various bug fixes in libzrtp

 * fixed bug with remote hello-hash buffer being too small
 * removed unused hello-hash storage in zrtp stream context
 * fixed bug with libzrtp rendered "empty" SAS hash from incoming
   SasRelay packet
 * incremented libzrtp version number to 1.15
Signed-off-by: Travis Cross <tc@traviscross.com>

libs/libzrtp/include/zrtp_types.h

@@ -527,7 +527,12 @@ typedef struct zrtp_stream_mescache_t
 	zrtp_retry_task_t       errorack_task;
 	zrtp_retry_task_t       sasrelay_task;
 	
-	zrtp_string16_t			signaling_hash;	
+	/*!
+	 * Hash pre-image of the remote party Hello retrieved from Signaling. When
+	 * user calls zrtp_signaling_hash_set() libzrtp stores hash value in this
+	 * variable and checks all incoming Hello-s to prevent DOS attacks.
+	 */
+	zrtp_string64_t			signaling_hash;
 } zrtp_stream_mescache_t;
 
 
@@ -722,14 +727,7 @@ struct zrtp_stream_t
 	 * crypto sources and performs traffic encryption/decryption.
 	 */
 	zrtp_protocol_t			*protocol;
-	
-	/*!
-	 * Hash pre-image of the remote party Hello retrieved from Signaling. When
-	 * user calls zrtp_signaling_hash_set() libzrtp stores hash value in this
-	 * variable and checks all incoming Hellos to prevent DOS attacks.
-	 */
-	zrtp_string128_t		signaling_hash;
-	
+
 	/*!< Holder for RTP/ZRTP media stream options. */
 	zrtp_media_context_t	media_ctx;
 	

libs/libzrtp/include/zrtp_version.h

@@ -12,8 +12,8 @@
 
 #define LIBZRTP_VERSION_MAJOR		1
 
-#define LIBZRTP_VERSION_MINOR		13
-#define LIBZRTP_VERSION_BUILD		604
-#define LIBZRTP_VERSION_STR			"v1.13 604"
+#define LIBZRTP_VERSION_MINOR		15
+#define LIBZRTP_VERSION_BUILD		607
+#define LIBZRTP_VERSION_STR			"v1.15 607"
 
 #endif /*__ZRTP_VERSION_H__*/

libs/libzrtp/projects/gnu/configure.in

@@ -32,7 +32,7 @@ case $target_os in
 esac
 
 
-AM_INIT_AUTOMAKE([libzrtp], [1.14])
+AM_INIT_AUTOMAKE([libzrtp], [1.15])
 AX_PREFIX_CONFIG_H(../../include/zrtp_config_unix.h,ZRTP,config/config.h)
 
 CFLAGS="$CFLAGS -Wno-unused-parameter -fno-strict-aliasing -fPIC -DZRTP_AUTOMAKE=1"

libs/libzrtp/src/zrtp.c

@@ -418,8 +418,6 @@ zrtp_status_t zrtp_stream_attach(zrtp_session_t *session, zrtp_stream_t** stream
 		return zrtp_status_alloc_fail;
 	}
 	
-	ZSTR_SET_EMPTY(new_stream->signaling_hash);
-	
 	/*
 	 * Initialize the private data stream with default initial values	 
 	 */
@@ -437,6 +435,8 @@ zrtp_status_t zrtp_stream_attach(zrtp_session_t *session, zrtp_stream_t** stream
 	ZSTR_SET_EMPTY(new_stream->cc.zrtp_key);
 	ZSTR_SET_EMPTY(new_stream->cc.peer_zrtp_key);
 	
+	ZSTR_SET_EMPTY(new_stream->messages.signaling_hash);
+
 	new_stream->dh_cc.initialized_with	= ZRTP_COMP_UNKN;
 	bnBegin(&new_stream->dh_cc.peer_pv);
 	ZSTR_SET_EMPTY(new_stream->dh_cc.dhss);		
@@ -638,8 +638,8 @@ zrtp_status_t zrtp_signaling_hash_set( zrtp_stream_t* ctx,
 	ctx->messages.signaling_hash.length = ZRTP_MESSAGE_HASH_SIZE;
 	
