Windows: Fix crash in SSLClientSocketNSS::SaveSnapStartInfo() when hello_data...

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2010 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.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 341 matching lines @@
   const unsigned char* hello_data;
   unsigned hello_data_len;
   rv = SSL_GetPredictedServerHelloData(nss_fd_, &hello_data, &hello_data_len);
   if (rv != SECSuccess) {
     NOTREACHED();
     return;
   }
   if (hello_data_len > std::numeric_limits<uint16>::max())
     return;
   SSLHostInfo::State* state = ssl_host_info_->mutable_state();
-  state->server_hello =
-      std::string(reinterpret_cast<const char *>(hello_data), hello_data_len);
 
   if (hello_data_len > 0) {
+    state->server_hello =
+        std::string(reinterpret_cast<const char *>(hello_data), hello_data_len);
     state->npn_valid = true;
     state->npn_status = GetNextProto(&state->npn_protocol);
   } else {
+    state->server_hello.clear();
     state->npn_valid = false;
   }
 
   state->certs.clear();
   PeerCertificateChain certs(nss_fd_);
   for (unsigned i = 0; i < certs.size(); i++) {
     if (certs[i]->derCert.len > std::numeric_limits<uint16>::max())
       return;
 
     state->certs.push_back(std::string(
@@ skipping 2103 matching lines @@
     case SSL_CONNECTION_VERSION_TLS1_1:
       UpdateConnectionTypeHistograms(CONNECTION_SSL_TLS1_1);
       break;
     case SSL_CONNECTION_VERSION_TLS1_2:
       UpdateConnectionTypeHistograms(CONNECTION_SSL_TLS1_2);
       break;
   };
 }
 
 }  // namespace net