Add support for GCM cipher suites from RFC 7714.

talk/session/media/channel.cc

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 177 matching lines @@
       enabled_(false),
       writable_(false),
       rtp_ready_to_send_(false),
       rtcp_ready_to_send_(false),
       was_ever_writable_(false),
       local_content_direction_(MD_INACTIVE),
       remote_content_direction_(MD_INACTIVE),
       has_received_packet_(false),
       dtls_keyed_(false),
       secure_required_(false),
+      enable_gcm_crypto_suites_(false),
       rtp_abs_sendtime_extn_id_(-1) {
   ASSERT(worker_thread_ == rtc::Thread::Current());
   LOG(LS_INFO) << "Created channel for " << content_name;
 }
 
 BaseChannel::~BaseChannel() {
   ASSERT(worker_thread_ == rtc::Thread::Current());
   Deinit();
   StopConnectionMonitor();
   FlushRtcpMessages();  // Send any outstanding RTCP packets.
@@ skipping 261 matching lines @@
       break;
     case ST_RTCP:
       channel = rtcp_transport_channel_;
       rtcp_socket_options_.push_back(
           std::pair<rtc::Socket::Option, int>(opt, value));
       break;
   }
   return channel ? channel->SetOption(opt, value) : -1;
 }
 
+bool BaseChannel::SetEnableGcmCryptoSuites(bool enable) {
+  enable_gcm_crypto_suites_ = enable;
+  return true;
+}
+
 void BaseChannel::OnWritableState(TransportChannel* channel) {
   ASSERT(channel == transport_channel_ || channel == rtcp_transport_channel_);
   UpdateWritableState_w();
 }
 
 void BaseChannel::OnChannelRead(TransportChannel* channel,
                                 const char* data, size_t len,
                                 const rtc::PacketTime& packet_time,
                                 int flags) {
   TRACE_EVENT0("webrtc", "BaseChannel::OnChannelRead");
@@ skipping 345 matching lines @@
       &BaseChannel::SignalDtlsSetupFailure_s, this, rtcp));
 }
 
 void BaseChannel::SignalDtlsSetupFailure_s(bool rtcp) {
   ASSERT(signaling_thread() == rtc::Thread::Current());
   SignalDtlsSetupFailure(this, rtcp);
 }
 
 bool BaseChannel::SetDtlsSrtpCryptoSuites(TransportChannel* tc, bool rtcp) {
   std::vector<int> crypto_suites;
+  MediaSessionOptions options;
+  options.enable_gcm_crypto_suites = enable_gcm_crypto_suites_;
   // We always use the default SRTP crypto suites for RTCP, but we may use
   // different crypto suites for RTP depending on the media type.
   if (!rtcp) {
-    GetSrtpCryptoSuites(&crypto_suites);
+    GetSrtpCryptoSuites(&crypto_suites, options);
   } else {
-    GetDefaultSrtpCryptoSuites(&crypto_suites);
+    GetDefaultSrtpCryptoSuites(&crypto_suites, options);
   }
   return tc->SetSrtpCryptoSuites(crypto_suites);
 }
 
 bool BaseChannel::ShouldSetupDtlsSrtp() const {
   // Since DTLS is applied to all channels, checking RTP should be enough.
   return transport_channel_ && transport_channel_->IsDtlsActive();
 }
 
 // This function returns true if either DTLS-SRTP is not in use
@@ skipping 10 matching lines @@
 
   if (!channel->GetSrtpCryptoSuite(&selected_crypto_suite)) {
     LOG(LS_ERROR) << "No DTLS-SRTP selected crypto suite";
     return false;
   }
 
   LOG(LS_INFO) << "Installing keys from DTLS-SRTP on "
                << content_name() << " "
                << PacketType(rtcp_channel);
 
+  int key_len;
+  int salt_len;
+  if (!rtc::GetSrtpKeyAndSaltLengths(selected_crypto_suite, &key_len,
+      &salt_len)) {
+    LOG(LS_ERROR) << "Unknown DTLS-SRTP crypto suite" << selected_crypto_suite;
+    return false;
+  }
+
   // OK, we're now doing DTLS (RFC 5764)
-  std::vector<unsigned char> dtls_buffer(SRTP_MASTER_KEY_KEY_LEN * 2 +
-                                         SRTP_MASTER_KEY_SALT_LEN * 2);
+  std::vector<unsigned char> dtls_buffer(key_len * 2 + salt_len * 2);
 
   // RFC 5705 exporter using the RFC 5764 parameters
   if (!channel->ExportKeyingMaterial(
           kDtlsSrtpExporterLabel,
           NULL, 0, false,
           &dtls_buffer[0], dtls_buffer.size())) {
     LOG(LS_WARNING) << "DTLS-SRTP key export failed";
     ASSERT(false);  // This should never happen
     return false;
   }
 
