As server don't try to send extensions we didn't receive.

3 files changed, 36 insertions, 29 deletions

diff --git a/lib/gnutls_extensions.c b/lib/gnutls_extensions.c
index 36ac43e8ee..565734f798 100644
--- a/lib/gnutls_extensions.c
+++ b/lib/gnutls_extensions.c
@@ -118,19 +118,14 @@ static const char *_gnutls_extension_get_name(uint16_t type)
 static int
 _gnutls_extension_list_check(gnutls_session_t session, uint16_t type)
 {
-	if (session->security_parameters.entity == GNUTLS_CLIENT) {
-		int i;
-
-		for (i = 0; i < session->internals.extensions_sent_size;
-		     i++) {
-			if (type == session->internals.extensions_sent[i])
-				return 0;	/* ok found */
-		}
+	int i;
 
-		return GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION;
+	for (i = 0; i < session->internals.extensions_sent_size; i++) {
+		if (type == session->internals.extensions_sent[i])
+			return 0;	/* ok found */
 	}
 
-	return 0;
+	return GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION;
 }
 
 int
@@ -171,10 +166,14 @@ _gnutls_parse_extensions(gnutls_session_t session,
 		type = _gnutls_read_uint16(&data[pos]);
 		pos += 2;
 
-		if ((ret =
-		     _gnutls_extension_list_check(session, type)) < 0) {
-			gnutls_assert();
-			return ret;
+		if (session->security_parameters.entity == GNUTLS_CLIENT) {
+			if ((ret =
+			     _gnutls_extension_list_check(session, type)) < 0) {
+				gnutls_assert();
+				return ret;
+			}
+		} else {
+			_gnutls_extension_list_add(session, type);
 		}
 
 		DECR_LENGTH_RET(next, 2, 0);
@@ -218,17 +217,15 @@ _gnutls_parse_extensions(gnutls_session_t session,
 void _gnutls_extension_list_add(gnutls_session_t session, uint16_t type)
 {
 
-	if (session->security_parameters.entity == GNUTLS_CLIENT) {
-		if (session->internals.extensions_sent_size <
-		    MAX_EXT_TYPES) {
-			session->internals.extensions_sent[session->
-							   internals.extensions_sent_size]
-			    = type;
-			session->internals.extensions_sent_size++;
-		} else {
-			_gnutls_handshake_log
-			    ("extensions: Increase MAX_EXT_TYPES\n");
-		}
+	if (session->internals.extensions_sent_size <
+	    MAX_EXT_TYPES) {
+		session->internals.extensions_sent[session->
+						   internals.extensions_sent_size]
+		    = type;
+		session->internals.extensions_sent_size++;
+	} else {
+		_gnutls_handshake_log
+		    ("extensions: Increase MAX_EXT_TYPES\n");
 	}
 }
 
@@ -257,6 +254,14 @@ _gnutls_gen_extensions(gnutls_session_t session,
 		    && p->parse_type != parse_type)
 			continue;
 
+		/* ensure we are sending only what we received */
+		if (session->security_parameters.entity == GNUTLS_SERVER) {
+			if ((ret =
+			     _gnutls_extension_list_check(session, p->type)) < 0) {
+				continue;
+			}
+		}
+
 		ret = _gnutls_buffer_append_prefix(extdata, 16, p->type);
 		if (ret < 0)
 			return gnutls_assert_val(ret);
@@ -280,7 +285,8 @@ _gnutls_gen_extensions(gnutls_session_t session,
 
 			/* add this extension to the extension list
 			 */
-			_gnutls_extension_list_add(session, p->type);
+			if (session->security_parameters.entity == GNUTLS_CLIENT)
+				_gnutls_extension_list_add(session, p->type);
 
 			_gnutls_handshake_log
 			    ("EXT[%p]: Sending extension %s (%d bytes)\n",
diff --git a/lib/gnutls_handshake.c b/lib/gnutls_handshake.c
index 500d25258e..415b3bbb02 100644
--- a/lib/gnutls_handshake.c
+++ b/lib/gnutls_handshake.c
@@ -2053,7 +2053,8 @@ static int send_client_hello(gnutls_session_t session, int again)
 			ret =
 			    copy_ciphersuites(session, &extdata,
 					      TRUE);
-			_gnutls_extension_list_add(session,
+			if (session->security_parameters.entity == GNUTLS_CLIENT)
+				_gnutls_extension_list_add(session,
 						   GNUTLS_EXTENSION_SAFE_RENEGOTIATION);
 		} else
 			ret =
diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h
index 09f319f60a..fd52e1e134 100644
--- a/lib/gnutls_int.h
+++ b/lib/gnutls_int.h
@@ -874,8 +874,8 @@ typedef struct {
 	struct gnutls_privkey_st *selected_key;
 	bool selected_need_free;
 
-	/* holds the extensions we sent to the peer
-	 * (in case of a client)
+	/* In case of a client holds the extensions we sent to the peer;
+	 * otherwise the extensions we received from the client.
 	 */
 	uint16_t extensions_sent[MAX_EXT_TYPES];
 	uint16_t extensions_sent_size;