asp.net - AccessToken for Windows Push Notifications returns Bad Request 400

Question

PLEASE HELP!! Can't figure out why this simple code given by MSDN doesn't work....

I am using the following code in GetAccessToken() as given in the this MSDN article to get the access token to be used in windows notifications, but it returns "Bad Request 400"

PACKAGE_SECURITY_IDENTIFIER, CLIENT_SECRET are the values obtained when the app was registered with the Windows Store Dashboard

string urlEncodedSid = HttpUtility.UrlEncode(PACKAGE_SECURITY_IDENTIFIER);
string urlEncodedSecret = HttpUtility.UrlEncode(CLIENT_SECRET);

string body = String.Format("grant_type=client_credentials&client_id={0}&client_secret={1}&scope=notify.windows.com", urlEncodedSid, urlEncodedSecret);

string response;

using (WebClient client = new WebClient())
{
    client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
    response = client.UploadString("https://login.live.com/accesstoken.srf", body);
}

Any help would be highly appreciated.......

Answer 1

I suspect the problem has to do with either an incorrect package identifier, and / or incorrect client secret.

From the MSDN page Push notification service request and response headers:

RESPONSE          DESCRIPTION
---------------   --------------------------
200 OK            The request was successful.
400 Bad Request   The authentication failed. 

Update - I ran the code from the question, using FAKE credentials.

Here is the RAW HTTP request:

POST https://login.live.com/accesstoken.srf HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: login.live.com
Content-Length: 88
Expect: 100-continue
Connection: Keep-Alive

grant_type=client_credentials&client_id=test&client_secret=test&scope=notify.windows.com

Here is the server's RAW response:

HTTP/1.1 400 Bad Request
Cache-Control: no-store
Content-Length: 66
Content-Type: application/json
Server: Microsoft-IIS/7.5
X-WLID-Error: 0x80045A78
PPServer: PPV: 30 H: BAYIDSLGN2A055 V: 0
Date: Thu, 21 Mar 2013 12:34:19 GMT
Connection: close

{"error":"invalid_client","error_description":"Invalid client id"}

You will note that the response is a 400. There is also some json that indicates the type of error. In my case, the error is Invalid client id. You probably want to take a look at your response - it will give you an indication of what happened.

I used Fiddler to debug the request/ response.