(Ruby) 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 Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require '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 == false)
    print privkey.lastErrorText() + "\n";
    exit
end

# 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(true)

jwtStr = jwt.createJwtPk(jsonHeader.emit(),jsonPayload.emit(),privkey)
if (jwt.get_LastMethodSuccess() != true)
    print jwt.lastErrorText() + "\n";
    exit
end

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 CkHttpResponse
resp = http.PostUrlEncoded("https://api-sandbox.abnamro.com/v1/oauth/token",req)
if (http.get_LastMethodSuccess() == false)
    print http.lastErrorText() + "\n";
    exit
end

if (resp.get_StatusCode() != 200)
    print resp.bodyStr() + "\n";

    exit
end

# 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") + "\n";
print "token_type: " + json.stringOf("token_type") + "\n";
print "expires_in: " + json.stringOf("expires_in") + "\n";
print "scope: " + json.stringOf("scope") + "\n";