--- /dev/null
+<?php
+/**
+ * htmlfilter.inc
+ * ---------------
+ * This set of functions allows you to filter html in order to remove
+ * any malicious tags from it. Useful in cases when you need to filter
+ * user input for any cross-site-scripting attempts.
+ *
+ * Copyright (C) 2002-2004 by Duke University
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ * @Author Konstantin Riabitsev <icon@linux.duke.edu>
+ * @Author Jim Jagielski <jim@jaguNET.com / jimjag@gmail.com>
+ * @Version 1.1 ($Date$)
+ */
+
+/**
+ * This function returns the final tag out of the tag name, an array
+ * of attributes, and the type of the tag. This function is called by
+ * tln_sanitize internally.
+ *
+ * @param string $tagname the name of the tag.
+ * @param array $attary the array of attributes and their values
+ * @param integer $tagtype The type of the tag (see in comments).
+ * @return string A string with the final tag representation.
+ */
+function tln_tagprint($tagname, $attary, $tagtype)
+{
+ if ($tagtype == 2) {
+ $fulltag = '</' . $tagname . '>';
+ } else {
+ $fulltag = '<' . $tagname;
+ if (is_array($attary) && sizeof($attary)) {
+ $atts = array();
+ while (list($attname, $attvalue) = each($attary)) {
+ array_push($atts, "$attname=$attvalue");
+ }
+ $fulltag .= ' ' . join(' ', $atts);
+ }
+ if ($tagtype == 3) {
+ $fulltag .= ' /';
+ }
+ $fulltag .= '>';
+ }
+ return $fulltag;
+}
+
+/**
+ * A small helper function to use with array_walk. Modifies a by-ref
+ * value and makes it lowercase.
+ *
+ * @param string $val a value passed by-ref.
+ * @return void since it modifies a by-ref value.
+ */
+function tln_casenormalize(&$val)
+{
+ $val = strtolower($val);
+}
+
+/**
+ * This function skips any whitespace from the current position within
+ * a string and to the next non-whitespace value.
+ *
+ * @param string $body the string
+ * @param integer $offset the offset within the string where we should start
+ * looking for the next non-whitespace character.
+ * @return integer the location within the $body where the next
+ * non-whitespace char is located.
+ */
+function tln_skipspace($body, $offset)
+{
+ preg_match('/^(\s*)/s', substr($body, $offset), $matches);
+ if (sizeof($matches[1])) {
+ $count = strlen($matches[1]);
+ $offset += $count;
+ }
+ return $offset;
+}
+
+/**
+ * This function looks for the next character within a string. It's
+ * really just a glorified "strpos", except it catches the failures
+ * nicely.
+ *
+ * @param string $body The string to look for needle in.
+ * @param integer $offset Start looking from this position.
+ * @param string $needle The character/string to look for.
+ * @return integer location of the next occurrence of the needle, or
+ * strlen($body) if needle wasn't found.
+ */
+function tln_findnxstr($body, $offset, $needle)
+{
+ $pos = strpos($body, $needle, $offset);
+ if ($pos === false) {
+ $pos = strlen($body);
+ }
+ return $pos;
+}
+
+/**
+ * This function takes a PCRE-style regexp and tries to match it
+ * within the string.
+ *
+ * @param string $body The string to look for needle in.
+ * @param integer $offset Start looking from here.
+ * @param string $reg A PCRE-style regex to match.
+ * @return array|boolean Returns a false if no matches found, or an array
+ * with the following members:
+ * - integer with the location of the match within $body
+ * - string with whatever content between offset and the match
+ * - string with whatever it is we matched
+ */
+function tln_findnxreg($body, $offset, $reg)
+{
+ $matches = array();
+ $retarr = array();
+ $preg_rule = '%^(.*?)(' . $reg . ')%s';
+ preg_match($preg_rule, substr($body, $offset), $matches);
+ if (!isset($matches[0]) || !$matches[0]) {
+ $retarr = false;
+ } else {
+ $retarr[0] = $offset + strlen($matches[1]);
+ $retarr[1] = $matches[1];
+ $retarr[2] = $matches[2];
+ }
+ return $retarr;
+}
+
+/**
+ * This function looks for the next tag.
+ *
+ * @param string $body String where to look for the next tag.
+ * @param integer $offset Start looking from here.
+ * @return array|boolean false if no more tags exist in the body, or
+ * an array with the following members:
+ * - string with the name of the tag
+ * - array with attributes and their values
+ * - integer with tag type (1, 2, or 3)
+ * - integer where the tag starts (starting "<")
+ * - integer where the tag ends (ending ">")
+ * first three members will be false, if the tag is invalid.
