[geeklog-devtalk] geeklog-devel digest, Vol 1 #494 - 1 msg
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Thu Jan 27 15:32:00 EST 2005
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Today's Topics:
1. kses PHP5 (actual attachment) (Tony Bibbs)
--__--__--
Message: 1
Date: Thu, 27 Jan 2005 14:30:26 -0600
From: Tony Bibbs <tony at tonybibbs.com>
To: geeklog-devel at lists.geeklog.net
Subject: [geeklog-devel] kses PHP5 (actual attachment)
Reply-To: geeklog-devel at lists.geeklog.net
This is a multi-part message in MIME format.
--------------020001000008050001080105
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sorry, my last email didn't include the attachment properly
-------- Original Message --------
Subject: Re: [Fwd: {Filename?} Re: Kses for PHP5?]
Date: Thu, 27 Jan 2005 14:30:20 -0600 (CST)
From: Chaos.org Webmaster <webfella at chaos.org>
Reply-To: webfella at chaos.org
To: Tony Bibbs <tony at tonybibbs.com>
On Thu, 27 Jan 2005, Tony Bibbs wrote:
| The updated php script got filtered out. Please try and resend or get
| me a URL where I can pull it down.
Oops. Let's try this again then.
Richard
--------------020001000008050001080105
Content-Type: TEXT/PLAIN;
name="kses.php5"
Content-Transfer-Encoding: 8bit
Content-Disposition: inline;
filename="kses.php5"
<?php
/*
* ==========================================================================================
*
* 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
*
* ==========================================================================================
*/
/**
* Class file for PHP5 OOP version of kses
*
* This is an updated version of kses to work with PHP5 that works under E_STRICT.
*
* This version is a bit of a rewrite to match my own coding style and use some of the
* capabilities allowed in PHP5. Since this was a significant rewrite, but it still
* maintains backward compatibility syntax-wise, the version number is now 1.0.0. Any
* minor changes that do not break compatibility will be indicated in the second or third
* digits. Anything that breaks compatibility will change the major version number.
*
* PHP5 specific changes:
* + Private methods are now in place
* + __construct() is now used rather then the standard class name 'kses()'
* + Kses will not load in any version less that PHP5
* Other modifications:
* + PHPdoc style documentation has been added to the class. See http://www.phpdoc.org/ for more info.
* + Method names have been changed to reflect status as verbs
* + One line methods have been folded into the code
* + Some methods are now deprecated due to nomenclature style change. See method documentation for specifics.
* + Kses5 now works in E_STRICT
* + Version number is 1.0.0 to reflect serious code changes
* + Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol(), RemoveProtocols() and SetProtocols()
* + Deprecated _hook(), Protocols()
*
* @package kses
* @subpackage kses5
*/
if(substr(phpversion(), 0, 1) < 5)
{
die("Class kses requires PHP 5 or higher.");
}
/**
* Only install KSES5 once
*/
if(!defined('KSES_CLASS_PHP5'))
{
define('KSES_CLASS_PHP5', true);
/**
* Kses strips evil scripts!
*
* This class provides the capability for removing unwanted HTML/XHTML, attributes from
* tags, and protocols contained in links. The net result is a much more powerful tool
* than the PHP internal strip_tags()
*
* This is a fork of a slick piece of procedural code called 'kses' written by Ulf Harnhammar.
*
* The original class for PHP4 was basically a wrapper around all of the functions in
* the procedural code written by Ulf, and was released 7/25/2003.
*
* This version is a bit of a rewrite to match my own coding style and use some of the
* capabilities allowed in PHP5. Since this was a significant rewrite, but it still
* maintains backward compatibility syntax-wise, the version number is now 1.0.0. Any
* minor changes that do not break compatibility will be indicated in the second or third
* digits. Anything that breaks compatibility will change the major version number.
