From: Andreas Weigel <andreas.weigel@securepoint.de>
Date: Wed, 18 Oct 2023 04:14:31 +0000 (+0000)
Subject: Fix validation of certificates with CN=* (#1523)
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=792ef23e6e1c05780fe17f733859eef6eb8c8be3;p=thirdparty%2Fsquid.git

Fix validation of certificates with CN=* (#1523)

The bug was discovered and detailed by Joshua Rogers at
https://megamansec.github.io/Squid-Security-Audit/
where it was filed as "Buffer UnderRead in SSL CN Parsing".
---

diff --git a/src/anyp/Uri.cc b/src/anyp/Uri.cc
index 77b6f0c920..a6a5d5d9ed 100644
--- a/src/anyp/Uri.cc
+++ b/src/anyp/Uri.cc
@@ -173,6 +173,10 @@ urlInitialize(void)
     assert(0 == matchDomainName("*.foo.com", ".foo.com", mdnHonorWildcards));
     assert(0 != matchDomainName("*.foo.com", "foo.com", mdnHonorWildcards));
 
+    assert(0 != matchDomainName("foo.com", ""));
+    assert(0 != matchDomainName("foo.com", "", mdnHonorWildcards));
+    assert(0 != matchDomainName("foo.com", "", mdnRejectSubsubDomains));
+
     /* more cases? */
 }
 
@@ -756,6 +760,8 @@ matchDomainName(const char *h, const char *d, MatchDomainNameFlags flags)
         return -1;
 
     dl = strlen(d);
+    if (dl == 0)
+        return 1;
 
     /*
      * Start at the ends of the two strings and work towards the