From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Fri, 21 Oct 2016 15:30:43 +0000 (+0200)
Subject: Terminate handshake if only unknown or disabled signatures are advertized by the... 
X-Git-Tag: gnutls_3_5_6~31
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=db2c84e6a8e5587fb5fe261c045ba2d3e168a248;p=thirdparty%2Fgnutls.git

Terminate handshake if only unknown or disabled signatures are advertized by the peer

That is, do not attempt to proceed assuming that the peer supports SHA-1.
---

diff --git a/lib/alert.c b/lib/alert.c
index da41d2747b..a4e30cf48c 100644
--- a/lib/alert.c
+++ b/lib/alert.c
@@ -242,6 +242,7 @@ int gnutls_error_to_alert(int err, int *level)
 	case GNUTLS_E_UNSUPPORTED_SIGNATURE_ALGORITHM:
 	case GNUTLS_E_SAFE_RENEGOTIATION_FAILED:
 	case GNUTLS_E_INCOMPAT_DSA_KEY_WITH_TLS_PROTOCOL:
+	case GNUTLS_E_UNKNOWN_PK_ALGORITHM:
 		ret = GNUTLS_A_HANDSHAKE_FAILURE;
 		_level = GNUTLS_AL_FATAL;
 		break;
diff --git a/lib/ext/signature.c b/lib/ext/signature.c
index adb19845f9..96b97cef94 100644
--- a/lib/ext/signature.c
+++ b/lib/ext/signature.c
@@ -1,5 +1,6 @@
 /*
- * Copyright (C) 2002-2012 Free Software Foundation, Inc.
+ * Copyright (C) 2002-2016 Free Software Foundation, Inc.
+ * Copyright (C) 2015-2016 Red Hat, Inc.
  *
  * Author: Nikos Mavrogiannopoulos
  *
@@ -150,12 +151,12 @@ _gnutls_sign_algorithm_parse_data(gnutls_session_t session,
 		     gnutls_sign_get_name(sig));
 
 		if (sig != GNUTLS_SIGN_UNKNOWN) {
-			priv->sign_algorithms[priv->
-					      sign_algorithms_size++] =
-			    sig;
 			if (priv->sign_algorithms_size ==
 			    MAX_SIGNATURE_ALGORITHMS)
 				break;
+			priv->sign_algorithms[priv->
+					      sign_algorithms_size++] =
+			    sig;
 		}
 	}
 
@@ -195,7 +196,7 @@ _gnutls_signature_algorithm_recv_params(gnutls_session_t session,
 	} else {
 		/* SERVER SIDE - we must check if the sent cert type is the right one
 		 */
-		if (data_size > 2) {
+		if (data_size >= 2) {
 			uint16_t len;
 
 			DECR_LEN(data_size, 2);
@@ -283,10 +284,8 @@ _gnutls_session_get_sign_algo(gnutls_session_t session,
 					 &epriv);
 	priv = epriv;
 
-	if (ret < 0 || !_gnutls_version_has_selectable_sighash(ver)
-	    || priv->sign_algorithms_size == 0)
+	if (ret < 0 || !_gnutls_version_has_selectable_sighash(ver)) {
 		/* none set, allow SHA-1 only */
-	{
 		ret = gnutls_pk_to_sign(cert_algo, GNUTLS_DIG_SHA1);
 
 		if (!client_cert && _gnutls_session_sign_algo_enabled(session, ret) < 0)