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htmlpurifier/library/HTMLPurifier/AttrDef/URI.php

143 lines
5.4 KiB
PHP

<?php
require_once 'HTMLPurifier/URIScheme.php';
require_once 'HTMLPurifier/URISchemeRegistry.php';
HTMLPurifier_ConfigDef::define(
'URI', 'DefaultScheme', 'http',
'Defines through what scheme the output will be served, in order to '.
'select the proper object validator when no scheme information is present.'
);
class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
{
function validate($uri, $config, &$context) {
// We'll write stack-based parsers later, for now, use regexps to
// get things working as fast as possible (irony)
// parse as CDATA
$uri = $this->parseCDATA($uri);
// while it would be nice to use parse_url(), that's specifically
// for HTTP and thus won't work for our generic URI parsing
// according to the RFC... (but this cuts corners, i.e. non-validating)
$r_URI = '!^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?!';
// 12 3 4 5 6 7 8 9
$matches = array();
$result = preg_match($r_URI, $uri, $matches);
if (!$result) return '';
// seperate out parts
$scheme = !empty($matches[1]) ? $matches[2] : null;
$authority = !empty($matches[3]) ? $matches[4] : null;
$path = $matches[5]; // always present
$query = !empty($matches[6]) ? $matches[7] : null;
$fragment = !empty($matches[8]) ? $matches[9] : null;
$registry =& HTMLPurifier_URISchemeRegistry::instance();
if ($scheme !== null) {
// no need to validate the scheme's fmt since we do that when we
// retrieve the specific scheme object from the registry
$scheme = ctype_lower($scheme) ? $scheme : strtolower($scheme);
$scheme_obj =& $registry->getScheme($scheme, $config);
if (!$scheme_obj) return ''; // invalid scheme, clean it out
} else {
$scheme_obj =& $registry->getScheme($config->get('URI', 'DefaultScheme'), $config);
}
if ($authority !== null) {
// define regexps
// this stuff may need to be factored out so Email can get to it
$HEXDIG = '[A-Fa-f0-9]';
$unreserved = 'A-Za-z0-9-._~'; // make sure you wrap with []
$sub_delims = '!$&\'()'; // needs []
$pct_encoded = "%$HEXDIG$HEXDIG";
$h16 = "{$HEXDIG}{1,4}";
$dec_octet = '(?:25[0-5]|2[0-4]\d|1\d\d|1\d|[0-9])';
$IPv4address = "$dec_octet.$dec_octet.$dec_octet.$dec_octet";
$ls32 = "(?:$h16:$h16|$IPv4address)";
$IPvFuture = "v$HEXDIG+\.[:$unreserved$sub_delims]+";
$IPv6Address = "(?:".
"(?:$h16:){6}$ls32" .
"|::(?:$h16:){5}$ls32" .
"|(?:$h16)?::(?:$h16:){4}$ls32" .
"|(?:(?:$h16:){1}$h16)?::(?:$h16:){3}$ls32" .
"|(?:(?:$h16:){2}$h16)?::(?:$h16:){2}$ls32" .
"|(?:(?:$h16:){3}$h16)?::(?:$h16:){1}$ls32" .
"|(?:(?:$h16:){4}$h16)?::$ls32" .
"|(?:(?:$h16:){5}$h16)?::$h16" .
"|(?:(?:$h16:){6}$h16)?::" .
")";
$IP_literal = "\[(?:$IPvFuture|$IPv6Address)\]";
$r_userinfo = "(?:[$unreserved$sub_delims:]|$pct_encoded)*";
// IPv6 is broken
$r_authority = "/^(($r_userinfo)@)?(\[$IP_literal\]|[^:]*)(:(\d*))?/";
$matches = array();
preg_match($r_authority, $authority, $matches);
// overloads regexp!
$userinfo = !empty($matches[1]) ? $matches[2] : null;
$host = !empty($matches[3]) ? $matches[3] : null;
$port = !empty($matches[4]) ? $matches[5] : null;
// validate port
if ($port !== null) {
$port = (int) $port;
if ($port < 1 || $port > 65535) $port = null;
}
// userinfo and host are validated within the regexp
// regenerate authority
$authority =
($userinfo === null ? '' : ($userinfo . '@')) .
$host .
($port === null ? '' : (':' . $port));
}
// query and fragment are quite simple in terms of definition:
// *( pchar / "/" / "?" ), so define their validation routines
// when we start fixing percent encoding
// path gets to be validated against a hodge-podge of rules depending
// on the status of authority and scheme, but it's not that important,
// esp. since it won't be applicable to everyone
// okay, now we defer execution to the subobject for more processing
list($authority, $path, $query, $fragment) =
$scheme_obj->validateComponents($authority, $path, $query, $fragment);
// reconstruct the result
$result = '';
if ($scheme !== null) $result .= "$scheme:";
if ($authority !== null) $result .= "//$authority";
$result .= $path;
if ($query !== null) $result .= "?$query";
if ($fragment !== null) $result .= "#$fragment";
return $result;
}
}
?>