(PHP ActiveX) OAuth2 for a GMail using a JSON Service Account Key

Demonstrates how get an OAuth2 access token for GMail (Google Service Account) using a JSON private key.

After the access token is obtained, it may be used to send email. When the access token expires, a new access token needs to be obtained (using this same procedure).

Note: This is for OAuth2 using Google Service account keys.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

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

// First load the JSON key into a string.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.FileAccess')
$fac = new COM("Chilkat.FileAccess");
$jsonKey = $fac->readEntireTextFile('qa_data/googleApi/ChilkatTest-ab2ecd52ef98.json','utf-8');
if ($fac->LastMethodSuccess != 1) {
    print $fac->LastErrorText . "\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"
// 	}

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.AuthGoogle')
$gAuth = new COM("Chilkat.AuthGoogle");
$gAuth->JsonKey = $jsonKey;

// Choose a scope.
$gAuth->Scope = 'https://mail.google.com/';

// 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 = '';

// 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.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Socket')
$tlsSock = new COM("Chilkat.Socket");
$success = $tlsSock->Connect('www.googleapis.com',443,1,5000);
if ($success != 1) {
    print $tlsSock->LastErrorText . "\n";
    exit;
}

// Send the request to obtain the access token.
$success = $gAuth->ObtainAccessToken($tlsSock);
if ($success != 1) {
    print $gAuth->LastErrorText . "\n";
    exit;
}

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

// Now that we have the access token, it may be used to send email
// while it remains valid.  Once the access token expires, a new access token 
// should be obtained using the same code as above.

// -----------------------------------------------------------------------
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.MailMan')
$mailman = new COM("Chilkat.MailMan");

// Set the properties for the GMail SMTP server:
$mailman->SmtpHost = 'smtp.gmail.com';
$mailman->SmtpPort = 587;
$mailman->StartTLS = 1;

$mailman->SmtpUsername = 'YOUR_GOOGLE_APPS_USER_EMAIL_ADDRESS';
$mailman->OAuth2AccessToken = $gAuth->AccessToken;

// Create a new email object
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Email')
$email = new COM("Chilkat.Email");

$email->Subject = 'This is a test';
$email->Body = 'This is a test';
$email->From = 'YOUR NAME <YOUR_GOOGLE_APPS_USER_EMAIL_ADDRESS>';
$success = $email->AddTo('Chilkat Admin','admin@chilkatsoft.com');
// To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

// Call SendEmail to connect to the SMTP server and send.
// The connection (i.e. session) to the SMTP server remains
// open so that subsequent SendEmail calls may use the
// same connection.  
$success = $mailman->SendEmail($email);
if ($success != 1) {
    print $mailman->LastErrorText . "\n";
    exit;
}

// You may close the connection here.  If the connection is kept open, 
// the next call to mailman.SendEmail will continue using the already-established connection
// (and automatically re-connect if needed).
$success = $mailman->CloseSmtpConnection();
if ($success != 1) {
    print 'Connection to SMTP server not closed cleanly.' . "\n";
}

print 'Email Sent via GMail using an OAuth2 Service Account Key.' . "\n";

?>