(Visual FoxPro) 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

LOCAL loJsonToken
LOCAL lnSuccess
LOCAL loJwt
LOCAL lcIdToken
LOCAL lcJose
LOCAL loJsonHeader
LOCAL lcClaims
LOCAL loJsonClaims
LOCAL lcVer
LOCAL lcIss
LOCAL lcS_sub
LOCAL lcAud
LOCAL lnExp
LOCAL lnIat
LOCAL lnNbf
LOCAL lcName
LOCAL lcPreferred_username
LOCAL lcOid
LOCAL lcTid
LOCAL lcAio

* 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')
loJsonToken = CreateObject('Chilkat.JsonObject')
lnSuccess = loJsonToken.LoadFile("qa_data/tokens/microsoftGraph.json")
IF (lnSuccess = 0) THEN
    ? "Failed to load the JSON file..."
    RELEASE loJsonToken
    CANCEL
ENDIF

* Use Chilkat's JWT API to examine the id_token..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Jwt')
loJwt = CreateObject('Chilkat.Jwt')
lcIdToken = loJsonToken.StringOf("id_token")

* Extract the JOSE header..
lcJose = loJwt.GetHeader(lcIdToken)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonHeader = CreateObject('Chilkat.JsonObject')
loJsonHeader.Load(lcJose)
loJsonHeader.EmitCompact = 0
? loJsonHeader.Emit()

* The JOSE header looks like this:

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

lcClaims = loJwt.GetPayload(lcIdToken)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonClaims = CreateObject('Chilkat.JsonObject')
loJsonClaims.Load(lcClaims)
loJsonClaims.EmitCompact = 0
? loJsonClaims.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..
lcVer = loJsonClaims.StringOf("ver")
lcIss = loJsonClaims.StringOf("iss")
lcS_sub = loJsonClaims.StringOf("sub")
lcAud = loJsonClaims.StringOf("aud")
lnExp = loJsonClaims.IntOf("exp")
lnIat = loJsonClaims.IntOf("iat")
lnNbf = loJsonClaims.IntOf("nbf")
lcName = loJsonClaims.StringOf("name")
lcPreferred_username = loJsonClaims.StringOf("preferred_username")
lcOid = loJsonClaims.StringOf("oid")
lcTid = loJsonClaims.StringOf("tid")
lcAio = loJsonClaims.StringOf("aio")

RELEASE loJsonToken
RELEASE loJwt
RELEASE loJsonHeader
RELEASE loJsonClaims