Add support for GCM cipher suites from RFC 7714.

talk/session/media/mediasession.h

 /*
  * 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 85 matching lines @@
 struct MediaSessionOptions {
   MediaSessionOptions() :
       recv_audio(true),
       recv_video(false),
       data_channel_type(DCT_NONE),
       is_muc(false),
       vad_enabled(true),  // When disabled, removes all CN codecs from SDP.
       rtcp_mux_enabled(true),
       bundle_enabled(false),
       video_bandwidth(kAutoBandwidth),
-      data_bandwidth(kDataMaxBandwidth) {
+      data_bandwidth(kDataMaxBandwidth),
+      enable_gcm_crypto_suites(false) {
   }
 
   bool has_audio() const {
     return recv_audio || HasSendMediaStream(MEDIA_TYPE_AUDIO);
   }
   bool has_video() const {
     return recv_video || HasSendMediaStream(MEDIA_TYPE_VIDEO);
   }
   bool has_data() const { return data_channel_type != DCT_NONE; }
 
@@ skipping 20 matching lines @@
   bool recv_audio;
   bool recv_video;
   DataChannelType data_channel_type;
   bool is_muc;
   bool vad_enabled;
   bool rtcp_mux_enabled;
   bool bundle_enabled;
   // bps. -1 == auto.
   int video_bandwidth;
   int data_bandwidth;
+  bool enable_gcm_crypto_suites;
   TransportOptions transport_options;
 
   struct Stream {
     Stream(MediaType type,
            const std::string& id,
            const std::string& sync_label,
            int num_sim_layers)
         : type(type), id(id), sync_label(sync_label),
           num_sim_layers(num_sim_layers) {
     }
@@ skipping 379 matching lines @@
 const ContentInfo* GetFirstAudioContent(const SessionDescription* sdesc);
 const ContentInfo* GetFirstVideoContent(const SessionDescription* sdesc);
 const ContentInfo* GetFirstDataContent(const SessionDescription* sdesc);
 const AudioContentDescription* GetFirstAudioContentDescription(
     const SessionDescription* sdesc);
 const VideoContentDescription* GetFirstVideoContentDescription(
     const SessionDescription* sdesc);
 const DataContentDescription* GetFirstDataContentDescription(
     const SessionDescription* sdesc);
 
-void GetSupportedAudioCryptoSuites(std::vector<int>* crypto_suites);
-void GetSupportedVideoCryptoSuites(std::vector<int>* crypto_suites);
-void GetSupportedDataCryptoSuites(std::vector<int>* crypto_suites);
-void GetDefaultSrtpCryptoSuites(std::vector<int>* crypto_suites);
+void GetSupportedAudioCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options);

[pthatcher1, 2015/12/21 22:30:27]

This looks a lot better, but two things:

1.  The out parameter should be last, and the options first.

2.  The MediaSessionOptions struct is huge.  Could you define a smaller struct
instead?  Perhaps something like CryptoOptions?  Then those could be passed
here.  In fact, it would be nice to pass that around and store that everywhere
you currently pass around store a bool.  So instead of 

SetEnableGcmCryptoSuites(bool enable_gcm_crypto_suites) {   
  enable_gcm_crypto_suites_ = enable_gcm_crypto_suites; 
}

And the like, we could have 

SetCryptoOptions(const CryptoOptions& crypto_options) { 
  crypto_options_ = crypto_options_; 
}.  

I think that would be cleaner and make it easier to add other controls over
crypto suites in the future.

[joachim, 2015/12/21 23:37:57]

Done
Ok, makes sense. Added struct in sslstreamadapter.h and changed various
methods/classes.

+void GetSupportedVideoCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options);
+void GetSupportedDataCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options);
+void GetDefaultSrtpCryptoSuites(std::vector<int>* crypto_suites,
+    const MediaSessionOptions& options);
 void GetSupportedAudioCryptoSuiteNames(
-    std::vector<std::string>* crypto_suite_names);
+    std::vector<std::string>* crypto_suite_names,
+    const MediaSessionOptions& options);
 void GetSupportedVideoCryptoSuiteNames(
-    std::vector<std::string>* crypto_suite_names);
+    std::vector<std::string>* crypto_suite_names,
+    const MediaSessionOptions& options);
 void GetSupportedDataCryptoSuiteNames(
-    std::vector<std::string>* crypto_suite_names);
+    std::vector<std::string>* crypto_suite_names,
+    const MediaSessionOptions& options);
 void GetDefaultSrtpCryptoSuiteNames(
-    std::vector<std::string>* crypto_suite_names);
+    std::vector<std::string>* crypto_suite_names,
+    const MediaSessionOptions& options);
 
 }  // namespace cricket
 
 #endif  // TALK_SESSION_MEDIA_MEDIASESSION_H_