+ */
+function tln_getnxtag($body, $offset)
+{
+ if ($offset > strlen($body)) {
+ return false;
+ }
+ $lt = tln_findnxstr($body, $offset, '<');
+ if ($lt == strlen($body)) {
+ return false;
+ }
+ /**
+ * We are here:
+ * blah blah <tag attribute="value">
+ * \---------^
+ */
+ $pos = tln_skipspace($body, $lt + 1);
+ if ($pos >= strlen($body)) {
+ return array(false, false, false, $lt, strlen($body));
+ }
+ /**
+ * There are 3 kinds of tags:
+ * 1. Opening tag, e.g.:
+ * <a href="blah">
+ * 2. Closing tag, e.g.:
+ * </a>
+ * 3. XHTML-style content-less tag, e.g.:
+ * <img src="blah"/>
+ */
+ switch (substr($body, $pos, 1)) {
+ case '/':
+ $tagtype = 2;
+ $pos++;
+ break;
+ case '!':
+ /**
+ * A comment or an SGML declaration.
+ */
+ if (substr($body, $pos + 1, 2) == '--') {
+ $gt = strpos($body, '-->', $pos);
+ if ($gt === false) {
+ $gt = strlen($body);
+ } else {
+ $gt += 2;
+ }
+ return array(false, false, false, $lt, $gt);
+ } else {
+ $gt = tln_findnxstr($body, $pos, '>');
+ return array(false, false, false, $lt, $gt);
+ }
+ break;
+ default:
+ /**
+ * Assume tagtype 1 for now. If it's type 3, we'll switch values
+ * later.
+ */
+ $tagtype = 1;
+ break;
+ }
+
+ /**
+ * Look for next [\W-_], which will indicate the end of the tag name.
+ */
+ $regary = tln_findnxreg($body, $pos, '[^\w\-_]');
+ if ($regary == false) {
+ return array(false, false, false, $lt, strlen($body));
+ }
+ list($pos, $tagname, $match) = $regary;
+ $tagname = strtolower($tagname);
+
+ /**
+ * $match can be either of these:
+ * '>' indicating the end of the tag entirely.
+ * '\s' indicating the end of the tag name.
+ * '/' indicating that this is type-3 xhtml tag.
+ *
+ * Whatever else we find there indicates an invalid tag.
+ */
+ switch ($match) {
+ case '/':
+ /**
+ * This is an xhtml-style tag with a closing / at the
+ * end, like so: <img src="blah"/>. Check if it's followed
+ * by the closing bracket. If not, then this tag is invalid
+ */
+ if (substr($body, $pos, 2) == '/>') {
+ $pos++;
+ $tagtype = 3;
+ } else {
+ $gt = tln_findnxstr($body, $pos, '>');
+ $retary = array(false, false, false, $lt, $gt);
+ return $retary;
+ }
+ //intentional fall-through
+ case '>':
+ return array($tagname, false, $tagtype, $lt, $pos);
+ break;
+ default:
+ /**
+ * Check if it's whitespace
+ */
+ if (!preg_match('/\s/', $match)) {
+ /**
+ * This is an invalid tag! Look for the next closing ">".
+ */
+ $gt = tln_findnxstr($body, $lt, '>');
+ return array(false, false, false, $lt, $gt);
+ }
+ break;
+ }
+
+ /**
+ * At this point we're here:
+ * <tagname attribute='blah'>
+ * \-------^
+ *
+ * At this point we loop in order to find all attributes.
+ */
+ $attary = array();
+
+ while ($pos <= strlen($body)) {
+ $pos = tln_skipspace($body, $pos);
+ if ($pos == strlen($body)) {
+ /**
+ * Non-closed tag.
+ */
+ return array(false, false, false, $lt, $pos);
+ }
+ /**
+ * See if we arrived at a ">" or "/>", which means that we reached
+ * the end of the tag.
+ */
+ $matches = array();
+ if (preg_match('%^(\s*)(>|/>)%s', substr($body, $pos), $matches)) {
+ /**
+ * Yep. So we did.
+ */
+ $pos += strlen($matches[1]);
+ if ($matches[2] == '/>') {
+ $tagtype = 3;
+ $pos++;
+ }
+ return array($tagname, $attary, $tagtype, $lt, $pos);
+ }
+
+ /**
+ * There are several types of attributes, with optional
+ * [:space:] between members.
+ * Type 1:
+ * attrname[:space:]=[:space:]'CDATA'
+ * Type 2:
+ * attrname[:space:]=[:space:]"CDATA"
+ * Type 3:
+ * attr[:space:]=[:space:]CDATA
+ * Type 4:
+ * attrname
+ *
+ * We leave types 1 and 2 the same, type 3 we check for
+ * '"' and convert to """ if needed, then wrap in
+ * double quotes. Type 4 we convert into:
+ * attrname="yes".
