Merge pull request #290 from paullouisageneau/revert-srtp-wildcards

Reverted SRTP inbound and outbound wildcards

src/dtlssrtptransport.cpp

@@ -109,32 +109,17 @@ bool DtlsSrtpTransport::sendMedia(message_ptr message) {
 	if (value2 >= 64 && value2 <= 95) { // Range 64-95 (inclusive) MUST be RTCP
 		if (srtp_err_status_t err = srtp_protect_rtcp(mSrtpOut, message->data(), &size)) {
 			if (err == srtp_err_status_replay_fail)
-				throw std::runtime_error("SRTCP packet is a replay");
-			else if (err == srtp_err_status_no_ctx) {
-				auto ssrc = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
-				PLOG_INFO << "Adding SSRC to SRTCP: " << ssrc;
-				addSSRC(ssrc);
-				if ((err = srtp_protect_rtcp(mSrtpOut, message->data(), &size)))
-					throw std::runtime_error("SRTCP protect error, status=" +
-					                         to_string(static_cast<int>(err)));
-			} else {
+				throw std::runtime_error("Outgoing SRTCP packet is a replay");
+			else
 				throw std::runtime_error("SRTCP protect error, status=" +
 				                         to_string(static_cast<int>(err)));
-			}
 		}
 		PLOG_VERBOSE << "Protected SRTCP packet, size=" << size;
 	} else {
 		if (srtp_err_status_t err = srtp_protect(mSrtpOut, message->data(), &size)) {
 			if (err == srtp_err_status_replay_fail)
 				throw std::runtime_error("Outgoing SRTP packet is a replay");
-			else if (err == srtp_err_status_no_ctx) {
-				auto ssrc = reinterpret_cast<RTP *>(message->data())->ssrc();
-				PLOG_INFO << "Adding SSRC to RTP: " << ssrc;
-				addSSRC(ssrc);
-				if ((err = srtp_protect(mSrtpOut, message->data(), &size)))
-					throw std::runtime_error("SRTP protect error, status=" +
-					                         to_string(static_cast<int>(err)));
-			} else
+			else
 				throw std::runtime_error("SRTP protect error, status=" +
 				                         to_string(static_cast<int>(err)));
 		}
@@ -196,19 +181,15 @@ void DtlsSrtpTransport::incoming(message_ptr message) {
 					PLOG_WARNING << "Incoming SRTCP packet is a replay";
 				else if (err == srtp_err_status_auth_fail)
 					PLOG_WARNING << "Incoming SRTCP packet failed authentication check";
-				else if (err == srtp_err_status_no_ctx) {
-					auto ssrc = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
-					PLOG_INFO << "Adding SSRC to RTCP: " << ssrc;
-					addSSRC(ssrc);
-				} else {
-					PLOG_WARNING << "SRTCP unprotect error, status=" << err
-					             << " SSRC=" << ((RTCP_SR *)message->data())->senderSSRC();
-				}
+				else
+					PLOG_WARNING << "SRTCP unprotect error, status=" << err;
+
 				return;
 			}
 			PLOG_VERBOSE << "Unprotected SRTCP packet, size=" << size;
 			message->type = Message::Type::Control;
 			message->stream = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
+
 		} else {
 			PLOG_VERBOSE << "Incoming SRTP packet, size=" << size;
 			if (srtp_err_status_t err = srtp_unprotect(mSrtpIn, message->data(), &size)) {
@@ -216,14 +197,9 @@ void DtlsSrtpTransport::incoming(message_ptr message) {
 					PLOG_WARNING << "Incoming SRTP packet is a replay";
 				else if (err == srtp_err_status_auth_fail)
 					PLOG_WARNING << "Incoming SRTP packet failed authentication check";
-				else if (err == srtp_err_status_no_ctx) {
-					auto ssrc = reinterpret_cast<RTP *>(message->data())->ssrc();
-					PLOG_INFO << "Adding SSRC to RTP: " << ssrc;
-					addSSRC(ssrc);
-				} else {
-					PLOG_WARNING << "SRTP unprotect error, status=" << err
-					             << " SSRC=" << reinterpret_cast<RTP *>(message->data())->ssrc();
-				}
+				else
+					PLOG_WARNING << "SRTP unprotect error, status=" << err;
+
 				return;
 			}
 			PLOG_VERBOSE << "Unprotected SRTP packet, size=" << size;
@@ -299,37 +275,14 @@ void DtlsSrtpTransport::postHandshake() {
 	std::memcpy(mServerSessionKey, serverKey, SRTP_AES_128_KEY_LEN);
 	std::memcpy(mServerSessionKey + SRTP_AES_128_KEY_LEN, serverSalt, SRTP_SALT_LEN);
 
-	// Add SSRC=1 as an inbound because that is what Chrome does.
 	srtp_policy_t inbound = {};
 	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&inbound.rtp);
 	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&inbound.rtcp);
-	inbound.ssrc.type = ssrc_specific;
-	inbound.ssrc.value = 1;
+	inbound.ssrc.type = ssrc_any_inbound;
 	inbound.key = mIsClient ? mServerSessionKey : mClientSessionKey;
 	inbound.window_size = 1024;
-	inbound.next = nullptr;
-
-	if (srtp_err_status_t err = srtp_add_stream(mSrtpIn, &inbound)) {
-		throw std::runtime_error("SRTP add inbound stream failed, status=" +
-		                         to_string(static_cast<int>(err)));
-	}
-
-	mInitDone = true;
-}
-
-void DtlsSrtpTransport::addSSRC(uint32_t ssrc) {
-	if (!mInitDone)
-		throw std::logic_error("Attempted to add SSRC before SRTP keying material is derived");
-
-	srtp_policy_t inbound = {};
-	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&inbound.rtp);
-	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&inbound.rtcp);
-	inbound.ssrc.type = ssrc_specific;
-	inbound.ssrc.value = ssrc;
-	inbound.key = mIsClient ? mServerSessionKey : mClientSessionKey;
-	inbound.window_size = 1024;
-	inbound.next = nullptr;
 	inbound.allow_repeat_tx = true;
+	inbound.next = nullptr;
 
 	if (srtp_err_status_t err = srtp_add_stream(mSrtpIn, &inbound))
 		throw std::runtime_error("SRTP add inbound stream failed, status=" +
@@ -338,16 +291,17 @@ void DtlsSrtpTransport::addSSRC(uint32_t ssrc) {
 	srtp_policy_t outbound = {};
 	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&outbound.rtp);
 	srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&outbound.rtcp);
-	outbound.ssrc.type = ssrc_specific;
-	outbound.ssrc.value = ssrc;
+	outbound.ssrc.type = ssrc_any_outbound;
 	outbound.key = mIsClient ? mClientSessionKey : mServerSessionKey;
 	outbound.window_size = 1024;
-	outbound.next = nullptr;
 	outbound.allow_repeat_tx = true;
+	outbound.next = nullptr;
 
 	if (srtp_err_status_t err = srtp_add_stream(mSrtpOut, &outbound))
 		throw std::runtime_error("SRTP add outbound stream failed, status=" +
 		                         to_string(static_cast<int>(err)));
+
+	mInitDone = true;
 }
 
 } // namespace rtc

src/dtlssrtptransport.hpp

@@ -45,7 +45,6 @@ public:
 	~DtlsSrtpTransport();
 
 	bool sendMedia(message_ptr message);
-	void addSSRC(uint32_t ssrc);
 
 private:
 	void incoming(message_ptr message) override;