absl::Status ExportKey()

in kmscng/main/bridge.cc [220:276]
51 lines of code
7 McCabe index (conditional complexity)

absl::Status ExportKey(
    __in NCRYPT_PROV_HANDLE hProvider, __in NCRYPT_KEY_HANDLE hKey,
    __in_opt NCRYPT_KEY_HANDLE hExportKey, __in LPCWSTR pszBlobType,
    __in_opt NCryptBufferDesc* pParameterList,
    __out_bcount_part_opt(cbOutput, *pcbResult) PBYTE pbOutput,
    __in DWORD cbOutput, __out DWORD* pcbResult, __in DWORD dwFlags) {
  LOG_IF(INFO, std::getenv(kVerboseLoggingEnvVariable))
      << "ExportKey invoked\n"
      << "Provider: " << hProvider << "\n"
      << "Key: " << hKey << "\n"
      << "Export Key: " << hExportKey << "\n"
      << "Blob type: " << WideToString(std::wstring(pszBlobType)) << "\n"
      << "Parameter list: " << uintptr_t(pParameterList) << "\n"
      << "Output: " << uintptr_t(pbOutput) << "\n"
      << "Output size: " << cbOutput << "\n"
      << "Output result size: " << uintptr_t(pcbResult) << "\n"
      << "Flags: " << dwFlags << "\n\n";
  ASSIGN_OR_RETURN(Object * object, ValidateKeyHandle(hProvider, hKey));
  if (hExportKey) {
    return NewInvalidArgumentError("hExportKey is not supported",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  constexpr std::wstring_view kEccPublicKeyType(BCRYPT_ECCPUBLIC_BLOB);
  constexpr std::wstring_view kRsaPublicKeyType(BCRYPT_RSAPUBLIC_BLOB);
  if (pszBlobType != kEccPublicKeyType && pszBlobType != kRsaPublicKeyType) {
    return NewInvalidArgumentError(
        absl::StrFormat("blob type not supported: %s",
                        WideToString(pszBlobType)),
        NTE_BAD_TYPE, SOURCE_LOCATION);
  }
  if (!pcbResult) {
    return NewInvalidArgumentError("pcbResult cannot be null",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  RETURN_IF_ERROR(ValidateFlags(dwFlags));

  ASSIGN_OR_RETURN(std::vector<uint8_t> serialized_pub_key,
                   SerializePublicKey(object));
  *pcbResult = serialized_pub_key.size();

  // Return size required to hold the property value if output buffer is null.
  if (!pbOutput) {
    return absl::OkStatus();
  }

  // Check provided buffer size to ensure the property value fits.
  if (cbOutput < serialized_pub_key.size()) {
    return NewOutOfRangeError(
        absl::StrFormat("cbOutput size=%u not large enough to fit "
                        "property value of size %u",
                        cbOutput, serialized_pub_key.size()),
        SOURCE_LOCATION);
  }

  std::copy(serialized_pub_key.begin(), serialized_pub_key.end(), pbOutput);
  return absl::OkStatus();
}