B4X Requires Chilkat v11.0.0+

PRODA Get OAuth2 Access Token using JWT

See more PRODA Examples

Demonstrates how to get an OAuth2 access token for the PRODA Australian Government Online Services using a JWT. B4X

Dim success As Boolean = False

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

'  First create a JWT to be sent in the POST to https://vnd.proda.humanservices.gov.au/mga/sps/oauth/oauth20/token

Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")

'  Load an RSA private key from a PEM file.
'  Chilkat provides alternative methods to load from other formats, or to load from a string or binary data.
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem", "passwd")
If success = False Then
    Log(privKey.LastErrorText)
    Return
End If


Dim jwt As ChilkatJwt
jwt.Initialize

'  Build the JOSE header
Dim jose As ChilkatJsonObject
jose.Initialize
'  Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
success = jose.AppendString("alg", "RS256")
success = jose.AppendString("typ", "JWT")
success = jose.AppendString("kid", "test-device")

'  Now build the JWT claims (also known as the payload)
Dim claims As ChilkatJsonObject
claims.Initialize
success = claims.AppendString("iss", "9646844092")
success = claims.AppendString("sub", "test-device")
success = claims.AppendString("aud", "https://proda.humanservices.gov.au")

'  Set the timestamp of when the JWT was created to now.
Dim curDateTime As Int = jwt.GenNumericDate(0)
success = claims.AddIntAt(-1, "iat", curDateTime)

'  Set the timestamp defining an expiration time (end time) for the token
'  to be now + 1 hour (3600 seconds)
success = claims.AddIntAt(-1, "exp", curDateTime + 3600)

'  Produce the smallest possible JWT:
jwt.AutoCompact = True

'  Create the JWT token.  This is where the RSA signature is created.
Dim jwtToken As String = jwt.CreateJwtPk(jose.Emit, claims.Emit, privKey)

'  ---------------------------------------------------------------------
'  Build and send the POST, which should look something like this:

'  POST https://vnd.proda.humanservices.gov.au/mga/sps/oauth/oauth20/token HTTP/1.1
'  Content-Type: application/x-www-form-urlencoded
'  Content-Length: 666
'  Host: vnd.proda.humanservices.gov.au
'  
'  grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer&assertion=<jwt>&client_id=VendorClient03

Dim http As ChilkatHttp
http.Initialize("http")

Dim req As ChilkatHttpRequest
req.Initialize
req.HttpVerb = "POST"
req.ContentType = "application/x-www-form-urlencoded"

'  Add the request params.
req.AddParam("grant_type", "urn:ietf:params:oauth:grant-type:jwt-bearer")
req.AddParam("assertion", jwtToken)
req.AddParam("client_id", "VendorClient03")

Dim resp As ChilkatHttpResponse
resp.Initialize
success = http.HttpReq("https://vnd.proda.humanservices.gov.au/mga/sps/oauth/oauth20/token", req, resp)
If success = False Then
    Log(http.LastErrorText)
    Return
End If


Log("Response status code = " & resp.StatusCode)
Log("Response body:")
Log(resp.BodyStr)