From 48f9b5e4faf3ea559e9f57038a7e7314c45a94fd Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Wed, 28 Nov 2018 18:21:41 -0500
Subject: [PATCH] implement NS PASSWD for password changes

---
 irc/accounts.go | 15 ++++++++-----
 irc/nickserv.go | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 5 deletions(-)

diff --git a/irc/accounts.go b/irc/accounts.go
index 910a3025..265f7f5f 100644
--- a/irc/accounts.go
+++ b/irc/accounts.go
@@ -565,14 +565,15 @@ func (am *AccountManager) SetNickReserved(client *Client, nick string, saUnreser
 	return nil
 }
 
-func (am *AccountManager) AuthenticateByPassphrase(client *Client, accountName string, passphrase string) error {
-	account, err := am.LoadAccount(accountName)
+func (am *AccountManager) checkPassphrase(accountName, passphrase string) (account ClientAccount, err error) {
+	account, err = am.LoadAccount(accountName)
 	if err != nil {
-		return err
+		return
 	}
 
 	if !account.Verified {
-		return errAccountUnverified
+		err = errAccountUnverified
+		return
 	}
 
 	switch account.Credentials.Version {
@@ -583,9 +584,13 @@ func (am *AccountManager) AuthenticateByPassphrase(client *Client, accountName s
 	default:
 		err = errAccountInvalidCredentials
 	}
+	return
+}
 
+func (am *AccountManager) AuthenticateByPassphrase(client *Client, accountName string, passphrase string) error {
+	account, err := am.checkPassphrase(accountName, passphrase)
 	if err != nil {
-		return errAccountInvalidCredentials
+		return err
 	}
 
 	am.Login(client, account)
diff --git a/irc/nickserv.go b/irc/nickserv.go
index 2c040e8c..72ca453e 100644
--- a/irc/nickserv.go
+++ b/irc/nickserv.go
@@ -121,6 +121,18 @@ or other verification.`,
 			helpShort: `$bVERIFY$b lets you complete account registration.`,
 			enabled:   servCmdRequiresAccreg,
 		},
+		"passwd": {
+			handler: nsPasswdHandler,
+			help: `Syntax: $bPASSWD <current> <new> <new_again>$b
+Or:     $bPASSWD <username> <new>$b
+
+PASSWD lets you change your account password. You must supply your current
+password and confirm the new one by typing it twice. If you're an IRC operator
+with the correct permissions, you can use PASSWD to reset someone else's
+password by supplying their username and then the desired password.`,
+			helpShort: `$bPASSWD$b lets you change your password.`,
+			enabled:   servCmdRequiresAuthEnabled,
+		},
 	}
 )
 
@@ -389,3 +401,49 @@ func nsVerifyHandler(server *Server, client *Client, command, params string, rb
 
 	sendSuccessfulRegResponse(client, rb, true)
 }
+
+func nsPasswdHandler(server *Server, client *Client, command, params string, rb *ResponseBuffer) {
+	var target string
+	var newPassword string
+	var errorMessage string
+
+	fields := strings.Fields(params)
+	switch len(fields) {
+	case 2:
+		if !client.HasRoleCapabs("accreg") {
+			errorMessage = "Insufficient privileges"
+		} else {
+			target, newPassword = fields[0], fields[1]
+		}
+	case 3:
+		target = client.Account()
+		if target == "" {
+			errorMessage = "You're not logged into an account"
+		} else if fields[1] != fields[2] {
+			errorMessage = "Passwords do not match"
+		} else {
+			// check that they correctly supplied the preexisting password
+			_, err := server.accounts.checkPassphrase(target, fields[0])
+			if err != nil {
+				errorMessage = "Password incorrect"
+			} else {
+				newPassword = fields[1]
+			}
+		}
+	default:
+		errorMessage = "Invalid parameters"
+	}
+
+	if errorMessage != "" {
+		nsNotice(rb, client.t(errorMessage))
+		return
+	}
+
+	err := server.accounts.setPassword(target, newPassword)
+	if err == nil {
+		nsNotice(rb, client.t("Password changed"))
+	} else {
+		server.logger.Error("internal", fmt.Sprintf("could not upgrade user password: %v", err))
+		nsNotice(rb, client.t("Password could not be changed due to server error"))
+	}
+}