name : Authentication.php <?php namespace Automattic\WooCommerce\StoreApi; use Automattic\WooCommerce\StoreApi\Utilities\RateLimits; use Automattic\WooCommerce\StoreApi\Utilities\JsonWebToken; /** * Authentication class. */ class Authentication { /** * Hook into WP lifecycle events. This is hooked by the StoreAPI class on `rest_api_init`. */ public function init() { if ( ! $this->is_request_to_store_api() ) { return; } add_filter( 'rest_authentication_errors', array( $this, 'check_authentication' ) ); add_action( 'set_logged_in_cookie', array( $this, 'set_logged_in_cookie' ) ); add_filter( 'rest_pre_serve_request', array( $this, 'send_cors_headers' ), 10, 3 ); add_filter( 'rest_allowed_cors_headers', array( $this, 'allowed_cors_headers' ) ); // Remove the default CORS headers--we will add our own. remove_filter( 'rest_pre_serve_request', 'rest_send_cors_headers' ); } /** * Add allowed cors headers for store API headers. * * @param array $allowed_headers Allowed headers. * @return array */ public function allowed_cors_headers( $allowed_headers ) { $allowed_headers[] = 'Cart-Token'; $allowed_headers[] = 'Nonce'; return $allowed_headers; } /** * Add CORS headers to a response object. * * These checks prevent access to the Store API from non-allowed origins. By default, the WordPress REST API allows * access from any origin. Because some Store API routes return PII, we need to add our own CORS headers. * * Allowed origins can be changed using the WordPress `allowed_http_origins` or `allowed_http_origin` filters if * access needs to be granted to other domains. * * Users of valid Cart Tokens are also allowed access from any origin. * * @param bool $value Whether the request has already been served. * @param \WP_HTTP_Response $result Result to send to the client. Usually a `WP_REST_Response`. * @param \WP_REST_Request $request Request used to generate the response. * @return bool */ public function send_cors_headers( $value, $result, $request ) { $origin = get_http_origin(); if ( 'null' !== $origin ) { $origin = esc_url_raw( $origin ); } // Send standard CORS headers. $server = rest_get_server(); $server->send_header( 'Access-Control-Allow-Methods', 'OPTIONS, GET, POST, PUT, PATCH, DELETE' ); $server->send_header( 'Access-Control-Allow-Credentials', 'true' ); $server->send_header( 'Vary', 'Origin', false ); // Allow preflight requests, certain http origins, and any origin if a cart token is present. Preflight requests // are allowed because we'll be unable to validate cart token headers at that point. if ( $this->is_preflight() || $this->has_valid_cart_token( $request ) || is_allowed_http_origin( $origin ) ) { $server->send_header( 'Access-Control-Allow-Origin', $origin ); } // Exit early during preflight requests. This is so someone cannot access API data by sending an OPTIONS request // with preflight headers and a _GET property to override the method. if ( $this->is_preflight() ) { exit; } return $value; } /** * Is the request a preflight request? Checks the request method * * @return boolean */ protected function is_preflight() { return isset( $_SERVER['REQUEST_METHOD'], $_SERVER['HTTP_ACCESS_CONTROL_REQUEST_METHOD'], $_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS'], $_SERVER['HTTP_ORIGIN'] ) && 'OPTIONS' === $_SERVER['REQUEST_METHOD']; } /** * Checks if we're using a cart token to access the Store API. * * @param \WP_REST_Request $request Request object. * @return boolean */ protected function has_valid_cart_token( \WP_REST_Request $request ) { $cart_token = $request->get_header( 'Cart-Token' ); return $cart_token && JsonWebToken::validate( $cart_token, $this->get_cart_token_secret() ); } /** * Gets the secret for the cart token using wp_salt. * * @return string */ protected function get_cart_token_secret() { return '@' . wp_salt(); } /** * The Store API does not require authentication. * * @param \WP_Error|mixed $result Error from another authentication handler, null if we should handle it, or another value if not. * @return \WP_Error|null|bool */ public function check_authentication( $result ) { // Enable Rate Limiting for logged-in users without 'edit posts' capability. if ( ! current_user_can( 'edit_posts' ) ) { $result = $this->apply_rate_limiting( $result ); } // Pass through errors from other authentication methods used before this one. return ! empty( $result ) ? $result : true; } /** * When the login cookies are set, they are not available until the next page reload. For the Store API, specifically * for returning updated nonces, we need this to be available immediately. * * @param string $logged_in_cookie The value for the logged in cookie. */ public function set_logged_in_cookie( $logged_in_cookie ) { if ( ! defined( 'LOGGED_IN_COOKIE' ) ) { return; } $_COOKIE[ LOGGED_IN_COOKIE ] = $logged_in_cookie; } /** * Applies Rate Limiting to the request, and passes through any errors from other authentication methods used before this one. * * @param \WP_Error|mixed $result Error from another authentication handler, null if we should handle it, or another value if not. * @return \WP_Error|null|bool */ protected function apply_rate_limiting( $result ) { $rate_limiting_options = RateLimits::get_options(); if ( $rate_limiting_options->enabled ) { $action_id = 'store_api_request_'; if ( is_user_logged_in() ) { $action_id .