Add support for GCM cipher suites from RFC 7714.

webrtc/api/peerconnectioninterface.h

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 553 matching lines @@
 // argument.
 class PeerConnectionFactoryInterface : public rtc::RefCountInterface {
  public:
   class Options {
    public:
     Options()
         : disable_encryption(false),
           disable_sctp_data_channels(false),
           disable_network_monitor(false),
           network_ignore_mask(rtc::kDefaultNetworkIgnoreMask),
           ssl_max_version(rtc::SSL_PROTOCOL_DTLS_12) {}

[mattdr, 2016/05/06 22:34:13]

Everything else here gets an explicit default. I'd like it to be more obvious
that the default options don't enable GCM.

Maybe add a static method to CryptoOptions, CryptoOptions::NoGcm(), which
returns an instance with GCM disabled, then use it here?

[joachim, 2016/05/09 23:21:40]

Right, that's a good idea. Done.

     bool disable_encryption;
     bool disable_sctp_data_channels;
     bool disable_network_monitor;
 
     // Sets the network types to ignore. For instance, calling this with
     // ADAPTER_TYPE_ETHERNET | ADAPTER_TYPE_LOOPBACK will ignore Ethernet and
     // loopback interfaces.
     int network_ignore_mask;
 
     // Sets the maximum supported protocol version. The highest version
     // supported by both ends will be used for the connection, i.e. if one
     // party supports DTLS 1.0 and the other DTLS 1.2, DTLS 1.0 will be used.
     rtc::SSLProtocolVersion ssl_max_version;
+
+    // Sets crypto related options, e.g. enabled cipher suites.
+    rtc::CryptoOptions crypto_options;
   };
 
   virtual void SetOptions(const Options& options) = 0;
 
   virtual rtc::scoped_refptr<PeerConnectionInterface> CreatePeerConnection(
       const PeerConnectionInterface::RTCConfiguration& configuration,
       const MediaConstraintsInterface* constraints,
       std::unique_ptr<cricket::PortAllocator> allocator,
       std::unique_ptr<DtlsIdentityStoreInterface> dtls_identity_store,
       PeerConnectionObserver* observer) = 0;
@@ skipping 97 matching lines @@
 CreatePeerConnectionFactory(
     rtc::Thread* worker_thread,
     rtc::Thread* signaling_thread,
     AudioDeviceModule* default_adm,
     cricket::WebRtcVideoEncoderFactory* encoder_factory,
     cricket::WebRtcVideoDecoderFactory* decoder_factory);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_PEERCONNECTIONINTERFACE_H_