+ */
+ $regary = tln_findnxreg($body, $pos, '[^\w\-_]');
+ if ($regary == false) {
+ /**
+ * Looks like body ended before the end of tag.
+ */
+ return array(false, false, false, $lt, strlen($body));
+ }
+ list($pos, $attname, $match) = $regary;
+ $attname = strtolower($attname);
+ /**
+ * We arrived at the end of attribute name. Several things possible
+ * here:
+ * '>' means the end of the tag and this is attribute type 4
+ * '/' if followed by '>' means the same thing as above
+ * '\s' means a lot of things -- look what it's followed by.
+ * anything else means the attribute is invalid.
+ */
+ switch ($match) {
+ case '/':
+ /**
+ * This is an xhtml-style tag with a closing / at the
+ * end, like so: <img src="blah"/>. Check if it's followed
+ * by the closing bracket. If not, then this tag is invalid
+ */
+ if (substr($body, $pos, 2) == '/>') {
+ $pos++;
+ $tagtype = 3;
+ } else {
+ $gt = tln_findnxstr($body, $pos, '>');
+ $retary = array(false, false, false, $lt, $gt);
+ return $retary;
+ }
+ //intentional fall-through
+ case '>':
+ $attary{$attname} = '"yes"';
+ return array($tagname, $attary, $tagtype, $lt, $pos);
+ break;
+ default:
+ /**
+ * Skip whitespace and see what we arrive at.
+ */
+ $pos = tln_skipspace($body, $pos);
+ $char = substr($body, $pos, 1);
+ /**
+ * Two things are valid here:
+ * '=' means this is attribute type 1 2 or 3.
+ * \w means this was attribute type 4.
+ * anything else we ignore and re-loop. End of tag and
+ * invalid stuff will be caught by our checks at the beginning
+ * of the loop.
+ */
+ if ($char == '=') {
+ $pos++;
+ $pos = tln_skipspace($body, $pos);
+ /**
+ * Here are 3 possibilities:
+ * "'" attribute type 1
+ * '"' attribute type 2
+ * everything else is the content of tag type 3
+ */
+ $quot = substr($body, $pos, 1);
+ if ($quot == '\'') {
+ $regary = tln_findnxreg($body, $pos + 1, '\'');
+ if ($regary == false) {
+ return array(false, false, false, $lt, strlen($body));
+ }
+ list($pos, $attval, $match) = $regary;
+ $pos++;
+ $attary{$attname} = '\'' . $attval . '\'';
+ } elseif ($quot == '"') {
+ $regary = tln_findnxreg($body, $pos + 1, '\"');
+ if ($regary == false) {
+ return array(false, false, false, $lt, strlen($body));
+ }
+ list($pos, $attval, $match) = $regary;
+ $pos++;
+ $attary{$attname} = '"' . $attval . '"';
+ } else {
+ /**
+ * These are hateful. Look for \s, or >.
+ */
+ $regary = tln_findnxreg($body, $pos, '[\s>]');
+ if ($regary == false) {
+ return array(false, false, false, $lt, strlen($body));
+ }
+ list($pos, $attval, $match) = $regary;
+ /**
+ * If it's ">" it will be caught at the top.
+ */
+ $attval = preg_replace('/\"/s', '"', $attval);
+ $attary{$attname} = '"' . $attval . '"';
+ }
+ } elseif (preg_match('|[\w/>]|', $char)) {
+ /**
+ * That was attribute type 4.
+ */
+ $attary{$attname} = '"yes"';
+ } else {
+ /**
+ * An illegal character. Find next '>' and return.
+ */
+ $gt = tln_findnxstr($body, $pos, '>');
+ return array(false, false, false, $lt, $gt);
+ }
+ break;
+ }
+ }
+ /**
+ * The fact that we got here indicates that the tag end was never
+ * found. Return invalid tag indication so it gets stripped.
+ */
+ return array(false, false, false, $lt, strlen($body));
+}
+
+/**
+ * Translates entities into literal values so they can be checked.
+ *
+ * @param string $attvalue the by-ref value to check.
+ * @param string $regex the regular expression to check against.
+ * @param boolean $hex whether the entites are hexadecimal.
+ * @return boolean True or False depending on whether there were matches.
