(VB.NET UWP/WinRT) Get Access Token for Google Tasks using Service Account JSON Key

Demonstrates how to get an access token for the Google Tasks API using a Service Account JSON key.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' 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.
Dim fac As New Chilkat.FileAccess
Dim jsonKey As String = fac.ReadEntireTextFile("qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json","utf-8")
If (fac.LastMethodSuccess <> True) Then
    Debug.WriteLine(fac.LastErrorText)
    Exit Sub
End If


' A JSON private key should look like this:

' {
'   "type": "service_account",
'   "project_id": "chilkatcloud",
'   "private_key_id": "48f7737c7505bb88eee6a20d09993e10605d466e",
'   "private_key": "-----BEGIN PRIVATE KEY----- ... -----END PRIVATE KEY-----\n",
'   "client_email": "pip-564@chilkatcloud.iam.gserviceaccount.com",
'   "client_id": "109982228323456925225",
'   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
'   "token_uri": "https://oauth2.googleapis.com/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/pip-564%40chilkatcloud.iam.gserviceaccount.com"
' }


Dim gAuth As New Chilkat.AuthGoogle
gAuth.JsonKey = jsonKey

' Choose the scope for read/write access.
gAuth.Scope = "https://www.googleapis.com/auth/tasks"

' Request an access token that is valid for this many seconds.
gAuth.ExpireNumSeconds = 3600

gAuth.SubEmailAddress = ""

' Connect to www.googleapis.com using TLS
Dim tlsSock As New Chilkat.Socket
Dim success As Boolean = Await tlsSock.ConnectAsync("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 = Await gAuth.ObtainAccessTokenAsync(tlsSock)
If (success <> True) Then
    Debug.WriteLine(gAuth.LastErrorText)
    Exit Sub
End If


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

' Save our access token to a file.
success = fac.WriteEntireTextFile("qa_data/tokens/googleTasks.txt",gAuth.AccessToken,"utf-8",False)