*
* PHP5 specific changes:
* + Private methods are now in place
* + __construct() is now used rather then the standard class name 'kses()'
* + Kses5 will not load in any version less that PHP5
* Other modifications:
* + PHPdoc style documentation has been added to the class. See http://www.phpdoc.org/ for more info.
* + Method names have been changed to reflect status as verbs
* + One line methods have been folded into the code
* + Some methods are now deprecated due to nomenclature style change. See method documentation for specifics.
* + Kses now works in E_STRICT
* + Initial Version number set to 1.0.0 to reflect serious code changes
* + Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol(), RemoveProtocols() and SetProtocols()
* + Deprecated _hook(), Protocols()
*
* @author Richard R. Vásquez, Jr. (Original procedural code by Ulf Härnhammar)
* @link http://sourceforge.net/projects/kses/ Home Page for Kses
* @link http://chaos.org/contact/ Contact page with current email address for Richard Vasquez
* @copyright Richard R. Vásquez, Jr. 2005
* @version PHP5 OOP 1.0.1
* @license http://www.gnu.org/licenses/gpl.html GNU Public License
* @package kses
*/
class kses5
{
/**#@+
* @access private
* @var array
*/
private $allowed_protocols;
private $allowed_html;
/**#@-*/
/**
* Constructor for kses.
*
* This sets a default collection of protocols allowed in links, and creates an
* empty set of allowed HTML tags.
* @since PHP5 OOP 1.0.0
*/
public function __construct()
{
/**
* You could add protocols such as ftp, new, gopher, mailto, irc, etc.
*
* The base values the original kses provided were:
* 'http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'gopher', 'mailto'
*/
$this->allowed_protocols = array('http', 'ftp', 'mailto');
$this->allowed_html = array();
}
/**
* Basic task of kses - parses $string and strips it as required.
*
* This method strips all the disallowed (X)HTML tags, attributes
* and protocols from the input $string.
*
* @access public
* @param string $string String to be stripped of 'evil scripts'
* @return string The stripped string
* @since PHP4 OOP 0.0.1
*/
public function Parse($string = "")
{
if (get_magic_quotes_gpc())
{
$string = stripslashes($string);
}
$string = $this->removeNulls($string);
// Remove JavaScript entities from early Netscape 4 versions
$string = preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string);
$string = $this->normalizeEntities($string);
$string = $this->filterKsesTextHook($string);
$string = preg_replace('%(<' . '[^>]*' . '(>|$)' . '|>)%e', "\$this->stripTags('\\1')", $string);
return $string;
}
/**
* Allows for single/batch addition of protocols
*
* This method accepts one argument that can be either a string
* or an array of strings. Invalid data will be ignored.
*
* The argument will be processed, and each string will be added
* via AddProtocol().
*
* @access public
* @param mixed , A string or array of protocols that will be added to the internal list of allowed protocols.
* @return bool Status of adding valid protocols.
* @see AddProtocol()
* @since PHP5 OOP 1.0.0
*/
public function AddProtocols()
{
$c_args = func_num_args();
if($c_args != 1)
{
trigger_error("kses::AddProtocols() did not receive an argument.", E_USER_WARNING);
return false;
}
$protocol_data = func_get_arg(0);
if(is_array($protocol_data) && count($protocol_data) > 0)
{
foreach($protocol_data as $protocol)
{
$this->AddProtocol($protocol);
}
return true;
}
elseif(is_string($protocol_data))
{
$this->AddProtocol($protocol_data);
return true;
}
else
{
trigger_error("kses::AddProtocols() did not receive a string or an array.", E_USER_WARNING);
return false;
}
}
/**
* Allows for single/batch addition of protocols
*
* @deprecated Use AddProtocols()
* @see AddProtocols()
* @return bool
* @since PHP4 OOP 0.0.1
*/
public function Protocols()
{
$c_args = func_num_args();
if($c_args != 1)
{
trigger_error("kses::Protocols() did not receive an argument.", E_USER_WARNING);
return false;
}
return $this->AddProtocols(func_get_arg(0));
}
/**
* Adds a single protocol to $this->allowed_protocols.
