(VBScript) Decode Microsoft Graph ID Token

Demonstrates how to decode a Microsoft Graph ID token.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

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

' In a previous example, we obtained a Microsoft Graph OAuth2 access token.
' This example loads the JSON saved from the previous example and decodes the id_token.

' Our Microsoft Graph OAuth2 token looks like this:

' {
'   "token_type": "Bearer",
'   "scope": "openid profile User.ReadWrite Mail.ReadWrite Mail.Send Files.ReadWrite User.Read Calendars.ReadWrite Group.ReadWrite.All",
'   "expires_in": 3600,
'   "ext_expires_in": 3600,
'   "access_token": "EwCQA8l6...0HhMKYwC",
'   "refresh_token": "MCWulIvzi2yD0S...igEFn51mqcByhZtAJg",
'   "id_token": "eyJ0eXAiOiJKV1...Q7lRDaR-7A",
'   "expires_on": "1562862714"
' }

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.JsonObject")
set jsonToken = CreateObject("Chilkat.JsonObject")
success = jsonToken.LoadFile("qa_data/tokens/microsoftGraph.json")
If (success = 0) Then
    outFile.WriteLine("Failed to load the JSON file...")
    WScript.Quit
End If

' Use Chilkat's JWT API to examine the id_token..
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Jwt")
set jwt = CreateObject("Chilkat.Jwt")
idToken = jsonToken.StringOf("id_token")

' Extract the JOSE header..
jose = jwt.GetHeader(idToken)

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.JsonObject")
set jsonHeader = CreateObject("Chilkat.JsonObject")
success = jsonHeader.Load(jose)
jsonHeader.EmitCompact = 0
outFile.WriteLine(jsonHeader.Emit())

' The JOSE header looks like this:

' {
'   "typ": "JWT",
'   "alg": "RS256",
'   "kid": "1LTMzakihiRla_8z2BEJVXeWMqo"
' }

claims = jwt.GetPayload(idToken)

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.JsonObject")
set jsonClaims = CreateObject("Chilkat.JsonObject")
success = jsonClaims.Load(claims)
jsonClaims.EmitCompact = 0
outFile.WriteLine(jsonClaims.Emit())

' The claims look like this:

' {
'   "ver": "2.0",
'   "iss": "https://login.microsoftonline.com/9188040d-6c67-4c5b-b112-36a304b66dad/v2.0",
'   "sub": "AAAAAAAAAAAAAAAAAAAAAHJFryd6Gydo-XtTd1nhUNQ",
'   "aud": "18c456bd-db75-43fe-9724-9e5d821c68ff",
'   "exp": 1562945513,
'   "iat": 1562858813,
'   "nbf": 1562858813,
'   "name": "Matt Chilkat",
'   "preferred_username": "matt@example.com",
'   "oid": "00000000-0000-0000-3a33-fceb9b74cc15",
'   "tid": "9188040d-6c67-4c5b-b112-36a304b66dad",
'   "aio": "DfibJqKnWC1c0FS6G ... W6pvTrQuYzyq16ghY$"
' }
' 

' Use this online tool to generate parsing code from sample JSON: 
' Generate Parsing Code from JSON

' Get each of the claims..
ver = jsonClaims.StringOf("ver")
iss = jsonClaims.StringOf("iss")
s_sub = jsonClaims.StringOf("sub")
aud = jsonClaims.StringOf("aud")
exp = jsonClaims.IntOf("exp")
iat = jsonClaims.IntOf("iat")
nbf = jsonClaims.IntOf("nbf")
name = jsonClaims.StringOf("name")
preferred_username = jsonClaims.StringOf("preferred_username")
oid = jsonClaims.StringOf("oid")
tid = jsonClaims.StringOf("tid")
aio = jsonClaims.StringOf("aio")

outFile.Close