+ */
+function tln_deent(&$attvalue, $regex, $hex = false)
+{
+ preg_match_all($regex, $attvalue, $matches);
+ if (is_array($matches) && sizeof($matches[0]) > 0) {
+ $repl = array();
+ for ($i = 0; $i < sizeof($matches[0]); $i++) {
+ $numval = $matches[1][$i];
+ if ($hex) {
+ $numval = hexdec($numval);
+ }
+ $repl{$matches[0][$i]} = chr($numval);
+ }
+ $attvalue = strtr($attvalue, $repl);
+ return true;
+ } else {
+ return false;
+ }
+}
+
+/**
+ * This function checks attribute values for entity-encoded values
+ * and returns them translated into 8-bit strings so we can run
+ * checks on them.
+ *
+ * @param string $attvalue A string to run entity check against.
+ * @return Void, modifies a reference value.
+ */
+function tln_defang(&$attvalue)
+{
+ /**
+ * Skip this if there aren't ampersands or backslashes.
+ */
+ if (strpos($attvalue, '&') === false
+ && strpos($attvalue, '\\') === false
+ ) {
+ return;
+ }
+ do {
+ $m = false;
+ $m = $m || tln_deent($attvalue, '/\�*(\d+);*/s');
+ $m = $m || tln_deent($attvalue, '/\�*((\d|[a-f])+);*/si', true);
+ $m = $m || tln_deent($attvalue, '/\\\\(\d+)/s', true);
+ } while ($m == true);
+ $attvalue = stripslashes($attvalue);
+}
+
+/**
+ * Kill any tabs, newlines, or carriage returns. Our friends the
+ * makers of the browser with 95% market value decided that it'd
+ * be funny to make "java[tab]script" be just as good as "javascript".
+ *
+ * @param string $attvalue The attribute value before extraneous spaces removed.
+ * @return Void, modifies a reference value.
+ */
+function tln_unspace(&$attvalue)
+{
+ if (strcspn($attvalue, "\t\r\n\0 ") != strlen($attvalue)) {
+ $attvalue = str_replace(
+ array("\t", "\r", "\n", "\0", " "),
+ array('', '', '', '', ''),
+ $attvalue
+ );
+ }
+}
+
+/**
+ * This function runs various checks against the attributes.
+ *
+ * @param string $tagname String with the name of the tag.
+ * @param array $attary Array with all tag attributes.
+ * @param array $rm_attnames See description for tln_sanitize
+ * @param array $bad_attvals See description for tln_sanitize
+ * @param array $add_attr_to_tag See description for tln_sanitize
+ * @param string $trans_image_path
+ * @param boolean $block_external_images
+ * @return Array with modified attributes.
+ */
+function tln_fixatts(
+ $tagname,
+ $attary,
+ $rm_attnames,
+ $bad_attvals,
+ $add_attr_to_tag,
+ $trans_image_path,
+ $block_external_images
+) {
+ while (list($attname, $attvalue) = each($attary)) {
+ /**
+ * See if this attribute should be removed.
+ */
+ foreach ($rm_attnames as $matchtag => $matchattrs) {
+ if (preg_match($matchtag, $tagname)) {
+ foreach ($matchattrs as $matchattr) {
+ if (preg_match($matchattr, $attname)) {
+ unset($attary{$attname});
+ continue;
+ }
+ }
+ }
+ }
+ /**
+ * Remove any backslashes, entities, or extraneous whitespace.
+ */
+ $oldattvalue = $attvalue;
+ tln_defang($attvalue);
+ if ($attname == 'style' && $attvalue !== $oldattvalue) {
+ $attvalue = "idiocy";
+ $attary{$attname} = $attvalue;
+ }
+ tln_unspace($attvalue);
+
+ /**
+ * Now let's run checks on the attvalues.
+ * I don't expect anyone to comprehend this. If you do,
+ * get in touch with me so I can drive to where you live and
+ * shake your hand personally. :)
+ */
+ foreach ($bad_attvals as $matchtag => $matchattrs) {
+ if (preg_match($matchtag, $tagname)) {
+ foreach ($matchattrs as $matchattr => $valary) {
+ if (preg_match($matchattr, $attname)) {
+ /**
+ * There are two arrays in valary.
+ * First is matches.
+ * Second one is replacements
+ */
+ list($valmatch, $valrepl) = $valary;
+ $newvalue = preg_replace($valmatch, $valrepl, $attvalue);
+ if ($newvalue != $attvalue) {
+ $attary{$attname} = $newvalue;
+ $attvalue = $newvalue;
+ }
+ }
+ }
+ }
+ }
+ if ($attname == 'style') {
+ if (preg_match('/[\0-\37\200-\377]+/', $attvalue)) {
+ $attary{$attname} = '"disallowed character"';
+ }
+ preg_match_all("/url\s*\((.+)\)/si", $attvalue, $aMatch);
+ if (count($aMatch)) {
+ foreach($aMatch[1] as $sMatch) {
+ $urlvalue = $sMatch;
+ tln_fixurl($attname, $urlvalue, $trans_image_path, $block_external_images);
+ $attary{$attname} = str_replace($sMatch, $urlvalue, $attvalue);
+ }
+ }
+ }
+ }
+ /**
+ * See if we need to append any attributes to this tag.