*
* This method accepts a string argument and adds it to
* the list of allowed protocols to keep when performing
* Parse().
*
* @access public
* @param string $protocol The name of the protocol to be added.
* @return bool Status of adding valid protocol.
* @since PHP4 OOP 0.0.1
*/
public function AddProtocol($protocol = "")
{
if(!is_string($protocol))
{
trigger_error("kses::AddProtocol() requires a string.", E_USER_WARNING);
return false;
}
// Remove any inadvertent ':' at the end of the protocol.
if(substr($protocol, strlen($protocol) - 1, 1) == ":")
{
$protocol = substr($protocol, 0, strlen($protocol) - 1);
}
$protocol = strtolower(trim($protocol));
if($protocol == "")
{
trigger_error("kses::AddProtocol() tried to add an empty/NULL protocol.", E_USER_WARNING);
return false;
}
// prevent duplicate protocols from being added.
if(!in_array($protocol, $this->allowed_protocols))
{
array_push($this->allowed_protocols, $protocol);
sort($this->allowed_protocols);
}
return true;
}
/**
* Removes a single protocol from $this->allowed_protocols.
*
* This method accepts a string argument and removes it from
* the list of allowed protocols to keep when performing
* Parse().
*
* @access public
* @param string $protocol The name of the protocol to be removed.
* @return bool Status of removing valid protocol.
* @since PHP5 OOP 1.0.0
*/
public function RemoveProtocol($protocol = "")
{
if(!is_string($protocol))
{
trigger_error("kses::RemoveProtocol() requires a string.", E_USER_WARNING);
return false;
}
// Remove any inadvertent ':' at the end of the protocol.
if(substr($protocol, strlen($protocol) - 1, 1) == ":")
{
$protocol = substr($protocol, 0, strlen($protocol) - 1);
}
$protocol = strtolower(trim($protocol));
if($protocol == "")
{
trigger_error("kses::RemoveProtocol() tried to remove an empty/NULL protocol.", E_USER_WARNING);
return false;
}
// Ensures that the protocol exists before removing it.
if(in_array($protocol, $this->allowed_protocols))
{
$this->allowed_protocols = array_diff($this->allowed_protocols, $protocol);
sort($this->allowed_protocols);
}
return true;
}
/**
* Allows for single/batch removal of protocols
*
* This method accepts one argument that can be either a string
* or an array of strings. Invalid data will be ignored.
*
* The argument will be processed, and each string will be removed
* via RemoveProtocol().
*
* @access public
* @param mixed , A string or array of protocols that will be removed from the internal list of allowed protocols.
* @return bool Status of removing valid protocols.
* @see RemoveProtocol()
* @since PHP5 OOP 1.0.0
*/
public function RemoveProtocols()
{
$c_args = func_num_args();
if($c_args != 1)
{
return false;
}
$protocol_data = func_get_arg(0);
if(is_array($protocol_data) && count($protocol_data) > 0)
{
foreach($protocol_data as $protocol)
{
$this->RemoveProtocol($protocol);
}
}
elseif(is_string($protocol_data))
{
$this->RemoveProtocol($protocol_data);
return true;
}
else
{
trigger_error("kses::RemoveProtocols() did not receive a string or an array.", E_USER_WARNING);
return false;
}
}
/**
* Allows for single/batch replacement of protocols
*
* This method accepts one argument that can be either a string
* or an array of strings. Invalid data will be ignored.
*
* Existing protocols will be removed, then the argument will be
* processed, and each string will be added via AddProtocol().
*
* @access public
* @param mixed , A string or array of protocols that will be the new internal list of allowed protocols.
* @return bool Status of replacing valid protocols.
