commit 1d4db392c71595f05a5258e16734ff3ec446c115
author henrika <henrika@webrtc.org> Mon Sep 18 09:34:30 2017
committer Commit Bot <commit-bot@chromium.org> Mon Sep 18 09:34:30 2017
tree c42ab6f696297de8c78be2b0d7ab3df6c1725662
parent 9a2e906b0c06ee1a9b75c734bf58326469db8e93

Revert of If SRTP sessions exist, don't create new ones when applying answer. (patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%28dbg%29%20%28L%20Nexus6%29

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
>
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
>
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
>
> BUG=webrtc:8251
>
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed: https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
NOTRY=TRUE

Review-Url: https://codereview.webrtc.org/3017543002
Cr-Commit-Position: refs/heads/master@{#19882}

pc/srtptransport.cc

diff --git a/pc/srtptransport.cc b/pc/srtptransport.cc
index 64889c6..f3b5309 100644
--- a/pc/srtptransport.cc
+++ b/pc/srtptransport.cc
@@ -174,42 +174,25 @@
                                  int recv_cs,
                                  const uint8_t* recv_key,
                                  int recv_key_len) {
-  // If parameters are being set for the first time, we should create new SRTP
-  // sessions and call "SetSend/SetRecv". Otherwise we should call
-  // "UpdateSend"/"UpdateRecv" on the existing sessions, which will internally
-  // call "srtp_update".
-  bool new_sessions = false;
-  if (!send_session_) {
-    RTC_DCHECK(!recv_session_);
-    CreateSrtpSessions();
-    new_sessions = true;
-  }
-
+  CreateSrtpSessions();
   send_session_->SetEncryptedHeaderExtensionIds(
       send_encrypted_header_extension_ids_);
   if (external_auth_enabled_) {
     send_session_->EnableExternalAuth();
   }
-  bool ret = new_sessions
-                 ? send_session_->SetSend(send_cs, send_key, send_key_len)
-                 : send_session_->UpdateSend(send_cs, send_key, send_key_len);
-  if (!ret) {
+  if (!send_session_->SetSend(send_cs, send_key, send_key_len)) {
     ResetParams();
     return false;
   }
 
   recv_session_->SetEncryptedHeaderExtensionIds(
       recv_encrypted_header_extension_ids_);
-  ret = new_sessions
-            ? recv_session_->SetRecv(recv_cs, recv_key, recv_key_len)
-            : recv_session_->UpdateRecv(recv_cs, recv_key, recv_key_len);
-  if (!ret) {
+  if (!recv_session_->SetRecv(recv_cs, recv_key, recv_key_len)) {
     ResetParams();
     return false;
   }
 
-  LOG(LS_INFO) << "SRTP " << (new_sessions ? "updated" : "activated")
-               << " with negotiated parameters:"
+  LOG(LS_INFO) << "SRTP activated with negotiated parameters:"
                << " send cipher_suite " << send_cs << " recv cipher_suite "
                << recv_cs;
   return true;