Support GCM ciphers even if ENABLE_EXTERNAL_AUTH is defined.

webrtc/pc/channel.cc

Index: webrtc/pc/channel.cc
diff --git a/webrtc/pc/channel.cc b/webrtc/pc/channel.cc
index 9ac9d201ab57eecf632fdfc514bb956058b0e994..6d2e45cdc2ae3fcba551a5fd5d02335d993094bd 100644
--- a/webrtc/pc/channel.cc
+++ b/webrtc/pc/channel.cc
@@ -43,7 +43,6 @@ struct SendPacketMessageData : public rtc::MessageData {
   rtc::PacketOptions options;
 };
 
-#if defined(ENABLE_EXTERNAL_AUTH)
 // Returns the named header extension if found among all extensions,
 // nullptr otherwise.
 const webrtc::RtpExtension* FindHeaderExtension(
@@ -55,7 +54,6 @@ const webrtc::RtpExtension* FindHeaderExtension(
   }
   return nullptr;
 }
-#endif
 
 }  // namespace
 
@@ -736,29 +734,29 @@ bool BaseChannel::SendPacket(bool rtcp,
     // a fake HMAC value. This is ONLY done for a RTP packet.
     // Socket layer will update rtp sendtime extension header if present in
     // packet with current time before updating the HMAC.
-#if !defined(ENABLE_EXTERNAL_AUTH)
-      res = srtp_filter_.ProtectRtp(
-          data, len, static_cast<int>(packet->capacity()), &len);
-#else
-      updated_options.packet_time_params.rtp_sendtime_extension_id =
-          rtp_abs_sendtime_extn_id_;
-      res = srtp_filter_.ProtectRtp(
-          data, len, static_cast<int>(packet->capacity()), &len,
-          &updated_options.packet_time_params.srtp_packet_index);
-      // If protection succeeds, let's get auth params from srtp.
-      if (res) {
-        uint8_t* auth_key = NULL;
-        int key_len;
-        res = srtp_filter_.GetRtpAuthParams(
-            &auth_key, &key_len,
-            &updated_options.packet_time_params.srtp_auth_tag_len);
+      if (!srtp_filter_.AllowExternalAuth()) {
+        res = srtp_filter_.ProtectRtp(
+            data, len, static_cast<int>(packet->capacity()), &len);
+      } else {
+        updated_options.packet_time_params.rtp_sendtime_extension_id =
+            rtp_abs_sendtime_extn_id_;
+        res = srtp_filter_.ProtectRtp(
+            data, len, static_cast<int>(packet->capacity()), &len,
+            &updated_options.packet_time_params.srtp_packet_index);
+        // If protection succeeds, let's get auth params from srtp.
         if (res) {
-          updated_options.packet_time_params.srtp_auth_key.resize(key_len);
-          updated_options.packet_time_params.srtp_auth_key.assign(
-              auth_key, auth_key + key_len);
+          uint8_t* auth_key = NULL;
+          int key_len;
+          res = srtp_filter_.GetRtpAuthParams(
+              &auth_key, &key_len,
+              &updated_options.packet_time_params.srtp_auth_tag_len);
+          if (res) {
+            updated_options.packet_time_params.srtp_auth_key.resize(key_len);
+            updated_options.packet_time_params.srtp_auth_key.assign(
+                auth_key, auth_key + key_len);
+          }
         }
       }
-#endif
       if (!res) {
         int seq_num = -1;
         uint32_t ssrc = 0;
@@ -1460,7 +1458,6 @@ void BaseChannel::MaybeCacheRtpAbsSendTimeHeaderExtension_w(
 // Absolute Send Time extension id is used only with external auth,
 // so do not bother searching for it and making asyncronious call to set
 // something that is not used.
-#if defined(ENABLE_EXTERNAL_AUTH)

[Taylor Brandstetter, 2017/02/28 22:53:40]

Replace #ifdef with "if (external_auth_enabled_)"?

   const webrtc::RtpExtension* send_time_extension =
       FindHeaderExtension(extensions, webrtc::RtpExtension::kAbsSendTimeUri);
   int rtp_abs_sendtime_extn_id =
@@ -1469,7 +1466,6 @@ void BaseChannel::MaybeCacheRtpAbsSendTimeHeaderExtension_w(
       RTC_FROM_HERE, network_thread_,
       Bind(&BaseChannel::CacheRtpAbsSendTimeHeaderExtension_n, this,
            rtp_abs_sendtime_extn_id));
-#endif
 }
 
 void BaseChannel::CacheRtpAbsSendTimeHeaderExtension_n(