From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
Date: Fri, 3 Jun 2011 12:09:45 +0000 (+0200)
Subject: Truncation of ECDSA and DSA signatures moved to _wrap_nettle_pk_sign()
X-Git-Tag: gnutls_2_99_3~60
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=16ee4a4a79cd998982e8248fcabaea1d8a5e201e;p=thirdparty%2Fgnutls.git

Truncation of ECDSA and DSA signatures moved to _wrap_nettle_pk_sign()
and _wrap_nettle_pk_verify().
---

diff --git a/lib/gnutls_pubkey.c b/lib/gnutls_pubkey.c
index 4400e6fe43..5dddae2b1c 100644
--- a/lib/gnutls_pubkey.c
+++ b/lib/gnutls_pubkey.c
@@ -1219,10 +1219,10 @@ int hash_algo;
     }
   else if (pubkey->pk_algorithm == GNUTLS_PK_ECC)
     {
-      hash_algo = _gnutls_dsa_q_to_hash (pubkey->pk_algorithm, &pubkey->params, &hash_size);
-
       if (_gnutls_version_has_selectable_sighash (ver) && sign != GNUTLS_SIGN_UNKNOWN)
         {
+          hash_algo = _gnutls_dsa_q_to_hash (pubkey->pk_algorithm, &pubkey->params, &hash_size);
+
           if (_gnutls_hash_get_algo_len(_gnutls_sign_get_hash_algorithm(sign)) != hash_size)
             return GNUTLS_E_UNWANTED_ALGORITHM;
         }
diff --git a/lib/nettle/pk.c b/lib/nettle/pk.c
index 478851b9bb..d0f2b96ddf 100644
--- a/lib/nettle/pk.c
+++ b/lib/nettle/pk.c
@@ -364,9 +364,10 @@ _wrap_nettle_pk_sign (gnutls_pk_algorithm_t algo,
           {
             gnutls_assert ();
             _gnutls_debug_log("Security level of algorithm requires hash %s(%d) or better\n", gnutls_mac_get_name(hash), hash_len);
+            hash_len = vdata->size;
           }
 
-        ret = ecc_sign_hash(vdata->data, vdata->size, 
+        ret = ecc_sign_hash(vdata->data, hash_len, 
                             &sig, NULL, rnd_func, &priv);
         if (ret != 0)
           {
@@ -405,12 +406,13 @@ _wrap_nettle_pk_sign (gnutls_pk_algorithm_t algo,
         if (hash_len > vdata->size)
           {
             gnutls_assert ();
-            _gnutls_debug_log("Security level of algorithm requires hash %s or better\n", gnutls_mac_get_name(hash));
+            _gnutls_debug_log("Security level of algorithm requires hash %s(%d) or better\n", gnutls_mac_get_name(hash), hash_len);
+            hash_len = vdata->size;
           }
 
         ret =
           _dsa_sign (&pub, &priv, NULL, rnd_func,
-                     vdata->size, vdata->data, &sig);
+                     hash_len, vdata->data, &sig);
         if (ret == 0)
           {
             gnutls_assert ();
@@ -523,6 +525,7 @@ _wrap_nettle_pk_verify (gnutls_pk_algorithm_t algo,
                         const gnutls_pk_params_st * pk_params)
 {
   int ret;
+  int hash_len;
   bigint_t tmp[2] = { NULL, NULL };
 
   switch (algo)
@@ -544,7 +547,11 @@ _wrap_nettle_pk_verify (gnutls_pk_algorithm_t algo,
         memcpy (&sig.r, tmp[0], sizeof (sig.r));
         memcpy (&sig.s, tmp[1], sizeof (sig.s));
 
-        ret = ecc_verify_hash(&sig, vdata->data, vdata->size, &stat, &pub);
+        _gnutls_dsa_q_to_hash (algo, pk_params, &hash_len);
+        if (hash_len > vdata->size)
+          hash_len = vdata->size;
+
+        ret = ecc_verify_hash(&sig, vdata->data, hash_len, &stat, &pub);
         if (ret != 0 || stat != 1)
           {
             gnutls_assert();
@@ -573,7 +580,11 @@ _wrap_nettle_pk_verify (gnutls_pk_algorithm_t algo,
         memcpy (&sig.r, tmp[0], sizeof (sig.r));
         memcpy (&sig.s, tmp[1], sizeof (sig.s));
 
-        ret = _dsa_verify (&pub, vdata->size, vdata->data, &sig);
+        _gnutls_dsa_q_to_hash (algo, pk_params, &hash_len);
+        if (hash_len > vdata->size)
+          hash_len = vdata->size;
+
+        ret = _dsa_verify (&pub, hash_len, vdata->data, &sig);
         if (ret == 0)
           {
             gnutls_assert();
diff --git a/lib/x509/verify.c b/lib/x509/verify.c
index df45746db3..6f0ab8da2b 100644
--- a/lib/x509/verify.c
+++ b/lib/x509/verify.c
@@ -847,11 +847,14 @@ dsa_verify_sig (const gnutls_datum_t * text,
       if (!hash->data || hash->size < hash_len)
         {
           gnutls_assert();
-          _gnutls_debug_log("Hash size (%d) does not correspond to hash %s or better.\n", (int)hash->size, gnutls_mac_get_name(algo));
-          return gnutls_assert_val(GNUTLS_E_PK_SIG_VERIFY_FAILED);
+          _gnutls_debug_log("Hash size (%d) does not correspond to hash %s(%d) or better.\n", (int)hash->size, gnutls_mac_get_name(algo), hash_len);
+          
+          if (hash->size != 20) /* SHA1 is allowed */
+            return gnutls_assert_val(GNUTLS_E_PK_SIG_VERIFY_FAILED);
         }
 
-      digest = *hash;
+      digest.data = hash->data;
+      digest.size = hash->size;
     }
   else
     {