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 c930db77eb60523b371ee57a7d5d47c5ab859d57..eba2a397037d5b3803753b5b04b24f18fe98ef9c 100644 (file)
--- 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 ();