10 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 		return nil, err
 	}
 
+	if mc.cfg.compress && mc.flags&clientCompress == clientCompress {
+		mc.compress = true
+		mc.compIO = newCompIO(mc)
+	}
 	if mc.cfg.MaxAllowedPacket > 0 {
 		mc.maxAllowedPacket = mc.cfg.MaxAllowedPacket
 	} else {
@@ -123,12 +180,36 @@ func (c *connector) Connect(ctx context.Context) (driver.Conn, error) {
 			mc.Close()
 			return nil, err
 		}
-		mc.maxAllowedPacket = stringToInt(maxap) - 1
+		n, err := strconv.Atoi(string(maxap))
+		if err != nil {
+			mc.Close()
+			return nil, fmt.Errorf("invalid max_allowed_packet value (%q): %w", maxap, err)
+		}
+		mc.maxAllowedPacket = n - 1
 	}
 	if mc.maxAllowedPacket < maxPacketSize {
 		mc.maxWriteSize = mc.maxAllowedPacket
 	}
 
+	// Charset: character_set_connection, character_set_client, character_set_results
+	if len(mc.cfg.charsets) > 0 {
+		for _, cs := range mc.cfg.charsets {
+			// ignore errors here - a charset may not exist
+			if mc.cfg.Collation != "" {
+				err = mc.exec("SET NAMES " + cs + " COLLATE " + mc.cfg.Collation)
+			} else {
+				err = mc.exec("SET NAMES " + cs)
+			}
+			if err == nil {
+				break
+			}
+		}
+		if err != nil {
+			mc.Close()
+			return nil, err
+		}
+	}
+
 	// Handle DSN Params
 	err = mc.handleParams()
 	if err != nil {

vendor/github.com/go-sql-driver/mysql/const.go

@@ -8,12 +8,27 @@
 
 package mysql
 
+import "runtime"
+
 const (
+	debug = false // for debugging. Set true only in development.
+
 	defaultAuthPlugin       = "mysql_native_password"
-	defaultMaxAllowedPacket = 4 << 20 // 4 MiB
+	defaultMaxAllowedPacket = 64 << 20 // 64 MiB. See https://github.com/go-sql-driver/mysql/issues/1355
 	minProtocolVersion      = 10
 	maxPacketSize           = 1<<24 - 1
 	timeFormat              = "2006-01-02 15:04:05.999999"
+
+	// Connection attributes
+	// See https://dev.mysql.com/doc/refman/8.0/en/performance-schema-connection-attribute-tables.html#performance-schema-connection-attributes-available
+	connAttrClientName      = "_client_name"
+	connAttrClientNameValue = "Go-MySQL-Driver"
+	connAttrOS              = "_os"
+	connAttrOSValue         = runtime.GOOS
+	connAttrPlatform        = "_platform"
+	connAttrPlatformValue   = runtime.GOARCH
+	connAttrPid             = "_pid"
+	connAttrServerHost      = "_server_host"
 )
 
 // MySQL constants documentation:
@@ -112,7 +127,10 @@ const (
 	fieldTypeBit
 )
 const (
-	fieldTypeJSON fieldType = iota + 0xf5
+	fieldTypeVector fieldType = iota + 0xf2
+	fieldTypeInvalid
+	fieldTypeBool
+	fieldTypeJSON
 	fieldTypeNewDecimal
 	fieldTypeEnum
 	fieldTypeSet

vendor/github.com/go-sql-driver/mysql/driver.go

@@ -55,6 +55,15 @@ func RegisterDialContext(net string, dial DialContextFunc) {
 	dials[net] = dial
 }
 
+// DeregisterDialContext removes the custom dial function registered with the given net.
+func DeregisterDialContext(net string) {
+	dialsLock.Lock()
+	defer dialsLock.Unlock()
+	if dials != nil {
+		delete(dials, net)
+	}
+}
+
 // RegisterDial registers a custom dial function. It can then be used by the
 // network address mynet(addr), where mynet is the registered new network.
 // addr is passed as a parameter to the dial function.
@@ -74,14 +83,18 @@ func (d MySQLDriver) Open(dsn string) (driver.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-	c := &connector{
-		cfg: cfg,
-	}
+	c := newConnector(cfg)
 	return c.Connect(context.Background())
 }
 
+// This variable can be replaced with -ldflags like below:
+// go build "-ldflags=-X github.com/go-sql-driver/mysql.driverName=custom"
+var driverName = "mysql"
+
 func init() {
-	sql.Register("mysql", &MySQLDriver{})
+	if driverName != "" {
+		sql.Register(driverName, &MySQLDriver{})
+	}
 }
 
 // NewConnector returns new driver.Connector.
@@ -92,7 +105,7 @@ func NewConnector(cfg *Config) (driver.Connector, error) {
 	if err := cfg.normalize(); err != nil {
 		return nil, err
 	}
-	return &connector{cfg: cfg}, nil
+	return newConnector(cfg), nil
 }
 
 // OpenConnector implements driver.DriverContext.
@@ -101,7 +114,5 @@ func (d MySQLDriver) OpenConnector(dsn string) (driver.Connector, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &connector{
-		cfg: cfg,
-	}, nil
+	return newConnector(cfg), nil
 }

vendor/github.com/go-sql-driver/mysql/dsn.go

@@ -10,6 +10,7 @@ package mysql
 
 import (
 	"bytes"
+	"context"
 	"crypto/rsa"
 	"crypto/tls"
 	"errors"
@@ -34,22 +35,29 @@ var (
 // If a new Config is created instead of being parsed from a DSN string,
 // the NewConfig function should be used, which sets default values.
 type Config struct {
-	User             string            // Username
-	Passwd           string            // Password (requires User)
-	Net              string            // Network type
-	Addr             string            // Network address (requires Net)
-	DBName           string            // Database name
-	Params           map[string]string // Connection parameters
-	Collation        string            // Connection collation
-	Loc              *time.Location    // Location for time.Time values
-	MaxAllowedPacket int               // Max packet size allowed
-	ServerPubKey     string            // Server public key name
-	pubKey           *rsa.PublicKey    // Server public key
-	TLSConfig        string            // TLS configuration name
-	TLS              *tls.Config       // TLS configuration, its priority is higher than TLSConfig
-	Timeout          time.Duration     // Dial timeout
-	ReadTimeout      time.Duration     // I/O read timeout
-	WriteTimeout     time.Duration     // I/O write timeout
+	// non boolean fields
+
+	User                 string            // Username
+	Passwd               string            // Password (requires User)
+	Net                  string            // Network (e.g. "tcp", "tcp6", "unix". default: "tcp")
+	Addr                 string            // Address (default: "127.0.0.1:3306" for "tcp" and "/tmp/mysql.sock" for "unix")
+	DBName               string            // Database name
+	Params               map[string]string // Connection parameters
+	ConnectionAttributes string            // Connection Attributes, comma-delimited string of user-defined "key:value" pairs
+	Collation            string            // Connection collation. When set, this will be set in SET NAMES <charset> COLLATE <collation> query
+	Loc                  *time.Location    // Location for time.Time values
+	MaxAllowedPacket     int               // Max packet size allowed
+	ServerPubKey         string            // Server public key name
+	TLSConfig            string            // TLS configuration name
+	TLS                  *tls.Config       // TLS configuration, its priority is higher than TLSConfig
+	Timeout              time.Duration     // Dial timeout
+	ReadTimeout          time.Duration     // I/O read timeout
+	WriteTimeout         time.Duration     // I/O write timeout
+	Logger               Logger            // Logger
+	// DialFunc specifies the dial function for creating connections
+	DialFunc func(ctx context.Context, network, addr string) (net.Conn, error)
+
+	// boolean fields
 
 	AllowAllFiles            bool // Allow all files to be used with LOAD DATA LOCAL INFILE
 	AllowCleartextPasswords  bool // Allows the cleartext client side plugin
@@ -63,17 +71,83 @@ type Config struct {
 	MultiStatements          bool // Allow multiple statements in one query
 	ParseTime                bool // Parse time values to time.Time
 	RejectReadOnly           bool // Reject read-only connections
+
+	// unexported fields. new options should be come here.
+	// boolean first. alphabetical order.
+
+	compress bool // Enable zlib compression
+
+	beforeConnect func(context.Context, *Config) error // Invoked before a connection is established
+	pubKey        *rsa.PublicKey                       // Server public key
+	timeTruncate  time.Duration                        // Truncate time.Time values to the specified duration
+	charsets      []string                             // Connection charset. When set, this will be set in SET NAMES <charset> query
 }
 
+// Functional Options Pattern
+// https://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis
+type Option func(*Config) error
+
 // NewConfig creates a new Config and sets default values.
 func NewConfig() *Config {
-	return &Config{
-		Collation:            defaultCollation,
+	cfg := &Config{
 		Loc:                  time.UTC,
 		MaxAllowedPacket:     defaultMaxAllowedPacket,
+		Logger:               defaultLogger,
 		AllowNativePasswords: true,
 		CheckConnLiveness:    true,
 	}
+	return cfg
+}
+
+// Apply applies the given options to the Config object.
+func (c *Config) Apply(opts ...Option) error {
+	for _, opt := range opts {
+		err := opt(c)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// TimeTruncate sets the time duration to truncate time.Time values in
+// query parameters.
+func TimeTruncate(d time.Duration) Option {
+	return func(cfg *Config) error {
+		cfg.timeTruncate = d
+		return nil
+	}
+}
+
+// BeforeConnect sets the function to be invoked before a connection is established.
+func BeforeConnect(fn func(context.Context, *Config) error) Option {
+	return func(cfg *Config) error {
+		cfg.beforeConnect = fn
+		return nil
+	}
+}
+
+// EnableCompress sets the compression mode.
+func EnableCompression(yes bool) Option {
+	return func(cfg *Config) error {
+		cfg.compress = yes
+		return nil
+	}
+}
+
+// Charset sets the connection charset and collation.
+//
+// charset is the connection charset.
+// collation is the connection collation. It can be null or empty string.
+//
+// When collation is not specified, `SET NAMES <charset>` command is sent when the connection is established.
+// When collation is specified, `SET NAMES <charset> COLLATE <collation>` command is sent when the connection is established.
+func Charset(charset, collation string) Option {
+	return func(cfg *Config) error {
+		cfg.charsets = []string{charset}
+		cfg.Collation = collation
+		return nil
+	}
 }
 
 func (cfg *Config) Clone() *Config {
@@ -97,7 +171,7 @@ func (cfg *Config) Clone() *Config {
 }
 
 func (cfg *Config) normalize() error {
-	if cfg.InterpolateParams && unsafeCollations[cfg.Collation] {
+	if cfg.InterpolateParams && cfg.Collation != "" && unsafeCollations[cfg.Collation] {
 		return errInvalidDSNUnsafeCollation
 	}
 
