(PureBasic) ABN AMRO Create Signed JSON Web Token

Demonstrates how to create a signed JWT to be used for authenticating requests to the ABN AMRO REST API's.

For more information, see https://developer.abnamro.com/get-started#headingFive

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkJwt.pb"
IncludeFile "CkPublicKey.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkRsa.pb"

Procedure ChilkatExample()

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

    ; Create public/private key pair (RSA)
    rsa.i = CkRsa::ckCreate()
    If rsa.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Generate a 2048-bit key.
    success.i = CkRsa::ckGenerateKey(rsa,2048)
    If success <> 1
        Debug CkRsa::ckLastErrorText(rsa)
        CkRsa::ckDispose(rsa)
        ProcedureReturn
    EndIf

    ; Export the key to PEM files.
    ; Write one PEM file for the private key, and one for the public key.
    privkey.i = CkRsa::ckExportPrivateKeyObj(rsa)
    success = CkPrivateKey::ckSavePemFile(privkey,"qa_data/pem/abnAmroPrivateKey.pem")

    pubkey.i = CkRsa::ckExportPublicKeyObj(rsa)
    success = CkPublicKey::ckSavePemFile(pubkey,1,"qa_data/pem/abnAmroPublicKey.pem")
    ; Note: Please share your public key along with your app name and developer email id at api.support@nl.abnamro.com. 
    ; Token generation will not work unless public key is associated with your app.

    ; Create the JWT.
    jwt.i = CkJwt::ckCreate()
    If jwt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Create the header:
    ; {
    ;     "typ": "JWT",
    ;     "alg": "RS256"
    ; }
    jsonHeader.i = CkJsonObject::ckCreate()
    If jsonHeader.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(jsonHeader,"typ","JWT")
    CkJsonObject::ckUpdateString(jsonHeader,"alg","RS256")

    ; Create the payload:
    ; {
    ;     "nbf": 1499947668,
    ;     "exp": 1499948668,
    ;     "iss": "me",
    ;     "sub": "anApiKey",
    ;     "aud": "https://auth-sandbox.abnamro.com/oauth/token"
    ; }
    jsonPayload.i = CkJsonObject::ckCreate()
    If jsonPayload.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    curDateTime.i = CkJwt::ckGenNumericDate(jwt,0)

    ; Set the "not process before" timestamp to now.
    success = CkJsonObject::ckAddIntAt(jsonPayload,-1,"nbf",curDateTime)

    ; Set the timestamp defining an expiration time (end time) for the token
    ; to be now + 1 hour (3600 seconds)
    success = CkJsonObject::ckAddIntAt(jsonPayload,-1,"exp",curDateTime + 3600)

    CkJsonObject::ckUpdateString(jsonPayload,"iss","me")
    CkJsonObject::ckUpdateString(jsonPayload,"sub","anApiKey")
    CkJsonObject::ckUpdateString(jsonPayload,"aud","https://auth-sandbox.abnamro.com/oauth/token")

    ; Produce the smallest possible JWT:
    CkJwt::setCkAutoCompact(jwt, 1)

    jwtStr.s = CkJwt::ckCreateJwtPk(jwt,CkJsonObject::ckEmit(jsonHeader),CkJsonObject::ckEmit(jsonPayload),privkey)
    If CkJwt::ckLastMethodSuccess(jwt) <> 1
        Debug CkJwt::ckLastErrorText(jwt)
        CkRsa::ckDispose(rsa)
        CkJwt::ckDispose(jwt)
        CkJsonObject::ckDispose(jsonHeader)
        CkJsonObject::ckDispose(jsonPayload)
        ProcedureReturn
    EndIf

    CkPrivateKey::ckDispose(privkey)

    CkPublicKey::ckDispose(pubkey)

    ; Here is the JWT:
    Debug jwtStr


    CkRsa::ckDispose(rsa)
    CkJwt::ckDispose(jwt)
    CkJsonObject::ckDispose(jsonHeader)
    CkJsonObject::ckDispose(jsonPayload)


    ProcedureReturn
EndProcedure