Created question in FIWARE Q/A platform on 09-07-2015 at 17:07
Please, ANSWER this question AT http://stackoverflow.com/questions/31322425/fiware-lab-keyrock-access-token-request-error

Question:
FIWARE-Lab KeyRock Access Token Request error

Description:
I'm testing the Authorization Code Grant protocol on the instance of KeyRock GE at FIWARE-Lab using DHC web client.

So far I have succeeded on implementing the Authorization Request, and I obtain the code to be used on the Access Token Request. The URL for the Authorization Request is the following (although not executed on DHC, but on a regular browser so I can introduce my user and password):

https://account.lab.fiware.org/oauth2/authorize/?response_type=code&client_id=2122&redirect_uri=http%3A%2F%2Flocalhost%2FCallback

I have checked that the client_id and the redirect_uri are both correct against the values related with my application at my account at FIWARE-Lab.

Executing the following request (can't post images, so I'll describe)

POST
https:// account.lab.fiware.org/oauth2/token?grant_type=authorization_code&code=<code>&redirect_uri=http%3A%2F%2Flocalhost%2FCallback – <code> is the code obtained on the Auth. Request
Authorization: Basic <XXXX> — <XXXX> is the result of base64(client_id+":"+client_secret)
Content-Type: application/x-www-form-urlencoded

...I get the following error message:

{
"error":{
"message": "create_access_token() takes exactly 3 arguments (2 given)",
"code": 400,
"title": "Bad Request"
}
}

I've checked the authorization is correct (Basic using the OAuth credentials from my application), and I'm using the same redirect_uri used at the previous Authorization Request, and the code obtained from it.

¿What is wrong?

P.S.: If I remove any or all of the query parameters, I still get the same error