@@ -153,6 +227,10 @@ func (cfg *Config) normalize() error {
 		}
 	}
 
+	if cfg.Logger == nil {
+		cfg.Logger = defaultLogger
+	}
+
 	return nil
 }
 
@@ -171,6 +249,8 @@ func writeDSNParam(buf *bytes.Buffer, hasParam *bool, name, value string) {
 
 // FormatDSN formats the given Config into a DSN string which can be passed to
 // the driver.
+//
+// Note: use [NewConnector] and [database/sql.OpenDB] to open a connection from a [*Config].
 func (cfg *Config) FormatDSN() string {
 	var buf bytes.Buffer
 
@@ -196,7 +276,7 @@ func (cfg *Config) FormatDSN() string {
 
 	// /dbname
 	buf.WriteByte('/')
-	buf.WriteString(cfg.DBName)
+	buf.WriteString(url.PathEscape(cfg.DBName))
 
 	// [?param1=value1&...&paramN=valueN]
 	hasParam := false
@@ -230,7 +310,11 @@ func (cfg *Config) FormatDSN() string {
 		writeDSNParam(&buf, &hasParam, "clientFoundRows", "true")
 	}
 
-	if col := cfg.Collation; col != defaultCollation && len(col) > 0 {
+	if charsets := cfg.charsets; len(charsets) > 0 {
+		writeDSNParam(&buf, &hasParam, "charset", strings.Join(charsets, ","))
+	}
+
+	if col := cfg.Collation; col != "" {
 		writeDSNParam(&buf, &hasParam, "collation", col)
 	}
 
@@ -238,6 +322,14 @@ func (cfg *Config) FormatDSN() string {
 		writeDSNParam(&buf, &hasParam, "columnsWithAlias", "true")
 	}
 
+	if cfg.ConnectionAttributes != "" {
+		writeDSNParam(&buf, &hasParam, "connectionAttributes", url.QueryEscape(cfg.ConnectionAttributes))
+	}
+
+	if cfg.compress {
+		writeDSNParam(&buf, &hasParam, "compress", "true")
+	}
+
 	if cfg.InterpolateParams {
 		writeDSNParam(&buf, &hasParam, "interpolateParams", "true")
 	}
@@ -254,6 +346,10 @@ func (cfg *Config) FormatDSN() string {
 		writeDSNParam(&buf, &hasParam, "parseTime", "true")
 	}
 
+	if cfg.timeTruncate > 0 {
+		writeDSNParam(&buf, &hasParam, "timeTruncate", cfg.timeTruncate.String())
+	}
+
 	if cfg.ReadTimeout > 0 {
 		writeDSNParam(&buf, &hasParam, "readTimeout", cfg.ReadTimeout.String())
 	}
@@ -358,7 +454,11 @@ func ParseDSN(dsn string) (cfg *Config, err error) {
 					break
 				}
 			}
-			cfg.DBName = dsn[i+1 : j]
+
+			dbname := dsn[i+1 : j]
+			if cfg.DBName, err = url.PathUnescape(dbname); err != nil {
+				return nil, fmt.Errorf("invalid dbname %q: %w", dbname, err)
+			}
 
 			break
 		}
@@ -378,13 +478,13 @@ func ParseDSN(dsn string) (cfg *Config, err error) {
 // Values must be url.QueryEscape'ed
 func parseDSNParams(cfg *Config, params string) (err error) {
 	for _, v := range strings.Split(params, "&") {
-		param := strings.SplitN(v, "=", 2)
-		if len(param) != 2 {
+		key, value, found := strings.Cut(v, "=")
+		if !found {
 			continue
 		}
 
 		// cfg params
-		switch value := param[1]; param[0] {
+		switch key {
 		// Disable INFILE allowlist / enable all files
 		case "allowAllFiles":
 			var isBool bool
@@ -441,6 +541,10 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 				return errors.New("invalid bool value: " + value)
 			}
 
+		// charset
+		case "charset":
+			cfg.charsets = strings.Split(value, ",")
+
 		// Collation
 		case "collation":
 			cfg.Collation = value
@@ -454,7 +558,11 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 
 		// Compression
 		case "compress":
-			return errors.New("compression not implemented yet")
+			var isBool bool
+			cfg.compress, isBool = readBool(value)
+			if !isBool {
+				return errors.New("invalid bool value: " + value)
+			}
 
 		// Enable client side placeholder substitution
 		case "interpolateParams":
@@ -490,6 +598,13 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 				return errors.New("invalid bool value: " + value)
 			}
 
+		// time.Time truncation
+		case "timeTruncate":
+			cfg.timeTruncate, err = time.ParseDuration(value)
+			if err != nil {
+				return fmt.Errorf("invalid timeTruncate value: %v, error: %w", value, err)
+			}
+
 		// I/O read Timeout
 		case "readTimeout":
 			cfg.ReadTimeout, err = time.ParseDuration(value)
@@ -554,13 +669,22 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 			if err != nil {
 				return
 			}
+
+		// Connection attributes
+		case "connectionAttributes":
+			connectionAttributes, err := url.QueryUnescape(value)
+			if err != nil {
+				return fmt.Errorf("invalid connectionAttributes value: %v", err)
+			}
+			cfg.ConnectionAttributes = connectionAttributes
+
 		default:
 			// lazy init
 			if cfg.Params == nil {
 				cfg.Params = make(map[string]string)
 			}
 
-			if cfg.Params[param[0]], err = url.QueryUnescape(value); err != nil {
+			if cfg.Params[key], err = url.QueryUnescape(value); err != nil {
 				return
 			}
 		}

vendor/github.com/go-sql-driver/mysql/errors.go

@@ -21,36 +21,42 @@ var (
 	ErrMalformPkt        = errors.New("malformed packet")
 	ErrNoTLS             = errors.New("TLS requested but server does not support TLS")
 	ErrCleartextPassword = errors.New("this user requires clear text authentication. If you still want to use it, please add 'allowCleartextPasswords=1' to your DSN")
-	ErrNativePassword    = errors.New("this user requires mysql native password authentication.")
+	ErrNativePassword    = errors.New("this user requires mysql native password authentication")
 	ErrOldPassword       = errors.New("this user requires old password authentication. If you still want to use it, please add 'allowOldPasswords=1' to your DSN. See also https://github.com/go-sql-driver/mysql/wiki/old_passwords")
 	ErrUnknownPlugin     = errors.New("this authentication plugin is not supported")
 	ErrOldProtocol       = errors.New("MySQL server does not support required protocol 41+")
 	ErrPktSync           = errors.New("commands out of sync. You can't run this command now")
 	ErrPktSyncMul        = errors.New("commands out of sync. Did you run multiple statements at once?")
-	ErrPktTooLarge       = errors.New("packet for query is too large. Try adjusting the 'max_allowed_packet' variable on the server")
+	ErrPktTooLarge       = errors.New("packet for query is too large. Try adjusting the `Config.MaxAllowedPacket`")
 	ErrBusyBuffer        = errors.New("busy buffer")
 
 	// errBadConnNoWrite is used for connection errors where nothing was sent to the database yet.
 	// If this happens first in a function starting a database interaction, it should be replaced by driver.ErrBadConn
-	// to trigger a resend.
+	// to trigger a resend. Use mc.markBadConn(err) to do this.
 	// See https://github.com/go-sql-driver/mysql/pull/302
 	errBadConnNoWrite = errors.New("bad connection")
 )
 
-var errLog = Logger(log.New(os.Stderr, "[mysql] ", log.Ldate|log.Ltime|log.Lshortfile))
+var defaultLogger = Logger(log.New(os.Stderr, "[mysql] ", log.Ldate|log.Ltime))
 
 // Logger is used to log critical error messages.
 type Logger interface {
-	Print(v ...interface{})
+	Print(v ...any)
 }
 
