<?php
/**
* HTML Purifier Phorum Mod. Filter your HTML the Standards-Compliant Way!
*
* This Phorum mod enables users to post raw HTML into Phorum. But never
* fear: with the help of HTML Purifier, this HTML will be beat into
* de-XSSed and standards-compliant form, safe for general consumption.
* It is not recommended, but possible to run this mod in parallel
* with other formatters (in short, please DISABLE the BBcode mod).
*
* For help migrating from your previous markup language to pure HTML
* please check the migrate.bbcode.php file.
*
* If you'd like to use this with a WYSIWYG editor, make sure that
* editor sets $PHORUM['mod_htmlpurifier']['wysiwyg'] to true. Otherwise,
* administrators who need to edit other people's comments may be at
* risk for some nasty attacks.
*
* Tested with Phorum 5.2.11.
*/
// Note: Cache data is base64 encoded because Phorum insists on flinging
// to the user and expecting it to come back unharmed, newlines and
// all, which ain't happening. It's slower, it takes up more space, but
// at least it won't get mutilated
/**
* Purifies a data array
*/
function phorum_htmlpurifier_format($data)
{
$PHORUM = $GLOBALS["PHORUM"];
$purifier =& HTMLPurifier::getInstance();
$cache_serial = $PHORUM['mod_htmlpurifier']['body_cache_serial'];
foreach($data as $message_id => $message){
if(isset($message['body'])) {
if ($message_id) {
// we're dealing with a real message, not a fake, so
// there a number of shortcuts that can be taken
if (isset($message['meta']['htmlpurifier_light'])) {
// format hook was called outside of Phorum's normal
// functions, do the abridged purification
$data[$message_id]['body'] = $purifier->purify($message['body']);
continue;
}
if (!empty($PHORUM['args']['purge'])) {
// purge the cache, must be below the following if
unset($message['meta']['body_cache']);
}
if (
isset($message['meta']['body_cache']) &&
isset($message['meta']['body_cache_serial']) &&
$message['meta']['body_cache_serial'] == $cache_serial
) {
// cached version is present, bail out early
$data[$message_id]['body'] = base64_decode($message['meta']['body_cache']);
continue;
}
}
// migration might edit this array, that's why it's defined
// so early
$updated_message = array();
// create the $body variable
if (
$message_id && // message must be real to migrate
!isset($message['meta']['body_cache_serial'])
) {
// perform migration
$fake_data = array();
list($signature, $edit_message) = phorum_htmlpurifier_remove_sig_and_editmessage($message);
$fake_data[$message_id] = $message;
$fake_data = phorum_htmlpurifier_migrate($fake_data);
$body = $fake_data[$message_id]['body'];
$body = str_replace("<phorum break>\n", "\n", $body);
$updated_message['body'] = $body; // save it in
$body .= $signature . $edit_message; // add it back in
} else {
// reverse Phorum's pre-processing
$body = $message['body'];
// order is important
$body = str_replace("<phorum break>\n", "\n", $body);
$body = str_replace(array('<','>','&', '"'), array('<','>','&','"'), $body);
if (!$message_id && defined('PHORUM_CONTROL_CENTER')) {
// we're in control.php, so it was double-escaped
$body = str_replace(array('<','>','&', '"'), array('<','>','&','"'), $body);
}
}
$body = $purifier->purify($body);
// dynamically update the cache (MUST BE DONE HERE!)
// this is inefficient because it's one db call per
// cache miss, but once the cache is in place things are
// a lot zippier.
if ($message_id) { // make sure it's not a fake id
$updated_message['meta'] = $message['meta'];
$updated_message['meta']['body_cache'] = base64_encode($body);
$updated_message['meta']['body_cache_serial'] = $cache_serial;
phorum_db_update_message($message_id, $updated_message);
}
// must not get overloaded until after we cache it, otherwise
// we'll inadvertently change the original text
$data[$message_id]['body'] = $body;
}
}
return $data;
}
// -----------------------------------------------------------------------
// This is fragile code, copied from read.php:596 (Phorum 5.2.6). Please
// keep this code in-sync with Phorum
/**
* Generates a signature based on a message array
*/
function phorum_htmlpurifier_generate_sig($row)
{
$phorum_sig = '';
if(isset($row["user"]["signature"])
&& isset($row['meta']['show_signature']) && $row['meta']['show_signature']==1){
$phorum_sig=trim($row["user"]["signature"]);
if(!empty($phorum_sig)){
$phorum_sig="\n\n$phorum_sig";
}
}
return $phorum_sig;
}
/**
* Generates an edit message based on a message array
*/
function phorum_htmlpurifier_generate_editmessage($row)
{
$PHORUM = $GLOBALS['PHORUM'];
$editmessage = '';
if(isset($row['meta']['edit_count']) && $row['meta']['edit_count'] > 0) {
$editmessage = str_replace ("%count%", $row['meta']['edit_count'], $PHORUM["DATA"]["LANG"]["EditedMessage"]);
$editmessage = str_replace ("%lastedit%", phorum_date($PHORUM["short_date_time"],$row['meta']['edit_date']), $editmessage);
$editmessage = str_replace ("%lastuser%", $row['meta']['edit_username'], $editmessage);
$editmessage = "\n\n\n\n$editmessage";
}
return $editmessage;
}
// End fragile code
// -----------------------------------------------------------------------
/**
* Removes the signature and edit message from a message
* @param $row Message passed by reference
*/
function phorum_htmlpurifier_remove_sig_and_editmessage(&$row)
{
$signature = phorum_htmlpurifier_generate_sig($row);
$editmessage = phorum_htmlpurifier_generate_editmessage($row);
$replacements = array();
// we need to remove add <phorum break> as that is the form these
// extra bits are in.
