absl::Status EnumKeys()

in kmscng/main/bridge.cc [330:397]
60 lines of code
8 McCabe index (conditional complexity)

absl::Status EnumKeys(__in NCRYPT_PROV_HANDLE hProvider,
                      __in_opt LPCWSTR pszScope,
                      __deref_out NCryptKeyName** ppKeyName,
                      __inout PVOID* ppEnumState, __in DWORD dwFlags,
                      __in_opt std::string test_config_path) {
  LOG_IF(INFO, std::getenv(kVerboseLoggingEnvVariable))
      << "EnumKeys invoked\n"
      << "Provider: " << hProvider << "\n"
      << "Flags: " << dwFlags << "\n\n";
  ASSIGN_OR_RETURN(Provider * prov, ValidateProviderHandle(hProvider));
  if (pszScope) {
    return NewInvalidArgumentError("pszScope should be null",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  if (!ppKeyName) {
    return NewInvalidArgumentError("ppKeyName cannot be null",
                                   NTE_INVALID_PARAMETER, SOURCE_LOCATION);
  }
  dwFlags = dwFlags & ~NCRYPT_SILENT_FLAG;
  dwFlags = dwFlags & ~NCRYPT_MACHINE_KEY_FLAG;
  if (dwFlags != 0) {
    return NewInvalidArgumentError(
        absl::StrFormat("unsupported flag specified: %u", dwFlags),
        NTE_BAD_FLAGS, SOURCE_LOCATION);
  }

  EnumState* enum_state;
  ProviderConfig config;
  // Generate CKV list if this is the first call to EnumKeys.
  if (!*ppEnumState) {
    // If test_config_path exists, load config from there. This is only used
    // for internal testing.
    if (!test_config_path.empty()) {
      ASSIGN_OR_RETURN(config, LoadConfigFromFile(test_config_path));
    } else {
      // Load config from well-known system path.
      ASSIGN_OR_RETURN(config,
                       LoadConfigFromFile("C:\\Windows\\KMSCNG\\config.yaml"));
    }
    // Load CKV list from config file.
    ASSIGN_OR_RETURN(std::vector<HeapAllocatedKeyDetails> ckv_list,
                     BuildCkvList(hProvider, config));
    *ppEnumState = new EnumState{
        .key_details = ckv_list,
        .current = 0,
    };
    enum_state = reinterpret_cast<EnumState*>(*ppEnumState);
  } else {
    // Check ppEnumState value to make sure it's a valid vector index.
    enum_state = reinterpret_cast<EnumState*>(*ppEnumState);
    if (enum_state->current > enum_state->key_details.size()) {
      return NewInvalidArgumentError(
          absl::StrFormat("unrecognized ppEnumState value: %u",
                          enum_state->current),
          NTE_INVALID_PARAMETER, SOURCE_LOCATION);
    }
  }
  if (enum_state->current == enum_state->key_details.size()) {
    return NewInvalidArgumentError(
        absl::StrFormat("end of enumeration reached: %u", enum_state->current),
        NTE_NO_MORE_ITEMS, SOURCE_LOCATION);
  }
  *ppKeyName =
      enum_state->key_details[enum_state->current].NewNCryptKeyName().release();
  enum_state->current += 1;

  return absl::OkStatus();
}