cryptohome/double_wrapped_compat_auth_block.h

// Copyright 2020 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.

#ifndef CRYPTOHOME_DOUBLE_WRAPPED_COMPAT_AUTH_BLOCK_H_
#define CRYPTOHOME_DOUBLE_WRAPPED_COMPAT_AUTH_BLOCK_H_

#include "cryptohome/auth_block.h"

#include <memory>

#include <base/gtest_prod_util.h>
#include <base/macros.h>

#include "cryptohome/libscrypt_compat_auth_block.h"
#include "cryptohome/tpm_not_bound_to_pcr_auth_block.h"

namespace cryptohome {

class Tpm;
class TpmInit;

class DoubleWrappedCompatAuthBlock : public AuthBlock {
 public:
  DoubleWrappedCompatAuthBlock(Tpm* tpm, TpmInit* tpm_init);
  DoubleWrappedCompatAuthBlock(const DoubleWrappedCompatAuthBlock&) = delete;
  DoubleWrappedCompatAuthBlock& operator=(const DoubleWrappedCompatAuthBlock&) =
      delete;

  // This auth block represents legacy keysets left in an inconsistent state, so
  // calling Create() here is FATAL.
  base::Optional<AuthBlockState> Create(const AuthInput& user_input,
                                        KeyBlobs* key_blobs,
                                        CryptoError* error) override;

  // First tries to derive the keys with scrypt, and falls back to the TPM.
  bool Derive(const AuthInput& auth_input,
              const AuthBlockState& state,
              KeyBlobs* key_blobs,
              CryptoError* error) override;

 private:
  TpmNotBoundToPcrAuthBlock tpm_auth_block_;
  LibScryptCompatAuthBlock lib_scrypt_compat_auth_block_;
};

}  // namespace cryptohome

#endif  // CRYPTOHOME_DOUBLE_WRAPPED_COMPAT_AUTH_BLOCK_H_