| 1 |
<?php |
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/** |
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* IP matching utilities |
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* |
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* Shared IP/pattern matching for the firewall and login modules. Supports |
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* exact addresses, CIDR ranges and wildcards, for both IPv4 and IPv6. |
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* |
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* @package Vigilante |
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*/ |
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|
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// Prevent direct access |
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if ( ! defined( 'ABSPATH' ) ) { |
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exit; |
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} |
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|
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/** |
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* Class Vigilante_IP_Utils |
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* |
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* Stateless helpers. All methods are static. |
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*/ |
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class Vigilante_IP_Utils { |
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|
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/** |
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* Check whether an IP matches a single pattern. |
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* |
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* Supported pattern forms (IPv4 and IPv6 alike): |
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* - Exact address: 203.0.113.5 / 2a02:c207::1 |
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* - CIDR range: 203.0.113.0/24 / 2a02:c207::/32 |
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* - Wildcard: 203.0.113.* / 2a02:c207:* |
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* |
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* @param string $ip IP address to test. |
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* @param string $pattern Pattern to match against. |
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* @return bool True on match. |
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*/ |
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public static function matches( $ip, $pattern ) { |
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$ip = trim( (string) $ip ); |
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$pattern = trim( (string) $pattern ); |
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|
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if ( '' === $ip || '' === $pattern ) { |
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return false; |
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} |
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|
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// Exact match (also covers fully-written IPv6). |
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if ( $ip === $pattern ) { |
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return true; |
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} |
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|
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// CIDR notation. |
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if ( false !== strpos( $pattern, '/' ) ) { |
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return self::cidr_match( $ip, $pattern ); |
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} |
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|
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// Wildcard notation. |
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if ( false !== strpos( $pattern, '*' ) ) { |
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return self::wildcard_match( $ip, $pattern ); |
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} |
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|
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return false; |
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} |
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|
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/** |
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* Check whether an IP matches any pattern in a list. |
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* |
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* @param string $ip IP address to test. |
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* @param array $list List of patterns. |
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* @return bool True if any pattern matches. |
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*/ |
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public static function in_list( $ip, $list ) { |
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if ( empty( $list ) || ! is_array( $list ) ) { |
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return false; |
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} |
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|
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foreach ( $list as $pattern ) { |
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if ( self::matches( $ip, (string) $pattern ) ) { |
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return true; |
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} |
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} |
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|
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return false; |
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} |
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|
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/** |
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* Whether a string is a pattern this class can actually match. |
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* |
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* The counterpart of matches(): everything this returns true for is |
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* something the matcher understands, and everything else is noise that |
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* would sit in an IP list looking effective while matching nothing. Kept |
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* next to the matcher on purpose, so validation and matching cannot drift |
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* apart again. |
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* |
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* @since 2.9.9 |
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* |
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* @param string $pattern Candidate pattern. |
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* @return bool |
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*/ |
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public static function is_valid_pattern( $pattern ) { |
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$pattern = trim( (string) $pattern ); |