-// SetLogger is used to set the logger for critical errors.
+// NopLogger is a nop implementation of the Logger interface.
+type NopLogger struct{}
+
+// Print implements Logger interface.
+func (nl *NopLogger) Print(_ ...any) {}
+
+// SetLogger is used to set the default logger for critical errors.
 // The initial logger is os.Stderr.
 func SetLogger(logger Logger) error {
 	if logger == nil {
 		return errors.New("logger is nil")
 	}
-	errLog = logger
+	defaultLogger = logger
 	return nil
 }
 

vendor/github.com/go-sql-driver/mysql/fields.go

@@ -18,7 +18,7 @@ func (mf *mysqlField) typeDatabaseName() string {
 	case fieldTypeBit:
 		return "BIT"
 	case fieldTypeBLOB:
-		if mf.charSet != collations[binaryCollation] {
+		if mf.charSet != binaryCollationID {
 			return "TEXT"
 		}
 		return "BLOB"
@@ -37,6 +37,9 @@ func (mf *mysqlField) typeDatabaseName() string {
 	case fieldTypeGeometry:
 		return "GEOMETRY"
 	case fieldTypeInt24:
+		if mf.flags&flagUnsigned != 0 {
+			return "UNSIGNED MEDIUMINT"
+		}
 		return "MEDIUMINT"
 	case fieldTypeJSON:
 		return "JSON"
@@ -46,7 +49,7 @@ func (mf *mysqlField) typeDatabaseName() string {
 		}
 		return "INT"
 	case fieldTypeLongBLOB:
-		if mf.charSet != collations[binaryCollation] {
+		if mf.charSet != binaryCollationID {
 			return "LONGTEXT"
 		}
 		return "LONGBLOB"
@@ -56,7 +59,7 @@ func (mf *mysqlField) typeDatabaseName() string {
 		}
 		return "BIGINT"
 	case fieldTypeMediumBLOB:
-		if mf.charSet != collations[binaryCollation] {
+		if mf.charSet != binaryCollationID {
 			return "MEDIUMTEXT"
 		}
 		return "MEDIUMBLOB"
@@ -74,7 +77,12 @@ func (mf *mysqlField) typeDatabaseName() string {
 		}
 		return "SMALLINT"
 	case fieldTypeString:
-		if mf.charSet == collations[binaryCollation] {
+		if mf.flags&flagEnum != 0 {
+			return "ENUM"
+		} else if mf.flags&flagSet != 0 {
+			return "SET"
+		}
+		if mf.charSet == binaryCollationID {
 			return "BINARY"
 		}
 		return "CHAR"
@@ -88,43 +96,47 @@ func (mf *mysqlField) typeDatabaseName() string {
 		}
 		return "TINYINT"
 	case fieldTypeTinyBLOB:
-		if mf.charSet != collations[binaryCollation] {
+		if mf.charSet != binaryCollationID {
 			return "TINYTEXT"
 		}
 		return "TINYBLOB"
 	case fieldTypeVarChar:
-		if mf.charSet == collations[binaryCollation] {
+		if mf.charSet == binaryCollationID {
 			return "VARBINARY"
 		}
 		return "VARCHAR"
 	case fieldTypeVarString:
-		if mf.charSet == collations[binaryCollation] {
+		if mf.charSet == binaryCollationID {
 			return "VARBINARY"
 		}
 		return "VARCHAR"
 	case fieldTypeYear:
 		return "YEAR"
+	case fieldTypeVector:
+		return "VECTOR"
 	default:
 		return ""
 	}
 }
 
 var (
-	scanTypeFloat32   = reflect.TypeOf(float32(0))
-	scanTypeFloat64   = reflect.TypeOf(float64(0))
-	scanTypeInt8      = reflect.TypeOf(int8(0))
-	scanTypeInt16     = reflect.TypeOf(int16(0))
-	scanTypeInt32     = reflect.TypeOf(int32(0))
-	scanTypeInt64     = reflect.TypeOf(int64(0))
-	scanTypeNullFloat = reflect.TypeOf(sql.NullFloat64{})
-	scanTypeNullInt   = reflect.TypeOf(sql.NullInt64{})
-	scanTypeNullTime  = reflect.TypeOf(sql.NullTime{})
-	scanTypeUint8     = reflect.TypeOf(uint8(0))
-	scanTypeUint16    = reflect.TypeOf(uint16(0))
-	scanTypeUint32    = reflect.TypeOf(uint32(0))
-	scanTypeUint64    = reflect.TypeOf(uint64(0))
-	scanTypeRawBytes  = reflect.TypeOf(sql.RawBytes{})
-	scanTypeUnknown   = reflect.TypeOf(new(interface{}))
+	scanTypeFloat32    = reflect.TypeOf(float32(0))
+	scanTypeFloat64    = reflect.TypeOf(float64(0))
+	scanTypeInt8       = reflect.TypeOf(int8(0))
+	scanTypeInt16      = reflect.TypeOf(int16(0))
+	scanTypeInt32      = reflect.TypeOf(int32(0))
+	scanTypeInt64      = reflect.TypeOf(int64(0))
+	scanTypeNullFloat  = reflect.TypeOf(sql.NullFloat64{})
+	scanTypeNullInt    = reflect.TypeOf(sql.NullInt64{})
+	scanTypeNullTime   = reflect.TypeOf(sql.NullTime{})
+	scanTypeUint8      = reflect.TypeOf(uint8(0))
+	scanTypeUint16     = reflect.TypeOf(uint16(0))
+	scanTypeUint32     = reflect.TypeOf(uint32(0))
+	scanTypeUint64     = reflect.TypeOf(uint64(0))
+	scanTypeString     = reflect.TypeOf("")
+	scanTypeNullString = reflect.TypeOf(sql.NullString{})
+	scanTypeBytes      = reflect.TypeOf([]byte{})
+	scanTypeUnknown    = reflect.TypeOf(new(any))
 )
 
 type mysqlField struct {
@@ -187,12 +199,18 @@ func (mf *mysqlField) scanType() reflect.Type {
 		}
 		return scanTypeNullFloat
 
+	case fieldTypeBit, fieldTypeTinyBLOB, fieldTypeMediumBLOB, fieldTypeLongBLOB,
+		fieldTypeBLOB, fieldTypeVarString, fieldTypeString, fieldTypeGeometry, fieldTypeVector:
+		if mf.charSet == binaryCollationID {
+			return scanTypeBytes
+		}
+		fallthrough
 	case fieldTypeDecimal, fieldTypeNewDecimal, fieldTypeVarChar,
-		fieldTypeBit, fieldTypeEnum, fieldTypeSet, fieldTypeTinyBLOB,
-		fieldTypeMediumBLOB, fieldTypeLongBLOB, fieldTypeBLOB,
-		fieldTypeVarString, fieldTypeString, fieldTypeGeometry, fieldTypeJSON,
-		fieldTypeTime:
-		return scanTypeRawBytes
+		fieldTypeEnum, fieldTypeSet, fieldTypeJSON, fieldTypeTime:
+		if mf.flags&flagNotNULL != 0 {
+			return scanTypeString
+		}
+		return scanTypeNullString
 
 	case fieldTypeDate, fieldTypeNewDate,
 		fieldTypeTimestamp, fieldTypeDateTime:

vendor/github.com/go-sql-driver/mysql/fuzz.go

@@ -1,25 +0,0 @@
-// Go MySQL Driver - A MySQL-Driver for Go's database/sql package.
-//
-// Copyright 2020 The Go-MySQL-Driver Authors. All rights reserved.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
-
-//go:build gofuzz
-// +build gofuzz
-
-package mysql
-
-import (
-	"database/sql"
-)
-
-func Fuzz(data []byte) int {
-	db, err := sql.Open("mysql", string(data))
-	if err != nil {
-		return 0
-	}
-	db.Close()
-	return 1
-}

vendor/github.com/go-sql-driver/mysql/infile.go

@@ -17,7 +17,7 @@ import (
 )
 
 var (
-	fileRegister       map[string]bool
+	fileRegister       map[string]struct{}
 	fileRegisterLock   sync.RWMutex
 	readerRegister     map[string]func() io.Reader
 	readerRegisterLock sync.RWMutex
@@ -37,10 +37,10 @@ func RegisterLocalFile(filePath string) {
 	fileRegisterLock.Lock()
 	// lazy map init
 	if fileRegister == nil {
-		fileRegister = make(map[string]bool)
+		fileRegister = make(map[string]struct{})
 	}
 
-	fileRegister[strings.Trim(filePath, `"`)] = true
+	fileRegister[strings.Trim(filePath, `"`)] = struct{}{}
 	fileRegisterLock.Unlock()
 }
 
@@ -93,9 +93,8 @@ func deferredClose(err *error, closer io.Closer) {
 
 const defaultPacketSize = 16 * 1024 // 16KB is small enough for disk readahead and large enough for TCP
 
-func (mc *mysqlConn) handleInFileRequest(name string) (err error) {
+func (mc *okHandler) handleInFileRequest(name string) (err error) {
 	var rdr io.Reader
-	var data []byte
 	packetSize := defaultPacketSize
 	if mc.maxWriteSize < packetSize {
 		packetSize = mc.maxWriteSize
@@ -116,17 +115,17 @@ func (mc *mysqlConn) handleInFileRequest(name string) (err error) {
 					defer deferredClose(&err, cl)
 				}
 			} else {
-				err = fmt.Errorf("Reader '%s' is <nil>", name)
+				err = fmt.Errorf("reader '%s' is <nil>", name)
 			}
 		} else {
-			err = fmt.Errorf("Reader '%s' is not registered", name)
+			err = fmt.Errorf("reader '%s' is not registered", name)
 		}
 	} else { // File
 		name = strings.Trim(name, `"`)
 		fileRegisterLock.RLock()
-		fr := fileRegister[name]
+		_, exists := fileRegister[name]
 		fileRegisterLock.RUnlock()
-		if mc.cfg.AllowAllFiles || fr {
+		if mc.cfg.AllowAllFiles || exists {
 			var file *os.File
 			var fi os.FileInfo
 
@@ -147,14 +146,16 @@ func (mc *mysqlConn) handleInFileRequest(name string) (err error) {
 	}
 
 	// send content packets
+	var data []byte
+
 	// if packetSize == 0, the Reader contains no data
 	if err == nil && packetSize > 0 {
-		data := make([]byte, 4+packetSize)
+		data = make([]byte, 4+packetSize)
 		var n int
 		for err == nil {
 			n, err = rdr.Read(data[4:])
 			if n > 0 {
-				if ioErr := mc.writePacket(data[:4+n]); ioErr != nil {
+				if ioErr := mc.conn().writePacket(data[:4+n]); ioErr != nil {
 					return ioErr
 				}
 			}
@@ -168,15 +169,16 @@ func (mc *mysqlConn) handleInFileRequest(name string) (err error) {
 	if data == nil {
 		data = make([]byte, 4)
 	}
-	if ioErr := mc.writePacket(data[:4]); ioErr != nil {
+	if ioErr := mc.conn().writePacket(data[:4]); ioErr != nil {
 		return ioErr
 	}
+	mc.conn().syncSequence()
 
