From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
Date: Fri, 6 Jan 2012 18:49:24 +0000 (+0100)
Subject: provide less timing information when decoding packets. Patch by Nadhem Alfardan.
X-Git-Tag: gnutls_3_0_11~4
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=35e26ca63c6da01db460d93e9c4bf86cd668534c;p=thirdparty%2Fgnutls.git

provide less timing information when decoding packets. Patch by Nadhem Alfardan.
---

diff --git a/NEWS b/NEWS
index 58b6a818dd..49372ad56d 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,15 @@ GnuTLS NEWS -- History of user-visible changes.                -*- outline -*-
 Copyright (C) 2000-2011 Free Software Foundation, Inc.
 See the end for copying conditions.
 
+* Version 3.0.11 (unreleased)
+
+** libgnutls: Provide less timing information when decoding
+TLS/DTLS record packets. Patch by Nadhem Alfardan.
+
+** API and ABI modifications:
+No changes since last version.
+
+
 * Version 3.0.10 (released 2012-01-04)
 
 ** gnutls-cli/serv: Set don't fragment bit in DTLS sessions
diff --git a/lib/gnutls_cipher.c b/lib/gnutls_cipher.c
index f04182189b..e593cfe919 100644
--- a/lib/gnutls_cipher.c
+++ b/lib/gnutls_cipher.c
@@ -560,7 +560,12 @@ ciphertext_to_compressed (gnutls_session_t session,
           }
 
       if (length < 0)
-        length = 0;
+        {
+          /* Setting a proper length to prevent timing differences in
+           * processing of records with invalid encryption.
+           */
+          length = ciphertext.size - tag_size;
+        }
 
       /* Pass the type, version, length and compressed through
        * MAC.