// 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.

#include "cryptohome/tpm.h"

#if USE_TPM2
#include "cryptohome/tpm2_impl.h"
#else
#include "cryptohome/tpm_impl.h"
#endif

namespace cryptohome {

Tpm* Tpm::singleton_ = NULL;
base::Lock Tpm::singleton_lock_;

const uint32_t Tpm::kLockboxIndex = cryptohome::kLockboxIndex;

ScopedKeyHandle::ScopedKeyHandle()
    : tpm_(nullptr), handle_(kInvalidKeyHandle) {}

ScopedKeyHandle::~ScopedKeyHandle() {
  if (tpm_ != nullptr && handle_ != kInvalidKeyHandle) {
    tpm_->CloseHandle(handle_);
  }
}

TpmKeyHandle ScopedKeyHandle::value() {
  return handle_;
}

TpmKeyHandle ScopedKeyHandle::release() {
  TpmKeyHandle return_handle = handle_;
  tpm_ = nullptr;
  handle_ = kInvalidKeyHandle;
  return return_handle;
}

void ScopedKeyHandle::reset(Tpm* tpm, TpmKeyHandle handle) {
  if ((tpm_ != tpm) || (handle_ != handle)) {
    if ((tpm_ != nullptr) && (handle_ != kInvalidKeyHandle)) {
      tpm_->CloseHandle(handle_);
    }
    tpm_ = tpm;
    handle_ = handle;
  }
}

Tpm* Tpm::GetSingleton() {
  // TODO(fes): Replace with a better atomic operation
  singleton_lock_.Acquire();
  if (!singleton_) {
#if USE_TPM2
    singleton_ = new Tpm2Impl();
#else
    singleton_ = new TpmImpl();
#endif
  }
  singleton_lock_.Release();
  return singleton_;
}

}  // namespace cryptohome