 	// read OK packet
 	if err == nil {
 		return mc.readResultOK()
 	}
 
-	mc.readPacket()
+	mc.conn().readPacket()
 	return err
 }

vendor/github.com/go-sql-driver/mysql/nulltime.go

@@ -38,7 +38,7 @@ type NullTime sql.NullTime
 // Scan implements the Scanner interface.
 // The value type must be time.Time or string / []byte (formatted time-string),
 // otherwise Scan fails.
-func (nt *NullTime) Scan(value interface{}) (err error) {
+func (nt *NullTime) Scan(value any) (err error) {
 	if value == nil {
 		nt.Time, nt.Valid = time.Time{}, false
 		return
@@ -59,7 +59,7 @@ func (nt *NullTime) Scan(value interface{}) (err error) {
 	}
 
 	nt.Valid = false
-	return fmt.Errorf("Can't convert %T to time.Time", value)
+	return fmt.Errorf("can't convert %T to time.Time", value)
 }
 
 // Value implements the driver Valuer interface.

vendor/github.com/go-sql-driver/mysql/packets.go

@@ -14,75 +14,108 @@ import (
 	"database/sql/driver"
 	"encoding/binary"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"math"
+	"os"
+	"strconv"
 	"time"
 )
 
-// Packets documentation:
-// http://dev.mysql.com/doc/internals/en/client-server-protocol.html
+// MySQL client/server protocol documentations.
+// https://dev.mysql.com/doc/dev/mysql-server/latest/PAGE_PROTOCOL.html
+// https://mariadb.com/kb/en/clientserver-protocol/
+
+// read n bytes from mc.buf
+func (mc *mysqlConn) readNext(n int) ([]byte, error) {
+	if mc.buf.len() < n {
+		err := mc.buf.fill(n, mc.readWithTimeout)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return mc.buf.readNext(n), nil
+}
 
 // Read packet to buffer 'data'
 func (mc *mysqlConn) readPacket() ([]byte, error) {
 	var prevData []byte
+	invalidSequence := false
+
+	readNext := mc.readNext
+	if mc.compress {
+		readNext = mc.compIO.readNext
+	}
+
 	for {
 		// read packet header
-		data, err := mc.buf.readNext(4)
+		data, err := readNext(4)
 		if err != nil {
+			mc.close()
 			if cerr := mc.canceled.Value(); cerr != nil {
 				return nil, cerr
 			}
-			errLog.Print(err)
-			mc.Close()
+			mc.log(err)
 			return nil, ErrInvalidConn
 		}
 
 		// packet length [24 bit]
-		pktLen := int(uint32(data[0]) | uint32(data[1])<<8 | uint32(data[2])<<16)
+		pktLen := getUint24(data[:3])
+		seq := data[3]
 
 		// check packet sync [8 bit]
-		if data[3] != mc.sequence {
-			if data[3] > mc.sequence {
-				return nil, ErrPktSyncMul
+		if seq != mc.sequence {
+			mc.log(fmt.Sprintf("[warn] unexpected sequence nr: expected %v, got %v", mc.sequence, seq))
+			// MySQL and MariaDB doesn't check packet nr in compressed packet.
+			if !mc.compress {
+				// For large packets, we stop reading as soon as sync error.
+				if len(prevData) > 0 {
+					mc.close()
+					return nil, ErrPktSyncMul
+				}
+				invalidSequence = true
 			}
-			return nil, ErrPktSync
 		}
-		mc.sequence++
+		mc.sequence = seq + 1
 
 		// packets with length 0 terminate a previous packet which is a
 		// multiple of (2^24)-1 bytes long
 		if pktLen == 0 {
 			// there was no previous packet
 			if prevData == nil {
-				errLog.Print(ErrMalformPkt)
-				mc.Close()
+				mc.log(ErrMalformPkt)
+				mc.close()
 				return nil, ErrInvalidConn
 			}
-
 			return prevData, nil
 		}
 
 		// read packet body [pktLen bytes]
-		data, err = mc.buf.readNext(pktLen)
+		data, err = readNext(pktLen)
 		if err != nil {
+			mc.close()
 			if cerr := mc.canceled.Value(); cerr != nil {
 				return nil, cerr
 			}
-			errLog.Print(err)
-			mc.Close()
+			mc.log(err)
 			return nil, ErrInvalidConn
 		}
 
 		// return data if this was the last packet
 		if pktLen < maxPacketSize {
 			// zero allocations for non-split packets
-			if prevData == nil {
-				return data, nil
+			if prevData != nil {
+				data = append(prevData, data...)
 			}
-
-			return append(prevData, data...), nil
+			if invalidSequence {
+				mc.close()
+				// return sync error only for regular packet.
+				// error packets may have wrong sequence number.
+				if data[0] != iERR {
+					return nil, ErrPktSync
+				}
+			}
+			return data, nil
 		}
 
 		prevData = append(prevData, data...)
@@ -92,88 +125,52 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
 // Write packet buffer 'data'
 func (mc *mysqlConn) writePacket(data []byte) error {
 	pktLen := len(data) - 4
-
 	if pktLen > mc.maxAllowedPacket {
 		return ErrPktTooLarge
 	}
 
-	// Perform a stale connection check. We only perform this check for
-	// the first query on a connection that has been checked out of the
-	// connection pool: a fresh connection from the pool is more likely
-	// to be stale, and it has not performed any previous writes that
-	// could cause data corruption, so it's safe to return ErrBadConn
-	// if the check fails.
-	if mc.reset {
-		mc.reset = false
-		conn := mc.netConn
-		if mc.rawConn != nil {
-			conn = mc.rawConn
-		}
-		var err error
-		if mc.cfg.CheckConnLiveness {
-			if mc.cfg.ReadTimeout != 0 {
-				err = conn.SetReadDeadline(time.Now().Add(mc.cfg.ReadTimeout))
-			}
-			if err == nil {
-				err = connCheck(conn)
-			}
-		}
-		if err != nil {
-			errLog.Print("closing bad idle connection: ", err)
-			mc.Close()
-			return driver.ErrBadConn
-		}
+	writeFunc := mc.writeWithTimeout
+	if mc.compress {
+		writeFunc = mc.compIO.writePackets
 	}
 
 	for {
-		var size int
-		if pktLen >= maxPacketSize {
-			data[0] = 0xff
-			data[1] = 0xff
-			data[2] = 0xff
-			size = maxPacketSize
-		} else {
-			data[0] = byte(pktLen)
-			data[1] = byte(pktLen >> 8)
-			data[2] = byte(pktLen >> 16)
-			size = pktLen
-		}
+		size := min(maxPacketSize, pktLen)
+		putUint24(data[:3], size)
 		data[3] = mc.sequence
 
 		// Write packet
-		if mc.writeTimeout > 0 {
-			if err := mc.netConn.SetWriteDeadline(time.Now().Add(mc.writeTimeout)); err != nil {
-				return err
-			}
+		if debug {
+			fmt.Fprintf(os.Stderr, "writePacket: size=%v seq=%v\n", size, mc.sequence)
 		}
 
-		n, err := mc.netConn.Write(data[:4+size])
-		if err == nil && n == 4+size {
-			mc.sequence++
-			if size != maxPacketSize {
-				return nil
-			}
-			pktLen -= size
-			data = data[size:]
-			continue
-		}
-
-		// Handle error
-		if err == nil { // n != len(data)
+		n, err := writeFunc(data[:4+size])
+		if err != nil {
 			mc.cleanup()
-			errLog.Print(ErrMalformPkt)
-		} else {
 			if cerr := mc.canceled.Value(); cerr != nil {
 				return cerr
 			}
 			if n == 0 && pktLen == len(data)-4 {
 				// only for the first loop iteration when nothing was written yet
+				mc.log(err)
 				return errBadConnNoWrite
+			} else {
+				return err
 			}
-			mc.cleanup()
-			errLog.Print(err)
 		}
-		return ErrInvalidConn
+		if n != 4+size {
+			// io.Writer(b) must return a non-nil error if it cannot write len(b) bytes.
+			// The io.ErrShortWrite error is used to indicate that this rule has not been followed.
+			mc.cleanup()
+			return io.ErrShortWrite
+		}
+
+		mc.sequence++
+		if size != maxPacketSize {
+			return nil
+		}
+		pktLen -= size
+		data = data[size:]
 	}
 }
 
@@ -186,11 +183,6 @@ func (mc *mysqlConn) writePacket(data []byte) error {
 func (mc *mysqlConn) readHandshakePacket() (data []byte, plugin string, err error) {
 	data, err = mc.readPacket()
 	if err != nil {
-		// for init we can rewrite this to ErrBadConn for sql.Driver to retry, since
-		// in connection initialization we don't risk retrying non-idempotent actions.
-		if err == ErrInvalidConn {
-			return nil, "", driver.ErrBadConn
-		}
 		return
 	}
 
@@ -234,12 +226,15 @@ func (mc *mysqlConn) readHandshakePacket() (data []byte, plugin string, err erro
 	if len(data) > pos {
 		// character set [1 byte]
 		// status flags [2 bytes]
+		pos += 3
 		// capability flags (upper 2 bytes) [2 bytes]
+		mc.flags |= clientFlag(binary.LittleEndian.Uint16(data[pos:pos+2])) << 16
+		pos += 2
 		// length of auth-plugin-data [1 byte]
 		// reserved (all [00]) [10 bytes]
-		pos += 1 + 2 + 2 + 1 + 10
+		pos += 11
 
-		// second part of the password cipher [mininum 13 bytes],
+		// second part of the password cipher [minimum 13 bytes],
 		// where len=MAX(13, length of auth-plugin-data - 8)
 		//
 		// The web documentation is ambiguous about the length. However,
@@ -285,12 +280,17 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string
 		clientLocalFiles |
 		clientPluginAuth |
 		clientMultiResults |
+		mc.flags&clientConnectAttrs |
 		mc.flags&clientLongFlag
 
