Add debugging information to the SSL blocking page

net/cert/x509_certificate_nss.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.
 
 #include "net/cert/x509_certificate.h"
 
 #include <cert.h>
 #include <cryptohi.h>
 #include <keyhi.h>
 #include <nss.h>
@@ skipping 123 matching lines @@
                                             arena.get(),
                                             &issuers)) {
     return false;
   }
   return x509_util::IsCertificateIssuedBy(cert_chain, issuers);
 }
 
 // static
 bool X509Certificate::GetDEREncoded(X509Certificate::OSCertHandle cert_handle,
                                     std::string* encoded) {
-  if (!cert_handle->derCert.len)
+  if (!cert_handle || !cert_handle->derCert.len)
     return false;
   encoded->assign(reinterpret_cast<char*>(cert_handle->derCert.data),
                   cert_handle->derCert.len);
   return true;
 }
 
 // static
 bool X509Certificate::IsSameOSCert(X509Certificate::OSCertHandle a,
                                    X509Certificate::OSCertHandle b) {
   DCHECK(a && b);
@@ skipping 105 matching lines @@
 }
 
 // static
 void X509Certificate::GetPublicKeyInfo(OSCertHandle cert_handle,
                                        size_t* size_bits,
                                        PublicKeyType* type) {
   x509_util::GetPublicKeyInfo(cert_handle, size_bits, type);
 }
 
 }  // namespace net