WP REST API how to check header basic authentication - wordpress

Question

A custom endpoint like this
add_action( 'rest_api_init', function () {
register_rest_route( 'myplugin/v1', '/author/(?P<id>\d+)', array(
'methods' => 'GET',
'callback' => 'my_awesome_func',
) );
} );
Using basic authentication in headers, let's say 'Authorization: Basic some64basePass'
How I can check the value of Authorization in the header is valid or not?

Answer 1

Here is my solution.
Inside the callback function I validate Authorization from the header like this:
function my_awesome_func($data) {
//Get HTTP request headers
$auth = apache_request_headers();
//Get only Authorization header
$valid = $auth['Authorization'];
// Validate
if ($valid == 'Basic Base64UsernamePassword') {
//Do what the function should do
} else {
$response = 'Please use a valid authentication';
}
return json_encode($response);
}
Maybe there is a better way.

Answer 2

WordPress has a hook for adding your own authentication handler.
add_filter( 'rest_authentication_errors', 'rest_basic_auth_check_errors', 99 );
Your rest_basic_auth_check_errors() should return true if basic authentication succeeds or WP_Error if it fails. Since the default REST authentication handler runs at priority 100 your rest_basic_auth_check_errors() will override the default handler.
See the function WP_REST_Server::check_authentication() in file ...\wp-includes\rest-api\class-wp-rest-server.php to understand how WordPress handles REST authentication and how to add your own authentication handler.
Also, you should read about $_SERVER['PHP_AUTH_USER'] and $_SERVER['PHP_AUTH_PW'] in http://php.net/manual/en/features.http-auth.php