* @since PHP5 OOP 1.0.1
* @see AddProtocol()
*/
public function SetProtocols()
{
$c_args = func_num_args();
if($c_args != 1)
{
trigger_error("kses::SetProtocols() did not receive an argument.", E_USER_WARNING);
return false;
}
$protocol_data = func_get_arg(0);
if(is_array($protocol_data) && count($protocol_data) > 0)
{
$this->allowed_protocols = array();
foreach($protocol_data as $protocol)
{
$this->AddProtocol($protocol);
}
return true;
}
elseif(is_string($protocol_data))
{
$this->allowed_protocols = array();
$this->AddProtocol($protocol_data);
return true;
}
else
{
trigger_error("kses::SetProtocols() did not receive a string or an array.", E_USER_WARNING);
return false;
}
}
/**
* Adds valid (X)HTML with corresponding attributes that will be kept when stripping 'evil scripts'.
*
* This method accepts one argument that can be either a string
* or an array of strings. Invalid data will be ignored.
*
* @access public
* @param string $tag (X)HTML tag that will be allowed after stripping text.
* @param array $attribs Associative array of allowed attributes - key => attribute name - value => attribute parameter
* @return bool Status of Adding (X)HTML and attributes.
* @since PHP4 OOP 0.0.1
*/
public function AddHTML($tag = "", $attribs = array())
{
if(!is_string($tag))
{
trigger_error("kses::AddHTML() requires the tag to be a string", E_USER_WARNING);
return false;
}
$tag = strtolower(trim($tag));
if($tag == "")
{
trigger_error("kses::AddHTML() tried to add an empty/NULL tag", E_USER_WARNING);
return false;
}
if(!is_array($attribs))
{
trigger_error("kses::AddHTML() requires an array (even an empty one) of attributes for '$tag'", E_USER_WARNING);
return false;
}
$new_attribs = array();
if(is_array($attribs) && count($attribs) > 0)
{
foreach($attribs as $idx1 => $val1)
{
$new_idx1 = strtolower($idx1);
$new_val1 = $attribs[$idx1];
if(is_array($new_val1) && count($attribs) > 0)
{
$tmp_val = array();
foreach($new_val1 as $idx2 => $val2)
{
$new_idx2 = strtolower($idx2);
$tmp_val[$new_idx2] = $val2;
}
$new_val1 = $tmp_val;
}
$new_attribs[$new_idx1] = $new_val1;
}
}
$this->allowed_html[$tag] = $new_attribs;
return true;
}
/**
* This method removes any NULL or chr(173) characters in $string.
*
* @access private
* @param string $string
* @return string String without any NULL/chr(173)
* @since PHP4 OOP 0.0.1
*/
private function removeNulls($string)
{
$string = preg_replace('/\0+/', '', $string);
$string = preg_replace('/(\\\\0)+/', '', $string);
$string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"
return $string;
}
/**
* Normalizes HTML entities
*
* This function normalizes HTML entities. It will convert "AT&T" to the correct
* "AT&T", ":" to ":", "&#XYZZY;" to "&#XYZZY;" and so on.
*
* @access private
* @param string $string
* @return string String with normalized entities
* @since PHP4 OOP 0.0.1
*/
private function normalizeEntities($string)
{
# Disarm all entities by converting & to &
$string = str_replace('&', '&', $string);
# TODO: Change back (Keep?) the allowed entities in our entity white list
# Keeps entities that start with [A-Za-z]
$string = preg_replace(
'/&([A-Za-z][A-Za-z0-9]{0,19});/',
'&\\1;',
$string
);
# Change numeric entities to valid 16 bit values
$string = preg_replace(
'/&#0*([0-9]{1,5});/e',
'\$this->normalizeEntities16bit("\\1")',
$string
);
# Change &XHHHHHHH (Hex digits) to 16 bit hex values
$string = preg_replace(
'/&#([Xx])0*(([0-9A-Fa-f]{2}){1,2});/',
'&#\\1\\2;',
$string
);
return $string;
}
/**
* Helper method used by normalizeEntites()
*
* This method helps normalizeEntities() to only accept 16 bit values
* and nothing more for &#number; entities.
