(Swift) 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.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // 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.
    let pfx = CkoPfx()!
    var success: Bool = pfx.loadFile("qa_data/pfx/chilkat25-cbd7b42afbd8.p12", password: "notasecret")
    if success != true {
        print("\(pfx.lastErrorText!)")
        return
    }

    let gAuth = CkoAuthGoogle()!
    success = gAuth.setP12(pfx)

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

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

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

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

    gAuth.emailAddress = iss
    gAuth.scope = scope
    gAuth.expireNumSeconds = numSec
    gAuth.subEmailAddress = oauth_sub

    // Connect to www.googleapis.com
    let tlsSock = CkoSocket()!
    success = tlsSock.connect("www.googleapis.com", port: 443, ssl: true, maxWaitMs: 5000)
    if success != true {
        print("\(tlsSock.lastErrorText!)")
        return
    }

    // Send the request to obtain the access token.
    success = gAuth.obtainAccessToken(tlsSock)
    if success != true {
        print("\(gAuth.lastErrorText!)")
        return
    }

    // Examine the access token:
    print("Access Token: \(gAuth.accessToken!)")

}