URL if headers are sent. Returns false * if headers are not sent. */ function send_origin_headers() { $origin = get_http_origin(); if ( is_allowed_http_origin( $origin ) ) { header( 'Access-Control-Allow-Origin: ' . $origin ); header( 'Access-Control-Allow-Credentials: true' ); if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) { exit; } return $origin; } if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) { status_header( 403 ); exit; } return false; } /** * Validates a URL for safe use in the HTTP API. * * Examples of URLs that are considered unsafe: * * - ftp://example.com/caniload.php - Invalid protocol - only http and https are allowed. * - http:///example.com/caniload.php - Malformed URL. * - http://user:pass@example.com/caniload.php - Login information. * - http://exampleeeee.com/caniload.php - Invalid hostname, as the IP cannot be looked up in DNS. * * Examples of URLs that are considered unsafe by default: * * - http://192.168.0.1/caniload.php - IPs from LAN networks. * This can be changed with the {@see 'http_request_host_is_external'} filter. * - http://198.143.164.252:81/caniload.php - By default, only 80, 443, and 8080 ports are allowed. * This can be changed with the {@see 'http_allowed_safe_ports'} filter. * * @since 3.5.2 * * @param string $url Request URL. * @return string|false URL or false on failure. */ function wp_http_validate_url( $url ) { if ( ! is_string( $url ) || '' === $url || is_numeric( $url ) ) { return false; } $original_url = $url; $url = wp_kses_bad_protocol( $url, array( 'http', 'https' ) ); if ( ! $url || strtolower( $url ) !== strtolower( $original_url ) ) { return false; } $parsed_url = parse_url( $url ); if ( ! $parsed_url || empty( $parsed_url['host'] ) ) { return false; } if ( isset( $parsed_url['user'] ) || isset( $parsed_url['pass'] ) ) { return false; } if ( false !== strpbrk( $parsed_url['host'], ':#?[]' ) ) { return false; } $parsed_home = parse_url( get_option( 'home' ) ); $same_host = isset( $parsed_home['host'] ) && strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] ); $host = trim( $parsed_url['host'], '.' ); if ( ! $same_host ) { if ( preg_match( '#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host ) ) { $ip = $host; } else { $ip = gethostbyname( $host ); if ( $ip === $host ) { // Error condition for gethostbyname(). return false; } } if ( $ip ) { $parts = array_map( 'intval', explode( '.', $ip ) ); if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0] || ( 172 === $parts[0] && 16 <= $parts[1] && 31 >= $parts[1] ) || ( 192 === $parts[0] && 168 === $parts[1] ) ) { // If host appears local, reject unless specifically allowed. /** * Checks if HTTP request is external or not. * * Allows to change and allow external requests for the HTTP request. * * @since 3.6.0 * * @param bool $external Whether HTTP request is external or not. * @param string $host Host name of the requested URL. * @param string $url Requested URL. */ if ( ! apply_filters( 'http_request_host_is_external', false, $host, $url ) ) { return false; } } } } if ( empty( $parsed_url['port'] ) ) { return $url; } $port = $parsed_url['port']; /** * Controls the list of ports considered safe in HTTP API. * * Allows to change and allow external requests for the HTTP request. * * @since 5.9.0 * * @param int[] $allowed_ports Array of integers for valid ports. * @param string $host Host name of the requested URL. * @param string $url Requested URL. */ $allowed_ports = apply_filters( 'http_allowed_safe_ports', array( 80, 443, 8080 ), $host, $url ); if ( is_array( $allowed_ports ) && in_array( $port, $allowed_ports, true ) ) { return $url; } if ( $parsed_home && $same_host && isset( $parsed_home['port'] ) && $parsed_home['port'] === $port ) { return $url; } return false; } /** * Marks allowed redirect hosts safe for HTTP requests as well. * * Attached to the {@see 'http_request_host_is_external'} filter. * * @since 3.6.0 * * @param bool $is_external * @param string $host * @return bool */ function allowed_http_request_hosts( $is_external, $host ) { if ( ! $is_external && wp_validate_redirect( 'http://' . $host ) ) { $is_external = true; } return $is_external; } /** * Adds any domain in a