*
* This method helps normalize_entities() during a preg_replace()
* where a &#(0)*XXXXX; occurs. The '(0)*XXXXXX' value is converted to
* a number and the result is returned as a numeric entity if the number
* is less than 65536. Otherwise, the value is returned 'as is'.
*
* @access private
* @param string $i
* @return string Normalized numeric entity
* @see normalizeEntities()
* @since PHP4 OOP 0.0.1
*/
private function normalizeEntities16bit($i)
{
return (($i > 65535) ? "&#$i;" : "&#$i;");
}
/**
* Allows for additional user defined modifications to text.
*
* This method allows for additional modifications to be performed on
* a string that's being run through Parse(). Currently, it returns the
* input string 'as is'.
*
* This method is provided for users to extend the kses class for their own
* requirements.
*
* @access public
* @param string $string String to perfrom additional modifications on.
* @return string User modified string.
* @see Parse()
* @since PHP5 OOP 1.0.0
*/
private function filterKsesTextHook($string)
{
return $string;
}
/**
* Allows for additional user defined modifications to text.
*
* @deprecated use filterKsesTextHook()
* @param string $string
* @return string
* @see filterKsesTextHook()
* @since PHP4 OOP 0.0.1
*/
private function _hook($string)
{
return $this->filterKsesTextHook($string);
}
/**
* This method goes through an array, and changes the keys to all lower case.
*
* @access private
* @param array $in_array Associative array
* @return array Modified array
* @since PHP4 OOP 0.0.1
*/
private function makeArrayKeysLowerCase($in_array)
{
$out_array = array();
if(is_array($in_array) && count($in_array) > 0)
{
foreach ($in_array as $in_key => $in_val)
{
$out_key = strtolower($in_key);
$out_array[$out_key] = array();
if(is_array($in_val) && count($in_val) > 0)
{
foreach ($in_val as $in_key2 => $in_val2)
{
$out_key2 = strtolower($in_key2);
$out_array[$out_key][$out_key2] = $in_val2;
}
}
}
}
return $out_array;
}
/**
* This method strips out disallowed and/or mangled (X)HTML tags along with assigned attributes.
*
* This method 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
* allowed attribute list.
*
* @access private
* @param string $string
* @return string Modified string minus disallowed/mangled (X)HTML and attributes
* @since PHP4 OOP 0.0.1
*/
private function stripTags($string)
{
$string = preg_replace('%\\\\"%', '"', $string);
if (substr($string, 0, 1) != '<')
{
# It matched a ">" character
return '>';
}
if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
{
# It's seriously malformed
return '';
}
$slash = trim($matches[1]);
$elem = $matches[2];
$attrlist = $matches[3];
if (
!isset($this->allowed_html[strtolower($elem)]) ||
!is_array($this->allowed_html[strtolower($elem)]))
{
# Found an HTML element not in the white list
return '';
}
return $this->stripAttributes("$slash$elem", $attrlist);
}
/**
* This method strips out disallowed attributes for (X)HTML tags.
*
* This method removes all attributes if none are allowed for this element.
* If some are allowed it calls combAttributes() to split them further, and then it
* builds up new HTML code from the data that combAttributes() 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.
*
* @access private
* @param string $element (X)HTML tag to check
* @param string $attr Text containing attributes to check for validity.
* @return string Resulting valid (X)HTML or ''
* @see combAttributes()
* @since PHP4 OOP 0.0.1
*/
private function stripAttributes($element, $attr)
