(Perl) Get Access Token using a Pre-Created JSON Web Token

Demonstrates how to get an access token using a pre-created JSON Web Token (JWT).

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

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

# We're going to duplicate this CURL statement:
# curl -X POST https://api-sandbox.abnamro.com/v1/oauth/token \
# -H "Content-Type: application/x-www-form-urlencoded" \
# -H "API-Key: xxxxxx" \
# -d 'client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&grant_type=client_credentials&client_assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ4eHh4eHgiLCJleHAiOiIxNDk5OTQ3NjY4IiwiaXNzIjoibWUiLCJhdWQiOiJodHRwczovL2F1dGgtc2FuZGJveC5hYm5hbXJvLmNvbS9vYXV0aC90b2tlbiJ9.jGwHKG_YjgKpR8NPpaLu6nJ97obeP2vcxg6fOWBKdJ0&scope=tikkie'

# Load our pre-creaed private key PEM file.
# 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.
$privkey = chilkat::CkPrivateKey->new();

$success = $privkey->LoadPemFile("qa_data/pem/abnAmroPrivateKey.pem");
if ($success == 0) {
    print $privkey->lastErrorText() . "\r\n";
    exit;
}

# Create the JWT.
$jwt = chilkat::CkJwt->new();

# Create the header:
# {
#     "typ": "JWT",
#     "alg": "RS256"
# }
$jsonHeader = chilkat::CkJsonObject->new();
$jsonHeader->UpdateString("typ","JWT");
$jsonHeader->UpdateString("alg","RS256");

# Create the payload:
# {
#     "nbf": 1499947668,
#     "exp": 1499948668,
#     "iss": "me",
#     "sub": "anApiKey",
#     "aud": "https://auth-sandbox.abnamro.com/oauth/token"
# }
$jsonPayload = chilkat::CkJsonObject->new();

$curDateTime = $jwt->GenNumericDate(0);

# Set the "not process before" timestamp to now.
$success = $jsonPayload->AddIntAt(-1,"nbf",$curDateTime);

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

$jsonPayload->UpdateString("iss","me");
$jsonPayload->UpdateString("sub","anApiKey");
$jsonPayload->UpdateString("aud","https://auth-sandbox.abnamro.com/oauth/token");

# Produce the smallest possible JWT:
$jwt->put_AutoCompact(1);

$jwtStr = $jwt->createJwtPk($jsonHeader->emit(),$jsonPayload->emit(),$privkey);
if ($jwt->get_LastMethodSuccess() != 1) {
    print $jwt->lastErrorText() . "\r\n";
    exit;
}

$http = chilkat::CkHttp->new();

$req = chilkat::CkHttpRequest->new();
$req->AddParam("client_assertion_type","urn:ietf:params:oauth:client-assertion-type:jwt-bearer");
$req->AddParam("grant_type","client_credentials");
$req->AddParam("client_assertion",$jwtStr);
$req->AddParam("scope","tikkie");

# resp is a HttpResponse
$resp = $http->PostUrlEncoded("https://api-sandbox.abnamro.com/v1/oauth/token",$req);
if ($http->get_LastMethodSuccess() == 0) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

if ($resp->get_StatusCode() != 200) {
    print $resp->bodyStr() . "\r\n";

    exit;
}

# Get the JSON result:
# {
#     "access_token": "{your access token}",
#     "expires_in": "{duration of validity in seconds}",
#     "scope": "{scope(s) for which the access token is valid}",
#     "token_type": "{it is always Bearer}"
# }
$json = chilkat::CkJsonObject->new();
$json->Load($resp->bodyStr());
print "access_token: " . $json->stringOf("access_token") . "\r\n";
print "token_type: " . $json->stringOf("token_type") . "\r\n";
print "expires_in: " . $json->stringOf("expires_in") . "\r\n";
print "scope: " . $json->stringOf("scope") . "\r\n";