From 6ffd595a06b624f869805e5066894afce16026d4 Mon Sep 17 00:00:00 2001
From: Martin Dosch <martin@mdosch.de>
Date: Thu, 1 Feb 2024 13:35:55 +0800
Subject: [PATCH] Improve RFC5802 compatibility.

According to RFC 5802 5.1 only the "m" attribute should
cause an authentication error.
---
 xmpp.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xmpp.go b/xmpp.go
index c009c7f..be30176 100644
--- a/xmpp.go
+++ b/xmpp.go
@@ -580,8 +580,8 @@ func (c *Client) init(o *Options) error {
 						return errors.New("SCRAM: downgrade protection hash mismatch")
 					}
 					dgh.Reset()
-				default:
-					return errors.New("unexpected content in SCRAM challenge")
+				case strings.HasPrefix(serverReply, "m="):
+					return errors.New("SCRAM: server sent reserved 'm' attribute.")
 				}
 			}
 			if scramPlus {