LinkedIn oAuth 2 issue with client_id parameter

Question

I'm trying to create an application on LinkedIn that's using OAuth2 for authentication and am running into some errors. The client runs on an iOS device and uses an oAuth library to make a call to LinkedIn's servers. My iOS client successfully gets the authorization_code. The client application then passes that authorization_code to my server, which attempts to connect to linkedIN again and get the access_token. This step consistently fails, I get the following error from LinkedIn: {"error":"invalid_request","error_description":"missing required parameters, includes an invalid parameter value, parameter more than once. : client_id"}

My POST method to LInkedIN does contain the client_id, it only contains it once, and I've triple checked the values for all the parameters, they are correct. I've also reset the access multiple times from https://www.linkedin.com/secure/settings and I've even created additional applications on LinkedIn, I keep getting the same result.

I've checked other responses, such as this one: unable to retrieve access token linkedin api and tried the suggestions: revoke keys, request new keys etc, nothing seems to be working.

Here is my server code:

$tokenURL = 'https://www.linkedin.com/uas/oauth2/accessToken';
$redirectURL = 'https://staging.textsuggestions.com';
$clientId = '75a4ezqh741sup';
$clientSecret = 'XXXXXXXX';

$tokenArguments = array("grant_type" => "authorization_code",
"code" => $code,
"redirect_uri" => $redirectURL,
"client_secret" => $clientSecret,
"client_id" => $clientId);

// send the request to the server getting data
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $tokenURL);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $tokenArguments);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = json_decode(curl_exec($ch), true);
curl_close($ch);

if (!empty($response["error"])) {
error_log("Error is: " . $response["error"]);
exit (0);
} else {
// no error, get the access_token and do stuff with it
$timeout = $response["expires_in"];
$access_token = $response["access_token"];
}

Anurag Anurag · Accepted Answer · 2014-05-12T18:24:27

Ok I realized what I was doing wrong, the client application library that I was using was generating the full access token (not the auth code). So I was trying to pass in the access token in the place of the auth code. The error that I was getting from Linked In was certainly misleading and I should have checked the client library I was using more carefully.

LinkedIn oAuth 2 issue with client_id parameter

3 Answers