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|
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if ( '' === $pattern ) { |
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return false; |
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} |
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|
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// Exact address, IPv4 or IPv6. |
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if ( filter_var( $pattern, FILTER_VALIDATE_IP ) ) { |
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return true; |
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} |
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|
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// CIDR range: same criterion cidr_match() applies, family included. |
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if ( false !== strpos( $pattern, '/' ) ) { |
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$parts = explode( '/', $pattern, 2 ); |
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if ( 2 !== count( $parts ) ) { |
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return false; |
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} |
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|
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$subnet = trim( $parts[0] ); |
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$bits = trim( $parts[1] ); |
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|
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if ( '' === $bits || ! ctype_digit( $bits ) ) { |
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return false; |
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} |
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|
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if ( ! filter_var( $subnet, FILTER_VALIDATE_IP ) ) { |
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return false; |
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} |
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|
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$packed = inet_pton( $subnet ); |
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if ( false === $packed ) { |
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return false; |
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} |
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|
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return ( (int) $bits <= strlen( $packed ) * 8 ); |
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} |
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|
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// Wildcard: what is left once the asterisks are gone has to be a |
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// plausible prefix, of one family only. |
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if ( false !== strpos( $pattern, '*' ) ) { |
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return self::is_valid_wildcard( $pattern ); |
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} |
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|
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return false; |
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} |
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|
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/** |
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* Split a list into the patterns that can match and the ones that cannot. |
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* |
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* @since 2.9.9 |
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* |
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* @param array|string $list List of patterns, or a newline separated string. |
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* @return array{valid: string[], rejected: string[]} |
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*/ |
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public static function split_list( $list ) { |
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if ( is_string( $list ) ) { |
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$list = preg_split( '/[\r\n]+/', $list ); |
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} |
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|
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$valid = array(); |
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$rejected = array(); |
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|
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foreach ( (array) $list as $entry ) { |
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$entry = trim( (string) $entry ); |
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|
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if ( '' === $entry ) { |
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continue; |
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} |
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|
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if ( self::is_valid_pattern( $entry ) ) { |
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$valid[] = $entry; |
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} else { |
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$rejected[] = $entry; |
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} |
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} |
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|
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return array( |
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'valid' => array_values( array_unique( $valid ) ), |
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'rejected' => array_values( array_unique( $rejected ) ), |
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); |
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} |
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|
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/** |
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* Whether a wildcard pattern is plausible for one address family. |
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* |
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* A bare '*' is rejected on purpose: as a whitelist it would let everyone |
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* in and as a blacklist it would lock everyone out, and nobody types that |
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* meaning to. |
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* |
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* @since 2.9.9 |
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* |
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* @param string $pattern Wildcard pattern. |
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* @return bool |
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*/ |
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private static function is_valid_wildcard( $pattern ) { |
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$bare = str_replace( '*', '', $pattern ); |
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|
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if ( '' === $bare || '.' === $bare || ':' === $bare ) { |
