Add a lock to the managed user settings page and require authentication for unlocking.

chrome/browser/managed_mode/managed_user_passphrase.h

Index: chrome/browser/managed_mode/managed_user_passphrase.h
diff --git a/chrome/browser/managed_mode/managed_user_passphrase.h b/chrome/browser/managed_mode/managed_user_passphrase.h
new file mode 100644
index 0000000000000000000000000000000000000000..e7e24015ee8a5c83bae88743f534e84684c96a4e
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+++ b/chrome/browser/managed_mode/managed_user_passphrase.h
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+// 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.
+
+#ifndef CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_PASSPHRASE_H_
+#define CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_PASSPHRASE_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+
+// This class can be used to derive a hash of a provided passphrase. When an
+// empty salt is given as parameter to the constructor, a new salt is
+// generated randomly, which can be accessed through the |GetSalt| method.
+class ManagedUserPassphrase {
+ public:
+  explicit ManagedUserPassphrase(const std::string& salt);
+  ~ManagedUserPassphrase();
+
+  std::string GetSalt();
+
+  // This function generates a hash from a passphrase, which should be provided
+  // as the first parameter. On return, the second parameter will contain the
+  // Base64-encoded hash of the password.
+  void GenerateHashFromPassphrase(const std::string& passphrase,
+                                  std::string* encoded_passphrase_hash) const;
+
+ private:
+  void GetPassphraseHash(const std::string& passphrase,
+                         std::string* passphrase_hash) const;
+  void GenerateRandomSalt();
+
+  std::string salt_;
+
+  DISALLOW_COPY_AND_ASSIGN(ManagedUserPassphrase);
+};
+
+#endif  // CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_PASSPHRASE_H_