Enable exporting SSLKEYLOGFILE on Android w/ command line arguments

net/socket/ssl_client_socket_openssl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // OpenSSL binding for SSLClientSocket. The class layout and general principle
 // of operation is derived from SSLClientSocketNSS.
 
 #include "net/socket/ssl_client_socket_openssl.h"
 
 #include <errno.h>
@@ skipping 454 matching lines @@
       policy_enforcer_(context.cert_policy_enforcer),
       net_log_(transport_->socket()->NetLog()),
       weak_factory_(this) {
   DCHECK(cert_verifier_);
 }
 
 SSLClientSocketOpenSSL::~SSLClientSocketOpenSSL() {
   Disconnect();
 }
 
+void SSLClientSocketOpenSSL::SetSslKeyLogFile(std::string ssl_keylog_file) {
+  std::string env_keylog_file;
+  scoped_ptr<base::Environment> env(base::Environment::Create());

[Bryan McQuade, 2015/10/14 00:38:54]

I think there's some benefit to centralizing the logic that decides what
filename to use here, and moving the env lookup to the code you've added in
io_thread.cc (and also removing the env lookup logic in the SSLContext
constructor). The logic in io_thread.cc could do something like:

1. check to see if env variable is set. if so, use it (pass its value to
SSLClientSocketOpenSSL::SetSSLKeyLogFile)
2. if env variable not set, check to see if command line flag is set. if so, use
it.
(and we may wish to log a warning if both the env variable and command line flag
are set to different values)

+  if (env->GetVar("SSLKEYLOGFILE", &env_keylog_file) &&
+      !env_keylog_file.empty()) {
+    return;
+  }
+
+  crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
+  BIO* bio = BIO_new_file(ssl_keylog_file.c_str(), "a");
+  if (!bio) {
+    LOG(ERROR) << "Failed to open " << ssl_keylog_file;
+    ERR_print_errors_cb(&LogErrorCallback, NULL);
+  } else {
+    SSL_CTX_set_keylog_bio(SSLContext::GetInstance()->ssl_ctx(), bio);
+  }
+}
+
 void SSLClientSocketOpenSSL::GetSSLCertRequestInfo(
     SSLCertRequestInfo* cert_request_info) {
   cert_request_info->host_and_port = host_and_port_;
   cert_request_info->cert_authorities = cert_authorities_;
   cert_request_info->cert_key_types = cert_key_types_;
 }
 
 SSLClientSocket::NextProtoStatus SSLClientSocketOpenSSL::GetNextProto(
     std::string* proto) const {
   *proto = npn_proto_;
@@ skipping 1682 matching lines @@
     OnHandshakeIOComplete(signature_result_);
     return;
   }
 
   // During a renegotiation, either Read or Write calls may be blocked on an
   // asynchronous private key operation.
   PumpReadWriteEvents();
 }
 
 }  // namespace net