<?php
/**
* Error Protection API: WP_Recovery_Mode_Cookie_Service class
*
* @package WordPress
* @since 5.2.0
*/

/**
* Core class used to set, validate, and clear cookies that identify a Recovery Mode session.
*
* @since 5.2.0
*/
#[AllowDynamicProperties]
final class WP_Recovery_Mode_Cookie_Service {

/**
* Checks whether the recovery mode cookie is set.
*
* @since 5.2.0
*
* @return bool True if the cookie is set, false otherwise.
*/
public function is_cookie_set() {
return ! empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] );
}

/**
* Sets the recovery mode cookie.
*
* This must be immediately followed by exiting the request.
*
* @since 5.2.0
*/
public function set_cookie() {

$value = $this->generate_cookie();

/**
* Filters the length of time a Recovery Mode cookie is valid for.
*
* @since 5.2.0
*
* @param int $length Length in seconds.
*/
$length = apply_filters( 'recovery_mode_cookie_length', WEEK_IN_SECONDS );

$expire = time() + $length;

setcookie( RECOVERY_MODE_COOKIE, $value, $expire, COOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );

if ( COOKIEPATH !== SITECOOKIEPATH ) {
setcookie( RECOVERY_MODE_COOKIE, $value, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );
}
}

/**
* Clears the recovery mode cookie.
*
* @since 5.2.0
*/
public function clear_cookie() {
setcookie( RECOVERY_MODE_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
setcookie( RECOVERY_MODE_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
}

/**
* Validates the recovery mode cookie.
*
* @since 5.2.0
*
* @param string $cookie Optionally specify the cookie string.
* If omitted, it will be retrieved from the super global.
* @return true|WP_Error True on success, error object on failure.
*/
public function validate_cookie( $cookie = '' ) {

if ( ! $cookie ) {
if ( empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] ) ) {
return new WP_Error( 'no_cookie', __( 'No cookie present.' ) );
}

$cookie = $_COOKIE[ RECOVERY_MODE_COOKIE ];
}

$parts = $this->parse_cookie( $cookie );

if ( is_wp_error( $parts ) ) {
return $parts;
}

list( , $created_at, $random, $signature ) = $parts;

if ( ! ctype_digit( $created_at ) ) {
return new WP_Error( 'invalid_created_at', __( 'Invalid cookie format.' ) );
}

/** This filter is documented in wp-includes/class-wp-recovery-mode-cookie-service.php */
$length = apply_filters( 'recovery_mode_cookie_length', WEEK_IN_SECONDS );

if ( time() > $created_at + $length ) {
return new WP_Error( 'expired', __( 'Cookie expired.' ) );
}

$to_sign = sprintf( 'recovery_mode|%s|%s', $created_at, $random );
$hashed = $this->recovery_mode_hash( $to_sign );

if ( ! hash_equals( $signature, $hashed ) ) {
return new WP_Error( 'signature_mismatch', __( 'Invalid cookie.' ) );
}

return true;
}

/**
* Gets the session identifier from the cookie.
*
* The cookie should be validated before calling this API.
*
* @since 5.2.0
*
* @param string $cookie Optionally specify the cookie string.
* If omitted, it will be retrieved from the super global.
* @return string|WP_Error Session ID on success, or error object on failure.
*/
public function get_session_id_from_cookie( $cookie = '' ) {
if ( ! $cookie ) {
if ( empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] ) ) {
return new WP_Error( 'no_cookie', __( 'No cookie present.' ) );
}

$cookie = $_COOKIE[ RECOVERY_MODE_COOKIE ];
}

$parts = $this->parse_cookie( $cookie );
if ( is_wp_error( $parts ) ) {
return $parts;
}

list( , , $random ) = $parts;

return sha1( $random );
}

/**
* Parses the cookie into its four parts.
*
* @since 5.2.0
*
* @param string $cookie Cookie content.
* @return array|WP_Error Cookie parts array, or error object on failure.
*/
private function parse_cookie( $cookie ) {
$cookie = base64_decode( $cookie );
$parts = explode( '|', $cookie );

if ( 4 !== count( $parts ) ) {
return new WP_Error( 'invalid_format', __( 'Invalid cookie format.' ) );
}

return $parts;
}

/**
* Generates the recovery mode cookie value.
*
* The cookie is a base64 encoded string with the following format:
*
* recovery_mode|iat|rand|signature
*
* Where "recovery_mode" is a constant string,
* iat is the time the cookie was generated at,
* rand is a randomly generated password that is also used as a session identifier
* and signature is an hmac of the preceding 3 parts.
*
* @since 5.2.0
*
* @return string Generated cookie content.
*/
private function generate_cookie() {
$to_sign = sprintf( 'recovery_mode|%s|%s', time(), wp_generate_password( 20, false ) );
$signed = $this->recovery_mode_hash( $to_sign );

return base64_encode( sprintf( '%s|%s', $to_sign, $signed ) );
}

/**
* Gets a form of `wp_hash()` specific to Recovery Mode.
*
* We cannot use `wp_hash()` because it is defined in `pluggable.php` which is not loaded until after plugins are loaded,
* which is too late to verify the recovery mode cookie.
*
* This tries to use the `AUTH` salts first, but if they aren't valid specific salts will be generated and stored.
*
* @since 5.2.0
*
* @param string $data Data to hash.
* @return string|false The hashed $data, or false on failure.
*/
private function recovery_mode_hash( $data ) {
$default_keys = array_unique(
array(
'put your unique phrase here',
/*
* translators: This string should only be translated if wp-config-sample.php is localized.
* You can check the localized release package or
* https://i18n.svn.wordpress.org/<locale code>/branches/<wp version>/dist/wp-config-sample.php
*/
__( 'put your unique phrase here' ),
)
);

if ( ! defined( 'AUTH_KEY' ) || in_array( AUTH_KEY, $default_keys, true ) ) {
$auth_key = get_site_option( 'recovery_mode_auth_key' );

if ( ! $auth_key ) {
if ( ! function_exists( 'wp_generate_password' ) ) {
require_once ABSPATH . WPINC . '/pluggable.php';
}

$auth_key = wp_generate_password( 64, true, true );
update_site_option( 'recovery_mode_auth_key', $auth_key );
}
} else {
$auth_key = AUTH_KEY;
}

if ( ! defined( 'AUTH_SALT' ) || in_array( AUTH_SALT, $default_keys, true ) || AUTH_SALT === $auth_key ) {
$auth_salt = get_site_option( 'recovery_mode_auth_salt' );

if ( ! $auth_salt ) {
if ( ! function_exists( 'wp_generate_password' ) ) {
require_once ABSPATH . WPINC . '/pluggable.php';
}

$auth_salt = wp_generate_password( 64, true, true );
update_site_option( 'recovery_mode_auth_salt', $auth_salt );
}
} else {
$auth_salt = AUTH_SALT;
}

$secret = $auth_key . $auth_salt;

return hash_hmac( 'sha1', $data, $secret );
}
}