Check that the specified curve is one of the client preferences.

Based on OpenSSL.

ok miod@

1 files changed, 20 insertions, 4 deletions

diff --git a/src/lib/libssl/s3_clnt.c b/src/lib/libssl/s3_clnt.c
index 1f64091f87..9aa599a1c6 100644
--- a/src/lib/libssl/s3_clnt.c
+++ b/src/lib/libssl/s3_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s3_clnt.c,v 1.90 2014/09/19 14:32:23 tedu Exp $ */
+/* $OpenBSD: s3_clnt.c,v 1.91 2014/09/27 11:01:05 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1330,8 +1330,8 @@ ssl3_get_key_exchange(SSL *s)
                 s->session->sess_cert->peer_dh_tmp = dh;
                 dh = NULL;
         } else if (alg_k & SSL_kECDHE) {
-                EC_GROUP *ngroup;
                 const EC_GROUP *group;
+                EC_GROUP *ngroup;
 
                 if ((ecdh = EC_KEY_new()) == NULL) {
                         SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,
@@ -1351,8 +1351,24 @@ ssl3_get_key_exchange(SSL *s)
                  * and the ECParameters in this case is just three bytes.
                  */
                 param_len = 3;
-                if ((param_len > n) || (*p != NAMED_CURVE_TYPE) ||
-                    ((curve_nid = tls1_ec_curve_id2nid(*(p + 2))) == 0)) {
+                if (param_len > n) {
+                        al = SSL_AD_DECODE_ERROR;
+                        SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,
+                            SSL_R_LENGTH_TOO_SHORT);
+                        goto f_err;
+                }
+
+                /*
+                 * Check curve is one of our preferences, if not server has
+                 * sent an invalid curve.
+                 */
+                if (tls1_check_curve(s, p, param_len) != 1) {
+                        al = SSL_AD_DECODE_ERROR;
+                        SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_WRONG_CURVE);
+                        goto f_err;
+                }
+
+                if ((curve_nid = tls1_ec_curve_id2nid(*(p + 2))) == 0) {
                         al = SSL_AD_INTERNAL_ERROR;
                         SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,
                             SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);