Unlock WP post with fobidden wp-login.php due to security

functions.php

<?php
/**
 * Change the password form action URL.
 */
add_filter('the_password_form', function($form, $post) {
	$url = add_query_arg('unlock', 'post', get_permalink($post->ID));
	$form = preg_replace('/action="([^\"]+)"/', 'action="' . $url . '"', $form);
	return $form;
}, 10, 2);

/**
 * Process password to unlock the post.
 * @see wp-login.php:722
 */
add_action('init', function() {
	if (!isset($_GET['unlock']) || $_GET['unlock'] !== 'post') return;

	if (!array_key_exists('post_password', $_POST)) {
		wp_safe_redirect(wp_get_referer());
		exit;
	}
	require_once ABSPATH . WPINC . '/class-phpass.php';
	$hasher = new PasswordHash(8, true);

	$expire  = apply_filters('post_password_expires', time() + 10 * DAY_IN_SECONDS);
	$referer = wp_get_referer();

	if ($referer) $secure = ('https' === parse_url($referer, PHP_URL_SCHEME));
	else $secure = false;

	setcookie('wp-postpass_' . COOKIEHASH, $hasher->HashPassword(wp_unslash($_POST['post_password'])), $expire, COOKIEPATH, COOKIE_DOMAIN, $secure);
	wp_safe_redirect(wp_get_referer());
	exit;
});