if ($signature) $replacements[str_replace("\n", "<phorum break>\n", $signature)] = '';
if ($editmessage) $replacements[str_replace("\n", "<phorum break>\n", $editmessage)] = '';
$row['body'] = strtr($row['body'], $replacements);
return array($signature, $editmessage);
}
/**
* Indicate that data is fully HTML and not from migration, invalidate
* previous caches
* @note This function could generate the actual cache entries, but
* since there's data missing that must be deferred to the first read
*/
function phorum_htmlpurifier_posting($message)
{
$PHORUM = $GLOBALS["PHORUM"];
unset($message['meta']['body_cache']); // invalidate the cache
$message['meta']['body_cache_serial'] = $PHORUM['mod_htmlpurifier']['body_cache_serial'];
return $message;
}
/**
* Overload quoting mechanism to prevent default, mail-style quote from happening
*/
function phorum_htmlpurifier_quote($array)
{
$PHORUM = $GLOBALS["PHORUM"];
$purifier =& HTMLPurifier::getInstance();
$text = $purifier->purify($array[1]);
$source = htmlspecialchars($array[0]);
return "<blockquote cite=\"$source\">\n$text\n</blockquote>";
}
/**
* Ensure that our format hook is processed last. Also, loads the library.
* @credits <http://secretsauce.phorum.org/snippets/make_bbcode_last_formatter.php.txt>
*/
function phorum_htmlpurifier_common()
{
require_once(dirname(__FILE__).'/htmlpurifier/HTMLPurifier.auto.php');
require(dirname(__FILE__).'/init-config.php');
$config = phorum_htmlpurifier_get_config();
HTMLPurifier::getInstance($config);
// increment revision.txt if you want to invalidate the cache
$GLOBALS['PHORUM']['mod_htmlpurifier']['body_cache_serial'] = $config->getSerial();
// load migration
if (file_exists(dirname(__FILE__) . '/migrate.php')) {
include(dirname(__FILE__) . '/migrate.php');
} else {
echo '<strong>Error:</strong> No migration path specified for HTML Purifier, please check
<tt>modes/htmlpurifier/migrate.bbcode.php</tt> for instructions on
how to migrate from your previous markup language.';
exit;
}
if (!function_exists('phorum_htmlpurifier_migrate')) {
// Dummy function
function phorum_htmlpurifier_migrate($data) {return $data;}
}
}
/**
* Pre-emptively performs purification if it looks like a WYSIWYG editor
* is being used
*/
function phorum_htmlpurifier_before_editor($message)
{
if (!empty($GLOBALS['PHORUM']['mod_htmlpurifier']['wysiwyg'])) {
if (!empty($message['body'])) {
$body = $message['body'];
// de-entity-ize contents
$body = str_replace(array('<','>','&'), array('<','>','&'), $body);
$purifier =& HTMLPurifier::getInstance();
$body = $purifier->purify($body);
// re-entity-ize contents
$body = htmlspecialchars($body, ENT_QUOTES, $GLOBALS['PHORUM']['DATA']['CHARSET']);
$message['body'] = $body;
}
}
return $message;
}
function phorum_htmlpurifier_editor_after_subject()
{
// don't show this message if it's a WYSIWYG editor, since it will
// then be handled automatically
if (!empty($GLOBALS['PHORUM']['mod_htmlpurifier']['wysiwyg'])) {
$i = $GLOBALS['PHORUM']['DATA']['MODE'];
if ($i == 'quote' || $i == 'edit' || $i == 'moderation') {
?>
<div>
<p>
<strong>Notice:</strong> HTML has been scrubbed for your safety.
If you would like to see the original, turn off WYSIWYG mode
(consult your administrator for details.)
</p>
</div>
<?php
}
return;
}
if (!empty($GLOBALS['PHORUM']['mod_htmlpurifier']['suppress_message'])) return;
?><div class="htmlpurifier-help">
<p>
<strong>HTML input</strong> is enabled. Make sure you escape all HTML and
angled brackets with <code>&lt;</code> and <code>&gt;</code>.
</p><?php
$purifier =& HTMLPurifier::getInstance();
$config = $purifier->config;
if ($config->get('AutoFormat.AutoParagraph')) {
?><p>
<strong>Auto-paragraphing</strong> is enabled. Double
newlines will be converted to paragraphs; for single
newlines, use the <code>pre</code> tag.
</p><?php
}
$html_definition = $config->getDefinition('HTML');
$allowed = array();
foreach ($html_definition->info as $name => $x) $allowed[] = "<code>$name</code>";
sort($allowed);
$allowed_text = implode(', ', $allowed);
?><p><strong>Allowed tags:</strong> <?php
echo $allowed_text;
?>.</p><?php
?>
</p>
<p>
For inputting literal code such as HTML and PHP for display, use
CDATA tags to auto-escape your angled brackets, and <code>pre</code>
to preserve newlines:
</p>
<pre><pre><![CDATA[
<em>Place code here</em>
]]></pre></pre>
<p>
Power users, you can hide this notice with:
<pre>.htmlpurifier-help {display:none;}</pre>
</p>
</div><?php
}
// vim: et sw=4 sts=4
