Support encrypted RTP extensions (RFC 6904)

webrtc/config.cc

Index: webrtc/config.cc
diff --git a/webrtc/config.cc b/webrtc/config.cc
index e0c490d1ecd8038d546b7298fc9a885ab02718df..80f9f12fa2199223cb0221d753e00c0952a72fc2 100644
--- a/webrtc/config.cc
+++ b/webrtc/config.cc
@@ -41,6 +41,9 @@ std::string RtpExtension::ToString() const {
   std::stringstream ss;
   ss << "{uri: " << uri;
   ss << ", id: " << id;
+  if (encrypt) {
+    ss << ", encrypt";
+  }
   ss << '}';
   return ss.str();
 }
@@ -72,6 +75,9 @@ const char* RtpExtension::kPlayoutDelayUri =
     "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay";
 const int RtpExtension::kPlayoutDelayDefaultId = 6;
 
+const char* RtpExtension::kEncryptHeaderExtensionsUri =
+    "urn:ietf:params:rtp-hdrext:encrypt";
+
 const int RtpExtension::kMinId = 1;
 const int RtpExtension::kMaxId = 14;
 
@@ -88,6 +94,26 @@ bool RtpExtension::IsSupportedForVideo(const std::string& uri) {
          uri == webrtc::RtpExtension::kPlayoutDelayUri;
 }
 
+bool RtpExtension::IsEncryptionSupported(const std::string& uri) {
+  // TODO(jbauch): Figure out a way to add "kTimestampOffsetUri" here
+  // and filter out later if external auth is used in srtpfilter.
+  return uri == webrtc::RtpExtension::kAudioLevelUri ||
+         uri == webrtc::RtpExtension::kTimestampOffsetUri ||
+         uri == webrtc::RtpExtension::kVideoRotationUri ||
+         uri == webrtc::RtpExtension::kTransportSequenceNumberUri ||
+         uri == webrtc::RtpExtension::kPlayoutDelayUri;
+}
+
+const RtpExtension* RtpExtension::FindHeaderExtensionByUri(
+    const std::vector<RtpExtension>& extensions,
+    const std::string& uri) {
+  for (const auto& extension : extensions) {
+    if (extension.uri == uri)

[Taylor Brandstetter, 2017/03/23 20:10:56]

nit: Our style is to use {}s even for single-line if statements

[joachim, 2017/03/30 22:43:49]

Done (mine too, looks like I missed this after moving the function from
channel.cc).

+      return &extension;
+  }
+  return nullptr;
+}
+
 VideoStream::VideoStream()
     : width(0),
       height(0),