Authenticate requests to the Google Wallet API

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.google.api.client.googleapis.batch.BatchRequest;
import com.google.api.client.googleapis.batch.json.JsonBatchCallback;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.googleapis.json.GoogleJsonError;
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.*;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.walletobjects.*;
import com.google.api.services.walletobjects.model.*;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import com.google.auth.oauth2.ServiceAccountCredentials;
import java.io.*;
import java.security.interfaces.RSAPrivateKey;
import java.util.*;

public class DemoTransit {
  /**
   * Path to service account key file from Google Cloud Console. Environment variable:
   * GOOGLE_APPLICATION_CREDENTIALS.
   */
  public static String keyFilePath;

  /** Service account credentials for Google Wallet APIs. */
  public static GoogleCredentials credentials;

  /** Google Wallet service client. */
  public static Walletobjects service;

  public DemoTransit() throws Exception {
    keyFilePath =
        System.getenv().getOrDefault("GOOGLE_APPLICATION_CREDENTIALS", "/path/to/key.json");

    auth();
  }

use Firebase\JWT\JWT;
use Google\Auth\Credentials\ServiceAccountCredentials;
use Google\Client as GoogleClient;
use Google\Service\Walletobjects;
use Google\Service\Walletobjects\TicketLeg;
use Google\Service\Walletobjects\LatLongPoint;
use Google\Service\Walletobjects\Barcode;
use Google\Service\Walletobjects\ImageModuleData;
use Google\Service\Walletobjects\LinksModuleData;
use Google\Service\Walletobjects\TextModuleData;
use Google\Service\Walletobjects\TransitObject;
use Google\Service\Walletobjects\Message;
use Google\Service\Walletobjects\AddMessageRequest;
use Google\Service\Walletobjects\Uri;
use Google\Service\Walletobjects\TranslatedString;
use Google\Service\Walletobjects\LocalizedString;
use Google\Service\Walletobjects\ImageUri;
use Google\Service\Walletobjects\Image;
use Google\Service\Walletobjects\TransitClass;

/** Demo class for creating and managing Transit passes in Google Wallet. */
class DemoTransit
{
  /**
   * The Google API Client
   * https://github.com/google/google-api-php-client
   */
  public GoogleClient $client;

  /**
   * Path to service account key file from Google Cloud Console. Environment
   * variable: GOOGLE_APPLICATION_CREDENTIALS.
   */
  public string $keyFilePath;

  /**
   * Service account credentials for Google Wallet APIs.
   */
  public ServiceAccountCredentials $credentials;

  /**
   * Google Wallet service client.
   */
  public Walletobjects $service;

  public function __construct()
  {
    $this->keyFilePath = getenv('GOOGLE_APPLICATION_CREDENTIALS') ?: '/path/to/key.json';

    $this->auth();
  }

import json
import os
import uuid

from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from googleapiclient.http import BatchHttpRequest
from google.oauth2.service_account import Credentials
from google.auth import jwt, crypt


class DemoTransit:
    """Demo class for creating and managing Transit passes in Google Wallet.

    Attributes:
        key_file_path: Path to service account key file from Google Cloud
            Console. Environment variable: GOOGLE_APPLICATION_CREDENTIALS.
        base_url: Base URL for Google Wallet API requests.
    """

    def __init__(self):
        self.key_file_path = os.environ.get('GOOGLE_APPLICATION_CREDENTIALS',
                                            '/path/to/key.json')
        # Set up authenticated client
        self.auth()

using System.IdentityModel.Tokens.Jwt;
using System.Net.Http.Headers;
using System.Text.RegularExpressions;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.Walletobjects.v1;
using Google.Apis.Walletobjects.v1.Data;
using Microsoft.IdentityModel.Tokens;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;


/// <summary>
/// Demo class for creating and managing Transit passes in Google Wallet.
/// </summary>
class DemoTransit
{
  /// <summary>
  /// Path to service account key file from Google Cloud Console. Environment
  /// variable: GOOGLE_APPLICATION_CREDENTIALS.
  /// </summary>
  public static string keyFilePath;

  /// <summary>
  /// Service account credentials for Google Wallet APIs
  /// </summary>
  public static ServiceAccountCredential credentials;

  /// <summary>
  /// Google Wallet service client
  /// </summary>
  public static WalletobjectsService service;

  public DemoTransit()
  {
    keyFilePath = Environment.GetEnvironmentVariable(
        "GOOGLE_APPLICATION_CREDENTIALS") ?? "/path/to/key.json";

    Auth();
  }

const { google } = require('googleapis');
const jwt = require('jsonwebtoken');
const { v4: uuidv4 } = require('uuid');

/**
 * Demo class for creating and managing Transit passes in Google Wallet.
 */
class DemoTransit {
  constructor() {
    /**
     * Path to service account key file from Google Cloud Console. Environment
     * variable: GOOGLE_APPLICATION_CREDENTIALS.
     */
    this.keyFilePath = process.env.GOOGLE_APPLICATION_CREDENTIALS || '/path/to/key.json';
    this.auth();
  }

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"github.com/golang-jwt/jwt"
	"github.com/google/uuid"
	"golang.org/x/oauth2"
	"golang.org/x/oauth2/google"
	oauthJwt "golang.org/x/oauth2/jwt"
	"google.golang.org/api/option"
	"google.golang.org/api/walletobjects/v1"
	"io"
	"log"
	"os"
	"strings"
)

/**
 * Create authenticated HTTP client using a service account file.
 *
 */
public void auth() throws Exception {
  credentials =
      GoogleCredentials.fromStream(new FileInputStream(keyFilePath))
          .createScoped(List.of(WalletobjectsScopes.WALLET_OBJECT_ISSUER));
  credentials.refresh();

  HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();

  // Initialize Google Wallet API service
  service =
      new Walletobjects.Builder(
              httpTransport,
              GsonFactory.getDefaultInstance(),
              new HttpCredentialsAdapter(credentials))
          .setApplicationName("APPLICATION_NAME")
          .build();
}

/**
 * Create authenticated HTTP client using a service account file.
 */
public function auth()
{
  $this->credentials = new ServiceAccountCredentials(
    Walletobjects::WALLET_OBJECT_ISSUER,
    $this->keyFilePath
  );

  // Initialize Google Wallet API service
  $this->client = new GoogleClient();
  $this->client->setApplicationName('APPLICATION_NAME');
  $this->client->setScopes(Walletobjects::WALLET_OBJECT_ISSUER);
  $this->client->setAuthConfig($this->keyFilePath);

  $this->service = new Walletobjects($this->client);
}

def auth(self):
    """Create authenticated HTTP client using a service account file."""
    self.credentials = Credentials.from_service_account_file(
        self.key_file_path,
        scopes=['https://www.googleapis.com/auth/wallet_object.issuer'])

    self.client = build('walletobjects', 'v1', credentials=self.credentials)

/// <summary>
/// Create authenticated service client using a service account file.
/// </summary>
public void Auth()
{
  credentials = (ServiceAccountCredential)GoogleCredential
      .FromFile(keyFilePath)
      .CreateScoped(new List<string>
      {
        WalletobjectsService.ScopeConstants.WalletObjectIssuer
      })
      .UnderlyingCredential;

  service = new WalletobjectsService(
      new BaseClientService.Initializer()
      {
        HttpClientInitializer = credentials
      });
}

/**
 * Create authenticated HTTP client using a service account file.
 */
auth() {
  const auth = new google.auth.GoogleAuth({
    keyFile: this.keyFilePath,
    scopes: ['https://www.googleapis.com/auth/wallet_object.issuer'],
  });

  this.credentials = require(this.keyFilePath);

  this.client = google.walletobjects({
    version: 'v1',
    auth: auth,
  });
}

// Create authenticated HTTP client using a service account file.
func (d *demoTransit) auth() {
	credentialsFile := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
	b, _ := os.ReadFile(credentialsFile)
	credentials, err := google.JWTConfigFromJSON(b, walletobjects.WalletObjectIssuerScope)
	if err != nil {
		fmt.Println(err)
		log.Fatalf("Unable to load credentials: %v", err)
	}
	d.credentials = credentials
	d.service, _ = walletobjects.NewService(context.Background(), option.WithCredentialsFile(credentialsFile))
}