← All changes | jetpack_vendor/automattic/jetpack-ip/src/class-utils.php +123 -1 16.3-a.3 → 16.3-beta View file →

		@@ -11,9 +11,9 @@
11	11	* Class that provides static methods for working with IP addresses.
12	12	*/
13	13	class Utils {
14	14
15		- const PACKAGE_VERSION = '0.6.0';
	15	+ const PACKAGE_VERSION = '0.7.0';
16	16
17	17	/**
18	18	* Get the current user's IP address.
19	19	*
		@@ -215,8 +215,130 @@
215	215	return true;
216	216	}
217	217
218	218	return false;
	219	+ }
	220	+
	221	+ /**
	222	+ * Checks whether a URL is a safe destination for a server-side request.
	223	+ *
	224	+ * The URL must pass wp_http_validate_url(), which rejects IPv6-literal hosts, and every
	225	+ * address its host resolves to must pass ip_is_public(). A host that resolves to none fails.
	226	+ * Not covered: redirect hops (check each one), DNS rebinding, or AAAA records without ext-dns.
	227	+ *
	228	+ * @since 0.7.0
	229	+ *
	230	+ * @param string $url URL to check.
	231	+ * @return bool True when the URL is safe to request, false otherwise.
	232	+ */
	233	+ public static function url_is_public( $url ) {
	234	+ if ( ! is_string( $url ) || '' === $url ) {
	235	+ return false;
	236	+ }
	237	+
	238	+ $validated_url = wp_http_validate_url( $url );
	239	+ if ( ! $validated_url ) {
	240	+ return false;
	241	+ }
	242	+
	243	+ $host = wp_parse_url( $validated_url, PHP_URL_HOST );
	244	+ if ( ! is_string( $host ) || '' === $host ) {
	245	+ return false;
	246	+ }
	247	+
	248	+ $ips = self::resolve_host_ips( $host );
	249	+
	250	+ // Fail closed: an unresolvable host is not assumed safe.
	251	+ if ( empty( $ips ) ) {
	252	+ return false;
	253	+ }
	254	+
	255	+ foreach ( $ips as $ip ) {
	256	+ if ( ! self::ip_is_public( $ip ) ) {
	257	+ return false;
	258	+ }
	259	+ }
	260	+
	261	+ return true;
	262	+ }
	263	+
	264	+ /**
	265	+ * Resolves a host to the distinct IPv4 and IPv6 addresses a request to it could reach.
	266	+ *
	267	+ * IP literals are returned as-is. An empty list means the host is malformed or resolved
	268	+ * to nothing, and callers must treat it as unsafe.
	269	+ *
	270	+ * @since 0.7.0
	271	+ *
	272	+ * @param string $host Host name or IP literal (IPv6 literals may be bracketed).
	273	+ * @return string[] List of IP addresses.
	274	+ */
	275	+ public static function resolve_host_ips( $host ) {
	276	+ if ( ! is_string( $host ) || '' === $host ) {
	277	+ return array();
	278	+ }
	279	+
	280	+ // Unwrap one bracket pair only, so "]8.8.8.8[" can't become a clean address.
	281	+ if ( preg_match( '/^\[(.*)\]$/', $host, $matches ) ) {
	282	+ $host = $matches[1];
	283	+ }
	284	+
	285	+ // Decode so "169%2e254%2e169%2e254" can't slip past the checks below.
	286	+ $host = rawurldecode( $host );
	287	+
	288	+ // Strip an IPv6 zone id ("fe80::1%eth0"); a '%' on any other host is malformed.
	289	+ if ( false !== strpos( $host, '%' ) ) {
	290	+ if ( false === strpos( $host, ':' ) ) {
	291	+ return array();
	292	+ }
	293	+ $host = preg_replace( '/%.*$/', '', $host );
	294	+ }
	295	+
	296	+ /*
	297	+ * Reject control bytes (gethostbynamel() throws on a NUL), stray brackets, and
	298	+ * raw non-ASCII, which the request layer would punycode into a different host.
	299	+ */
	300	+ if ( '' === $host || preg_match( '/[\x00-\x20\x7f-\xff\[\]]/', $host ) ) {
	301	+ return array();
	302	+ }
	303	+
	304	+ if ( filter_var( $host, FILTER_VALIDATE_IP ) ) {
	305	+ return array( $host );
	306	+ }
	307	+
	308	+ $ips = array();
	309	+
	310	+ if ( function_exists( 'gethostbynamel' ) ) {
	311	+ // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- gethostbynamel() warns on an unresolvable host.
	312	+ $ipv4 = @gethostbynamel( $host );
	313	+ if ( is_array( $ipv4 ) ) {
	314	+ $ips = $ipv4;
	315	+ }
	316	+ }
	317	+
	318	+ // gethostbynamel() only resolves IPv4; check AAAA records too. dns_get_record()
	319	+ // can be disabled on some hosts and may warn on lookup failure.
	320	+ if ( function_exists( 'dns_get_record' ) ) {
	321	+ // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- dns_get_record may fail on some systems.
	322	+ $aaaa = @dns_get_record( $host, DNS_AAAA );
	323	+ if ( is_array( $aaaa ) ) {
	324	+ foreach ( $aaaa as $record ) {
	325	+ if ( ! empty( $record['ipv6'] ) ) {
	326	+ $ips[] = $record['ipv6'];
	327	+ }
	328	+ }
	329	+ }
	330	+ }
	331	+
	332	+ // Drop anything a resolver returned that is not an IP address.
	333	+ $ips = array_filter(
	334	+ $ips,
	335	+ function ( $ip ) {
	336	+ return is_string( $ip ) && false !== filter_var( $ip, FILTER_VALIDATE_IP );
	337	+ }
	338	+ );
	339	+
	340	+ return array_values( array_unique( $ips ) );
219	341	}
220	342
221	343	/**
222	344	* Validate an IP address.