+	sendConnectAttrs := mc.flags&clientConnectAttrs != 0
+
 	if mc.cfg.ClientFoundRows {
 		clientFlags |= clientFoundRows
 	}
-
+	if mc.cfg.compress && mc.flags&clientCompress == clientCompress {
+		clientFlags |= clientCompress
+	}
 	// To enable TLS / SSL
 	if mc.cfg.TLS != nil {
 		clientFlags |= clientSSL
@@ -318,34 +318,38 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string
 		pktLen += n + 1
 	}
 
+	// encode length of the connection attributes
+	var connAttrsLEI []byte
+	if sendConnectAttrs {
+		var connAttrsLEIBuf [9]byte
+		connAttrsLen := len(mc.connector.encodedAttributes)
+		connAttrsLEI = appendLengthEncodedInteger(connAttrsLEIBuf[:0], uint64(connAttrsLen))
+		pktLen += len(connAttrsLEI) + len(mc.connector.encodedAttributes)
+	}
+
 	// Calculate packet length and get buffer with that size
-	data, err := mc.buf.takeSmallBuffer(pktLen + 4)
+	data, err := mc.buf.takeBuffer(pktLen + 4)
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		mc.cleanup()
+		return err
 	}
 
 	// ClientFlags [32 bit]
-	data[4] = byte(clientFlags)
-	data[5] = byte(clientFlags >> 8)
-	data[6] = byte(clientFlags >> 16)
-	data[7] = byte(clientFlags >> 24)
+	binary.LittleEndian.PutUint32(data[4:], uint32(clientFlags))
 
 	// MaxPacketSize [32 bit] (none)
-	data[8] = 0x00
-	data[9] = 0x00
-	data[10] = 0x00
-	data[11] = 0x00
+	binary.LittleEndian.PutUint32(data[8:], 0)
 
-	// Charset [1 byte]
-	var found bool
-	data[12], found = collations[mc.cfg.Collation]
-	if !found {
-		// Note possibility for false negatives:
-		// could be triggered  although the collation is valid if the
-		// collations map does not contain entries the server supports.
-		return errors.New("unknown collation")
+	// Collation ID [1 byte]
+	data[12] = defaultCollationID
+	if cname := mc.cfg.Collation; cname != "" {
+		colID, ok := collations[cname]
+		if ok {
+			data[12] = colID
+		} else if len(mc.cfg.charsets) > 0 {
+			// When cfg.charset is set, the collation is set by `SET NAMES <charset> COLLATE <collation>`.
+			return fmt.Errorf("unknown collation: %q", cname)
+		}
 	}
 
 	// Filler [23 bytes] (all 0x00)
@@ -365,11 +369,12 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string
 		// Switch to TLS
 		tlsConn := tls.Client(mc.netConn, mc.cfg.TLS)
 		if err := tlsConn.Handshake(); err != nil {
+			if cerr := mc.canceled.Value(); cerr != nil {
+				return cerr
+			}
 			return err
 		}
-		mc.rawConn = mc.netConn
 		mc.netConn = tlsConn
-		mc.buf.nc = tlsConn
 	}
 
 	// User [null terminated string]
@@ -394,6 +399,12 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string
 	data[pos] = 0x00
 	pos++
 
+	// Connection Attributes
+	if sendConnectAttrs {
+		pos += copy(data[pos:], connAttrsLEI)
+		pos += copy(data[pos:], []byte(mc.connector.encodedAttributes))
+	}
+
 	// Send Auth packet
 	return mc.writePacket(data[:pos])
 }
@@ -401,11 +412,10 @@ func (mc *mysqlConn) writeHandshakeResponsePacket(authResp []byte, plugin string
 // http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchResponse
 func (mc *mysqlConn) writeAuthSwitchPacket(authData []byte) error {
 	pktLen := 4 + len(authData)
-	data, err := mc.buf.takeSmallBuffer(pktLen)
+	data, err := mc.buf.takeBuffer(pktLen)
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		mc.cleanup()
+		return err
 	}
 
 	// Add the auth data [EOF]
@@ -419,32 +429,30 @@ func (mc *mysqlConn) writeAuthSwitchPacket(authData []byte) error {
 
 func (mc *mysqlConn) writeCommandPacket(command byte) error {
 	// Reset Packet Sequence
-	mc.sequence = 0
+	mc.resetSequence()
 
 	data, err := mc.buf.takeSmallBuffer(4 + 1)
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		return err
 	}
 
 	// Add command byte
 	data[4] = command
 
 	// Send CMD packet
-	return mc.writePacket(data)
+	err = mc.writePacket(data)
+	mc.syncSequence()
+	return err
 }
 
 func (mc *mysqlConn) writeCommandPacketStr(command byte, arg string) error {
 	// Reset Packet Sequence
-	mc.sequence = 0
+	mc.resetSequence()
 
 	pktLen := 1 + len(arg)
 	data, err := mc.buf.takeBuffer(pktLen + 4)
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		return err
 	}
 
 	// Add command byte
@@ -454,31 +462,30 @@ func (mc *mysqlConn) writeCommandPacketStr(command byte, arg string) error {
 	copy(data[5:], arg)
 
 	// Send CMD packet
-	return mc.writePacket(data)
+	err = mc.writePacket(data)
+	mc.syncSequence()
+	return err
 }
 
 func (mc *mysqlConn) writeCommandPacketUint32(command byte, arg uint32) error {
 	// Reset Packet Sequence
-	mc.sequence = 0
+	mc.resetSequence()
 
 	data, err := mc.buf.takeSmallBuffer(4 + 1 + 4)
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		return err
 	}
 
 	// Add command byte
 	data[4] = command
 
 	// Add arg [32 bit]
-	data[5] = byte(arg)
-	data[6] = byte(arg >> 8)
-	data[7] = byte(arg >> 16)
-	data[8] = byte(arg >> 24)
+	binary.LittleEndian.PutUint32(data[5:], arg)
 
 	// Send CMD packet
-	return mc.writePacket(data)
+	err = mc.writePacket(data)
+	mc.syncSequence()
+	return err
 }
 
 /******************************************************************************
@@ -495,7 +502,9 @@ func (mc *mysqlConn) readAuthResult() ([]byte, string, error) {
 	switch data[0] {
 
 	case iOK:
-		return nil, "", mc.handleOkPacket(data)
+		// resultUnchanged, since auth happens before any queries or
+		// commands have been executed.
+		return nil, "", mc.resultUnchanged().handleOkPacket(data)
 
 	case iAuthMoreData:
 		return data[1:], "", err
@@ -511,6 +520,9 @@ func (mc *mysqlConn) readAuthResult() ([]byte, string, error) {
 		}
 		plugin := string(data[1:pluginEndIndex])
 		authData := data[pluginEndIndex+1:]
+		if len(authData) > 0 && authData[len(authData)-1] == 0 {
+			authData = authData[:len(authData)-1]
+		}
 		return authData, plugin, nil
 
 	default: // Error otherwise
@@ -518,9 +530,9 @@ func (mc *mysqlConn) readAuthResult() ([]byte, string, error) {
 	}
 }
 
-// Returns error if Packet is not an 'Result OK'-Packet
-func (mc *mysqlConn) readResultOK() error {
-	data, err := mc.readPacket()
+// Returns error if Packet is not a 'Result OK'-Packet
+func (mc *okHandler) readResultOK() error {
+	data, err := mc.conn().readPacket()
 	if err != nil {
 		return err
 	}
@@ -528,35 +540,37 @@ func (mc *mysqlConn) readResultOK() error {
 	if data[0] == iOK {
 		return mc.handleOkPacket(data)
 	}
-	return mc.handleErrorPacket(data)
+	return mc.conn().handleErrorPacket(data)
 }
 
 // Result Set Header Packet
-// http://dev.mysql.com/doc/internals/en/com-query-response.html#packet-ProtocolText::Resultset
-func (mc *mysqlConn) readResultSetHeaderPacket() (int, error) {
-	data, err := mc.readPacket()
-	if err == nil {
-		switch data[0] {
+// https://dev.mysql.com/doc/dev/mysql-server/latest/page_protocol_com_query_response.html
+func (mc *okHandler) readResultSetHeaderPacket() (int, error) {
+	// handleOkPacket replaces both values; other cases leave the values unchanged.
+	mc.result.affectedRows = append(mc.result.affectedRows, 0)
+	mc.result.insertIds = append(mc.result.insertIds, 0)
 
-		case iOK:
-			return 0, mc.handleOkPacket(data)
-
-		case iERR:
-			return 0, mc.handleErrorPacket(data)
-
-		case iLocalInFile:
-			return 0, mc.handleInFileRequest(string(data[1:]))
-		}
-
-		// column count
-		num, _, n := readLengthEncodedInteger(data)
-		if n-len(data) == 0 {
-			return int(num), nil
-		}
-
-		return 0, ErrMalformPkt
+	data, err := mc.conn().readPacket()
+	if err != nil {
+		return 0, err
 	}
-	return 0, err
+
+	switch data[0] {
+	case iOK:
+		return 0, mc.handleOkPacket(data)
+
+	case iERR:
+		return 0, mc.conn().handleErrorPacket(data)
+
+	case iLocalInFile:
+		return 0, mc.handleInFileRequest(string(data[1:]))
+	}
+
+	// column count
+	// https://dev.mysql.com/doc/dev/mysql-server/latest/page_protocol_com_query_response_text_resultset.html
+	num, _, _ := readLengthEncodedInteger(data)
+	// ignore remaining data in the packet. see #1478.
+	return int(num), nil
 }
 
 // Error Packet
@@ -573,7 +587,8 @@ func (mc *mysqlConn) handleErrorPacket(data []byte) error {
 