= get_current_user_id(); } else { $ip_address = self::get_ip_address( $rate_limiting_options->proxy_support ); $action_id .= md5( $ip_address ); } $retry = RateLimits::is_exceeded_retry_after( $action_id ); $server = rest_get_server(); $server->send_header( 'RateLimit-Limit', $rate_limiting_options->limit ); if ( false !== $retry ) { $server->send_header( 'RateLimit-Retry-After', $retry ); $server->send_header( 'RateLimit-Remaining', 0 ); $server->send_header( 'RateLimit-Reset', time() + $retry ); $ip_address = $ip_address ?? self::get_ip_address( $rate_limiting_options->proxy_support ); /** * Fires when the rate limit is exceeded. * * @since 8.9.0 * * @param string $ip_address The IP address of the request. */ do_action( 'woocommerce_store_api_rate_limit_exceeded', $ip_address ); return new \WP_Error( 'rate_limit_exceeded', sprintf( 'Too many requests. Please wait %d seconds before trying again.', $retry ), array( 'status' => 400 ) ); } $rate_limit = RateLimits::update_rate_limit( $action_id ); $server->send_header( 'RateLimit-Remaining', $rate_limit->remaining ); $server->send_header( 'RateLimit-Reset', $rate_limit->reset ); } return $result; } /** * Check if is request to the Store API. * * @return bool */ protected function is_request_to_store_api() { if ( empty( $GLOBALS['wp']->query_vars['rest_route'] ) ) { return false; } return 0 === strpos( $GLOBALS['wp']->query_vars['rest_route'], '/wc/store/' ); } /** * Get current user IP Address. * * X_REAL_IP and CLIENT_IP are custom implementations designed to facilitate obtaining a user's ip through proxies, load balancers etc. * * _FORWARDED_FOR (XFF) request header is a de-facto standard header for identifying the originating IP address of a client connecting to a web server through a proxy server. * Note for X_FORWARDED_FOR, Proxy servers can send through this header like this: X-Forwarded-For: client1, proxy1, proxy2. * Make sure we always only send through the first IP in the list which should always be the client IP. * Documentation at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For * * Forwarded request header contains information that may be added by reverse proxy servers (load balancers, CDNs, and so on). * Documentation at https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Forwarded * Full RFC at https://datatracker.ietf.org/doc/html/rfc7239 * * @param boolean $proxy_support Enables/disables proxy support. * * @return string */ protected static function get_ip_address( bool $proxy_support = false ) { if ( ! $proxy_support ) { return self::validate_ip( sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ?? 'unresolved_ip' ) ) ); } if ( array_key_exists( 'HTTP_X_REAL_IP', $_SERVER ) ) { return self::validate_ip( sanitize_text_field( wp_unslash( $_SERVER['HTTP_X_REAL_IP'] ) ) ); } if ( array_key_exists( 'HTTP_CLIENT_IP', $_SERVER ) ) { return self::validate_ip( sanitize_text_field( wp_unslash( $_SERVER['HTTP_CLIENT_IP'] ) ) ); } if ( array_key_exists( 'HTTP_X_FORWARDED_FOR', $_SERVER ) ) { $ips = explode( ',', sanitize_text_field( wp_unslash( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) ); if ( is_array( $ips ) && ! empty( $ips ) ) { return self::validate_ip( trim( $ips[0] ) ); } } if ( array_key_exists( 'HTTP_FORWARDED', $_SERVER ) ) { // Using regex instead of explode() for a smaller code footprint. // Expected format: Forwarded: for=192.0.2.60;proto=http;by=203.0.113.43,for="[2001:db8:cafe::17]:4711"... preg_match( '/(?<=for\=)[^;,]*/i', // We catch everything on the first "for" entry, and validate later. sanitize_text_field( wp_unslash( $_SERVER['HTTP_FORWARDED'] ) ), $matches ); if ( strpos( $matches[0] ?? '', '"[' ) !== false ) { // Detect for ipv6, eg "[ipv6]:port". preg_match( '/(?<=\[).*(?=\])/i', // We catch only the ipv6 and overwrite $matches. $matches[0], $matches ); } if ( ! empty( $matches ) ) { return self::validate_ip( trim( $matches[0] ) ); } } return '0.0.0.0'; } /** * Uses filter_var() to validate and return ipv4 and ipv6 addresses * Will return 0.0.0.0 if the ip is not valid. This is done to group and still rate limit invalid ips. * * @param string $ip ipv4 or ipv6 ip string. * * @return string */ protected static function validate_ip( $ip ) { $ip = filter_var( $ip, FILTER_VALIDATE_IP, array( FILTER_FLAG_NO_RES_RANGE, FILTER_FLAG_IPV6 ) ); return $ip ?: '0.0.0.0'; } }