317 lines
10 KiB
PHP
317 lines
10 KiB
PHP
|
<?php
|
||
|
|
|
||
|
|
/**
|
||
|
|
* HTML Purifier's internal representation of a URI.
|
||
|
|
* @note
|
||
|
|
* Internal data-structures are completely escaped. If the data needs
|
||
|
|
* to be used in a non-URI context (which is very unlikely), be sure
|
||
|
|
* to decode it first. The URI may not necessarily be well-formed until
|
||
|
|
* validate() is called.
|
||
|
|
*/
|
||
|
|
class HTMLPurifier_URI
|
||
|
|
{
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $scheme;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $userinfo;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $host;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type int
|
||
|
|
*/
|
||
|
|
public $port;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $path;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $query;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @type string
|
||
|
|
*/
|
||
|
|
public $fragment;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @param string $scheme
|
||
|
|
* @param string $userinfo
|
||
|
|
* @param string $host
|
||
|
|
* @param int $port
|
||
|
|
* @param string $path
|
||
|
|
* @param string $query
|
||
|
|
* @param string $fragment
|
||
|
|
* @note Automatically normalizes scheme and port
|
||
|
|
*/
|
||
|
|
public function __construct($scheme, $userinfo, $host, $port, $path, $query, $fragment)
|
||
|
|
{
|
||
|
|
$this->scheme = is_null($scheme) || ctype_lower($scheme) ? $scheme : strtolower($scheme);
|
||
|
|
$this->userinfo = $userinfo;
|
||
|
|
$this->host = $host;
|
||
|
|
$this->port = is_null($port) ? $port : (int)$port;
|
||
|
|
$this->path = $path;
|
||
|
|
$this->query = $query;
|
||
|
|
$this->fragment = $fragment;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieves a scheme object corresponding to the URI's scheme/default
|
||
|
|
* @param HTMLPurifier_Config $config
|
||
|
|
* @param HTMLPurifier_Context $context
|
||
|
|
* @return HTMLPurifier_URIScheme Scheme object appropriate for validating this URI
|
||
|
|
*/
|
||
|
|
public function getSchemeObj($config, $context)
|
||
|
|
{
|
||
|
|
$registry = HTMLPurifier_URISchemeRegistry::instance();
|
||
|
|
if ($this->scheme !== null) {
|
||
|
|
$scheme_obj = $registry->getScheme($this->scheme, $config, $context);
|
||
|
|
if (!$scheme_obj) {
|
||
|
|
return false;
|
||
|
|
} // invalid scheme, clean it out
|
||
|
|
} else {
|
||
|
|
// no scheme: retrieve the default one
|
||
|
|
$def = $config->getDefinition('URI');
|
||
|
|
$scheme_obj = $def->getDefaultScheme($config, $context);
|
||
|
|
if (!$scheme_obj) {
|
||
|
|
if ($def->defaultScheme !== null) {
|
||
|
|
// something funky happened to the default scheme object
|
||
|
|
trigger_error(
|
||
|
|
'Default scheme object "' . $def->defaultScheme . '" was not readable',
|
||
|
|
E_USER_WARNING
|
||
|
|
);
|
||
|
|
} // suppress error if it's null
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return $scheme_obj;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Generic validation method applicable for all schemes. May modify
|
||
|
|
* this URI in order to get it into a compliant form.
|
||
|
|
* @param HTMLPurifier_Config $config
|
||
|
|
* @param HTMLPurifier_Context $context
|
||
|
|
* @return bool True if validation/filtering succeeds, false if failure
|
||
|
|
*/
|
||
|
|
public function validate($config, $context)
|
||
|
|
{
|
||
|
|
// ABNF definitions from RFC 3986
|
||
|
|
$chars_sub_delims = '!$&\'()*+,;=';
|
||
|
|
$chars_gen_delims = ':/?#[]@';
|
||
|
|
$chars_pchar = $chars_sub_delims . ':@';
|
||
|
|
|
||
|
|
// validate host
|
||
|
|
if (!is_null($this->host)) {
|
||
|
|
$host_def = new HTMLPurifier_AttrDef_URI_Host();
|
||
|
|
$this->host = $host_def->validate($this->host, $config, $context);
|
||
|
|
if ($this->host === false) {
|
||
|
|
$this->host = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// validate scheme
|
||
|
|
// NOTE: It's not appropriate to check whether or not this
|
||
|
|
// scheme is in our registry, since a URIFilter may convert a
|
||
|
|
// URI that we don't allow into one we do. So instead, we just
|
||
|
|
// check if the scheme can be dropped because there is no host
|
||
|
|
// and it is our default scheme.
