/**
* Sign certain keys in a message
* @param $association - object loaded from openid_association or openid_server_association table
* - important fields are ->assoc_type and ->mac_key
* @param $message_array - array of entire message about to be sent
* @param $keys_to_sign - keys in the message to include in signature (without
* 'openid.' appended)
*/
function _openid_signature($association, $message_array, $keys_to_sign)
{
$signature = '';
$sign_data = array();
foreach ($keys_to_sign as $key) {
if (isset($message_array['openid.' . $key])) {
$sign_data[$key] = $message_array['openid.' . $key];
}
}
$message = _openid_create_message($sign_data);
$secret = base64_decode($association->mac_key);
$signature = _openid_hmac($secret, $message);
return base64_encode($signature);
}
/**
* Attempt to verify the response received from the OpenID Provider.
*
* @param $op_endpoint The OpenID Provider URL.
* @param $response Array of repsonse values from the provider.
*
* @return boolean
*/
function openid_verify_assertion($op_endpoint, $response)
{
$valid = FALSE;
//TODO
$openid_association = Database::get_main_table(TABLE_MAIN_OPENID_ASSOCIATION);
$sql = sprintf("SELECT * FROM {$openid_association} WHERE assoc_handle = '%s'", $response['openid.assoc_handle']);
$res = Database::query($sql);
$association = Database::fetch_object($res);
if ($association && isset($association->session_type)) {
$keys_to_sign = explode(',', $response['openid.signed']);
$self_sig = _openid_signature($association, $response, $keys_to_sign);
if ($self_sig == $response['openid.sig']) {
$valid = TRUE;
} else {
$valid = FALSE;
}
} else {
$request = $response;
$request['openid.mode'] = 'check_authentication';
$message = _openid_create_message($request);
$headers = array('Content-Type' => 'application/x-www-form-urlencoded; charset=utf-8');
$result = openid_http_request($op_endpoint, $headers, 'POST', _openid_encode_message($message));
if (!isset($result->error)) {
$response = _openid_parse_message($result->data);
if (strtolower(trim($response['is_valid'])) == 'true') {
$valid = TRUE;
} else {
$valid = FALSE;
}
}
}
return $valid;
}
