Add support for GCM cipher suites from RFC 7714.

webrtc/pc/srtpfilter.h

Index: webrtc/pc/srtpfilter.h
diff --git a/webrtc/pc/srtpfilter.h b/webrtc/pc/srtpfilter.h
index cde9ad7e09c84dbc4a0214cba3505768c3bfcf5b..26a335fbaebf2fe11f7307cc53b5db072b7bb375 100644
--- a/webrtc/pc/srtpfilter.h
+++ b/webrtc/pc/srtpfilter.h
@@ -33,13 +33,6 @@ struct srtp_policy_t;
 
 namespace cricket {
 
-// Key is 128 bits and salt is 112 bits == 30 bytes. B64 bloat => 40 bytes.
-extern const int SRTP_MASTER_KEY_BASE64_LEN;
-
-// Needed for DTLS-SRTP
-extern const int SRTP_MASTER_KEY_KEY_LEN;
-extern const int SRTP_MASTER_KEY_SALT_LEN;
-
 class SrtpSession;
 class SrtpStat;
 
@@ -140,7 +133,9 @@ class SrtpFilter {
                        CryptoParams* selected_params);
   bool ApplyParams(const CryptoParams& send_params,
                    const CryptoParams& recv_params);
-  static bool ParseKeyParams(const std::string& params, uint8_t* key, int len);
+  static bool ParseKeyParams(const std::string& params,
+                             uint8_t* key,
+                             size_t len);
 
  private:
   enum State {
@@ -185,10 +180,10 @@ 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, int len);
+  bool SetSend(int cs, const uint8_t* key, size_t len);
   // 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, int len);
+  bool SetRecv(int cs, const uint8_t* key, size_t len);
 
   // Encrypts/signs an individual RTP/RTCP packet, in-place.
   // If an HMAC is used, this will increase the packet size.
@@ -218,7 +213,7 @@ class SrtpSession {
       SignalSrtpError;
 
  private:
-  bool SetKey(int type, int cs, const uint8_t* key, int len);
+  bool SetKey(int type, int cs, const uint8_t* key, size_t len);
     // Returns send stream current packet index from srtp db.
   bool GetSendStreamPacketIndex(void* data, int in_len, int64_t* index);