|
||
|
|
if (!is_null($this->scheme) && is_null($this->host) || $this->host === '') {
|
||
|
|
// support for relative paths is pretty abysmal when the
|
||
|
|
// scheme is present, so axe it when possible
|
||
|
|
$def = $config->getDefinition('URI');
|
||
|
|
if ($def->defaultScheme === $this->scheme) {
|
||
|
|
$this->scheme = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// validate username
|
||
|
|
if (!is_null($this->userinfo)) {
|
||
|
|
$encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . ':');
|
||
|
|
$this->userinfo = $encoder->encode($this->userinfo);
|
||
|
|
}
|
||
|
|
|
||
|
|
// validate port
|
||
|
|
if (!is_null($this->port)) {
|
||
|
|
if ($this->port < 1 || $this->port > 65535) {
|
||
|
|
$this->port = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// validate path
|
||
|
|
$segments_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/');
|
||
|
|
if (!is_null($this->host)) { // this catches $this->host === ''
|
||
|
|
// path-abempty (hier and relative)
|
||
|
|
// http://www.example.com/my/path
|
||
|
|
// //www.example.com/my/path (looks odd, but works, and
|
||
|
|
// recognized by most browsers)
|
||
|
|
// (this set is valid or invalid on a scheme by scheme
|
||
|
|
// basis, so we'll deal with it later)
|
||
|
|
// file:///my/path
|
||
|
|
// ///my/path
|
||
|
|
$this->path = $segments_encoder->encode($this->path);
|
||
|
|
} elseif ($this->path !== '') {
|
||
|
|
if ($this->path[0] === '/') {
|
||
|
|
// path-absolute (hier and relative)
|
||
|
|
// http:/my/path
|
||
|
|
// /my/path
|
||
|
|
if (strlen($this->path) >= 2 && $this->path[1] === '/') {
|
||
|
|
// This could happen if both the host gets stripped
|
||
|
|
// out
|
||
|
|
// http://my/path
|
||
|
|
// //my/path
|
||
|
|
$this->path = '';
|
||
|
|
} else {
|
||
|
|
$this->path = $segments_encoder->encode($this->path);
|
||
|
|
}
|
||
|
|
} elseif (!is_null($this->scheme)) {
|
||
|
|
// path-rootless (hier)
|
||
|
|
// http:my/path
|
||
|
|
// Short circuit evaluation means we don't need to check nz
|
||
|
|
$this->path = $segments_encoder->encode($this->path);
|
||
|
|
} else {
|
||
|
|
// path-noscheme (relative)
|
||
|
|
// my/path
|
||
|
|
// (once again, not checking nz)
|
||
|
|
$segment_nc_encoder = new HTMLPurifier_PercentEncoder($chars_sub_delims . '@');
|
||
|
|
$c = strpos($this->path, '/');
|
||
|
|
if ($c !== false) {
|
||
|
|
$this->path =
|
||
|
|
$segment_nc_encoder->encode(substr($this->path, 0, $c)) .