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return false; |
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} |
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|
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// IPv6 when there is a colon, IPv4 otherwise. The two never mix. |
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if ( false !== strpos( $pattern, ':' ) ) { |
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if ( ! preg_match( '/^[0-9A-Fa-f:*]+$/', $pattern ) ) { |
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return false; |
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} |
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|
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$groups = explode( ':', $pattern ); |
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if ( count( $groups ) > 8 ) { |
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return false; |
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} |
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|
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foreach ( $groups as $group ) { |
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if ( '' === $group || '*' === $group ) { |
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continue; |
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} |
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if ( ! preg_match( '/^[0-9A-Fa-f]{1,4}\*?$/', $group ) ) { |
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return false; |
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} |
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} |
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|
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return true; |
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} |
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|
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if ( ! preg_match( '/^[0-9.*]+$/', $pattern ) ) { |
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return false; |
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} |
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|
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$octets = explode( '.', $pattern ); |
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if ( count( $octets ) > 4 ) { |
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return false; |
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} |
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|
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foreach ( $octets as $octet ) { |
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if ( '' === $octet || '*' === $octet ) { |
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continue; |
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} |
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// A partial octet such as 2* is a prefix, so it is not range checked. |
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if ( ! preg_match( '/^[0-9]{1,3}\*?$/', $octet ) ) { |
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return false; |
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} |
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if ( '*' !== substr( $octet, -1 ) && (int) $octet > 255 ) { |
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return false; |
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} |
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} |
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|
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return true; |
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} |
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|
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/** |
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* Match an IP against a CIDR range. Works for IPv4 and IPv6. |
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* |
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* The comparison is done on the packed binary form, so the textual |
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* representation of an IPv6 address (compressed or not) does not matter. |
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* |
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* @param string $ip IP address to test. |
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* @param string $cidr CIDR range (e.g. 203.0.113.0/24 or 2a02::/32). |
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* @return bool True on match. |
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*/ |
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private static function cidr_match( $ip, $cidr ) { |
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$parts = explode( '/', $cidr, 2 ); |
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if ( 2 !== count( $parts ) ) { |
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return false; |
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} |
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|
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$subnet = trim( $parts[0] ); |
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$bits = trim( $parts[1] ); |
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|
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// Prefix length must be a plain integer. |
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if ( '' === $bits || ! ctype_digit( $bits ) ) { |
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return false; |
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} |
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$bits = (int) $bits; |
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|
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// Validate both addresses before packing so inet_pton never warns. |
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if ( ! filter_var( $ip, FILTER_VALIDATE_IP ) || ! filter_var( $subnet, FILTER_VALIDATE_IP ) ) { |
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return false; |
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} |
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|
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$ip_packed = inet_pton( $ip ); |
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$subnet_packed = inet_pton( $subnet ); |
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if ( false === $ip_packed || false === $subnet_packed ) { |
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return false; |
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} |
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|
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// Different address family (4 bytes for IPv4, 16 for IPv6). |
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if ( strlen( $ip_packed ) !== strlen( $subnet_packed ) ) { |
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return false; |
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} |
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|
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$max_bits = strlen( $ip_packed ) * 8; |
| 288 |
if ( $bits < 0 || $bits > $max_bits ) { |
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return false; |
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} |
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|
