From: Simon Josefsson <simon@josefsson.org>
Date: Wed, 27 Dec 2006 20:31:57 +0000 (+0000)
Subject: Fix signature verification for DSA signatures in TLS 1.2, reported by
X-Git-Tag: gnutls_1_6_1~7
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8fd2854b3b438492ae5762e330f63ea130dc4bc8;p=thirdparty%2Fgnutls.git

Fix signature verification for DSA signatures in TLS 1.2, reported by
ludovic.courtes@laas.fr (Ludovic Courtès).
(_gnutls_pkcs1_rsa_verify_sig): Rename to _gnutls_verify_sig, and add
new parameter SHA1POS to indicate where in hash_concat the SHA.1 hash
is stored (for DSA).
(_gnutls_verify_sig_hdata): Pass proper SHA1POS.
(_gnutls_verify_sig_params): Likewise.
---

diff --git a/lib/gnutls_sig.c b/lib/gnutls_sig.c
index c930db77eb..eba2a39703 100644
--- a/lib/gnutls_sig.c
+++ b/lib/gnutls_sig.c
@@ -259,9 +259,10 @@ _gnutls_tls_sign (gnutls_cert * cert, gnutls_privkey * pkey,
 
 
 static int
-_gnutls_pkcs1_rsa_verify_sig (gnutls_cert * cert,
-			      const gnutls_datum_t * hash_concat,
-			      gnutls_datum_t * signature)
+_gnutls_verify_sig (gnutls_cert * cert,
+		    const gnutls_datum_t * hash_concat,
+		    gnutls_datum_t * signature,
+		    size_t sha1pos)
 {
   int ret;
   gnutls_datum_t vdata;
@@ -302,7 +303,7 @@ _gnutls_pkcs1_rsa_verify_sig (gnutls_cert * cert,
       break;
     case GNUTLS_PK_DSA:
 
-      vdata.data = &hash_concat->data[16];
+      vdata.data = &hash_concat->data[sha1pos];
       vdata.size = 20;		/* sha1 */
 
       /* verify signature */
@@ -380,7 +381,7 @@ _gnutls_verify_sig_hdata (gnutls_session_t session, gnutls_cert * cert,
   dconcat.data = concat;
   dconcat.size = 20 + 16;	/* md5+ sha */
 
-  ret = _gnutls_pkcs1_rsa_verify_sig (cert, &dconcat, signature);
+  ret = _gnutls_verify_sig (cert, &dconcat, signature, 16);
   if (ret < 0)
     {
       gnutls_assert ();
@@ -461,7 +462,7 @@ _gnutls_verify_sig_params (gnutls_session_t session, gnutls_cert * cert,
 
   dconcat.data = concat;
 
-  ret = _gnutls_pkcs1_rsa_verify_sig (cert, &dconcat, signature);
+  ret = _gnutls_verify_sig (cert, &dconcat, signature, dconcat.size - 20);
   if (ret < 0)
     {
       gnutls_assert ();