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author | marcus <marcus@36083f99-b078-4883-b0ff-0f9b5a30f544> | 2009-04-17 15:41:16 +0000 |
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committer | marcus <marcus@36083f99-b078-4883-b0ff-0f9b5a30f544> | 2009-04-17 15:41:16 +0000 |
commit | 07155a084db111c0586ce7ed958c87eed6116704 (patch) | |
tree | e5e64cd58d20bdb2a0ad896403d8814f11018f52 /vendors/kses/kses.php | |
parent | 566de88eb3a15b58600f5195dc7b185b8aae0d41 (diff) | |
download | elgg-07155a084db111c0586ce7ed958c87eed6116704.tar.gz elgg-07155a084db111c0586ce7ed958c87eed6116704.tar.bz2 |
Closes #833: Kses now built as module
git-svn-id: https://code.elgg.org/elgg/trunk@3222 36083f99-b078-4883-b0ff-0f9b5a30f544
Diffstat (limited to 'vendors/kses/kses.php')
-rw-r--r-- | vendors/kses/kses.php | 555 |
1 files changed, 0 insertions, 555 deletions
diff --git a/vendors/kses/kses.php b/vendors/kses/kses.php deleted file mode 100644 index 65da29599..000000000 --- a/vendors/kses/kses.php +++ /dev/null @@ -1,555 +0,0 @@ -<?php - -# kses 0.2.2 - HTML/XHTML filter that only allows some elements and attributes -# Copyright (C) 2002, 2003, 2005 Ulf Harnhammar -# -# This program is free software and open source software; you can redistribute -# it and/or modify it under the terms of the GNU General Public License as -# published by the Free Software Foundation; either version 2 of the License, -# or (at your option) any later version. -# -# This program 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 General Public License for -# more details. -# -# You should have received a copy of the GNU General Public License along -# with this program; if not, write to the Free Software Foundation, Inc., -# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA or visit -# http://www.gnu.org/licenses/gpl.html -# -# *** CONTACT INFORMATION *** -# -# E-mail: metaur at users dot sourceforge dot net -# Web page: http://sourceforge.net/projects/kses -# Paper mail: Ulf Harnhammar -# Ymergatan 17 C -# 753 25 Uppsala -# SWEDEN -# -# [kses strips evil scripts!] - - -function kses($string, $allowed_html, $allowed_protocols = - array('http', 'https', 'ftp', 'news', 'nntp', 'telnet', - 'gopher', 'mailto')) -############################################################################### -# This function makes sure that only the allowed HTML element names, attribute -# names and attribute values plus only sane HTML entities will occur in -# $string. You have to remove any slashes from PHP's magic quotes before you -# call this function. -############################################################################### -{ - $string = kses_no_null($string); - $string = kses_js_entities($string); - $string = kses_normalize_entities($string); - $string = kses_hook($string); - $allowed_html_fixed = kses_array_lc($allowed_html); - return kses_split($string, $allowed_html_fixed, $allowed_protocols); -} # function kses - - -function kses_hook($string) -############################################################################### -# You add any kses hooks here. -############################################################################### -{ - return $string; -} # function kses_hook - - -function kses_version() -############################################################################### -# This function returns kses' version number. -############################################################################### -{ - return '0.2.2'; -} # function kses_version - - -function kses_split($string, $allowed_html, $allowed_protocols) -############################################################################### -# This function searches for HTML tags, no matter how malformed. It also -# matches stray ">" characters. -############################################################################### -{ - return preg_replace('%(<'. # EITHER: < - '[^>]*'. # things that aren't > - '(>|$)'. # > or end of string - '|>)%e', # OR: just a > - "kses_split2('\\1', \$allowed_html, ". - '$allowed_protocols)', - $string); -} # function kses_split - - -function kses_split2($string, $allowed_html, $allowed_protocols) -############################################################################### -# This function does a lot of work. It rejects some very malformed things -# like <:::>. It returns an empty string, if the element isn't allowed (look -# ma, no strip_tags()!). Otherwise it splits the tag into an element and an -# attribute list. -############################################################################### -{ - $string = kses_stripslashes($string); - - if (substr($string, 0, 1) != '<') - return '>'; - # It matched a ">" character - - if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches)) - return ''; - # It's seriously malformed - - $slash = trim($matches[1]); - $elem = $matches[2]; - $attrlist = $matches[3]; - - if (!