(VB.NET) 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 Framework Chilkat for .NET Core

' 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.
Dim pfx As New Chilkat.Pfx
Dim success As Boolean = pfx.LoadPfxFile("qa_data/pfx/chilkat25-cbd7b42afbd8.p12","notasecret")
If (success <> True) Then
    Debug.WriteLine(pfx.LastErrorText)
    Exit Sub
End If


Dim gAuth As New Chilkat.AuthGoogle
success = gAuth.SetP12(pfx)

' The ISS is your service account email address ending in gserviceaccount.com.
Dim iss As String = "chilkatsvc@chilkat25.iam.gserviceaccount.com"

' The scope is always the following string:
Dim scope As String = "https://mail.google.com/"

' The sub is your company email address
Dim oauth_sub As String = "info@chilkat.xyz"

' The access token is valid for this number of seconds.
Dim numSec As Integer = 3600

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

' Connect to www.googleapis.com
Dim tlsSock As New Chilkat.Socket
success = tlsSock.Connect("www.googleapis.com",443,True,5000)
If (success <> True) Then
    Debug.WriteLine(tlsSock.LastErrorText)
    Exit Sub
End If


' Send the request to obtain the access token.
success = gAuth.ObtainAccessToken(tlsSock)
If (success <> True) Then
    Debug.WriteLine(gAuth.LastErrorText)
    Exit Sub
End If


' Examine the access token:
Debug.WriteLine("Access Token: " & gAuth.AccessToken)