/common/libraries/plugin/kses-0.2.2/oop/php4.class.kses.php

<?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 PHP4 OOP version of kses

 *

 * This is an updated version of kses to work with PHP4 that works under E_STRICT.

 *

 * This upgrade provides the following:

 * + Version number synced to procedural version number

 * + PHPdoc style documentation has been added to the class.  See http://www.phpdoc.org/ for more info.

 * + Some methods are now deprecated due to nomenclature style change.  See method documentation for specifics.

 * + Kses4 now works in E_STRICT

 * + Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol() and RemoveProtocols()

 * + Deprecated _hook(), Protocols()

 * + Integrated code from kses 0.2.2 into class.

 * + Added methods DumpProtocols(), DumpMethods()

 *

 * @package    kses

 * @subpackage kses4

 */



if (substr(phpversion(), 0, 1) < 4)

{

    die("Class kses requires PHP 4 or higher.");

}



/**

 * Only install KSES4 once

 */

if (! defined('KSES_CLASS_PHP4'))

{

    define('KSES_CLASS_PHP4', 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 entire set of functions was wrapped in a PHP object with some internal modifications

     * by Richard Vasquez (http://www.chaos.org/) 7/25/2003

     *

     * This upgrade provides the following:

     * + Version number synced to procedural version number

     * + PHPdoc style documentation has been added to the class.  See http://www.phpdoc.org/ for more info.

     * + Some methods are now deprecated due to nomenclature style change.  See method documentation for specifics.

     * + Kses4 now works in E_STRICT

     * + Addition of methods AddProtocols(), filterKsestextHook(), RemoveProtocol(), RemoveProtocols() and SetProtocols()

     * + Deprecated _hook(), Protocols()

     * + Integrated code from kses 0.2.2 into class.

     *

     * @author     Richard R. V�squez, Jr. (Original procedural code by Ulf H�rnhammar)

     * @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. V�squez, Jr. 2003-2005

     * @version    PHP4 OOP 0.2.2

     * @license    http://www.gnu.org/licenses/gpl.html GNU Public License

     * @package    kses

     */

    class kses4

    {

        /**#@+

         * @access private

         * @var array

         */

        var $allowed_protocols = array();

        var $allowed_html = array();



        /**#@-*/

        

        /**

         * Constructor for kses.

         *

         * This sets a default collection of protocols allowed in links, and creates an

         * empty set of allowed HTML tags.

         * @since PHP4 OOP 0.0.1

         */

        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 0.2.1

         */

        function Parse($string = "")

        {

            if (get_magic_quotes_gpc())

            {

                $string = stripslashes($string);

            }

            $string = $this->_no_null($string);

            $string = $this->_js_entities($string);

            $string = $this->_normalize_entities($string);

            $string = $this->filterKsesTextHook($string);

            return $this->_split($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 PHP4 OOP 0.2.1

         */

        function AddProtocols()

        {

            $c_args = func_num_args();

            if ($c_args != 1)

            {

                trigger_error("kses4::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("kses4::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

         */

        function Protocols()

        {

            $c_args = func_num_args();

            if ($c_args != 1)

            {

                trigger_error("kses4::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

         */

        function AddProtocol($protocol = "")

        {

            if (! is_string($protocol))

            {

                trigger_error("kses4::AddProtocol() requires a string.", E_USER_WARNING);

                return false;

            }

            

            $protocol = strtolower(trim($protocol));

            if ($protocol == "")

            {

                trigger_error("kses4::AddProtocol() tried to add an empty/NULL protocol.", 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);

            }

            

            if (! in_array($protocol, $this->allowed_protocols))

            {

                array_push($this->allowed_protocols, $protocol);

                sort($this->allowed_protocols);

            }

            return true;

        }



        /**

         * 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 PHP4 OOP 0.2.2

         * @see AddProtocol()

         */

        function SetProtocols()

        {

            $c_args = func_num_args();

            if ($c_args != 1)

            {

                trigger_error("kses4::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("kses4::SetProtocols() did not receive a string or an array.", E_USER_WARNING);

                return false;

            }

        }



        /**

         * Raw dump of allowed protocols

         *

         * This returns an indexed array of allowed protocols for a particular KSES

         * instantiation.

         *

         * @access public

         * @return array The list of allowed protocols.

