(C#) Decode Microsoft Graph ID Token

Demonstrates how to decode a Microsoft Graph ID token.

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// 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"
// }

Chilkat.JsonObject jsonToken = new Chilkat.JsonObject();
bool success = jsonToken.LoadFile("qa_data/tokens/microsoftGraph.json");
if (success == false) {
    Debug.WriteLine("Failed to load the JSON file...");
    return;
}

// Use Chilkat's JWT API to examine the id_token..
Chilkat.Jwt jwt = new Chilkat.Jwt();
string idToken = jsonToken.StringOf("id_token");

// Extract the JOSE header..
string jose = jwt.GetHeader(idToken);

Chilkat.JsonObject jsonHeader = new Chilkat.JsonObject();
jsonHeader.Load(jose);
jsonHeader.EmitCompact = false;
Debug.WriteLine(jsonHeader.Emit());

// The JOSE header looks like this:

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

string claims = jwt.GetPayload(idToken);

Chilkat.JsonObject jsonClaims = new Chilkat.JsonObject();
jsonClaims.Load(claims);
jsonClaims.EmitCompact = false;
Debug.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..
string ver = jsonClaims.StringOf("ver");
string iss = jsonClaims.StringOf("iss");
string s_sub = jsonClaims.StringOf("sub");
string aud = jsonClaims.StringOf("aud");
int exp = jsonClaims.IntOf("exp");
int iat = jsonClaims.IntOf("iat");
int nbf = jsonClaims.IntOf("nbf");
string name = jsonClaims.StringOf("name");
string preferred_username = jsonClaims.StringOf("preferred_username");
string oid = jsonClaims.StringOf("oid");
string tid = jsonClaims.StringOf("tid");
string aio = jsonClaims.StringOf("aio");