Support encrypted RTP extensions (RFC 6904)

webrtc/pc/srtpfilter.h

Index: webrtc/pc/srtpfilter.h
diff --git a/webrtc/pc/srtpfilter.h b/webrtc/pc/srtpfilter.h
index 3df787646c740eb819f93986e697de0daabf1237..9e1197e1bd8f9cb84b727a6a29ca534465f6fd79 100644
--- a/webrtc/pc/srtpfilter.h
+++ b/webrtc/pc/srtpfilter.h
@@ -23,6 +23,7 @@
 #include "webrtc/base/sigslotrepeater.h"
 #include "webrtc/base/sslstreamadapter.h"
 #include "webrtc/base/thread_checker.h"
+#include "webrtc/config.h"
 #include "webrtc/media/base/cryptoparams.h"
 #include "webrtc/p2p/base/sessiondescription.h"
 
@@ -78,6 +79,12 @@ class SrtpFilter {
   bool SetAnswer(const std::vector<CryptoParams>& answer_params,
                  ContentSource source);
 
+  // Set the header extensions that should be encrypted for the given source.
+  // Only header extensions that should be encrypted for both sides will be
+  // encrypted.
+  void SetEncryptedHeaderExtensions(ContentSource source,
+      const std::vector<webrtc::RtpExtension>& extensions);
+
   // Just set up both sets of keys directly.
   // Used with DTLS-SRTP.
   bool SetRtpParams(int send_cs,
@@ -143,6 +150,8 @@ class SrtpFilter {
                      ContentSource source,
                      bool final);
   void CreateSrtpSessions();
+  void GetSendRecvEncryptedHeaderExtensions(
+    std::vector<int>* send_extensions, std::vector<int>* recv_extensions);
   bool NegotiateParams(const std::vector<CryptoParams>& answer_params,
                        CryptoParams* selected_params);
   bool ApplyParams(const CryptoParams& send_params,
@@ -185,6 +194,8 @@ class SrtpFilter {
   std::unique_ptr<SrtpSession> recv_rtcp_session_;
   CryptoParams applied_send_params_;
   CryptoParams applied_recv_params_;
+  std::vector<webrtc::RtpExtension> local_encrypted_header_extensions_;
+  std::vector<webrtc::RtpExtension> remote_encrypted_header_extensions_;
 };
 
 // Class that wraps a libSRTP session.
@@ -195,10 +206,12 @@ class SrtpSession {
 
   // Configures the session for sending data using the specified
   // cipher-suite and key. Receiving must be done by a separate session.
-  bool SetSend(int cs, const uint8_t* key, size_t len);
+  bool SetSend(int cs, const uint8_t* key, size_t len,
+      const std::vector<int>& encrypted_header_extensions);
   // Configures the session for receiving data using the specified
   // cipher-suite and key. Sending must be done by a separate session.
-  bool SetRecv(int cs, const uint8_t* key, size_t len);
+  bool SetRecv(int cs, const uint8_t* key, size_t len,
+      const std::vector<int>& encrypted_header_extensions);
 
   // Encrypts/signs an individual RTP/RTCP packet, in-place.
   // If an HMAC is used, this will increase the packet size.
@@ -243,7 +256,8 @@ class SrtpSession {
       SignalSrtpError;
 
  private:
-  bool SetKey(int type, int cs, const uint8_t* key, size_t len);
+  bool SetKeyAndEncryptedHeaderExtensions(int type, int cs, const uint8_t* key,
+      size_t len, const std::vector<int>& encrypted_header_extensions);
     // Returns send stream current packet index from srtp db.
   bool GetSendStreamPacketIndex(void* data, int in_len, int64_t* index);