public StsAccessToken issueAccessToken()

in token-service/src/main/java/com/google/solutions/tokenservice/oauth/WorkloadIdentityPool.java [78:143]
53 lines of code
5 McCabe index (conditional complexity)

  public StsAccessToken issueAccessToken(
    IdToken idToken,
    String scope
  ) throws IOException {
    Preconditions.checkNotNull(idToken, "idToken");
    Preconditions.checkNotNull(scope, "scope");

    try {
      var client = createStsClient();
      var requestBody = new GoogleIdentityStsV1ExchangeTokenRequest()
        .setGrantType(GRANT_TYPE)
        .setAudience(this.options.audience())
        .setScope(scope)
        .setRequestedTokenType(ACCESS_TOKEN_TYPE)
        .setSubjectToken(idToken.value())
        .setSubjectTokenType(ID_TOKEN_TYPE);

      //
      // The token API returns errors in OAuth format, not in the standard
      // Google API error format as the client library expects.
      //
      // Add hook to extract error details.
      //
      var request = client.v1().new Token(requestBody) {
        @Override
        protected GoogleJsonResponseException newExceptionOnError(HttpResponse response) {
          try {
            var builder = new HttpResponseException.Builder(
              response.getStatusCode(),
              response.getStatusMessage(),
              response.getHeaders());

            var errorDetails = client
              .getJsonFactory()
              .fromInputStream(response.getContent(), TokenErrorDetails.class);

            return new GoogleJsonResponseException(builder, errorDetails.toError());
          }
          catch (IOException e)
          {
            return super.newExceptionOnError(response);
          }
        }
      };

      var issueTime = Instant.now();
      var response = request.execute();

      return new StsAccessToken(
        response.getAccessToken(),
        scope,
        issueTime,
        issueTime.plusSeconds(response.getExpiresIn()));
    }
    catch (GoogleJsonResponseException e) {
      switch (e.getStatusCode()) {
        case 400:
          throw new IllegalArgumentException(e.getDetails() != null
            ? e.getDetails().getMessage()
            : e.getMessage());

        default:
          throw (GoogleJsonResponseException) e.fillInStackTrace();
      }
    }
  }