(Node.js) Get Google API Access Token using P12 Service Account Key

Demonstrates how to get a Google API access token using a P12 service account key.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOS

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

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

    // --------------------------------------------------------------------------------
    // For a step-by-step guide for setting up your Google Workspace service account,
    // see Setup Google Workspace Account for Sending SMTP GMail from a Service Account
    // --------------------------------------------------------------------------------

    // First load the PKCS12 (.p12 / .pfx) into a PFX object.
    var pfx = new chilkat.Pfx();
    var success = pfx.LoadPfxFile("qa_data/pfx/chilkat25-cbd7b42afbd8.p12","notasecret");
    if (success !== true) {
        console.log(pfx.LastErrorText);
        return;
    }

    var gAuth = new chilkat.AuthGoogle();
    success = gAuth.SetP12(pfx);

    // The ISS is your service account email address ending in gserviceaccount.com.
    var iss = "chilkatsvc@chilkat25.iam.gserviceaccount.com";

    // The scope is always the following string:
    var scope = "https://mail.google.com/";

    // The sub is your company email address
    var oauth_sub = "info@chilkat.xyz";

    // The access token is valid for this number of seconds.
    var numSec = 3600;

    gAuth.EmailAddress = iss;
    gAuth.Scope = scope;
    gAuth.ExpireNumSeconds = numSec;
    gAuth.SubEmailAddress = oauth_sub;

    // Connect to www.googleapis.com
    var tlsSock = new chilkat.Socket();
    success = tlsSock.Connect("www.googleapis.com",443,true,5000);
    if (success !== true) {
        console.log(tlsSock.LastErrorText);
        return;
    }

    // Send the request to obtain the access token.
    success = gAuth.ObtainAccessToken(tlsSock);
    if (success !== true) {
        console.log(gAuth.LastErrorText);
        return;
    }

    // Examine the access token:
    console.log("Access Token: " + gAuth.AccessToken);

}

chilkatExample();