   // Sync up the keys with the DTLS-SRTP interface
-  std::vector<unsigned char> client_write_key(SRTP_MASTER_KEY_KEY_LEN +
-    SRTP_MASTER_KEY_SALT_LEN);
-  std::vector<unsigned char> server_write_key(SRTP_MASTER_KEY_KEY_LEN +
-    SRTP_MASTER_KEY_SALT_LEN);
+  std::vector<unsigned char> client_write_key(key_len + salt_len);
+  std::vector<unsigned char> server_write_key(key_len + salt_len);
   size_t offset = 0;
-  memcpy(&client_write_key[0], &dtls_buffer[offset],
-    SRTP_MASTER_KEY_KEY_LEN);
-  offset += SRTP_MASTER_KEY_KEY_LEN;
-  memcpy(&server_write_key[0], &dtls_buffer[offset],
-    SRTP_MASTER_KEY_KEY_LEN);
-  offset += SRTP_MASTER_KEY_KEY_LEN;
-  memcpy(&client_write_key[SRTP_MASTER_KEY_KEY_LEN],
-    &dtls_buffer[offset], SRTP_MASTER_KEY_SALT_LEN);
-  offset += SRTP_MASTER_KEY_SALT_LEN;
-  memcpy(&server_write_key[SRTP_MASTER_KEY_KEY_LEN],
-    &dtls_buffer[offset], SRTP_MASTER_KEY_SALT_LEN);
+  memcpy(&client_write_key[0], &dtls_buffer[offset], key_len);
+  offset += key_len;
+  memcpy(&server_write_key[0], &dtls_buffer[offset], key_len);
+  offset += key_len;
+  memcpy(&client_write_key[key_len], &dtls_buffer[offset], salt_len);
+  offset += salt_len;
+  memcpy(&server_write_key[key_len], &dtls_buffer[offset], salt_len);
 
   std::vector<unsigned char> *send_key, *recv_key;
   rtc::SSLRole role;
   if (!channel->GetSslRole(&role)) {
     LOG(LS_WARNING) << "GetSslRole failed";
     return false;
   }
 
   if (role == rtc::SSL_SERVER) {
     send_key = &server_write_key;
@@ skipping 697 matching lines @@
     VoiceMediaChannel* media_channel, const VoiceMediaInfo& info) {
   ASSERT(media_channel == this->media_channel());
   SignalMediaMonitor(this, info);
 }
 
 void VoiceChannel::OnAudioMonitorUpdate(AudioMonitor* monitor,
                                         const AudioInfo& info) {
   SignalAudioMonitor(this, info);
 }
 
-void VoiceChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const {
-  GetSupportedAudioCryptoSuites(crypto_suites);
+void VoiceChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options) const {
+  GetSupportedAudioCryptoSuites(crypto_suites, options);
 }
 
 VideoChannel::VideoChannel(rtc::Thread* thread,
                            VideoMediaChannel* media_channel,
                            TransportController* transport_controller,
                            const std::string& content_name,
                            bool rtcp)
     : BaseChannel(thread,
                   media_channel,
                   transport_controller,
@@ skipping 369 matching lines @@
   for (ScreencastMap::iterator iter = screencast_capturers_.begin();
        iter != screencast_capturers_.end(); ++iter) {
     if (iter->second == capturer) {
       *ssrc = iter->first;
       return true;
     }
   }
   return false;
 }
 
-void VideoChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const {
-  GetSupportedVideoCryptoSuites(crypto_suites);
+void VideoChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options) const {
+  GetSupportedVideoCryptoSuites(crypto_suites, options);
 }
 
 DataChannel::DataChannel(rtc::Thread* thread,
                          DataMediaChannel* media_channel,
                          TransportController* transport_controller,
                          const std::string& content_name,
                          bool rtcp)
     : BaseChannel(thread,
                   media_channel,
                   transport_controller,
@@ skipping 287 matching lines @@
 }
 
 void DataChannel::OnDataChannelReadyToSend(bool writable) {
   // This is usded for congestion control to indicate that the stream is ready
   // to send by the MediaChannel, as opposed to OnReadyToSend, which indicates
   // that the transport channel is ready.
   signaling_thread()->Post(this, MSG_READYTOSENDDATA,
                            new DataChannelReadyToSendMessageData(writable));
 }
 
-void DataChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const {
-  GetSupportedDataCryptoSuites(crypto_suites);
+void DataChannel::GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options) const {
+  GetSupportedDataCryptoSuites(crypto_suites, options);
 }
 
 bool DataChannel::ShouldSetupDtlsSrtp() const {
   return (data_channel_type_ == DCT_RTP) && BaseChannel::ShouldSetupDtlsSrtp();
 }
 
 void DataChannel::OnStreamClosedRemotely(uint32_t sid) {
   rtc::TypedMessageData<uint32_t>* message =
       new rtc::TypedMessageData<uint32_t>(sid);
   signaling_thread()->Post(this, MSG_STREAMCLOSEDREMOTELY, message);
 }
 
 }  // namespace cricket