 	{
-	char buff[66];
-	ZRTP_LOG(3, (_ZTU_,"SIGNALLING HAS was ADDED for the comparing. ID=%u\n", ctx->id));
+	char buff[64];
+	ZRTP_LOG(3, (_ZTU_,"SIGNALLING HAS was ADDED for the comparision. ID=%u\n", ctx->id));
 	ZRTP_LOG(3, (_ZTU_,"Hash=%s.\n", hex2str(hash_buff, hash_buff_length, buff, sizeof(buff))));
 	}
 

libs/libzrtp/src/zrtp_pbx.c

@@ -128,13 +128,15 @@ zrtp_status_t _zrtp_machine_process_sasrelay(zrtp_stream_t *stream, zrtp_rtp_inf
 	zrtp_status_t s = zrtp_status_fail;
 	zrtp_string128_t hmac = ZSTR_INIT_EMPTY(hmac);
 	char zerosashash[32];
+	unsigned sas_scheme_did_change = 0;
+	unsigned sas_hash_did_change = 0;
 	
 	/* (padding + sig_len + flags) + SAS scheme and SAS hash */
 	const uint8_t encrypted_body_size = (2 + 1 + 1) + 4 + 32;
 	
 	zrtp_memset(zerosashash, 0, sizeof(zerosashash));
 
-	/* Check if the remote endpoint is assiggneed to relay the SAS values */
+	/* Check if the remote endpoint is assigned to relay the SAS values */
 	if (!stream->peer_mitm_flag) {
 		ZRTP_LOG(2,(_ZTU_, ZRTP_RELAYED_SAS_FROM_NONMITM_STR));
 		return zrtp_status_fail;
@@ -157,7 +159,7 @@ zrtp_status_t _zrtp_machine_process_sasrelay(zrtp_stream_t *stream, zrtp_rtp_inf
 		return zrtp_status_fail;
 	}
 
-	ZRTP_LOG(3,(_ZTU_, "\tHMAC value for the SASRELAY is correct - decryptiong...\n"));
+	ZRTP_LOG(3,(_ZTU_, "\tHMAC value for the SASRELAY is correct - decrypting...\n"));
 
 	/* Then we need to decrypt Confirm body */
 	do
@@ -217,9 +219,14 @@ zrtp_status_t _zrtp_machine_process_sasrelay(zrtp_stream_t *stream, zrtp_rtp_inf
 		_zrtp_machine_enter_initiatingerror(stream, zrtp_error_invalid_packet, 1);
 		return zrtp_status_fail;
 	}
-	session->sasscheme = zrtp_comp_find(ZRTP_CC_SAS, rendering_id, session->zrtp );
 
-	ZRTP_LOG(3,(_ZTU_,"\tSasrelay: New Rendering scheme %.4s.\n", session->sasscheme->base.type));
+	/* Check is SAS rendering did change */
+	if (rendering_id != session->sasscheme->base.id) {
+		session->sasscheme = zrtp_comp_find(ZRTP_CC_SAS, rendering_id, session->zrtp );
+
+		sas_scheme_did_change = 1;
+		ZRTP_LOG(3,(_ZTU_,"\tSasrelay: Rendering scheme was updated to %.4s.\n", session->sasscheme->base.type));
+	}
 
 	if (session->secrets.matches & ZRTP_BIT_PBX) {
 		if ( ( ((uint32_t) *sasrelay->sas_scheme) != (uint32_t)0x0L ) &&
@@ -231,7 +238,8 @@ zrtp_status_t _zrtp_machine_process_sasrelay(zrtp_stream_t *stream, zrtp_rtp_inf
 			zrtp_memcpy(session->sasbin.buffer, sasrelay->sashash, session->sasbin.length);
 			stream->mitm_mode = ZRTP_MITM_MODE_RECONFIRM_CLIENT;
 	
