From d6e3f188cf2bf68d8869bc4732f4dbe845ad3148 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Mon, 6 Apr 2020 00:06:06 -0400
Subject: [PATCH] enforce nick protection immediately after verification

---
 irc/accounts.go | 15 ++++++++++++++-
 irc/nickname.go |  4 ++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/irc/accounts.go b/irc/accounts.go
index 0626e4b7..35227c3c 100644
--- a/irc/accounts.go
+++ b/irc/accounts.go
@@ -750,6 +750,7 @@ func (am *AccountManager) dispatchMailtoCallback(client *Client, casefoldedAccou
 
 func (am *AccountManager) Verify(client *Client, account string, code string) error {
 	casefoldedAccount, err := CasefoldName(account)
+	var skeleton string
 	if err != nil || account == "" || account == "*" {
 		return errAccountVerificationFailed
 	}
@@ -820,7 +821,7 @@ func (am *AccountManager) Verify(client *Client, account string, code string) er
 		})
 
 		if err == nil {
-			skeleton, _ := Skeleton(raw.Name)
+			skeleton, _ = Skeleton(raw.Name)
 			am.Lock()
 			am.nickToAccount[casefoldedAccount] = casefoldedAccount
 			am.skeletonToAccount[skeleton] = casefoldedAccount
@@ -845,6 +846,18 @@ func (am *AccountManager) Verify(client *Client, account string, code string) er
 	if client != nil {
 		am.Login(client, clientAccount)
 	}
+	_, method := am.EnforcementStatus(casefoldedAccount, skeleton)
+	if method != NickEnforcementNone {
+		currentClient := am.server.clients.Get(casefoldedAccount)
+		if currentClient == nil || currentClient == client || currentClient.Account() == casefoldedAccount {
+			return nil
+		}
+		if method == NickEnforcementStrict {
+			am.server.RandomlyRename(currentClient)
+		} else if method == NickEnforcementWithTimeout {
+			currentClient.nickTimer.Touch(nil)
+		}
+	}
 	return nil
 }
 
diff --git a/irc/nickname.go b/irc/nickname.go
index 2dd7ae33..a49a2137 100644
--- a/irc/nickname.go
+++ b/irc/nickname.go
@@ -98,6 +98,10 @@ func (server *Server) RandomlyRename(client *Client) {
 	nick := strings.Replace(format, "*", utils.B32Encoder.EncodeToString(buf), -1)
 	sessions := client.Sessions()
 	if len(sessions) == 0 {
+		// this can happen if they are anonymous and BRB (in general, an always-on
+		// client has title to its nickname and will never be the victim of
+		// a call to RandomlyRename)
+		client.destroy(nil)
 		return
 	}
 	// XXX arbitrarily pick the first session to receive error messages;