public final Authentication authenticate()

in token-service/src/main/java/com/google/solutions/tokenservice/oauth/ClientCredentialsFlow.java [166:242]
61 lines of code
6 McCabe index (conditional complexity)

  public final Authentication authenticate(
    AuthenticationRequest request
  ) throws Authentication.AuthenticationException {
    Preconditions.checkNotNull(request, "request");

    //
    // Authenticate the client.
    //
    AuthenticatedClient client;
    try
    {
      client = authenticateClient(request);
    }
    catch (Exception e) {
      throw new Authentication.InvalidClientException(
        "The client or its credentials are invalid", e);
    }

    //
    // Issue an ID token.
    //
    IdToken idToken;
    try {
      idToken = issueIdToken(client);
    }
    catch (Exception e) {
      throw new Authentication.TokenIssuanceException(
        String.format("Issuing ID token for client '%s' failed", client.clientId()),
        e);
    }

    //
    // Issue an access token (if requested).
    //
    try {
      var accessToken = issueAccessToken(request, client, idToken);

      if (accessToken instanceof StsAccessToken stsAccessToken)
      {
        this.logAdapter
          .newInfoEntry(
            LogEvents.API_TOKEN,
            String.format(
              "Issued ID token and STS access token for client '%s' and scope '%s'",
              client.clientId(),
              stsAccessToken.scope()))
          .write();

      }
      else if (accessToken instanceof ServiceAccountAccessToken saAccessToken)
      {
        this.logAdapter
          .newInfoEntry(
            LogEvents.API_TOKEN,
            String.format(
              "Issued ID token and service account access token for client '%s' and scope '%s'",
              client.clientId(),
              saAccessToken.scope()))
          .write();

      }
      else {
        this.logAdapter
          .newInfoEntry(
            LogEvents.API_TOKEN,
            String.format("Issued ID token for client '%s'", client.clientId()))
          .write();
      }

      return new Authentication(client, idToken, accessToken);
    }
    catch (Exception e) {
      throw new Authentication.TokenIssuanceException(
        String.format("Issuing access token for client '%s' failed", client.clientId()),
        e);
    }
  }