+ */
+ foreach ($add_attr_to_tag as $matchtag => $addattary) {
+ if (preg_match($matchtag, $tagname)) {
+ $attary = array_merge($attary, $addattary);
+ }
+ }
+ return $attary;
+}
+
+function tln_fixurl($attname, &$attvalue, $trans_image_path, $block_external_images)
+{
+ $sQuote = '"';
+ $attvalue = trim($attvalue);
+ if ($attvalue && ($attvalue[0] =='"'|| $attvalue[0] == "'")) {
+ // remove the double quotes
+ $sQuote = $attvalue[0];
+ $attvalue = trim(substr($attvalue,1,-1));
+ }
+
+ /**
+ * Replace empty src tags with the blank image. src is only used
+ * for frames, images, and image inputs. Doing a replace should
+ * not affect them working as should be, however it will stop
+ * IE from being kicked off when src for img tags are not set
+ */
+ if ($attvalue == '') {
+ $attvalue = $sQuote . $trans_image_path . $sQuote;
+ } else {
+ // first, disallow 8 bit characters and control characters
+ if (preg_match('/[\0-\37\200-\377]+/',$attvalue)) {
+ switch ($attname) {
+ case 'href':
+ $attvalue = $sQuote . 'http://invalid-stuff-detected.example.com' . $sQuote;
+ break;
+ default:
+ $attvalue = $sQuote . $trans_image_path . $sQuote;
+ break;
+ }
+ } else {
+ $aUrl = parse_url($attvalue);
+ if (isset($aUrl['scheme'])) {
+ switch(strtolower($aUrl['scheme'])) {
+ case 'mailto':
+ case 'http':
+ case 'https':
+ case 'ftp':
+ if ($attname != 'href') {
+ if ($block_external_images == true) {
+ $attvalue = $sQuote . $trans_image_path . $sQuote;
+ } else {
+ if (!isset($aUrl['path'])) {
+ $attvalue = $sQuote . $trans_image_path . $sQuote;
+ }
+ }
+ } else {
+ $attvalue = $sQuote . $attvalue . $sQuote;
+ }
+ break;
+ case 'outbind':
+ $attvalue = $sQuote . $attvalue . $sQuote;
+ break;
+ case 'cid':
+ $attvalue = $sQuote . $attvalue . $sQuote;
+ break;
+ default:
+ $attvalue = $sQuote . $trans_image_path . $sQuote;
+ break;
+ }
+ } else {
+ if (!isset($aUrl['path']) || $aUrl['path'] != $trans_image_path) {
+ $$attvalue = $sQuote . $trans_image_path . $sQuote;
+ }
+ }
+ }
+ }
+}
+
+function tln_fixstyle($body, $pos, $trans_image_path, $block_external_images)
+{
+ $me = 'tln_fixstyle';
+ // workaround for </style> in between comments
+ $iCurrentPos = $pos;
+ $content = '';
+ $sToken = '';
+ $bSucces = false;
+ $bEndTag = false;
+ for ($i=$pos,$iCount=strlen($body);$i<$iCount;++$i) {
+ $char = $body{$i};
+ switch ($char) {
+ case '<':
+ $sToken = $char;
+ break;
+ case '/':
+ if ($sToken == '<') {
+ $sToken .= $char;
+ $bEndTag = true;
+ } else {
+ $content .= $char;
+ }
+ break;
+ case '>':
+ if ($bEndTag) {
+ $sToken .= $char;
+ if (preg_match('/\<\/\s*style\s*\>/i',$sToken,$aMatch)) {
+ $newpos = $i + 1;
+ $bSucces = true;
+ break 2;
+ } else {
+ $content .= $sToken;
+ }
+ $bEndTag = false;
+ } else {
+ $content .= $char;
+ }
+ break;
+ case '!':
+ if ($sToken == '<') {
+ // possible comment
+ if (isset($body{$i+2}) && substr($body,$i,3) == '!--') {
+ $i = strpos($body,'-->',$i+3);
+ if ($i === false) { // no end comment
+ $i = strlen($body);
+ }
+ $sToken = '';
+ }
+ } else {
+ $content .= $char;
+ }
+ break;
+ default:
+ if ($bEndTag) {
+ $sToken .= $char;
+ } else {
+ $content .= $char;
+ }
+ break;
+ }
+ }
+ if ($bSucces == FALSE){
+ return array(FALSE, strlen($body));
+ }
+
+
+
+ /**
+ * First look for general BODY style declaration, which would be
+ * like so:
+ * body {background: blah-blah}
+ * and change it to .bodyclass so we can just assign it to a <div>
+ */
+ $content = preg_replace("|body(\s*\{.*?\})|si", ".bodyclass\\1", $content);
+
+ $trans_image_path = $trans_image_path;
+
+ /**
+ * Fix url('blah') declarations.