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// Compare whole bytes first. |
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$whole_bytes = intdiv( $bits, 8 ); |
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if ( $whole_bytes > 0 && substr( $ip_packed, 0, $whole_bytes ) !== substr( $subnet_packed, 0, $whole_bytes ) ) { |
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return false; |
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} |
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|
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// Then the remaining bits of the partial byte, if any. |
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$remaining = $bits % 8; |
| 300 |
if ( $remaining > 0 ) { |
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$mask = 0xFF << ( 8 - $remaining ) & 0xFF; |
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$ip_byte = ord( $ip_packed[ $whole_bytes ] ); |
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$sub_byte = ord( $subnet_packed[ $whole_bytes ] ); |
| 304 |
if ( ( $ip_byte & $mask ) !== ( $sub_byte & $mask ) ) { |
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return false; |
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} |
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} |
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|
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return true; |
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} |
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|
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/** |
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* Match an IP against a wildcard pattern (e.g. 203.0.113.* or 2a02:c207:*). |
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* |
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* Operates on the textual form. The '*' stands for any run of characters; |
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* every other character is matched literally, so it works for the dots of |
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* IPv4 and the colons of IPv6. |
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* |
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* @param string $ip IP address to test. |
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* @param string $pattern Wildcard pattern. |
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* @return bool True on match. |
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*/ |
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private static function wildcard_match( $ip, $pattern ) { |
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$quoted = preg_quote( $pattern, '/' ); |
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$regex = '/^' . str_replace( '\*', '.*', $quoted ) . '$/'; |
| 326 |
|
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return (bool) preg_match( $regex, $ip ); |
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} |
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|
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/** |
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* Proxy headers an admin may declare as trusted, mapped to their $_SERVER key. |
| 332 |
* |
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* @return array<string,string> |
| 334 |
*/ |
| 335 |
public static function trusted_header_map() { |
| 336 |
return array( |
| 337 |
'cf-connecting-ip' => 'HTTP_CF_CONNECTING_IP', |
| 338 |
'x-forwarded-for' => 'HTTP_X_FORWARDED_FOR', |
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'x-real-ip' => 'HTTP_X_REAL_IP', |
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); |
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} |
| 342 |
|
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/** |
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* The proxy header the admin has declared as trusted, or '' for none. |
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* |
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* @return string |
| 347 |
*/ |
| 348 |
public static function trusted_proxy_header() { |
| 349 |
$options = get_option( 'vigilante_options' ); |
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if ( is_array( $options ) && ! empty( $options['firewall']['trusted_proxy_header'] ) ) { |
| 351 |
$header = (string) $options['firewall']['trusted_proxy_header']; |
| 352 |
if ( isset( self::trusted_header_map()[ $header ] ) ) { |
| 353 |
return $header; |
| 354 |
} |
| 355 |
} |
| 356 |
return ''; |
| 357 |
} |
| 358 |
|
| 359 |
/** |
| 360 |
* Resolve the client IP from a $_SERVER-like array. |
| 361 |
* |
| 362 |
* Only the real TCP peer (REMOTE_ADDR) is trusted by default, because it |
| 363 |
* cannot be spoofed. A forwarded-for / connecting-ip header is honoured |
| 364 |
* ONLY when the admin has explicitly declared their site sits behind that |
| 365 |
* proxy; otherwise any visitor could forge the header and impersonate any |
| 366 |
* IP (bypassing the whitelist, evading the blacklist, poisoning the rate |
| 367 |
* limiter, etc.). |
| 368 |
* |
| 369 |
* @param array $server A $_SERVER-like array. |
| 370 |
* @param string $trusted_header One of the keys in trusted_header_map(), or '' for none. |
| 371 |
* @return string Validated IP, or '0.0.0.0' when none could be determined. |
| 372 |
*/ |
| 373 |
public static function resolve_client_ip( $server, $trusted_header = '' ) { |
| 374 |
$map = self::trusted_header_map(); |
| 375 |
|
| 376 |
if ( '' !== $trusted_header && isset( $map[ $trusted_header ] ) ) { |
| 377 |
$key = $map[ $trusted_header ]; |
| 378 |
if ( ! empty( $server[ $key ] ) ) { |
| 379 |
$value = (string) $server[ $key ]; |
| 380 |
// X-Forwarded-For may be a "client, proxy1, proxy2" chain; the |
| 381 |
// original client is the first entry. |
| 382 |
if ( false !== strpos( $value, ',' ) ) { |
| 383 |
$parts = explode( ',', $value ); |
| 384 |
$value = $parts[0]; |
| 385 |
} |
| 386 |
$value = trim( $value ); |
| 387 |
if ( filter_var( $value, FILTER_VALIDATE_IP ) ) { |
| 388 |
return $value; |
| 389 |
} |
| 390 |
} |
| 391 |
} |
| 392 |
|
| 393 |
if ( ! empty( $server['REMOTE_ADDR'] ) ) { |
| 394 |
$remote = trim( (string) $server['REMOTE_ADDR'] ); |
| 395 |
if ( filter_var( $remote, FILTER_VALIDATE_IP ) ) { |
| 396 |
return $remote; |
| 397 |
} |
| 398 |
} |
| 399 |
|
| 400 |
return '0.0.0.0'; |
| 401 |
} |
| 402 |
|
| 403 |
/** |
| 404 |
* Current request client IP, honouring the configured trusted proxy header. |
| 405 |
* |
| 406 |
* Reads only the needed headers, each sanitized at the point of access, so |
| 407 |
* the input-sanitization sniff is satisfied without any suppression. |
| 408 |
* |
| 409 |
* @return string |
| 410 |
*/ |
| 411 |
public static function get_client_ip() { |
| 412 |
$trusted = self::trusted_proxy_header(); |
| 413 |
$server = array(); |
| 414 |
|
| 415 |
if ( isset( $_SERVER['REMOTE_ADDR'] ) ) { |
| 416 |
$server['REMOTE_ADDR'] = sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ) ); |
| 417 |
} |
| 418 |
|
| 419 |
if ( '' !== $trusted ) { |
| 420 |
$map = self::trusted_header_map(); |
| 421 |
$key = $map[ $trusted ]; |
| 422 |
if ( isset( $_SERVER[ $key ] ) ) { |
| 423 |
$server[ $key ] = sanitize_text_field( wp_unslash( $_SERVER[ $key ] ) ); |
| 424 |
} |
| 425 |
} |
| 426 |
|
| 427 |
return self::resolve_client_ip( $server, $trusted ); |
| 428 |
} |
| 429 |
} |
| 430 |
|
