Initial patch from Will.

src/platform/cryptohome/username_passkey.h

Index: src/platform/cryptohome/username_passkey.h
diff --git a/src/platform/cryptohome/username_passkey.h b/src/platform/cryptohome/username_passkey.h
new file mode 100644
index 0000000000000000000000000000000000000000..e2dc99f67891babb3ee176dbe1cfdb2556cc0bbd
--- /dev/null
+++ b/src/platform/cryptohome/username_passkey.h
@@ -0,0 +1,60 @@
+// Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// UsernamePasskey wraps a username/passkey pair that can be used to
+// authenticate a user.
+
+#ifndef CRYPTOHOME_USERNAME_PASSKEY_H_
+#define CRYPTOHOME_USERNAME_PASSKEY_H_
+
+#include "cryptohome/credentials.h"
+
+#include <string.h>
+
+#include "base/basictypes.h"
+
+namespace cryptohome {
+
+class UsernamePasskey : public Credentials {
+ public:
+  // Constructs UsernamePasskey from username strings and passkeys
+  UsernamePasskey(const char *username, const int username_length,
+                   const char *passkey, const int passkey_length);
+  UsernamePasskey(const char *username, const int username_length,
+                   const chromeos::Blob& passkey);
+  UsernamePasskey(const char *username, const int username_length,
+                   const std::string& passkey);
+  UsernamePasskey(const UsernamePasskey& rhs);
+
+  ~UsernamePasskey();
+
+  UsernamePasskey& operator=(const UsernamePasskey& rhs);
+
+  // Constructs UsernamePasskey from a username and password, converting the
+  // password to a passkey using the given salt
+  static UsernamePasskey FromUsernamePassword(const char* username,
+                                              const char* password,
+                                              const chromeos::Blob& salt);
+
+  // Overridden from cryptohome::Credentials
+  void GetFullUsername(char *name_buffer, int length) const;
+  std::string GetFullUsername() const;
+  void GetPartialUsername(char *name_buffer, int length) const;
+  std::string GetObfuscatedUsername(const chromeos::Blob &system_salt) const;
+  SecureBlob GetPasskey() const;
+
+ private:
+  static SecureBlob PasswordToPasskey(const char *password,
+                                      const chromeos::Blob& salt);
+  static void AsciiEncodeToBuffer(const unsigned char* source,
+                                  int source_length, char* buffer,
+                                  int buffer_length);
+
+  std::string username_;
+  SecureBlob passkey_;
+};
+
+}  // namespace cryptohome
+
+#endif  // CRYPTOHOME_USERNAME_PASSKEY_H_