(PowerShell) 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 .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

# 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.
$pfx = New-Object Chilkat.Pfx
$success = $pfx.LoadPfxFile("qa_data/pfx/chilkat25-cbd7b42afbd8.p12","notasecret")
if ($success -ne $true) {
    $($pfx.LastErrorText)
    exit
}

$gAuth = New-Object Chilkat.AuthGoogle
$success = $gAuth.SetP12($pfx)

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

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

# The sub is your company email address
$oauth_sub = "info@chilkat.xyz"

# The access token is valid for this number of seconds.
$numSec = 3600

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

# Connect to www.googleapis.com
$tlsSock = New-Object Chilkat.Socket
$success = $tlsSock.Connect("www.googleapis.com",443,$true,5000)
if ($success -ne $true) {
    $($tlsSock.LastErrorText)
    exit
}

# Send the request to obtain the access token.
$success = $gAuth.ObtainAccessToken($tlsSock)
if ($success -ne $true) {
    $($gAuth.LastErrorText)
    exit
}

# Examine the access token:
$("Access Token: " + $gAuth.AccessToken)