Missing required parameters, includes an invalid parameter value, parameter more than once with LinkedIn API
api, curl, linkedin-api, oauth-2.0, php
Solution
You need to add the following header in your cURL POST call to ensure that the values you are passing in the body of your POST are interpreted correctly:
Content-Type: application/x-www-form-urlencoded
For additional info, see https://www.rfc-editor.org/rfc/rfc6749#section-4.1.3 for the actual OAuth 2.0 RFC spec.
Problem
I try to authenticate with LinkedIn API with OAuth2. Code: ``` if ((isset($_GET["code"])) AND (isset($_GET["state"]))) { $code = $_GET["code"]; $state = $_GET["state"]; $curl_request = curl_init(); curl_setopt_array($curl_request, array( CURLOPT_RETURNTRANSFER => 1, CURLOPT_URL => "https://www.linkedin.com/uas/oauth2/accessToken", CURLOPT_POST => 1, CURLOPT_POSTFIELDS => array( grant_type => "authorization_code", code => "$code", redirect_uri => "SECRET", client_id => "SECRET", client_secret => "SECRET" ) )); $curl_result = curl_exec($curl_request); var_dump($curl_result); } ``` I got this message: string(153) "{"error_description":"missing required parameters, includes an invalid parameter value, parameter more than once. : client_id","error":"invalid_request"}" Could you help m?