@isset($allowed_html[strtolower($elem)])) - return ''; - # They are using a not allowed HTML element - - if ($slash != '') - return "<$slash$elem>"; - # No attributes are allowed for closing elements - - return kses_attr("$slash$elem", $attrlist, $allowed_html, - $allowed_protocols); -} # function kses_split2 - - -function kses_attr($element, $attr, $allowed_html, $allowed_protocols) -############################################################################### -# This function removes all attributes, if none are allowed for this element. -# If some are allowed it calls kses_hair() to split them further, and then it -# builds up new HTML code from the data that kses_hair() returns. It also -# removes "<" and ">" characters, if there are any left. One more thing it -# does is to check if the tag has a closing XHTML slash, and if it does, -# it puts one in the returned code as well. -############################################################################### -{ -# Is there a closing XHTML slash at the end of the attributes? - - $xhtml_slash = ''; - if (preg_match('%\s/\s*$%', $attr)) - $xhtml_slash = ' /'; - -# Are any attributes allowed at all for this element? - - if (@count($allowed_html[strtolower($element)]) == 0) - return "<$element$xhtml_slash>"; - -# Split it - - $attrarr = kses_hair($attr, $allowed_protocols); - -# Go through $attrarr, and save the allowed attributes for this element -# in $attr2 - - $attr2 = ''; - - foreach ($attrarr as $arreach) - { - if (!@isset($allowed_html[strtolower($element)] - [strtolower($arreach['name'])])) - continue; # the attribute is not allowed - - $current = $allowed_html[strtolower($element)] - [strtolower($arreach['name'])]; - - if (!is_array($current)) - $attr2 .= ' '.$arreach['whole']; - # there are no checks - - else - { - # there are some checks - $ok = true; - foreach ($current as $currkey => $currval) - if (!kses_check_attr_val($arreach['value'], $arreach['vless'], - $currkey, $currval)) - { $ok = false; break; } - - if ($ok) - $attr2 .= ' '.$arreach['whole']; # it passed them - } # if !is_array($current) - } # foreach - -# Remove any "<" or ">" characters - - $attr2 = preg_replace('/[<>]/', '', $attr2); - - return "<$element$attr2$xhtml_slash>"; -} # function kses_attr - - -function kses_hair($attr, $allowed_protocols) -############################################################################### -# This function does a lot of work. It parses an attribute list into an array -# with attribute data, and tries to do the right thing even if it gets weird -# input. It will add quotes around attribute values that don't have any quotes -# or apostrophes around them, to make it easier to produce HTML code that will -# conform to W3C's HTML specification. It will also remove bad URL protocols -# from attribute values. -############################################################################### -{ - $attrarr = array(); - $mode = 0; - $attrname = ''; - -# Loop through the whole attribute list - - while (strlen($attr) != 0) - { - $working = 0; # Was the last operation successful? - - switch ($mode) - { - case 0: # attribute name, href for instance - - if (preg_match('/^([-a-zA-Z]+)/', $attr, $match)) - { - $attrname = $match[1]; - $working = $mode = 1; - $attr = preg_replace('/^[-a-zA-Z]+/', '', $attr); - } - - break; - - case 1: # equals sign or valueless ("selected") - - if (preg_match('/^\s*=\s*/', $attr)) # equals sign - { - $working = 1; $mode = 2; - $attr = preg_replace('/^\s*=\s*/', '', $attr); - break; - } - - if (preg_match('/^\s+/', $attr)) # valueless - { - $working = 1; $mode = 0; - $attrarr[] = array - ('name' => $attrname, - 'value' => '', - 'whole' => $attrname, - 'vless' => 'y'); - $attr = preg_replace('/^\s+/', '', $attr); - } - - break; - - case 2: # attribute value, a URL after href= for instance - - if (preg_match('/^"([^"]*)"(\s+|$)/', $attr, $match)) - # "value" - { - $thisval = kses_bad_protocol($match[1], $allowed_protocols); - - $attrarr[] = array - ('name' => $attrname, - 'value' => $thisval, - 'whole' => "$attrname=\"$thisval\"", - 'vless' => 'n'); - $working = 1; $mode = 0; - $attr = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr); - break; - } - - if (preg_match("/^'([^']*)'(\s+|$)/", $attr, $match)) - # 'value' - { - $thisval = kses_bad_protocol($match[1], $allowed_protocols); - - $attrarr[] = array - ('name' => $attrname, - 'value' => $thisval, - 'whole' => "$attrname='$thisval'", - 'vless' => 'n'); - $working = 1; $mode = 0; - $attr = preg_replace("/^'[^']*'(\s+|$)/", '', $attr); - break; - } - - if (preg_match("%^([^\s\"']+)(\s+|$)%", $attr, $match)) - # value - { - $thisval = kses_bad_protocol($match[1], $allowed_protocols); - - $attrarr[] = array - ('name' => $attrname, - 'value' => $thisval, - 'whole' => "$attrname=\"$thisval\"", - 'vless' => 'n'); - # We add quotes to conform to W3C's HTML spec. - $working = 1; $mode = 0; - $attr = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr); - } - - break; - } # switch - - if ($working == 0) # not well formed, remove and try again - { - $attr = kses_html_error($attr); - $mode = 0; - } - } # while - - if ($mode == 1) - # special case, for when the attribute list ends with a valueless - # attribute like "selected" - $attrarr[] = array - ('name' => $attrname, - 'value' => '', - 'whole' => $attrname, - 'vless' => 'y'); - - return $attrarr; -} # function kses_hair - - -function kses_check_attr_val($value, $vless, $checkname, $checkvalue) -############################################################################### -# This function performs different checks for attribute values. The currently -# implemented checks are "maxlen", "minlen", "maxval", "minval" and "valueless" -# with even more checks to come soon. -############################################################################### -{ - $ok = true; - - switch (strtolower($checkname)) - { - case 'maxlen': - # The maxlen check makes sure that the attribute value has a length not - # greater than the given value. This can be used to avoid Buffer Overflows - # in WWW clients and various Internet servers. - - if (strlen($value) > $checkvalue) - $ok = false; - break; - - case 'minlen': - # The minlen check makes sure that the attribute value has a length not - # smaller than the given value. - - if (strlen($value) < $checkvalue) - $ok = false; - break; - - case 'maxval': - # The maxval check does two things: it checks that the attribute value is - # an integer from 0 and up, without an excessive amount of zeroes or - # whitespace (to avoid Buffer Overflows). It also checks that the attribute - # value is not greater than the given value. - # This check can be used to avoid Denial of Service attacks. - - if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value)) - $ok = false; - if ($value > $checkvalue) - $ok = false; - break; - - case 'minval': - # The minval check checks that the attribute value is a positive integer, - # and that it is not smaller than the given value. - - if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value)) - $ok = false; - if ($value < $checkvalue) - $ok = false; - break; - - case 'valueless': - # The valueless check checks if the attribute has a value - # (like <a href="blah">) or not (<option selected>). If the given value - # is a "y" or a "Y", the attribute must not have a value. - # If the given value is an "n" or an "N", the attribute must have one. - - if (strtolower($checkvalue) != $vless) - $ok = false; - break; - } # switch - - return $ok; -} # function kses_check_attr_val - - -function kses_bad_protocol($string, $allowed_protocols) -############################################################################### -# This function removes all non-allowed protocols from the beginning of -# $string. It ignores whitespace and the case of the letters, and it does -# understand HTML entities. It does its work in a while loop, so it won't be -# fooled by a string like "javascript:javascript:alert(57)". -############################################################################### -{ - $string = kses_no_null($string); - $string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature" - $string2 = $string.'a'; - - while ($string != $string2) - { - $string2 = $string; - $string = kses_bad_protocol_once($string, $allowed_protocols); - } # while - - return $string; -} # function kses_bad_protocol - - -function kses_no_null($string) -############################################################################### -# This function removes any NULL characters in $string. -############################################################################### -{ - $string = preg_replace('/\0+/', '', $string); - $string = preg_replace('/(\\\\0)+/', '', $string); - - return $string; -} # function kses_no_null - - -function kses_stripslashes($string) -############################################################################### -# This function changes the character sequence \" to just " -# It leaves all other slashes alone. It's really weird, but the quoting from -# preg_replace(//e) seems to require this. -############################################################################### -{ - return preg_replace('%\\\\"%', '"', $string); -} # function kses_stripslashes - - -function kses_array_lc($inarray) -############################################################################### -# This function goes through an array, and changes the keys to all lower case. -############################################################################### -{ - $outarray = array(); -
