116 lines
3.2 KiB
PHP
116 lines
3.2 KiB
PHP
<?php
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class HTMLPurifier_URIFilter_Munge extends HTMLPurifier_URIFilter
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{
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/**
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* @type string
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*/
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public $name = 'Munge';
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/**
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* @type bool
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*/
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public $post = true;
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/**
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* @type string
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*/
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private $target;
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/**
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* @type HTMLPurifier_URIParser
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*/
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private $parser;
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/**
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* @type bool
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*/
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private $doEmbed;
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/**
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* @type string
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*/
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private $secretKey;
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/**
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* @type array
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*/
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protected $replace = array();
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/**
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* @param HTMLPurifier_Config $config
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* @return bool
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*/
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public function prepare($config)
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{
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$this->target = $config->get('URI.' . $this->name);
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$this->parser = new HTMLPurifier_URIParser();
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$this->doEmbed = $config->get('URI.MungeResources');
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$this->secretKey = $config->get('URI.MungeSecretKey');
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if ($this->secretKey && !function_exists('hash_hmac')) {
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throw new Exception("Cannot use %URI.MungeSecretKey without hash_hmac support.");
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}
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return true;
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}
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/**
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* @param HTMLPurifier_URI $uri
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* @param HTMLPurifier_Config $config
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* @param HTMLPurifier_Context $context
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* @return bool
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*/
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public function filter(&$uri, $config, $context)
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{
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if ($context->get('EmbeddedURI', true) && !$this->doEmbed) {
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return true;
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}
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$scheme_obj = $uri->getSchemeObj($config, $context);
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if (!$scheme_obj) {
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return true;
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} // ignore unknown schemes, maybe another postfilter did it
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if (!$scheme_obj->browsable) {
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return true;
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} // ignore non-browseable schemes, since we can't munge those in a reasonable way
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if ($uri->isBenign($config, $context)) {
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return true;
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} // don't redirect if a benign URL
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$this->makeReplace($uri, $config, $context);
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$this->replace = array_map('rawurlencode', $this->replace);
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$new_uri = strtr($this->target, $this->replace);
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$new_uri = $this->parser->parse($new_uri);
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// don't redirect if the target host is the same as the
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// starting host
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if ($uri->host === $new_uri->host) {
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return true;
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}
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$uri = $new_uri; // overwrite
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return true;
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}
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/**
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* @param HTMLPurifier_URI $uri
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* @param HTMLPurifier_Config $config
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* @param HTMLPurifier_Context $context
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*/
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protected function makeReplace($uri, $config, $context)
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{
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$string = $uri->toString();
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// always available
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$this->replace['%s'] = $string;
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$this->replace['%r'] = $context->get('EmbeddedURI', true);
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$token = $context->get('CurrentToken', true);
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$this->replace['%n'] = $token ? $token->name : null;
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$this->replace['%m'] = $context->get('CurrentAttr', true);
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$this->replace['%p'] = $context->get('CurrentCSSProperty', true);
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// not always available
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if ($this->secretKey) {
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$this->replace['%t'] = hash_hmac("sha256", $string, $this->secretKey);
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}
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}
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}
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// vim: et sw=4 sts=4
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