File SQUID-2023_3.patch of Package squid.31747

From dc0e10bec3334053c1a5297e50dd7052ea18aef0 Mon Sep 17 00:00:00 2001
From: Alex Bason <nonsleepr@gmail.com>
Date: Sun, 15 Oct 2023 13:04:47 +0000
Subject: [PATCH] Fix stack buffer overflow when parsing Digest Authorization
 (#1517)

The bug was discovered and detailed by Joshua Rogers at
https://megamansec.github.io/Squid-Security-Audit/digest-overflow.html
where it was filed as "Stack Buffer Overflow in Digest Authentication".
---
 src/auth/digest/Config.cc | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Index: squid-3.5.21/src/auth/digest/Config.cc
===================================================================
--- squid-3.5.21.orig/src/auth/digest/Config.cc
+++ squid-3.5.21/src/auth/digest/Config.cc
@@ -858,11 +858,15 @@ Auth::Digest::Config::decode(char const
             break;
 
         case DIGEST_NC:
-            if (value.size() != 8) {
+            if (value.size() == 8) {
+                // for historical reasons, the nc value MUST be exactly 8 bytes
+                // [FAILS on SLE-12] static_assert(sizeof(digest_request->nc) == 8 + 1);
+                xstrncpy(digest_request->nc, value.rawBuf(), value.size() + 1);
+                debugs(29, 9, "Found noncecount '" << digest_request->nc << "'");
+            } else {
                 debugs(29, 9, "Invalid nc '" << value << "' in '" << temp << "'");
+                digest_request->nc[0] = 0;
             }
-            xstrncpy(digest_request->nc, value.rawBuf(), value.size() + 1);
-            debugs(29, 9, "Found noncecount '" << digest_request->nc << "'");
             break;
 
         case DIGEST_CNONCE: