PHP

Get Google API Access Token using JSON Private Key using NIST Time Server Date/Time

Demonstrates how to get a Google API access token using a JSON service account private key, using the NIST time server date/time rather than the local system date/time. Chilkat2 PHP

<?php

use Chilkat2\AuthGoogle;
use Chilkat2\DateTime;
use Chilkat2\FileAccess;
use Chilkat2\Socket;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// First, let's get the current date/time from time-c.nist.gov
$socket = new Socket();

// Connect to an NIST time server and read the current date/time
$maxWaitMs = 8000;
$useTls = false;
try {
    $socket->Connect('time-c.nist.gov', 37, $useTls, $maxWaitMs);

    // The time server will send a big-endian 32-bit integer representing
    // the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
    // The ReceiveInt32 method will receive a 4-byte integer, but returns
    // true or false to indicate success.  If successful, the integer
    // is obtained via the ReceivedInt property.
    $bigEndian = true;
    $socket->ReceiveInt32($bigEndian);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

$dt = new DateTime();
$dt->SetFromNtpTime($socket->ReceivedInt);

// Show the current local date/time
$bLocalTime = true;
echo 'Current local date/time: ', $dt->GetAsRfc822($bLocalTime), "\n";

$maxWaitMs = 10;
$socket->Close($maxWaitMs);

// ------------------------------------------------------------------------
// OK, we have the current date/time.  We'll use it to set the IAT property
// in the code below.

// First load the JSON key into a string.
$fac = new FileAccess();
try {
    $jsonKey = $fac->ReadEntireTextFile('qa_data/googleApi/ChilkatTest-ab2ecd52ef98.json', 'utf-8');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// A JSON private key should look like this:

//     {
//       "type": "service_account",
//       "project_id": "chilkattest-1350",
//       "private_key_id": "fa2e36ee26986eab628b59868af8bec1d1c64c38",
//       "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIjFa...28N64N2n1E4FYzBZjSdy\n-----END PRIVATE KEY-----\n",
//       "client_email": "598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a@developer.gserviceaccount.com",
//       "client_id": "598922945226-00rb0ppfg0snd9jo7bhvd4v17jtj2d3a.apps.googleusercontent.com",
//       "auth_uri": "https://accounts.google.com/o/oauth2/auth",
//       "token_uri": "https://accounts.google.com/o/oauth2/token",
//       "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
//       "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a%40developer.gserviceaccount.com"
//     }

$gAuth = new AuthGoogle();
$gAuth->JsonKey = $jsonKey;

// Choose a scope.
$gAuth->Scope = 'https://www.googleapis.com/auth/cloud-platform';

// Request an access token that is valid for this many seconds.
$gAuth->ExpireNumSeconds = 3600;

// If the application is requesting delegated access:
// The email address of the user for which the application is requesting delegated access,
// then set the email address here. (Otherwise leave it empty.)
$gAuth->SubEmailAddress = '';

// ------------------------------------------------------------------------
// Set the IAT using the date/time from the NIST time server.
$unixTime = $dt->GetAsUnixTime(false);
echo 'unixTime = ', $unixTime, "\n";
$gAuth->Iat = $unixTime;

// Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
// The Chilkat socket object is used so that the connection can be established
// through proxies or an SSH tunnel if desired.
$tlsSock = new Socket();
try {
    $tlsSock->Connect('www.googleapis.com', 443, true, 5000);

    // Send the request to obtain the access token.
    $gAuth->ObtainAccessToken($tlsSock);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// Examine the access token:
echo 'Access Token: ', $gAuth->AccessToken, "\n";