|
||
|
|
$segments_encoder->encode(substr($this->path, $c));
|
||
|
|
} else {
|
||
|
|
$this->path = $segment_nc_encoder->encode($this->path);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
// path-empty (hier and relative)
|
||
|
|
$this->path = ''; // just to be safe
|
||
|
|
}
|
||
|
|
|
||
|
|
// qf = query and fragment
|
||
|
|
$qf_encoder = new HTMLPurifier_PercentEncoder($chars_pchar . '/?');
|
||
|
|
|
||
|
|
if (!is_null($this->query)) {
|
||
|
|
$this->query = $qf_encoder->encode($this->query);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!is_null($this->fragment)) {
|
||
|
|
$this->fragment = $qf_encoder->encode($this->fragment);
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Convert URI back to string
|
||
|
|
* @return string URI appropriate for output
|
||
|
|
*/
|
||
|
|
public function toString()
|
||
|
|
{
|
||
|
|
// reconstruct authority
|
||
|
|
$authority = null;
|
||
|
|
// there is a rendering difference between a null authority
|
||
|
|
// (http:foo-bar) and an empty string authority
|
||
|
|
// (http:///foo-bar).
|
||
|
|
if (!is_null($this->host)) {
|
||
|
|
$authority = '';
|
||
|
|
if (!is_null($this->userinfo)) {
|
||
|
|
$authority .= $this->userinfo . '@';
|
||
|
|
}
|
||
|
|
$authority .= $this->host;
|
||
|
|
if (!is_null($this->port)) {
|
||
|
|
$authority .= ':' . $this->port;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Reconstruct the result
|
||
|
|
// One might wonder about parsing quirks from browsers after
|
||
|
|
// this reconstruction. Unfortunately, parsing behavior depends
|
||
|
|
// on what *scheme* was employed (file:///foo is handled *very*
|
||
|
|
// differently than http:///foo), so unfortunately we have to
|
||
|
|
// defer to the schemes to do the right thing.
|
||
|
|
$result = '';
|
||
|
|
if (!is_null($this->scheme)) {
|
||
|
|
$result .= $this->scheme . ':';
|
||
|
|
}
|
||
|
|
if (!is_null($authority)) {
|
||
|
|
$result .= '//' . $authority;
|
||
|
|
}
|
||
|
|
$result .= $this->path;
|
||
|
|
if (!is_null($this->query)) {
|
||
|
|
$result .= '?' . $this->query;
|
||
|
|
}
|
||
|
|
if (!is_null($this->fragment)) {
|
||
|
|
$result .= '#' . $this->fragment;
|
||
|
|
}
|
||
|
|
|
||
|
|
return $result;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns true if this URL might be considered a 'local' URL given
|
||
|
|
* the current context. This is true when the host is null, or
|
||
|
|
* when it matches the host supplied to the configuration.
|
||
|
|
*
|
||
|
|
* Note that this does not do any scheme checking, so it is mostly
|
||
|
|
* only appropriate for metadata that doesn't care about protocol
|
||
|
|
* security. isBenign is probably what you actually want.
|
||
|
|
* @param HTMLPurifier_Config $config
|
||
|
|
* @param HTMLPurifier_Context $context
|
||
|
|
* @return bool
|
||
|
|
*/
|
||
|
|
public function isLocal($config, $context)
|
||
|
|
{
|
||
|
|
if ($this->host === null) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
$uri_def = $config->getDefinition('URI');
|
||
|
|
if ($uri_def->host === $this->host) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns true if this URL should be considered a 'benign' URL,
|
||
|
|
* that is:
|
||
|
|
*
|
||
|
|
* - It is a local URL (isLocal), and
|
||
|
|
* - It has a equal or better level of security
|
||
|
|
* @param HTMLPurifier_Config $config
|
||
|
|
* @param HTMLPurifier_Context $context
|
||
|
|
* @return bool
|
||
|
|
*/
|
||
|
|
public function isBenign($config, $context)
|
||
|
|
{
|
||
|
|
if (!$this->isLocal($config, $context)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
$scheme_obj = $this->getSchemeObj($config, $context);
|
||
|
|
if (!$scheme_obj) {
|
||
|
|
return false;
|
||
|
|
} // conservative approach
|
||
|
|
|
||
|
|
$current_scheme_obj = $config->getDefinition('URI')->getDefaultScheme($config, $context);
|
||
|
|
if ($current_scheme_obj->secure) {
|
||
|
|
if (!$scheme_obj->secure) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// vim: et sw=4 sts=4
|