multisite installation for safe HTTP requests to the * allowed list. * * Attached to the {@see 'http_request_host_is_external'} filter. * * @since 3.6.0 * * @global wpdb $wpdb WordPress database abstraction object. * * @param bool $is_external * @param string $host * @return bool */ function ms_allowed_http_request_hosts( $is_external, $host ) { global $wpdb; static $queried = array(); if ( $is_external ) { return $is_external; } if ( get_network()->domain === $host ) { return true; } if ( isset( $queried[ $host ] ) ) { return $queried[ $host ]; } $queried[ $host ] = (bool) $wpdb->get_var( $wpdb->prepare( "SELECT domain FROM $wpdb->blogs WHERE domain = %s LIMIT 1", $host ) ); return $queried[ $host ]; } /** * A wrapper for PHP's parse_url() function that handles consistency in the return values * across PHP versions. * * PHP 5.4.7 expanded parse_url()'s ability to handle non-absolute URLs, including * schemeless and relative URLs with "://" in the path. This function works around * those limitations providing a standard output on PHP 5.2~5.4+. * * Secondly, across various PHP versions, schemeless URLs containing a ":" in the query * are being handled inconsistently. This function works around those differences as well. * * @since 4.4.0 * @since 4.7.0 The `$component` parameter was added for parity with PHP's `parse_url()`. * * @link https://www.php.net/manual/en/function.parse-url.php * * @param string $url The URL to parse. * @param int $component The specific component to retrieve. Use one of the PHP * predefined constants to specify which one. * Defaults to -1 (= return all parts as an array). * @return mixed False on parse failure; Array of URL components on success; * When a specific component has been requested: null if the component * doesn't exist in the given URL; a string or - in the case of * PHP_URL_PORT - integer when it does. See parse_url()'s return values. */ function wp_parse_url( $url, $component = -1 ) { $to_unset = array(); $url = (string) $url; if ( str_starts_with( $url, '//' ) ) { $to_unset[] = 'scheme'; $url = 'placeholder:' . $url; } elseif ( str_starts_with( $url, '/' ) ) { $to_unset[] = 'scheme'; $to_unset[] = 'host'; $url = 'placeholder://placeholder' . $url; } $parts = parse_url( $url ); if ( false === $parts ) { // Parsing failure. return $parts; } // Remove the placeholder values. foreach ( $to_unset as $key ) { unset( $parts[ $key ] ); } return _get_component_from_parsed_url_array( $parts, $component ); } /** * Retrieves a specific component from a parsed URL array. * * @internal * * @since 4.7.0 * @access private * * @link https://www.php.net/manual/en/function.parse-url.php * * @param array|false $url_parts The parsed URL. Can be false if the URL failed to parse. * @param int $component The specific component to retrieve. Use one of the PHP * predefined constants to specify which one. * Defaults to -1 (= return all parts as an array). * @return mixed False on parse failure; Array of URL components on success; * When a specific component has been requested: null if the component * doesn't exist in the given URL; a string or - in the case of * PHP_URL_PORT - integer when it does. See parse_url()'s return values. */ function _get_component_from_parsed_url_array( $url_parts, $component = -1 ) { if ( -1 === $component ) { return $url_parts; } $key = _wp_translate_php_url_constant_to_key( $component ); if ( false !== $key && is_array( $url_parts ) && isset( $url_parts[ $key ] ) ) { return $url_parts[ $key ]; } else { return null; } } /** * Translates a PHP_URL_* constant to the named array keys PHP uses. * * @internal * * @since 4.7.0 * @access private * * @link https://www.php.net/manual/en/url.constants.php * * @param int $constant PHP_URL_* constant. * @return string|false The named key or false. */ function _wp_translate_php_url_constant_to_key( $constant ) { $translation = array( PHP_URL_SCHEME => 'scheme', PHP_URL_HOST => 'host', PHP_URL_PORT => 'port', PHP_URL_USER => 'user', PHP_URL_PASS => 'pass', PHP_URL_PATH => 'path', PHP_URL_QUERY => 'query', PHP_URL_FRAGMENT => 'fragment', ); if ( isset( $translation[ $constant ] ) ) { return $translation[ $constant ]; } else { return false; } }