- if (sizeof($inarray)) - foreach ($inarray as $inkey => $inval) - { - $outkey = strtolower($inkey); - $outarray[$outkey] = array(); - - foreach ($inval as $inkey2 => $inval2) - { - $outkey2 = strtolower($inkey2); - $outarray[$outkey][$outkey2] = $inval2; - } # foreach $inval - } # foreach $inarray - - return $outarray; -} # function kses_array_lc - - -function kses_js_entities($string) -############################################################################### -# This function removes the HTML JavaScript entities found in early versions of -# Netscape 4. -############################################################################### -{ - return preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string); -} # function kses_js_entities - - -function kses_html_error($string) -############################################################################### -# This function deals with parsing errors in kses_hair(). The general plan is -# to remove everything to and including some whitespace, but it deals with -# quotes and apostrophes as well. -############################################################################### -{ - return preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $string); -} # function kses_html_error - - -function kses_bad_protocol_once($string, $allowed_protocols) -############################################################################### -# This function searches for URL protocols at the beginning of $string, while -# handling whitespace and HTML entities. -############################################################################### -{ - return preg_replace('/^((&[^;]*;|[\sA-Za-z0-9])*)'. - '(:|:|&#[Xx]3[Aa];)\s*/e', - 'kses_bad_protocol_once2("\\1", $allowed_protocols)', - $string); -} # function kses_bad_protocol_once - - -function kses_bad_protocol_once2($string, $allowed_protocols) -############################################################################### -# This function processes URL protocols, checks to see if they're in the white- -# list or not, and returns different data depending on the answer. -############################################################################### -{ - $string2 = kses_decode_entities($string); - $string2 = preg_replace('/\s/', '', $string2); - $string2 = kses_no_null($string2); - $string2 = preg_replace('/\xad+/', '', $string2); - # deals with Opera "feature" - $string2 = strtolower($string2); - - $allowed = false; - foreach ($allowed_protocols as $one_protocol) - if (strtolower($one_protocol) == $string2) - { - $allowed = true; - break; - } - - if ($allowed) - return "$string2:"; - else - return ''; -} # function kses_bad_protocol_once2 - - -function kses_normalize_entities($string) -############################################################################### -# This function normalizes HTML entities. It will convert "AT&T" to the correct -# "AT&T", ":" to ":", "&#XYZZY;" to "&#XYZZY;" and so on. -############################################################################### -{ -# Disarm all entities by converting & to & - - // $string = str_replace('&', '&', $string); // [Marcus Povey 20090212: Commented out in ref #561. Needs a better solution. ] - -# Change back the allowed entities in our entity whitelist - - $string = preg_replace('/&([A-Za-z][A-Za-z0-9]{0,19});/', - '&\\1;', $string); - $string = preg_replace('/&#0*([0-9]{1,5});/e', - 'kses_normalize_entities2("\\1")', $string); - $string = preg_replace('/&#([Xx])0*(([0-9A-Fa-f]{2}){1,2});/', - '&#\\1\\2;', $string); - - return $string; -} # function kses_normalize_entities - - -function kses_normalize_entities2($i) -############################################################################### -# This function helps kses_normalize_entities() to only accept 16 bit values -# and nothing more for &#number; entities. -############################################################################### -{ - return (($i > 65535) ? "&#$i;" : "&#$i;"); -} # function kses_normalize_entities2 - - -function kses_decode_entities($string) -############################################################################### -# This function decodes numeric HTML entities (A and A). It doesn't -# do anything with other entities like ä, but we don't need them in the -# URL protocol whitelisting system anyway. -############################################################################### -{ - $string = preg_replace('/&#([0-9]+);/e', 'chr("\\1")', $string); - $string = preg_replace('/&#[Xx]([0-9A-Fa-f]+);/e', 'chr(hexdec("\\1"))', - $string); - - return $string; -} # function kses_decode_entities - -?> |