(DataFlex) 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.

For more information, see https://www.servicesaustralia.gov.au/organisations/business/services/proda-provider-digital-access

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

Use ChilkatAx-win32.pkg

Procedure Test
    Variant vPrivKey
    Handle hoPrivKey
    Boolean iSuccess
    Handle hoJwt
    Handle hoJose
    Handle hoClaims
    Integer iCurDateTime
    String sJwtToken
    Handle hoHttp
    Variant vReq
    Handle hoReq
    Variant vResp
    Handle hoResp
    String sTemp1
    String sTemp2
    Integer iTemp1
    Boolean bTemp1

    // 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

    Get Create (RefClass(cComChilkatPrivateKey)) To hoPrivKey
    If (Not(IsComObjectCreated(hoPrivKey))) Begin
        Send CreateComObject of hoPrivKey
    End

    // 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.
    Get ComLoadEncryptedPemFile Of hoPrivKey "qa_data/pem/rsa_passwd.pem" "passwd" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoPrivKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatJwt)) To hoJwt
    If (Not(IsComObjectCreated(hoJwt))) Begin
        Send CreateComObject of hoJwt
    End

    // Build the JOSE header
    Get Create (RefClass(cComChilkatJsonObject)) To hoJose
    If (Not(IsComObjectCreated(hoJose))) Begin
        Send CreateComObject of hoJose
    End
    // Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
    Get ComAppendString Of hoJose "alg" "RS256" To iSuccess
    Get ComAppendString Of hoJose "typ" "JWT" To iSuccess
    Get ComAppendString Of hoJose "kid" "test-device" To iSuccess

    // Now build the JWT claims (also known as the payload)
    Get Create (RefClass(cComChilkatJsonObject)) To hoClaims
    If (Not(IsComObjectCreated(hoClaims))) Begin
        Send CreateComObject of hoClaims
    End
    Get ComAppendString Of hoClaims "iss" "9646844092" To iSuccess
    Get ComAppendString Of hoClaims "sub" "test-device" To iSuccess
    Get ComAppendString Of hoClaims "aud" "https://proda.humanservices.gov.au" To iSuccess

    // Set the timestamp of when the JWT was created to now.
    Get ComGenNumericDate Of hoJwt 0 To iCurDateTime
    Get ComAddIntAt Of hoClaims -1 "iat" iCurDateTime To iSuccess

    // Set the timestamp defining an expiration time (end time) for the token
    // to be now + 1 hour (3600 seconds)
    Get ComAddIntAt Of hoClaims -1 "exp" (iCurDateTime + 3600) To iSuccess

    // Produce the smallest possible JWT:
    Set ComAutoCompact Of hoJwt To True

    // Create the JWT token.  This is where the RSA signature is created.
    Get ComEmit Of hoJose To sTemp1
    Get ComEmit Of hoClaims To sTemp2
    Get pvComObject of hoPrivKey to vPrivKey
    Get ComCreateJwtPk Of hoJwt sTemp1 sTemp2 vPrivKey To sJwtToken

    // ---------------------------------------------------------------------
    // 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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get Create (RefClass(cComChilkatHttpRequest)) To hoReq
    If (Not(IsComObjectCreated(hoReq))) Begin
        Send CreateComObject of hoReq
    End

    // Add the request params.
    Send ComAddParam To hoReq "grant_type" "urn:ietf:params:oauth:grant-type:jwt-bearer"
    Send ComAddParam To hoReq "assertion" sJwtToken
    Send ComAddParam To hoReq "client_id" "VendorClient03"

    // Send the POST
    // Chilkat automatically adds the Content-Type (which is application/x-www-form-urlencoded for the PostUrlEncoded method)
    // Chilkat also automatically adds the Host and Content-Length headers.

    Get pvComObject of hoReq to vReq
    Get ComPostUrlEncoded Of hoHttp "https://vnd.proda.humanservices.gov.au/mga/sps/oauth/oauth20/token" vReq To vResp
    If (IsComObject(vResp)) Begin
        Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
        Set pvComObject Of hoResp To vResp
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComStatusCode Of hoResp To iTemp1
    Showln "Response status code = " iTemp1
    Showln "Response body:"
    Get ComBodyStr Of hoResp To sTemp1
    Showln sTemp1

    Send Destroy of hoResp


End_Procedure