{
# Is there a closing XHTML slash at the end of the attributes?
$xhtml_slash = '';
if (preg_match('%\s/\s*$%', $attr))
{
$xhtml_slash = ' /';
}
# Are any attributes allowed at all for this element?
if (
!isset($this->allowed_html[strtolower($element)]) ||
count($this->allowed_html[strtolower($element)]) == 0
)
{
return "<$element$xhtml_slash>";
}
# Split it
$attrarr = $this->combAttributes($attr);
# Go through $attrarr, and save the allowed attributes for this element
# in $attr2
$attr2 = '';
if(is_array($attrarr) && count($attrarr) > 0)
{
foreach ($attrarr as $arreach)
{
if(!isset($this->allowed_html[strtolower($element)][strtolower($arreach['name'])]))
{
continue;
}
$current = $this->allowed_html[strtolower($element)][strtolower($arreach['name'])];
if (!is_array($current))
{
# there are no checks
$attr2 .= ' '.$arreach['whole'];
}
else
{
# there are some checks
$ok = true;
if(is_array($current) && count($current) > 0)
{
foreach ($current as $currkey => $currval)
{
if (!$this->checkAttributeValue($arreach['value'], $arreach['vless'], $currkey, $currval))
{
$ok = false;
break;
}
}
}
if ($ok)
{
# it passed them
$attr2 .= ' '.$arreach['whole'];
}
}
}
}
# Remove any "<" or ">" characters
$attr2 = preg_replace('/[<>]/', '', $attr2);
return "<$element$attr2$xhtml_slash>";
}
/**
* This method combs through an attribute list string and returns an associative array of attributes and values.
*
* This method 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.
*
* @access private
* @param string $attr Text containing tag attributes for parsing
* @return array Associative array containing data on attribute and value
* @since PHP4 OOP 0.0.1
*/
private function combAttributes($attr)
{
$attrarr = array();
$mode = 0;
$attrname = '';
# Loop through the whole attribute list
while (strlen($attr) != 0)
{
# Was the last operation successful?
$working = 0;
switch ($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 = $this->removeBadProtocols($match[1]);
$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 = $this->removeBadProtocols($match[1]);
$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 = $this->removeBadProtocols($match[1]);
$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;
$attr = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr);
}
break;
}
if ($working == 0) # not well formed, remove and try again
{
$attr = preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $attr);
$mode = 0;
}
}
# special case, for when the attribute list ends with a valueless
# attribute like "selected"
if ($mode == 1)
{
$attrarr[] = array(
'name' => $attrname,
'value' => '',
'whole' => $attrname,
'vless' => 'y'
);
}
return $attrarr;
}
/**
* This method removes disallowed protocols.
*
* This method 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)".
*
* @access private
* @param string $string String to check for protocols
* @return string String with removed protocols
* @since PHP4 OOP 0.0.1
*/
private function removeBadProtocols($string)
{
$string = $this->RemoveNulls($string);
$string2 = $string . 'a';
while ($string != $string2)
{
$string2 = $string;
$string = preg_replace(
'/^((&[^;]*;|[\sA-Za-z0-9])*)'.
'(:|:|&#[Xx]3[Aa];)\s*/e',
'\$this->filterProtocols("\\1")',
$string
);
}
return $string;
}
/**
* Helper method used by removeBadProtocols()
*
* 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.
*
* @access private
* @param string $string String to check for protocols
* @return string String with removed protocols
* @see removeBadProtocols()
* @since PHP4 OOP 0.0.1
*/
private function filterProtocols($string)
{
$string = $this->decodeEntities($string);
$string = preg_replace('/\s/', '', $string);
$string = $this->removeNulls($string);
$string = strtolower($string);
if(is_array($this->allowed_protocols) && count($this->allowed_protocols) > 0)
{
foreach ($this->allowed_protocols as $one_protocol)
{
if (strtolower($one_protocol) == $string)
{
return "$string:";
}
}
}
return '';
}
/**
* Controller method for performing checks on attribute values.
*
* This method calls the appropriate method as specified by $checkname with
* the parameters $value, $vless, and $checkvalue, and returns the result
* of the call.
*
* This method's functionality can be expanded by creating new methods
* that would match checkAttributeValue[$checkname].
*
* Current checks implemented are: "maxlen", "minlen", "maxval", "minval" and "valueless"
*
* @access private
* @param string $value The value of the attribute to be checked.
