(Tcl) Decode Microsoft Graph ID Token

Demonstrates how to decode a Microsoft Graph ID token.

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load ./chilkat.dll

# 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"
# }

set jsonToken [new_CkJsonObject]

set success [CkJsonObject_LoadFile $jsonToken "qa_data/tokens/microsoftGraph.json"]
if {$success == 0} then {
    puts "Failed to load the JSON file..."
    delete_CkJsonObject $jsonToken
    exit
}

# Use Chilkat's JWT API to examine the id_token..
set jwt [new_CkJwt]

set idToken [CkJsonObject_stringOf $jsonToken "id_token"]

# Extract the JOSE header..
set jose [CkJwt_getHeader $jwt $idToken]

set jsonHeader [new_CkJsonObject]

CkJsonObject_Load $jsonHeader $jose
CkJsonObject_put_EmitCompact $jsonHeader 0
puts [CkJsonObject_emit $jsonHeader]

# The JOSE header looks like this:

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

set claims [CkJwt_getPayload $jwt $idToken]

set jsonClaims [new_CkJsonObject]

CkJsonObject_Load $jsonClaims $claims
CkJsonObject_put_EmitCompact $jsonClaims 0
puts [CkJsonObject_emit $jsonClaims]

# 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..
set ver [CkJsonObject_stringOf $jsonClaims "ver"]
set iss [CkJsonObject_stringOf $jsonClaims "iss"]
set s_sub [CkJsonObject_stringOf $jsonClaims "sub"]
set aud [CkJsonObject_stringOf $jsonClaims "aud"]
set exp [CkJsonObject_IntOf $jsonClaims "exp"]
set iat [CkJsonObject_IntOf $jsonClaims "iat"]
set nbf [CkJsonObject_IntOf $jsonClaims "nbf"]
set name [CkJsonObject_stringOf $jsonClaims "name"]
set preferred_username [CkJsonObject_stringOf $jsonClaims "preferred_username"]
set oid [CkJsonObject_stringOf $jsonClaims "oid"]
set tid [CkJsonObject_stringOf $jsonClaims "tid"]
set aio [CkJsonObject_stringOf $jsonClaims "aio"]

delete_CkJsonObject $jsonToken
delete_CkJwt $jwt
delete_CkJsonObject $jsonHeader
delete_CkJsonObject $jsonClaims