 	// 1792: ER_CANT_EXECUTE_IN_READ_ONLY_TRANSACTION
 	// 1290: ER_OPTION_PREVENTS_STATEMENT (returned by Aurora during failover)
-	if (errno == 1792 || errno == 1290) && mc.cfg.RejectReadOnly {
+	// 1836: ER_READ_ONLY_MODE
+	if (errno == 1792 || errno == 1290 || errno == 1836) && mc.cfg.RejectReadOnly {
 		// Oops; we are connected to a read-only connection, and won't be able
 		// to issue any write statements. Since RejectReadOnly is configured,
 		// we throw away this connection hoping this one would have write
@@ -607,18 +622,61 @@ func readStatus(b []byte) statusFlag {
 	return statusFlag(b[0]) | statusFlag(b[1])<<8
 }
 
+// Returns an instance of okHandler for codepaths where mysqlConn.result doesn't
+// need to be cleared first (e.g. during authentication, or while additional
+// resultsets are being fetched.)
+func (mc *mysqlConn) resultUnchanged() *okHandler {
+	return (*okHandler)(mc)
+}
+
+// okHandler represents the state of the connection when mysqlConn.result has
+// been prepared for processing of OK packets.
+//
+// To correctly populate mysqlConn.result (updated by handleOkPacket()), all
+// callpaths must either:
+//
+// 1. first clear it using clearResult(), or
+// 2. confirm that they don't need to (by calling resultUnchanged()).
+//
+// Both return an instance of type *okHandler.
+type okHandler mysqlConn
+
+// Exposes the underlying type's methods.
+func (mc *okHandler) conn() *mysqlConn {
+	return (*mysqlConn)(mc)
+}
+
+// clearResult clears the connection's stored affectedRows and insertIds
+// fields.
+//
+// It returns a handler that can process OK responses.
+func (mc *mysqlConn) clearResult() *okHandler {
+	mc.result = mysqlResult{}
+	return (*okHandler)(mc)
+}
+
 // Ok Packet
 // http://dev.mysql.com/doc/internals/en/generic-response-packets.html#packet-OK_Packet
-func (mc *mysqlConn) handleOkPacket(data []byte) error {
+func (mc *okHandler) handleOkPacket(data []byte) error {
 	var n, m int
+	var affectedRows, insertId uint64
 
 	// 0x00 [1 byte]
 
 	// Affected rows [Length Coded Binary]
-	mc.affectedRows, _, n = readLengthEncodedInteger(data[1:])
+	affectedRows, _, n = readLengthEncodedInteger(data[1:])
 
 	// Insert id [Length Coded Binary]
-	mc.insertId, _, m = readLengthEncodedInteger(data[1+n:])
+	insertId, _, m = readLengthEncodedInteger(data[1+n:])
+
+	// Update for the current statement result (only used by
+	// readResultSetHeaderPacket).
+	if len(mc.result.affectedRows) > 0 {
+		mc.result.affectedRows[len(mc.result.affectedRows)-1] = int64(affectedRows)
+	}
+	if len(mc.result.insertIds) > 0 {
+		mc.result.insertIds[len(mc.result.insertIds)-1] = int64(insertId)
+	}
 
 	// server_status [2 bytes]
 	mc.status = readStatus(data[1+n+m : 1+n+m+2])
@@ -769,7 +827,8 @@ func (rows *textRows) readRow(dest []driver.Value) error {
 
 	for i := range dest {
 		// Read bytes and convert to string
-		dest[i], isNull, n, err = readLengthEncodedString(data[pos:])
+		var buf []byte
+		buf, isNull, n, err = readLengthEncodedString(data[pos:])
 		pos += n
 
 		if err != nil {
@@ -781,19 +840,40 @@ func (rows *textRows) readRow(dest []driver.Value) error {
 			continue
 		}
 
-		if !mc.parseTime {
-			continue
-		}
-
-		// Parse time field
 		switch rows.rs.columns[i].fieldType {
 		case fieldTypeTimestamp,
 			fieldTypeDateTime,
 			fieldTypeDate,
 			fieldTypeNewDate:
-			if dest[i], err = parseDateTime(dest[i].([]byte), mc.cfg.Loc); err != nil {
-				return err
+			if mc.parseTime {
+				dest[i], err = parseDateTime(buf, mc.cfg.Loc)
+			} else {
+				dest[i] = buf
 			}
+
+		case fieldTypeTiny, fieldTypeShort, fieldTypeInt24, fieldTypeYear, fieldTypeLong:
+			dest[i], err = strconv.ParseInt(string(buf), 10, 64)
+
+		case fieldTypeLongLong:
+			if rows.rs.columns[i].flags&flagUnsigned != 0 {
+				dest[i], err = strconv.ParseUint(string(buf), 10, 64)
+			} else {
+				dest[i], err = strconv.ParseInt(string(buf), 10, 64)
+			}
+
+		case fieldTypeFloat:
+			var d float64
+			d, err = strconv.ParseFloat(string(buf), 32)
+			dest[i] = float32(d)
+
+		case fieldTypeDouble:
+			dest[i], err = strconv.ParseFloat(string(buf), 64)
+
+		default:
+			dest[i] = buf
+		}
+		if err != nil {
+			return err
 		}
 	}
 
@@ -875,32 +955,26 @@ func (stmt *mysqlStmt) writeCommandLongData(paramID int, arg []byte) error {
 			pktLen = dataOffset + argLen
 		}
 
-		stmt.mc.sequence = 0
 		// Add command byte [1 byte]
 		data[4] = comStmtSendLongData
 
 		// Add stmtID [32 bit]
-		data[5] = byte(stmt.id)
-		data[6] = byte(stmt.id >> 8)
-		data[7] = byte(stmt.id >> 16)
-		data[8] = byte(stmt.id >> 24)
+		binary.LittleEndian.PutUint32(data[5:], stmt.id)
 
 		// Add paramID [16 bit]
-		data[9] = byte(paramID)
-		data[10] = byte(paramID >> 8)
+		binary.LittleEndian.PutUint16(data[9:], uint16(paramID))
 
 		// Send CMD packet
 		err := stmt.mc.writePacket(data[:4+pktLen])
+		// Every COM_LONG_DATA packet reset Packet Sequence
+		stmt.mc.resetSequence()
 		if err == nil {
 			data = data[pktLen-dataOffset:]
 			continue
 		}
 		return err
-
 	}
 
-	// Reset Packet Sequence
-	stmt.mc.sequence = 0
 	return nil
 }
 
@@ -925,7 +999,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 	}
 
 	// Reset packet-sequence
-	mc.sequence = 0
+	mc.resetSequence()
 
 	var data []byte
 	var err error
@@ -937,28 +1011,20 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 		// In this case the len(data) == cap(data) which is used to optimise the flow below.
 	}
 	if err != nil {
-		// cannot take the buffer. Something must be wrong with the connection
-		errLog.Print(err)
-		return errBadConnNoWrite
+		return err
 	}
 
 	// command [1 byte]
 	data[4] = comStmtExecute
 
 	// statement_id [4 bytes]
-	data[5] = byte(stmt.id)
-	data[6] = byte(stmt.id >> 8)
-	data[7] = byte(stmt.id >> 16)
-	data[8] = byte(stmt.id >> 24)
+	binary.LittleEndian.PutUint32(data[5:], stmt.id)
 
 	// flags (0: CURSOR_TYPE_NO_CURSOR) [1 byte]
 	data[9] = 0x00
 
 	// iteration_count (uint32(1)) [4 bytes]
-	data[10] = 0x01
-	data[11] = 0x00
-	data[12] = 0x00
-	data[13] = 0x00
+	binary.LittleEndian.PutUint32(data[10:], 1)
 
 	if len(args) > 0 {
 		pos := minPktLen
@@ -1012,50 +1078,17 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 			case int64:
 				paramTypes[i+i] = byte(fieldTypeLongLong)
 				paramTypes[i+i+1] = 0x00
-
-				if cap(paramValues)-len(paramValues)-8 >= 0 {
-					paramValues = paramValues[:len(paramValues)+8]
-					binary.LittleEndian.PutUint64(
-						paramValues[len(paramValues)-8:],
-						uint64(v),
-					)
-				} else {
-					paramValues = append(paramValues,
-						uint64ToBytes(uint64(v))...,
-					)
-				}
+				paramValues = binary.LittleEndian.AppendUint64(paramValues, uint64(v))
 
 			case uint64:
 				paramTypes[i+i] = byte(fieldTypeLongLong)
 				paramTypes[i+i+1] = 0x80 // type is unsigned
-
-				if cap(paramValues)-len(paramValues)-8 >= 0 {
-					paramValues = paramValues[:len(paramValues)+8]
-					binary.LittleEndian.PutUint64(
-						paramValues[len(paramValues)-8:],
-						uint64(v),
-					)
-				} else {
-					paramValues = append(paramValues,
-						uint64ToBytes(uint64(v))...,
-					)
-				}
+				paramValues = binary.LittleEndian.AppendUint64(paramValues, uint64(v))
 
 			case float64:
 				paramTypes[i+i] = byte(fieldTypeDouble)
 				paramTypes[i+i+1] = 0x00
-
-				if cap(paramValues)-len(paramValues)-8 >= 0 {
-					paramValues = paramValues[:len(paramValues)+8]
-					binary.LittleEndian.PutUint64(
-						paramValues[len(paramValues)-8:],
-						math.Float64bits(v),
-					)
-				} else {
-					paramValues = append(paramValues,
-						uint64ToBytes(math.Float64bits(v))...,
-					)
-				}
+				paramValues = binary.LittleEndian.AppendUint64(paramValues, math.Float64bits(v))
 
 			case bool:
 				paramTypes[i+i] = byte(fieldTypeTiny)
@@ -1116,7 +1149,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 				if v.IsZero() {
 					b = append(b, "0000-00-00"...)
 				} else {
-					b, err = appendDateTime(b, v.In(mc.cfg.Loc))
+					b, err = appendDateTime(b, v.In(mc.cfg.Loc), mc.cfg.timeTruncate)
 					if err != nil {
 						return err
 					}
@@ -1136,20 +1169,21 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 		// In that case we must build the data packet with the new values buffer
 		if valuesCap != cap(paramValues) {
 			data = append(data[:pos], paramValues...)
-			if err = mc.buf.store(data); err != nil {
-				errLog.Print(err)
-				return errBadConnNoWrite
-			}
+			mc.buf.store(data) // allow this buffer to be reused
 		}
 
 		pos += len(paramValues)
 		data = data[:pos]
 	}
 
-	return mc.writePacket(data)
+	err = mc.writePacket(data)
+	mc.syncSequence()
+	return err
 }
 