* @param string $vless Indicates whether the the value is supposed to be valueless
* @param string $checkname The check to be performed
* @param string $checkvalue The value that is to be checked against
* @return bool Indicates whether the check passed or not
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValue($value, $vless, $checkname, $checkvalue)
{
$ok = true;
$check_attribute_method_name = 'checkAttributeValue' . ucfirst(strtolower($checkname));
if(method_exists($this, $check_attribute_method_name))
{
$ok = $this->$check_attribute_method_name($value, $checkvalue, $vless);
}
return $ok;
}
/**
* Helper method invoked by checkAttributeValue().
*
* 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.
*
* @access private
* @param string $value The value of the attribute to be checked.
* @param int $checkvalue The maximum value allowed
* @return bool Indicates whether the check passed or not
* @see checkAttributeValue()
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValueMaxlen($value, $checkvalue)
{
if (strlen($value) > intval($checkvalue))
{
return false;
}
return true;
}
/**
* Helper method invoked by checkAttributeValue().
*
* The minlen check makes sure that the attribute value has a length not
* smaller than the given value.
*
* @access private
* @param string $value The value of the attribute to be checked.
* @param int $checkvalue The minimum value allowed
* @return bool Indicates whether the check passed or not
* @see checkAttributeValue()
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValueMinlen($value, $checkvalue)
{
if (strlen($value) < intval($checkvalue))
{
return false;
}
return true;
}
/**
* Helper method invoked by checkAttributeValue().
*
* 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.
*
* @access private
* @param int $value The value of the attribute to be checked.
* @param int $checkvalue The maximum numeric value allowed
* @return bool Indicates whether the check passed or not
* @see checkAttributeValue()
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValueMaxval($value, $checkvalue)
{
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
{
return false;
}
if (intval($value) > intval($checkvalue))
{
return false;
}
return true;
}
/**
* Helper method invoked by checkAttributeValue().
*
* The minval check checks that the attribute value is a positive integer,
* and that it is not smaller than the given value.
*
* @access private
* @param int $value The value of the attribute to be checked.
* @param int $checkvalue The minimum numeric value allowed
* @return bool Indicates whether the check passed or not
* @see checkAttributeValue()
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValueMinval($value, $checkvalue)
{
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
{
return false;
}
if (intval($value) < ($checkvalue))
{
return false;
}
return true;
}
/**
* Helper method invoked by checkAttributeValue().
*
* 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.
*
* @access private
* @param int $value The value of the attribute to be checked.
* @param mixed $checkvalue This variable is ignored for this test
* @param string $vless Flag indicating if this attribute is not supposed to have an attribute
* @return bool Indicates whether the check passed or not
* @see checkAttributeValue()
* @since PHP5 OOP 1.0.0
*/
private function checkAttributeValueValueless($value, $checkvalue, $vless)
{
if (strtolower($checkvalue) != $vless)
{
return false;
}
return true;
}
/**
* Decodes numeric HTML entities
*
* This method 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 white listing system anyway.
*
* @access private
* @param string $value The entitiy to be decoded.
* @return string Decoded entity
* @since PHP4 OOP 0.0.1
*/
private function decodeEntities($string)
{
$string = preg_replace('/&#([0-9]+);/e', 'chr("\\1")', $string);
$string = preg_replace('/&#[Xx]([0-9A-Fa-f]+);/e', 'chr(hexdec("\\1"))', $string);
return $string;
}
/**
* Returns PHP5 OOP version # of kses.
*
* Since this class has been refactored and documented and proven to work,
* I'm fixing the version number at 1.0.0.
*
* This version is syntax compatible with the PHP4 OOP version 0.0.2. Future
* versions may not be syntax compatible.
*
* @access public
* @return string Version number
* @since PHP4 OOP 0.0.1
*/
public function Version()
{
return 'PHP5 OOP 1.0.0';
}
}
}
?>
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