Add a histogram for measuring the number of times we fall back to common name matching, when a cert…

net/cert/cert_verify_proc_mac.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/cert_verify_proc_mac.h"
 
 #include <CommonCrypto/CommonDigest.h>
 #include <CoreServices/CoreServices.h>
 #include <Security/Security.h>
 
@@ skipping 638 matching lines @@
       if (!IsCertStatusError(verify_result->cert_status)) {
         LOG(WARNING) << "trust_result=" << trust_result;
         verify_result->cert_status |= CERT_STATUS_INVALID;
       }
       break;
   }
 
   // Perform hostname verification independent of SecTrustEvaluate. In order to
   // do so, mask off any reported name errors first.
   verify_result->cert_status &= ~CERT_STATUS_COMMON_NAME_INVALID;
-  if (!cert->VerifyNameMatch(hostname))
+  if (!cert->VerifyNameMatch(hostname,
+                             &verify_result->common_name_fallback_used)) {
     verify_result->cert_status |= CERT_STATUS_COMMON_NAME_INVALID;
+  }
 
   // TODO(wtc): Suppress CERT_STATUS_NO_REVOCATION_MECHANISM for now to be
   // compatible with Windows, which in turn implements this behavior to be
   // compatible with WinHTTP, which doesn't report this error (bug 3004).
   verify_result->cert_status &= ~CERT_STATUS_NO_REVOCATION_MECHANISM;
 
   AppendPublicKeyHashes(completed_chain, &verify_result->public_key_hashes);
   verify_result->is_issued_by_known_root = IsIssuedByKnownRoot(completed_chain);
 
   if (IsCertStatusError(verify_result->cert_status))
@@ skipping 34 matching lines @@
           }
         }
       }
     }
   }
 
   return OK;
 }
 
 }  // namespace net