-			ZRTP_LOG(3,(_ZTU_,"\tSasRelay: SAS value was updated bin=%s.\n",
+			sas_hash_did_change = 1;
+			ZRTP_LOG(3,(_ZTU_,"\tSasRelay: SAS value was updated to bin=%s.\n",
 							hex2str(buff, sizeof(buff), session->sasbin.buffer, session->sasbin.length)));
 		}
 	} else if (0 != zrtp_memcmp(sasrelay->sashash, zerosashash, sizeof(sasrelay->sashash))) {
@@ -242,16 +250,24 @@ zrtp_status_t _zrtp_machine_process_sasrelay(zrtp_stream_t *stream, zrtp_rtp_inf
 		ZRTP_LOG(1,(_ZTU_, "\rERROR! For SasRelay Other secret doesn't match. ID=%u\n", stream->id));
 	}
 
-	s = session->sasscheme->compute(session->sasscheme, stream, session->hash, 1);
-	if (zrtp_status_ok != s) {
-		_zrtp_machine_enter_initiatingerror(stream, zrtp_error_software, 1);
-		return s;
-	}
 
-	ZRTP_LOG(3,(_ZTU_,"\tSasRelay: Updated SAS is <%s> <%s>.\n", session->sas1.buffer, session->sas2.buffer));
+	/* Generate new SAS if hash or rendering scheme did change.
+	 * Note: latest libzrtp may send "empty" SasRelay with the same SAS rendering
+	 *       scheme and empty Hello hash for consistency reasons, we should ignore
+	 *       such packets.
+	 */
+	if (sas_scheme_did_change || sas_hash_did_change) {
+		s = session->sasscheme->compute(session->sasscheme, stream, session->hash, 1);
+		if (zrtp_status_ok != s) {
+			_zrtp_machine_enter_initiatingerror(stream, zrtp_error_software, 1);
+			return s;
+		}
 
-	if (session->zrtp->cb.event_cb.on_zrtp_protocol_event) {
-		session->zrtp->cb.event_cb.on_zrtp_protocol_event(stream, ZRTP_EVENT_LOCAL_SAS_UPDATED);
+		ZRTP_LOG(3,(_ZTU_,"\tSasRelay: Updated SAS is <%s> <%s>.\n", session->sas1.buffer, session->sas2.buffer));
+
+		if (session->zrtp->cb.event_cb.on_zrtp_protocol_event) {
+			session->zrtp->cb.event_cb.on_zrtp_protocol_event(stream, ZRTP_EVENT_LOCAL_SAS_UPDATED);
+		}
 	}
 
 	return zrtp_status_ok;
@@ -492,7 +508,7 @@ zrtp_status_t zrtp_update_remote_options( zrtp_stream_t* stream,
 		return zrtp_status_bad_param;
 	}
 	
-	/* Don't allow to transfer the SAS if the library wasn't initalized as MiTM endpoint */
+	/* Don't allow to transfer the SAS if the library wasn't initialized as MiTM endpoint */
 	if (!stream->zrtp->is_mitm) {
 		ZRTP_LOG(3,(_ZTU_,"\tERROR! The endpoint can't transfer SAS values to other endpoints"
 					" without introducing itself by M-flag in Hello. see zrtp_init().\n"));

libs/libzrtp/src/zrtp_utils.c

@@ -488,7 +488,7 @@ zrtp_status_t _zrtp_packet_preparse( zrtp_stream_t* stream,
 							 (const char*) info->message,
 							  zrtp_ntoh16(((zrtp_packet_Hello_t*) info->message)->hdr.length)*4,
 							  ZSTR_GV(hash_str) );
-				if (!zrtp_memcmp(stream->messages.signaling_hash.buffer, hash_str.buffer, ZRTP_MESSAGE_HASH_SIZE)) {
+				if (zrtp_memcmp(stream->messages.signaling_hash.buffer, hash_str.buffer, ZRTP_MESSAGE_HASH_SIZE)) {
 					if (stream->zrtp->cb.event_cb.on_zrtp_security_event) {
 						stream->zrtp->cb.event_cb.on_zrtp_security_event(stream, ZRTP_EVENT_WRONG_SIGNALING_HASH);
 					}