Added histogram on successful check. Safe verification

chrome/browser/protector/protector.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 "chrome/browser/protector/protector.h"
 
 #include "base/logging.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/protector/settings_change_global_error.h"
 #include "chrome/browser/protector/keys.h"
@@ skipping 59 matching lines @@
 std::string SignSetting(const std::string& value) {
   crypto::HMAC hmac(crypto::HMAC::SHA256);
   DCHECK(hmac.Init(kProtectorSigningKey));
 
   std::vector<unsigned char> digest(hmac.DigestLength());
   DCHECK(hmac.Sign(value, &digest[0], digest.size()));
 
   return std::string(&digest[0], &digest[0] + digest.size());
 }
 
+bool IsSettingValid(const std::string& value, const std::string& signature) {
+  crypto::HMAC hmac(crypto::HMAC::SHA256);
+  DCHECK(hmac.Init(kProtectorSigningKey));

[Ivan Korotkov, 2011/11/01 14:18:39]

Init should be called outside of DCHECK.

+  return hmac.Verify(value, signature);
+}
+
 }  // namespace protector