// Copyright 2015 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 TPM_MANAGER_SERVER_TPM_NVRAM_H_
#define TPM_MANAGER_SERVER_TPM_NVRAM_H_

#include <string>
#include <vector>

#include <tpm_manager/proto_bindings/tpm_manager.pb.h>

namespace tpm_manager {

// TpmNvram is an interface for working with TPM NVRAM.
class TpmNvram {
 public:
  TpmNvram() = default;
  virtual ~TpmNvram() = default;

  // Creates an NVRAM space in the TPM. Returns true on success.
  virtual NvramResult DefineSpace(
      uint32_t index,
      size_t size,
      const std::vector<NvramSpaceAttribute>& attributes,
      const std::string& authorization_value,
      NvramSpacePolicy policy) = 0;

  // Destroys an NVRAM space in the TPM. Returns true on success.
  virtual NvramResult DestroySpace(uint32_t index) = 0;

  // Writes |data| to the NVRAM space at |index|. The size of |data| must be
  // equal or less than the size of the NVRAM space. Returns true on success.
  virtual NvramResult WriteSpace(uint32_t index,
                                 const std::string& data,
                                 const std::string& authorization_value) = 0;

  // Reads all the |data| in the NVRAM space at |index|. Returns true on
  // success.
  virtual NvramResult ReadSpace(uint32_t index,
                                std::string* data,
                                const std::string& authorization_value) = 0;

  // Locks the NVRAM space at |index|. Returns true on success.
  virtual NvramResult LockSpace(uint32_t index,
                                bool lock_read,
                                bool lock_write,
                                const std::string& authorization_value) = 0;

  // Lists all existing NVRAM spaces. Returns true on success.
  virtual NvramResult ListSpaces(std::vector<uint32_t>* index_list) = 0;

  // Provides basic information about a given space. All pointer are optional
  // and may be NULL. Returns true on success.
  virtual NvramResult GetSpaceInfo(uint32_t index,
                                   uint32_t* size,
                                   bool* is_read_locked,
                                   bool* is_write_locked,
                                   std::vector<NvramSpaceAttribute>* attributes,
                                   NvramSpacePolicy* policy) = 0;

  // Removes stale NVRAM policies from the on-disk local data, if any. If the
  // data is fresh, or if we cannot determine that, the data won't be touched.
  //
  // Note that this function doesn't guarantee to remove all stale data if there
  // is a TPM and/or disk IO error. It does the work in its best effort.
  //
  // Currently this is supported by TPM 2.0 only.
  virtual void PrunePolicies() = 0;
};

}  // namespace tpm_manager

#endif  // TPM_MANAGER_SERVER_TPM_NVRAM_H_