<?php
/**
* The nonce handler.
*
* @package automattic/jetpack-connection
*/
namespace Automattic\Jetpack\Connection;
/**
* The nonce handler.
*/
class Nonce_Handler {
/**
* How long the scheduled cleanup can run (in seconds).
* Can be modified using the filter `jetpack_connection_nonce_scheduled_cleanup_limit`.
*/
const SCHEDULED_CLEANUP_TIME_LIMIT = 5;
/**
* How many nonces should be removed per batch during the `clean_all()` run.
*/
const CLEAN_ALL_LIMIT_PER_BATCH = 1000;
/**
* Nonce lifetime in seconds.
*/
const LIFETIME = HOUR_IN_SECONDS;
/**
* The nonces used during the request are stored here to keep them valid.
* The property is static to keep the nonces accessible between the `Nonce_Handler` instances.
*
* @var array
*/
private static $nonces_used_this_request = array();
/**
* The database object.
*
* @var \wpdb
*/
private $db;
/**
* Initializing the object.
*/
public function __construct() {
global $wpdb;
$this->db = $wpdb;
}
/**
* Scheduling the WP-cron cleanup event.
*/
public function init_schedule() {
add_action( 'jetpack_clean_nonces', array( __CLASS__, 'clean_scheduled' ) );
if ( ! wp_next_scheduled( 'jetpack_clean_nonces' ) ) {
wp_schedule_event( time(), 'hourly', 'jetpack_clean_nonces' );
}
}
/**
* Reschedule the WP-cron cleanup event to make it start sooner.
*/
public function reschedule() {
wp_clear_scheduled_hook( 'jetpack_clean_nonces' );
wp_schedule_event( time(), 'hourly', 'jetpack_clean_nonces' );
}
/**
* Adds a used nonce to a list of known nonces.
*
* @param int $timestamp the current request timestamp.
* @param string $nonce the nonce value.
*
* @return bool whether the nonce is unique or not.
*/
public function add( $timestamp, $nonce ) {
if ( isset( static::$nonces_used_this_request[ "$timestamp:$nonce" ] ) ) {
return static::$nonces_used_this_request[ "$timestamp:$nonce" ];
}
// This should always have gone through Jetpack_Signature::sign_request() first to check $timestamp and $nonce.
$timestamp = (int) $timestamp;
$nonce = esc_sql( $nonce );
// Raw query so we can avoid races: add_option will also update.
$show_errors = $this->db->hide_errors();
// Running `try...finally` to make sure that we re-enable errors in case of an exception.
try {
$old_nonce = $this->db->get_row(
$this->db->prepare( "SELECT 1 FROM `{$this->db->options}` WHERE option_name = %s", "jetpack_nonce_{$timestamp}_{$nonce}" )
);
if ( $old_nonce === null ) {
$return = (bool) $this->db->query(
$this->db->prepare(
"INSERT INTO `{$this->db->options}` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s)",
"jetpack_nonce_{$timestamp}_{$nonce}",
time(),
'no'
)
);
} else {
$return = false;
}
} finally {
$this->db->show_errors( $show_errors );
}
static::$nonces_used_this_request[ "$timestamp:$nonce" ] = $return;
return $return;
}
/**
* Removing all existing nonces, or at least as many as possible.
* Capped at 20 seconds to avoid breaking the site.
*
* @param int $cutoff_timestamp All nonces added before this timestamp will be removed.
* @param int $time_limit How long the cleanup can run (in seconds).
*
* @return true
*/
public function clean_all( $cutoff_timestamp = PHP_INT_MAX, $time_limit = 20 ) {
// phpcs:ignore Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
for ( $end_time = time() + $time_limit; time() < $end_time; ) {
$result = $this->delete( static::CLEAN_ALL_LIMIT_PER_BATCH, $cutoff_timestamp );
if ( ! $result ) {
break;
}
}
return true;
}
/**
* Scheduled clean up of the expired nonces.
*/
public static function clean_scheduled() {
/**
* Adjust the time limit for the scheduled cleanup.
*
* @since 9.5.0
*
* @param int $time_limit How long the cleanup can run (in seconds).
*/
$time_limit = apply_filters( 'jetpack_connection_nonce_cleanup_runtime_limit', static::SCHEDULED_CLEANUP_TIME_LIMIT );
( new static() )->clean_all( time() - static::LIFETIME, $time_limit );
}
/**
* Delete the nonces.
*
* @param int $limit How many nonces to delete.
* @param null|int $cutoff_timestamp All nonces added before this timestamp will be removed.
*
* @return int|false Number of removed nonces, or `false` if nothing to remove (or in case of a database error).
*/
public function delete( $limit = 10, $cutoff_timestamp = null ) {
global $wpdb;
$ids = $wpdb->get_col(
$wpdb->prepare(
"SELECT option_id FROM `{$wpdb->options}`"
. " WHERE `option_name` >= 'jetpack_nonce_' AND `option_name` < %s"
. ' LIMIT %d',
'jetpack_nonce_' . $cutoff_timestamp,
$limit
)
);
if ( ! is_array( $ids ) ) {
// There's an error and we can't proceed.
return false;
}
// Removing zeroes in case AUTO_INCREMENT of the options table is broken, and all ID's are zeroes.
$ids = array_filter( $ids );
if ( array() === $ids ) {
// There's nothing to remove.
return false;
}
$ids_fill = implode( ', ', array_fill( 0, count( $ids ), '%d' ) );
$args = $ids;
$args[] = 'jetpack_nonce_%';
// The Code Sniffer is unable to understand what's going on...
// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber
return $wpdb->query( $wpdb->prepare( "DELETE FROM `{$wpdb->options}` WHERE `option_id` IN ( {$ids_fill} ) AND option_name LIKE %s", $args ) );
}
/**
* Clean the cached nonces valid during the current request, therefore making them invalid.
*
* @return bool
*/
public static function invalidate_request_nonces() {
static::$nonces_used_this_request = array();
return true;
}
}