+ */
+ // $content = preg_replace("|url\s*\(\s*([\'\"])\s*\S+script\s*:.*?([\'\"])\s*\)|si",
+ // "url(\\1$trans_image_path\\2)", $content);
+
+ // first check for 8bit sequences and disallowed control characters
+ if (preg_match('/[\16-\37\200-\377]+/',$content)) {
+ $content = '<!-- style block removed by html filter due to presence of 8bit characters -->';
+ return array($content, $newpos);
+ }
+
+ // remove @import line
+ $content = preg_replace("/^\s*(@import.*)$/mi","\n<!-- @import rules forbidden -->\n",$content);
+
+ $content = preg_replace("/(\\\\)?u(\\\\)?r(\\\\)?l(\\\\)?/i", 'url', $content);
+ preg_match_all("/url\s*\((.+)\)/si",$content,$aMatch);
+ if (count($aMatch)) {
+ $aValue = $aReplace = array();
+ foreach($aMatch[1] as $sMatch) {
+ // url value
+ $urlvalue = $sMatch;
+ tln_fixurl('style',$urlvalue, $trans_image_path, $block_external_images);
+ $aValue[] = $sMatch;
+ $aReplace[] = $urlvalue;
+ }
+ $content = str_replace($aValue,$aReplace,$content);
+ }
+
+ /**
+ * Remove any backslashes, entities, and extraneous whitespace.
+ */
+ $contentTemp = $content;
+ tln_defang($contentTemp);
+ tln_unspace($contentTemp);
+
+ $match = Array('/\/\*.*\*\//',
+ '/expression/i',
+ '/behaviou*r/i',
+ '/binding/i',
+ '/include-source/i',
+ '/javascript/i',
+ '/script/i',
+ '/position/i');
+ $replace = Array('','idiocy', 'idiocy', 'idiocy', 'idiocy', 'idiocy', 'idiocy', '');
+ $contentNew = preg_replace($match, $replace, $contentTemp);
+ if ($contentNew !== $contentTemp) {
+ $content = $contentNew;
+ }
+ return array($content, $newpos);
+}
+
+function tln_body2div($attary, $trans_image_path)
+{
+ $me = 'tln_body2div';
+ $divattary = array('class' => "'bodyclass'");
+ $text = '#000000';
+ $has_bgc_stl = $has_txt_stl = false;
+ $styledef = '';
+ if (is_array($attary) && sizeof($attary) > 0){
+ foreach ($attary as $attname=>$attvalue){
+ $quotchar = substr($attvalue, 0, 1);
+ $attvalue = str_replace($quotchar, "", $attvalue);
+ switch ($attname){
+ case 'background':
+ $styledef .= "background-image: url('$trans_image_path'); ";
+ break;
+ case 'bgcolor':
+ $has_bgc_stl = true;
+ $styledef .= "background-color: $attvalue; ";
+ break;
+ case 'text':
+ $has_txt_stl = true;
+ $styledef .= "color: $attvalue; ";
+ break;
+ }
+ }
+ // Outlook defines a white bgcolor and no text color. This can lead to
+ // white text on a white bg with certain themes.
+ if ($has_bgc_stl && !$has_txt_stl) {
+ $styledef .= "color: $text; ";
+ }
+ if (strlen($styledef) > 0){
+ $divattary{"style"} = "\"$styledef\"";
+ }
+ }
+ return $divattary;
+}
+
+/**
+ *
+ * @param string $body The HTML you wish to filter
+ * @param array $tag_list see description above
+ * @param array $rm_tags_with_content see description above
+ * @param array $self_closing_tags see description above
+ * @param boolean $force_tag_closing see description above
+ * @param array $rm_attnames see description above
+ * @param array $bad_attvals see description above
+ * @param array $add_attr_to_tag see description above
+ * @param string $trans_image_path
+ * @param boolean $block_external_images
+
+ * @return string Sanitized html safe to show on your pages.