-func (mc *mysqlConn) discardResults() error {
+// For each remaining resultset in the stream, discards its rows and updates
+// mc.affectedRows and mc.insertIds.
+func (mc *okHandler) discardResults() error {
 	for mc.status&statusMoreResultsExists != 0 {
 		resLen, err := mc.readResultSetHeaderPacket()
 		if err != nil {
@@ -1157,11 +1191,11 @@ func (mc *mysqlConn) discardResults() error {
 		}
 		if resLen > 0 {
 			// columns
-			if err := mc.readUntilEOF(); err != nil {
+			if err := mc.conn().readUntilEOF(); err != nil {
 				return err
 			}
 			// rows
-			if err := mc.readUntilEOF(); err != nil {
+			if err := mc.conn().readUntilEOF(); err != nil {
 				return err
 			}
 		}
@@ -1268,7 +1302,8 @@ func (rows *binaryRows) readRow(dest []driver.Value) error {
 		case fieldTypeDecimal, fieldTypeNewDecimal, fieldTypeVarChar,
 			fieldTypeBit, fieldTypeEnum, fieldTypeSet, fieldTypeTinyBLOB,
 			fieldTypeMediumBLOB, fieldTypeLongBLOB, fieldTypeBLOB,
-			fieldTypeVarString, fieldTypeString, fieldTypeGeometry, fieldTypeJSON:
+			fieldTypeVarString, fieldTypeString, fieldTypeGeometry, fieldTypeJSON,
+			fieldTypeVector:
 			var isNull bool
 			var n int
 			dest[i], isNull, n, err = readLengthEncodedString(data[pos:])

vendor/github.com/go-sql-driver/mysql/result.go

@@ -8,15 +8,43 @@
 
 package mysql
 
+import "database/sql/driver"
+
+// Result exposes data not available through *connection.Result.
+//
+// This is accessible by executing statements using sql.Conn.Raw() and
+// downcasting the returned result:
+//
+//	res, err := rawConn.Exec(...)
+//	res.(mysql.Result).AllRowsAffected()
+type Result interface {
+	driver.Result
+	// AllRowsAffected returns a slice containing the affected rows for each
+	// executed statement.
+	AllRowsAffected() []int64
+	// AllLastInsertIds returns a slice containing the last inserted ID for each
+	// executed statement.
+	AllLastInsertIds() []int64
+}
+
 type mysqlResult struct {
-	affectedRows int64
-	insertId     int64
+	// One entry in both slices is created for every executed statement result.
+	affectedRows []int64
+	insertIds    []int64
 }
 
 func (res *mysqlResult) LastInsertId() (int64, error) {
-	return res.insertId, nil
+	return res.insertIds[len(res.insertIds)-1], nil
 }
 
 func (res *mysqlResult) RowsAffected() (int64, error) {
-	return res.affectedRows, nil
+	return res.affectedRows[len(res.affectedRows)-1], nil
+}
+
+func (res *mysqlResult) AllLastInsertIds() []int64 {
+	return append([]int64{}, res.insertIds...) // defensive copy
+}
+
+func (res *mysqlResult) AllRowsAffected() []int64 {
+	return append([]int64{}, res.affectedRows...) // defensive copy
 }

vendor/github.com/go-sql-driver/mysql/rows.go

@@ -111,19 +111,13 @@ func (rows *mysqlRows) Close() (err error) {
 		return err
 	}
 
-	// flip the buffer for this connection if we need to drain it.
-	// note that for a successful query (i.e. one where rows.next()
-	// has been called until it returns false), `rows.mc` will be nil
-	// by the time the user calls `(*Rows).Close`, so we won't reach this
-	// see: https://github.com/golang/go/commit/651ddbdb5056ded455f47f9c494c67b389622a47
-	mc.buf.flip()
-
 	// Remove unread packets from stream
 	if !rows.rs.done {
 		err = mc.readUntilEOF()
 	}
 	if err == nil {
-		if err = mc.discardResults(); err != nil {
+		handleOk := mc.clearResult()
+		if err = handleOk.discardResults(); err != nil {
 			return err
 		}
 	}
@@ -160,7 +154,15 @@ func (rows *mysqlRows) nextResultSet() (int, error) {
 		return 0, io.EOF
 	}
 	rows.rs = resultSet{}
-	return rows.mc.readResultSetHeaderPacket()
+	// rows.mc.affectedRows and rows.mc.insertIds accumulate on each call to
+	// nextResultSet.
+	resLen, err := rows.mc.resultUnchanged().readResultSetHeaderPacket()
+	if err != nil {
+		// Clean up about multi-results flag
+		rows.rs.done = true
+		rows.mc.status = rows.mc.status & (^statusMoreResultsExists)
+	}
+	return resLen, err
 }
 
 func (rows *mysqlRows) nextNotEmptyResultSet() (int, error) {

vendor/github.com/go-sql-driver/mysql/statement.go

@@ -24,11 +24,12 @@ type mysqlStmt struct {
 
 func (stmt *mysqlStmt) Close() error {
 	if stmt.mc == nil || stmt.mc.closed.Load() {
-		// driver.Stmt.Close can be called more than once, thus this function
-		// has to be idempotent.
-		// See also Issue #450 and golang/go#16019.
-		//errLog.Print(ErrInvalidConn)
-		return driver.ErrBadConn
+		// driver.Stmt.Close could be called more than once, thus this function
+		// had to be idempotent. See also Issue #450 and golang/go#16019.
+		// This bug has been fixed in Go 1.8.
+		// https://github.com/golang/go/commit/90b8a0ca2d0b565c7c7199ffcf77b15ea6b6db3a
+		// But we keep this function idempotent because it is safer.
+		return nil
 	}
 
 	err := stmt.mc.writeCommandPacketUint32(comStmtClose, stmt.id)
@@ -51,7 +52,6 @@ func (stmt *mysqlStmt) CheckNamedValue(nv *driver.NamedValue) (err error) {
 
 func (stmt *mysqlStmt) Exec(args []driver.Value) (driver.Result, error) {
 	if stmt.mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	// Send command
@@ -61,12 +61,10 @@ func (stmt *mysqlStmt) Exec(args []driver.Value) (driver.Result, error) {
 	}
 
 	mc := stmt.mc
-
-	mc.affectedRows = 0
-	mc.insertId = 0
+	handleOk := stmt.mc.clearResult()
 
 	// Read Result
-	resLen, err := mc.readResultSetHeaderPacket()
+	resLen, err := handleOk.readResultSetHeaderPacket()
 	if err != nil {
 		return nil, err
 	}
@@ -83,14 +81,12 @@ func (stmt *mysqlStmt) Exec(args []driver.Value) (driver.Result, error) {
 		}
 	}
 
-	if err := mc.discardResults(); err != nil {
+	if err := handleOk.discardResults(); err != nil {
 		return nil, err
 	}
 
-	return &mysqlResult{
-		affectedRows: int64(mc.affectedRows),
-		insertId:     int64(mc.insertId),
-	}, nil
+	copied := mc.result
+	return &copied, nil
 }
 
 func (stmt *mysqlStmt) Query(args []driver.Value) (driver.Rows, error) {
@@ -99,7 +95,6 @@ func (stmt *mysqlStmt) Query(args []driver.Value) (driver.Rows, error) {
 
 func (stmt *mysqlStmt) query(args []driver.Value) (*binaryRows, error) {
 	if stmt.mc.closed.Load() {
-		errLog.Print(ErrInvalidConn)
 		return nil, driver.ErrBadConn
 	}
 	// Send command
@@ -111,7 +106,8 @@ func (stmt *mysqlStmt) query(args []driver.Value) (*binaryRows, error) {
 	mc := stmt.mc
 
 	// Read Result
-	resLen, err := mc.readResultSetHeaderPacket()
+	handleOk := stmt.mc.clearResult()
+	resLen, err := handleOk.readResultSetHeaderPacket()
 	if err != nil {
 		return nil, err
 	}
@@ -144,7 +140,7 @@ type converter struct{}
 // implementation does not.  This function should be kept in sync with
 // database/sql/driver defaultConverter.ConvertValue() except for that
 // deliberate difference.
-func (c converter) ConvertValue(v interface{}) (driver.Value, error) {
+func (c converter) ConvertValue(v any) (driver.Value, error) {
 	if driver.IsValue(v) {
 		return v, nil
 	}

vendor/github.com/go-sql-driver/mysql/transaction.go

@@ -13,18 +13,32 @@ type mysqlTx struct {
 }
 
 func (tx *mysqlTx) Commit() (err error) {
-	if tx.mc == nil || tx.mc.closed.Load() {
+	if tx.mc == nil {
 		return ErrInvalidConn
 	}
+	if tx.mc.closed.Load() {
+		err = tx.mc.error()
+		if err == nil {
+			err = ErrInvalidConn
+		}
+		return
+	}
 	err = tx.mc.exec("COMMIT")
 	tx.mc = nil
 	return
 }
 
 func (tx *mysqlTx) Rollback() (err error) {
-	if tx.mc == nil || tx.mc.closed.Load() {
+	if tx.mc == nil {
 		return ErrInvalidConn
 	}
+	if tx.mc.closed.Load() {
+		err = tx.mc.error()
+		if err == nil {
+			err = ErrInvalidConn
+		}
+		return
+	}
 	err = tx.mc.exec("ROLLBACK")
 	tx.mc = nil
 	return

vendor/github.com/go-sql-driver/mysql/utils.go

@@ -36,7 +36,7 @@ var (
 // registering it.
 //
 //	rootCertPool := x509.NewCertPool()
-//	pem, err := ioutil.ReadFile("/path/ca-cert.pem")
+//	pem, err := os.ReadFile("/path/ca-cert.pem")
 //	if err != nil {
 //	    log.Fatal(err)
 //	}
@@ -265,7 +265,11 @@ func parseBinaryDateTime(num uint64, data []byte, loc *time.Location) (driver.Va
 	return nil, fmt.Errorf("invalid DATETIME packet length %d", num)
 }
 
