Add support for GCM cipher suites from RFC 7714.

talk/session/media/channel_unittest.cc

Index: talk/session/media/channel_unittest.cc
diff --git a/talk/session/media/channel_unittest.cc b/talk/session/media/channel_unittest.cc
index 35e7142c13d649ac5bf529989831bc403cc794a0..78c781de67895884aa942c4c675adc401fdca1fe 100644
--- a/talk/session/media/channel_unittest.cc
+++ b/talk/session/media/channel_unittest.cc
@@ -125,7 +125,7 @@ template<class T>
 class ChannelTest : public testing::Test, public sigslot::has_slots<> {
  public:
   enum Flags { RTCP = 0x1, RTCP_MUX = 0x2, SECURE = 0x4, SSRC_MUX = 0x8,
-               DTLS = 0x10 };
+               DTLS = 0x10, GCM_CIPHER = 0x20 };
 
   ChannelTest(bool verify_playout,
               const uint8_t* rtp_data,
@@ -152,6 +152,8 @@ class ChannelTest : public testing::Test, public sigslot::has_slots<> {
       int flags1, int flags2, rtc::Thread* thread) {
     media_channel1_ = ch1;
     media_channel2_ = ch2;
+    transport_controller1_.SetEnableGcmCiphers((flags1 & GCM_CIPHER) != 0);
+    transport_controller2_.SetEnableGcmCiphers((flags2 & GCM_CIPHER) != 0);
     channel1_.reset(CreateChannel(thread, &media_engine_, ch1,
                                   &transport_controller1_,
                                   (flags1 & RTCP) != 0));
@@ -399,6 +401,20 @@ class ChannelTest : public testing::Test, public sigslot::has_slots<> {
   bool CheckNoRtcp2() {
     return media_channel2_->CheckNoRtcp();
   }
+  bool CheckGcmCipher(typename T::Channel* channel, int flags) {
+    int suite;
+    if (!channel->transport_channel()->GetSrtpCryptoSuite(&suite)) {
+      return false;
+    }
+
+    if (flags & GCM_CIPHER) {
+      return (suite == rtc::SRTP_AEAD_AES_128_GCM ||
+          suite == rtc::SRTP_AEAD_AES_256_GCM);
+    } else {
+      return (suite == rtc::SRTP_AES128_CM_SHA1_80 ||
+          suite == rtc::SRTP_AES128_CM_SHA1_32);
+    }
+  }
 
   void CreateContent(int flags,
                      const cricket::AudioCodec& audio_codec,
@@ -1246,8 +1262,8 @@ class ChannelTest : public testing::Test, public sigslot::has_slots<> {
   // Test that we properly send SRTP with RTCP in both directions.
   // You can pass in DTLS and/or RTCP_MUX as flags.
   void SendSrtpToSrtp(int flags1_in = 0, int flags2_in = 0) {
-    ASSERT((flags1_in & ~(RTCP_MUX | DTLS)) == 0);
-    ASSERT((flags2_in & ~(RTCP_MUX | DTLS)) == 0);
+    ASSERT((flags1_in & ~(RTCP_MUX | DTLS | GCM_CIPHER)) == 0);
+    ASSERT((flags2_in & ~(RTCP_MUX | DTLS | GCM_CIPHER)) == 0);
 
     int flags1 = RTCP | SECURE | flags1_in;
     int flags2 = RTCP | SECURE | flags2_in;
@@ -1264,6 +1280,10 @@ class ChannelTest : public testing::Test, public sigslot::has_slots<> {
     EXPECT_TRUE(channel2_->secure());
     EXPECT_EQ(dtls1 && dtls2, channel1_->secure_dtls());
     EXPECT_EQ(dtls1 && dtls2, channel2_->secure_dtls());
+    // A GCM cipher is only used if both channels support GCM ciphers.
+    int common_gcm_flags = (flags1 & GCM_CIPHER) & (flags2 & GCM_CIPHER);
+    EXPECT_TRUE(CheckGcmCipher(channel1_.get(), common_gcm_flags));
+    EXPECT_TRUE(CheckGcmCipher(channel2_.get(), common_gcm_flags));
     EXPECT_TRUE(SendRtp1());
     EXPECT_TRUE(SendRtp2());
     EXPECT_TRUE(SendRtcp1());
@@ -2087,6 +2107,21 @@ TEST_F(VoiceChannelTest, SendDtlsSrtpToDtlsSrtp) {
   Base::SendSrtpToSrtp(DTLS, DTLS);
 }
 
+TEST_F(VoiceChannelTest, SendDtlsSrtpToDtlsSrtpGcmBoth) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS | GCM_CIPHER, DTLS | GCM_CIPHER);
+}
+
+TEST_F(VoiceChannelTest, SendDtlsSrtpToDtlsSrtpGcmOne) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS | GCM_CIPHER, DTLS);
+}
+
+TEST_F(VoiceChannelTest, SendDtlsSrtpToDtlsSrtpGcmTwo) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS, DTLS | GCM_CIPHER);
+}
+
 TEST_F(VoiceChannelTest, SendDtlsSrtpToDtlsSrtpRtcpMux) {
   MAYBE_SKIP_TEST(HaveDtlsSrtp);
   Base::SendSrtpToSrtp(DTLS | RTCP_MUX, DTLS | RTCP_MUX);
@@ -2423,6 +2458,21 @@ TEST_F(VideoChannelTest, SendDtlsSrtpToDtlsSrtp) {
   Base::SendSrtpToSrtp(DTLS, DTLS);
 }
 
+TEST_F(VideoChannelTest, SendDtlsSrtpToDtlsSrtpGcmBoth) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS | GCM_CIPHER, DTLS | GCM_CIPHER);
+}
+
+TEST_F(VideoChannelTest, SendDtlsSrtpToDtlsSrtpGcmOne) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS | GCM_CIPHER, DTLS);
+}
+
+TEST_F(VideoChannelTest, SendDtlsSrtpToDtlsSrtpGcmTwo) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  Base::SendSrtpToSrtp(DTLS, DTLS | GCM_CIPHER);
+}
+
 TEST_F(VideoChannelTest, SendDtlsSrtpToDtlsSrtpRtcpMux) {
   MAYBE_SKIP_TEST(HaveDtlsSrtp);
   Base::SendSrtpToSrtp(DTLS | RTCP_MUX, DTLS | RTCP_MUX);