+ */
+function tln_sanitize(
+ $body,
+ $tag_list,
+ $rm_tags_with_content,
+ $self_closing_tags,
+ $force_tag_closing,
+ $rm_attnames,
+ $bad_attvals,
+ $add_attr_to_tag,
+ $trans_image_path,
+ $block_external_images
+) {
+ /**
+ * Normalize rm_tags and rm_tags_with_content.
+ */
+ $rm_tags = array_shift($tag_list);
+ @array_walk($tag_list, 'tln_casenormalize');
+ @array_walk($rm_tags_with_content, 'tln_casenormalize');
+ @array_walk($self_closing_tags, 'tln_casenormalize');
+ /**
+ * See if tag_list is of tags to remove or tags to allow.
+ * false means remove these tags
+ * true means allow these tags
+ */
+ $curpos = 0;
+ $open_tags = array();
+ $trusted = "<!-- begin tln_sanitized html -->\n";
+ $skip_content = false;
+ /**
+ * Take care of netscape's stupid javascript entities like
+ * &{alert('boo')};
+ */
+ $body = preg_replace('/&(\{.*?\};)/si', '&\\1', $body);
+ while (($curtag = tln_getnxtag($body, $curpos)) != false) {
+ list($tagname, $attary, $tagtype, $lt, $gt) = $curtag;
+ $free_content = substr($body, $curpos, $lt-$curpos);
+ /**
+ * Take care of <style>
+ */
+ if ($tagname == "style" && $tagtype == 1){
+ list($free_content, $curpos) =
+ tln_fixstyle($body, $gt+1, $trans_image_path, $block_external_images);
+ if ($free_content != FALSE){
+ if ( !empty($attary) ) {
+ $attary = tln_fixatts($tagname,
+ $attary,
+ $rm_attnames,
+ $bad_attvals,
+ $add_attr_to_tag,
+ $trans_image_path,
+ $block_external_images
+ );
+ }
+ $trusted .= tln_tagprint($tagname, $attary, $tagtype);
+ $trusted .= $free_content;
+ $trusted .= tln_tagprint($tagname, false, 2);
+ }
+ continue;
+ }
+ if ($skip_content == false){
+ $trusted .= $free_content;
+ }
+ if ($tagname != false) {
+ if ($tagtype == 2) {
+ if ($skip_content == $tagname) {
+ /**
+ * Got to the end of tag we needed to remove.
+ */
+ $tagname = false;
+ $skip_content = false;
+ } else {
+ if ($skip_content == false) {
+ if ($tagname == "body") {
+ $tagname = "div";
+ }
+ if (isset($open_tags{$tagname}) &&
+ $open_tags{$tagname} > 0
+ ) {
+ $open_tags{$tagname}--;
+ } else {
+ $tagname = false;
+ }
+ }
+ }
+ } else {
+ /**
+ * $rm_tags_with_content
+ */
+ if ($skip_content == false) {
+ /**
+ * See if this is a self-closing type and change
+ * tagtype appropriately.
+ */
+ if ($tagtype == 1
+ && in_array($tagname, $self_closing_tags)
+ ) {
+ $tagtype = 3;
+ }
+ /**
+ * See if we should skip this tag and any content
+ * inside it.
+ */
+ if ($tagtype == 1
+ && in_array($tagname, $rm_tags_with_content)
+ ) {
+ $skip_content = $tagname;
+ } else {
+ if (($rm_tags == false
+ && in_array($tagname, $tag_list)) ||
+ ($rm_tags == true
+ && !in_array($tagname, $tag_list))
+ ) {
+ $tagname = false;
+ } else {
+ /**
+ * Convert body into div.
+ */
+ if ($tagname == "body"){
+ $tagname = "div";
+ $attary = tln_body2div($attary, $trans_image_path);
+ }
+ if ($tagtype == 1) {
+ if (isset($open_tags{$tagname})) {
+ $open_tags{$tagname}++;
+ } else {
+ $open_tags{$tagname} = 1;
+ }
+ }
+ /**
+ * This is where we run other checks.
