net: fix crash when failing to import a client-side cert into NSS.

net/socket/ssl_server_socket_nss.cc

 // Copyright (c) 2011 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.
 
 #include "net/socket/ssl_server_socket_nss.h"
 
 #if defined(OS_WIN)
 #include <winsock2.h>
 #endif
 
@@ skipping 351 matching lines @@
 
   SECItem der_cert;
   der_cert.data = reinterpret_cast<unsigned char*>(const_cast<char*>(
       der_string.data()));
   der_cert.len  = der_string.length();
   der_cert.type = siDERCertBuffer;
 
   // Parse into a CERTCertificate structure.
   CERTCertificate* cert = CERT_NewTempCertificate(
       CERT_GetDefaultCertDB(), &der_cert, NULL, PR_FALSE, PR_TRUE);
+  if (!cert) {
+    LogFailedNSSFunction(net_log_, "CERT_NewTempCertificate", "");
+    return MapNSSError(PORT_GetError());
+  }
 
   // Get a key of SECKEYPrivateKey* structure.
   std::vector<uint8> key_vector;
   if (!key_->ExportPrivateKey(&key_vector)) {
     CERT_DestroyCertificate(cert);
     return ERR_UNEXPECTED;
   }
 
   SECKEYPrivateKeyStr* private_key = NULL;
   PK11SlotInfo* slot = crypto::GetPrivateNSSKeySlot();
@@ skipping 378 matching lines @@
   // Initialize the NSS SSL library in a threadsafe way.  This also
   // initializes the NSS base library.
   EnsureNSSSSLInit();
   if (!NSS_IsInitialized())
     return ERR_UNEXPECTED;
 
   return OK;
 }
 
 }  // namespace net