commit 6e8076577486a5d3d67682dbc4acae932daa6731
author David Benjamin <davidben@chromium.org> Mon Nov 02 12:02:20 2015 -0500
committer Adam Langley <agl@google.com> Fri Nov 06 22:35:28 2015 +0000
tree fbdbe9de19eb380892e6e6a559945333f41ccc9f
parent 788be4a3f47cea5fcb86abf59321c729057830ed

Add SSL_get_server_key_exchange_hash.

This exposes the ServerKeyExchange signature hash type used in the most recent
handshake, for histogramming on the client.

BUG=549662

Change-Id: I8a4e00ac735b1ecd2c2df824112c3a0bc62332a7
Reviewed-on: https://boringssl-review.googlesource.com/6413
Reviewed-by: Adam Langley <agl@google.com>

ssl/t1_lib.c

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 301d49a..9a29028 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -640,16 +640,11 @@
   return sizeof(tls12_sigalgs);
 }
 
-/* tls12_check_peer_sigalg parses a SignatureAndHashAlgorithm out of |cbs|. It
- * checks it is consistent with |s|'s sent supported signature algorithms and,
- * if so, writes the relevant digest into |*out_md| and returns 1. Otherwise it
- * returns 0 and writes an alert into |*out_alert|. */
-int tls12_check_peer_sigalg(const EVP_MD **out_md, int *out_alert, SSL *s,
-                            CBS *cbs, EVP_PKEY *pkey) {
+int tls12_check_peer_sigalg(SSL *ssl, const EVP_MD **out_md, int *out_alert,
+                            uint8_t hash, uint8_t signature, EVP_PKEY *pkey) {
   const uint8_t *sent_sigs;
   size_t sent_sigslen, i;
   int sigalg = tls12_get_sigid(pkey->type);
-  uint8_t hash, signature;
 
   /* Should never happen */
   if (sigalg == -1) {
@@ -658,13 +653,6 @@
     return 0;
   }
 
-  if (!CBS_get_u8(cbs, &hash) ||
-      !CBS_get_u8(cbs, &signature)) {
-    OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
-    *out_alert = SSL_AD_DECODE_ERROR;
-    return 0;
-  }
-
   /* Check key type is consistent with signature */
   if (sigalg != signature) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
@@ -681,8 +669,8 @@
       return 0;
     }
 
-    if (s->server && (!tls1_check_curve_id(s, curve_id) ||
-                      comp_id != TLSEXT_ECPOINTFORMAT_uncompressed)) {
+    if (ssl->server && (!tls1_check_curve_id(ssl, curve_id) ||
+                        comp_id != TLSEXT_ECPOINTFORMAT_uncompressed)) {
       OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
       *out_alert = SSL_AD_ILLEGAL_PARAMETER;
       return 0;
@@ -690,7 +678,7 @@
   }
 
   /* Check signature matches a type we sent */
-  sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
+  sent_sigslen = tls12_get_psigalgs(ssl, &sent_sigs);
   for (i = 0; i < sent_sigslen; i += 2, sent_sigs += 2) {
     if (hash == sent_sigs[0] && signature == sent_sigs[1]) {
       break;