+ */
+ if (is_array($attary) && sizeof($attary) > 0) {
+ $attary = tln_fixatts(
+ $tagname,
+ $attary,
+ $rm_attnames,
+ $bad_attvals,
+ $add_attr_to_tag,
+ $trans_image_path,
+ $block_external_images
+ );
+ }
+ }
+ }
+ }
+ }
+ if ($tagname != false && $skip_content == false) {
+ $trusted .= tln_tagprint($tagname, $attary, $tagtype);
+ }
+ }
+ $curpos = $gt + 1;
+ }
+ $trusted .= substr($body, $curpos, strlen($body) - $curpos);
+ if ($force_tag_closing == true) {
+ foreach ($open_tags as $tagname => $opentimes) {
+ while ($opentimes > 0) {
+ $trusted .= '</' . $tagname . '>';
+ $opentimes--;
+ }
+ }
+ $trusted .= "\n";
+ }
+ $trusted .= "<!-- end tln_sanitized html -->\n";
+ return $trusted;
+}
+
+//
+// Use the nifty htmlfilter library
+//
+
+
+function HTMLFilter($body, $trans_image_path, $block_external_images = false)
+{
+
+ $tag_list = array(
+ false,
+ "object",
+ "meta",
+ "html",
+ "head",
+ "base",
+ "link",
+ "frame",
+ "iframe",
+ "plaintext",
+ "marquee"
+ );
+
+ $rm_tags_with_content = array(
+ "script",
+ "applet",
+ "embed",
+ "title",
+ "frameset",
+ "xmp",
+ "xml"
+ );
+
+ $self_closing_tags = array(
+ "img",
+ "br",
+ "hr",
+ "input",
+ "outbind"
+ );
+
+ $force_tag_closing = true;
+
+ $rm_attnames = array(
+ "/.*/" =>
+ array(
+ // "/target/i",
+ "/^on.*/i",
+ "/^dynsrc/i",
+ "/^data.*/i",
+ "/^lowsrc.*/i"
+ )
+ );
+
+ $bad_attvals = array(
+ "/.*/" =>
+ array(
+ "/^src|background/i" =>
+ array(
+ array(
+ '/^([\'"])\s*\S+script\s*:.*([\'"])/si',
+ '/^([\'"])\s*mocha\s*:*.*([\'"])/si',
+ '/^([\'"])\s*about\s*:.*([\'"])/si'
+ ),
+ array(
+ "\\1$trans_image_path\\2",
+ "\\1$trans_image_path\\2",
+ "\\1$trans_image_path\\2"
+ )
+ ),
+ "/^href|action/i" =>
+ array(
+ array(
+ '/^([\'"])\s*\S+script\s*:.*([\'"])/si',
+ '/^([\'"])\s*mocha\s*:*.*([\'"])/si',
+ '/^([\'"])\s*about\s*:.*([\'"])/si'
+ ),
+ array(
+ "\\1#\\1",
+ "\\1#\\1",
+ "\\1#\\1"
+ )
+ ),
+ "/^style/i" =>
+ array(
+ array(
+ "/\/\*.*\*\//",
+ "/expression/i",
+ "/binding/i",
+ "/behaviou*r/i",
+ "/include-source/i",
+ '/position\s*:/i',
+ '/(\\\\)?u(\\\\)?r(\\\\)?l(\\\\)?/i',
+ '/url\s*\(\s*([\'"])\s*\S+script\s*:.*([\'"])\s*\)/si',
+ '/url\s*\(\s*([\'"])\s*mocha\s*:.*([\'"])\s*\)/si',
+ '/url\s*\(\s*([\'"])\s*about\s*:.*([\'"])\s*\)/si',
+ '/(.*)\s*:\s*url\s*\(\s*([\'"]*)\s*\S+script\s*:.*([\'"]*)\s*\)/si'
+ ),
+ array(
+ "",
+ "idiocy",
+ "idiocy",
+ "idiocy",
+ "idiocy",
+ "idiocy",
+ "url",
+ "url(\\1#\\1)",
+ "url(\\1#\\1)",
+ "url(\\1#\\1)",
+ "\\1:url(\\2#\\3)"
+ )
+ )
+ )
+ );
+
+ if ($block_external_images) {
+ array_push(
+ $bad_attvals{'/.*/'}{'/^src|background/i'}[0],
+ '/^([\'\"])\s*https*:.*([\'\"])/si'
+ );
+ array_push(
+ $bad_attvals{'/.*/'}{'/^src|background/i'}[1],
+ "\\1$trans_image_path\\1"
+ );
+ array_push(
+ $bad_attvals{'/.*/'}{'/^style/i'}[0],
+ '/url\(([\'\"])\s*https*:.*([\'\"])\)/si'
+ );
+ array_push(
+ $bad_attvals{'/.*/'}{'/^style/i'}[1],
+ "url(\\1$trans_image_path\\1)"
+ );
+ }
+
+ $add_attr_to_tag = array(
+ "/^a$/i" =>
+ array('target' => '"_blank"')
+ );
+
+ $trusted = tln_sanitize(
+ $body,
+ $tag_list,
+ $rm_tags_with_content,
+ $self_closing_tags,
+ $force_tag_closing,
+ $rm_attnames,
+ $bad_attvals,
+ $add_attr_to_tag,
+ $trans_image_path,
+ $block_external_images
+ );
+ return $trusted;
+}
dépôts / lhc / web / www.git / blobdiff