// Copyright 2022 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine License
// Agreement.
//
// Implements utility functions for serializing and deserializing the fake key
// handles used by the Ref and Testbed.
//
#ifndef WVOEC_UTIL_KEY_HANDLE_H_
#define WVOEC_UTIL_KEY_HANDLE_H_

#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include "OEMCryptoCENC.h"
#include "log.h"

namespace wvoec {
namespace util {
// Size of a key handle, which for this implementation is just a session ID.
constexpr size_t kKeyHandleSize = sizeof(OEMCrypto_SESSION);

OEMCryptoResult SerializeSessionToKeyHandle(OEMCrypto_SESSION session,
                                            uint8_t* key_handle,
                                            size_t* key_handle_length) {
  if (key_handle_length == nullptr) {
    LOGE("Null key handle length");
    return OEMCrypto_ERROR_INVALID_CONTEXT;
  }

  if (key_handle == nullptr || *key_handle_length < kKeyHandleSize) {
    *key_handle_length = kKeyHandleSize;
    return OEMCrypto_ERROR_SHORT_BUFFER;
  }

  *key_handle_length = kKeyHandleSize;
  memcpy(key_handle, &session, kKeyHandleSize);
  return OEMCrypto_SUCCESS;
}

OEMCryptoResult DeserializeKeyHandleToSession(const uint8_t* key_handle,
                                              size_t key_handle_length,
                                              OEMCrypto_SESSION* session) {
  if (key_handle == nullptr) {
    LOGE("Null key handle");
    return OEMCrypto_ERROR_INVALID_CONTEXT;
  }
  if (session == nullptr) {
    LOGE("Null session");
    return OEMCrypto_ERROR_INVALID_CONTEXT;
  }

  if (key_handle_length != kKeyHandleSize) {
    LOGE("Invalid key handle length");
    return OEMCrypto_ERROR_INVALID_CONTEXT;
  }

  memcpy(session, key_handle, kKeyHandleSize);
  return OEMCrypto_SUCCESS;
}
}  // namespace util
}  // namespace wvoec
#endif  // WVOEC_UTIL_KEY_HANDLE_H_