// 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_AUTH_BLOCKS_TPM_NOT_BOUND_TO_PCR_AUTH_BLOCK_H_
#define CRYPTOHOME_AUTH_BLOCKS_TPM_NOT_BOUND_TO_PCR_AUTH_BLOCK_H_

#include "cryptohome/auth_blocks/auth_block.h"

#include <string>

#include <base/gtest_prod_util.h>

#include "cryptohome/auth_blocks/auth_block_state.h"
#include "cryptohome/auth_blocks/tpm_auth_block_utils.h"
#include "cryptohome/crypto.h"
#include "cryptohome/cryptohome_keys_manager.h"
#include "cryptohome/tpm.h"
#include "cryptohome/vault_keyset.pb.h"

namespace cryptohome {

class TpmNotBoundToPcrAuthBlock : public SyncAuthBlock {
 public:
  TpmNotBoundToPcrAuthBlock(Tpm* tpm,
                            CryptohomeKeysManager* cryptohome_keys_manager);
  TpmNotBoundToPcrAuthBlock(const TpmNotBoundToPcrAuthBlock&) = delete;
  TpmNotBoundToPcrAuthBlock& operator=(const TpmNotBoundToPcrAuthBlock&) =
      delete;

  CryptoStatus Create(const AuthInput& user_input,
                      AuthBlockState* auth_block_state,
                      KeyBlobs* key_blobs) override;

  CryptoStatus Derive(const AuthInput& auth_input,
                      const AuthBlockState& state,
                      KeyBlobs* key_blobs) override;

 private:
  // Decrypt the |vault_key| that is not bound to PCR, returning the |vkk_iv|
  // and |vkk_key|.
  CryptoStatus DecryptTpmNotBoundToPcr(
      const TpmNotBoundToPcrAuthBlockState& tpm_state,
      const brillo::SecureBlob& vault_key,
      const brillo::SecureBlob& tpm_key,
      const brillo::SecureBlob& salt,
      brillo::SecureBlob* vkk_iv,
      brillo::SecureBlob* vkk_key) const;

  Tpm* tpm_;
  CryptohomeKeyLoader* cryptohome_key_loader_;
  TpmAuthBlockUtils utils_;

  FRIEND_TEST_ALL_PREFIXES(TPMAuthBlockTest, DecryptNotBoundToPcrTest);
};

}  // namespace cryptohome

#endif  // CRYPTOHOME_AUTH_BLOCKS_TPM_NOT_BOUND_TO_PCR_AUTH_BLOCK_H_