-func appendDateTime(buf []byte, t time.Time) ([]byte, error) {
+func appendDateTime(buf []byte, t time.Time, timeTruncate time.Duration) ([]byte, error) {
+	if timeTruncate > 0 {
+		t = t.Truncate(timeTruncate)
+	}
+
 	year, month, day := t.Date()
 	hour, min, sec := t.Clock()
 	nsec := t.Nanosecond()
@@ -486,17 +490,16 @@ func formatBinaryTime(src []byte, length uint8) (driver.Value, error) {
 *                       Convert from and to bytes                             *
 ******************************************************************************/
 
-func uint64ToBytes(n uint64) []byte {
-	return []byte{
-		byte(n),
-		byte(n >> 8),
-		byte(n >> 16),
-		byte(n >> 24),
-		byte(n >> 32),
-		byte(n >> 40),
-		byte(n >> 48),
-		byte(n >> 56),
-	}
+// 24bit integer: used for packet headers.
+
+func putUint24(data []byte, n int) {
+	data[2] = byte(n >> 16)
+	data[1] = byte(n >> 8)
+	data[0] = byte(n)
+}
+
+func getUint24(data []byte) int {
+	return int(data[2])<<16 | int(data[1])<<8 | int(data[0])
 }
 
 func uint64ToString(n uint64) []byte {
@@ -521,16 +524,6 @@ func uint64ToString(n uint64) []byte {
 	return a[i:]
 }
 
-// treats string value as unsigned integer representation
-func stringToInt(b []byte) int {
-	val := 0
-	for i := range b {
-		val *= 10
-		val += int(b[i] - 0x30)
-	}
-	return val
-}
-
 // returns the string read as a bytes slice, whether the value is NULL,
 // the number of bytes read and an error, in case the string is longer than
 // the input slice
@@ -582,18 +575,15 @@ func readLengthEncodedInteger(b []byte) (uint64, bool, int) {
 
 	// 252: value of following 2
 	case 0xfc:
-		return uint64(b[1]) | uint64(b[2])<<8, false, 3
+		return uint64(binary.LittleEndian.Uint16(b[1:])), false, 3
 
 	// 253: value of following 3
 	case 0xfd:
-		return uint64(b[1]) | uint64(b[2])<<8 | uint64(b[3])<<16, false, 4
+		return uint64(getUint24(b[1:])), false, 4
 
 	// 254: value of following 8
 	case 0xfe:
-		return uint64(b[1]) | uint64(b[2])<<8 | uint64(b[3])<<16 |
-				uint64(b[4])<<24 | uint64(b[5])<<32 | uint64(b[6])<<40 |
-				uint64(b[7])<<48 | uint64(b[8])<<56,
-			false, 9
+		return uint64(binary.LittleEndian.Uint64(b[1:])), false, 9
 	}
 
 	// 0-250: value of first byte
@@ -607,13 +597,19 @@ func appendLengthEncodedInteger(b []byte, n uint64) []byte {
 		return append(b, byte(n))
 
 	case n <= 0xffff:
-		return append(b, 0xfc, byte(n), byte(n>>8))
+		b = append(b, 0xfc)
+		return binary.LittleEndian.AppendUint16(b, uint16(n))
 
 	case n <= 0xffffff:
 		return append(b, 0xfd, byte(n), byte(n>>8), byte(n>>16))
 	}
-	return append(b, 0xfe, byte(n), byte(n>>8), byte(n>>16), byte(n>>24),
-		byte(n>>32), byte(n>>40), byte(n>>48), byte(n>>56))
+	b = append(b, 0xfe)
+	return binary.LittleEndian.AppendUint64(b, n)
+}
+
+func appendLengthEncodedString(b []byte, s string) []byte {
+	b = appendLengthEncodedInteger(b, uint64(len(s)))
+	return append(b, s...)
 }
 
 // reserveBuffer checks cap(buf) and expand buffer to len(buf) + appendSize.

vendor/github.com/golang-jwt/jwt/v5/MIGRATION_GUIDE.md

@@ -155,7 +155,7 @@ stored in base64 encoded form, which was redundant with the information in the
 type Token struct {
 	Raw       string                 // Raw contains the raw token
 	Method    SigningMethod          // Method is the signing method used or to be used
-	Header    map[string]interface{} // Header is the first segment of the token in decoded form
+	Header    map[string]any         // Header is the first segment of the token in decoded form
 	Claims    Claims                 // Claims is the second segment of the token in decoded form
 	Signature []byte                 // Signature is the third segment of the token in decoded form
 	Valid     bool                   // Valid specifies if the token is valid

vendor/github.com/golang-jwt/jwt/v5/ecdsa.go

@@ -55,7 +55,7 @@ func (m *SigningMethodECDSA) Alg() string {
 
 // Verify implements token verification for the SigningMethod.
 // For this verify method, key must be an ecdsa.PublicKey struct
-func (m *SigningMethodECDSA) Verify(signingString string, sig []byte, key interface{}) error {
+func (m *SigningMethodECDSA) Verify(signingString string, sig []byte, key any) error {
 	// Get the key
 	var ecdsaKey *ecdsa.PublicKey
 	switch k := key.(type) {
@@ -89,7 +89,7 @@ func (m *SigningMethodECDSA) Verify(signingString string, sig []byte, key interf
 
 // Sign implements token signing for the SigningMethod.
 // For this signing method, key must be an ecdsa.PrivateKey struct
-func (m *SigningMethodECDSA) Sign(signingString string, key interface{}) ([]byte, error) {
+func (m *SigningMethodECDSA) Sign(signingString string, key any) ([]byte, error) {
 	// Get the key
 	var ecdsaKey *ecdsa.PrivateKey
 	switch k := key.(type) {

vendor/github.com/golang-jwt/jwt/v5/ecdsa_utils.go

@@ -23,7 +23,7 @@ func ParseECPrivateKeyFromPEM(key []byte) (*ecdsa.PrivateKey, error) {
 	}
 
 	// Parse the key
-	var parsedKey interface{}
+	var parsedKey any
 	if parsedKey, err = x509.ParseECPrivateKey(block.Bytes); err != nil {
 		if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {
 			return nil, err
@@ -50,7 +50,7 @@ func ParseECPublicKeyFromPEM(key []byte) (*ecdsa.PublicKey, error) {
 	}
 
 	// Parse the key
-	var parsedKey interface{}
+	var parsedKey any
 	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
 		if cert, err := x509.ParseCertificate(block.Bytes); err == nil {
 			parsedKey = cert.PublicKey

vendor/github.com/golang-jwt/jwt/v5/ed25519.go

@@ -33,7 +33,7 @@ func (m *SigningMethodEd25519) Alg() string {
 
 // Verify implements token verification for the SigningMethod.
 // For this verify method, key must be an ed25519.PublicKey
-func (m *SigningMethodEd25519) Verify(signingString string, sig []byte, key interface{}) error {
+func (m *SigningMethodEd25519) Verify(signingString string, sig []byte, key any) error {
 	var ed25519Key ed25519.PublicKey
 	var ok bool
 
@@ -55,7 +55,7 @@ func (m *SigningMethodEd25519) Verify(signingString string, sig []byte, key inte
 
 // Sign implements token signing for the SigningMethod.
 // For this signing method, key must be an ed25519.PrivateKey
-func (m *SigningMethodEd25519) Sign(signingString string, key interface{}) ([]byte, error) {
+func (m *SigningMethodEd25519) Sign(signingString string, key any) ([]byte, error) {
 	var ed25519Key crypto.Signer
 	var ok bool
 

vendor/github.com/golang-jwt/jwt/v5/ed25519_utils.go

@@ -24,7 +24,7 @@ func ParseEdPrivateKeyFromPEM(key []byte) (crypto.PrivateKey, error) {
 	}
 
 	// Parse the key
-	var parsedKey interface{}
+	var parsedKey any
 	if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {
 		return nil, err
 	}
@@ -49,7 +49,7 @@ func ParseEdPublicKeyFromPEM(key []byte) (crypto.PublicKey, error) {
 	}
 
 	// Parse the key
-	var parsedKey interface{}
+	var parsedKey any
 	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
 		return nil, err
 	}

vendor/github.com/golang-jwt/jwt/v5/errors.go

@@ -2,6 +2,7 @@ package jwt
 
 import (
 	"errors"
+	"fmt"
 	"strings"
 )
 
@@ -47,3 +48,42 @@ func joinErrors(errs ...error) error {
 		errs: errs,
 	}
 }
+
+// Unwrap implements the multiple error unwrapping for this error type, which is
+// possible in Go 1.20.
+func (je joinedError) Unwrap() []error {
+	return je.errs
+}
+
+// newError creates a new error message with a detailed error message. The
+// message will be prefixed with the contents of the supplied error type.
+// Additionally, more errors, that provide more context can be supplied which
+// will be appended to the message. This makes use of Go 1.20's possibility to
+// include more than one %w formatting directive in [fmt.Errorf].
+//
+// For example,
+//
+//	newError("no keyfunc was provided", ErrTokenUnverifiable)
+//
+// will produce the error string
+//
+//	"token is unverifiable: no keyfunc was provided"
+func newError(message string, err error, more ...error) error {
+	var format string
+	var args []any
+	if message != "" {
+		format = "%w: %s"
+		args = []any{err, message}
+	} else {
+		format = "%w"
+		args = []any{err}
+	}
+
+	for _, e := range more {
+		format += ": %w"
+		args = append(args, e)
+	}
+
+	err = fmt.Errorf(format, args...)
+	return err
+}