Header in requestClientCredentialsToken

[saskiaschild]

In requestClientCredentialsToken the headers are set to an empty array. Since the documentation of OAuth and OpenId Connect says that HTTP Basic Authentication is needed, there should be the at least the basic header in there.

public function requestClientCredentialsToken() {
   $token_endpoint = $this->getProviderConfigValue('token_endpoint');

   $headers = [
      'Authorization: Basic ' . base64_encode(urlencode($this->clientID) . ':' . urlencode($this->clientSecret))
   ];

   $grant_type = 'client_credentials';

   $post_data = array(
      'grant_type'    => $grant_type,
      'client_id'     => $this->clientID,
      'client_secret' => $this->clientSecret,
      'scope'         => implode(' ', $this->scopes)
   );

   // Convert token params to string format
   $post_params = http_build_query($post_data, null, '&', $this->enc_type);

   return json_decode($this->fetchURL($token_endpoint, $post_params, $headers));
}

Would be nice to have the header there (or at least the possibility to set headers via method parameters).

[azmeuk]

Fixed by #271