         * @since PHP4 OOP 0.2.2

         */

        function DumpProtocols()

        {

            return $this->allowed_protocols;

        }



        /**

         * Raw dump of allowed (X)HTML elements

         *

         * This returns an indexed array of allowed (X)HTML elements and attributes

         * for a particular KSES instantiation.

         *

         * @access public

         * @return array The list of allowed elements.

         * @since PHP4 OOP 0.2.2

         */

        function DumpElements()

        {

            return $this->allowed_html;

        }



        /**

         * 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

         */

        function AddHTML($tag = "", $attribs = array())

        {

            if (! is_string($tag))

            {

                trigger_error("kses4::AddHTML() requires the tag to be a string", E_USER_WARNING);

                return false;

            }

            

            $tag = strtolower(trim($tag));

            if ($tag == "")

            {

                trigger_error("kses4::AddHTML() tried to add an empty/NULL tag", E_USER_WARNING);

                return false;

            }

            

            if (! is_array($attribs))

            {

                trigger_error("kses4::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($new_val1) && count($new_val1) > 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;

        }



        /**

         * 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 PHP4 OOP 0.2.1

         */

        function RemoveProtocol($protocol = "")

        {

            if (! is_string($protocol))

            {

                trigger_error("kses4::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("kses4::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, array($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 0.2.1

         */

        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("kses4::RemoveProtocols() did not receive a string or an array.", E_USER_WARNING);

                return false;

            }

        }



        /**

         * This method removes any NULL or characters in $string.

         *

         * @access private

         * @param string $string

         * @return string String without any NULL/chr(173)

         * @since PHP4 OOP 0.0.1

         */

        function _no_null($string)

        {

            $string = preg_replace('/\0+/', '', $string);

            $string = preg_replace('/(\\\\0)+/', '', $string);

            return $string;

        }



        /**

         * This function removes the HTML JavaScript entities found in early versions of

         * Netscape 4.

         *

         * @access private

         * @param string $string

         * @return string String without any NULL/chr(173)

         * @since PHP4 OOP 0.0.1

         */

        function _js_entities($string)

        {

            return preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string);

        }



        /**

         * Normalizes HTML entities

         *

         * This function normalizes HTML entities. It will convert "AT&T" to the correct

         * "AT&amp;T", "&#00058;" to "&#58;", "&#XYZZY;" to "&amp;#XYZZY;" and so on.

         *

         * @access private

         * @param string $string

         * @return string String with normalized entities

         * @since PHP4 OOP 0.0.1

         */

        function _normalize_entities($string)

        {

            # Disarm all entities by converting & to &amp;

            $string = str_replace('&', '&amp;', $string);

            

            # Change back the allowed entities in our entity white list

            



            $string = preg_replace('/&amp;([A-Za-z][A-Za-z0-9]{0,19});/', '&\\1;', $string);

            $string = preg_replace('/&amp;#0*([0-9]{1,5});/e', '\$this->_normalize_entities2("\\1")', $string);

            $string = preg_replace('/&amp;#([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 _normalize_entities()

         * @since PHP4 OOP 0.0.1

         */

        function _normalize_entities2($i)

        {

            return (($i > 65535) ? "&amp;#$i;" : "&#$i;");

        }



        /**

         * Allows for additional user defined modifications to text.

         *

         * @deprecated use filterKsesTextHook()

         * @param string $string

         * @see filterKsesTextHook()

         * @return string

         * @since PHP4 OOP 0.0.1

         */

        function _hook($string)

        {

            return $this->filterKsesTextHook($string);

        }



        /**

         * 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

         */

        function filterKsesTextHook($string)

        {

            return $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

         */

        function _array_lc($inarray)

        {

            $outarray = array();

            

            if (is_array($inarray) && count($inarray) > 0)

            {

                foreach ($inarray as $inkey => $inval)

                {

                    $outkey = strtolower($inkey);

                    $outarray[$outkey] = array();

                    

                    if (is_array($inval) && count($inval) > 0)

                    {

                        foreach ($inval as $inkey2 => $inval2)

                        {

                            $outkey2 = strtolower($inkey2);

                            $outarray[$outkey][$outkey2] = $inval2;

                        }

                    }

                }

            }

            

            return $outarray;

        }



        /**

         * This method searched for HTML tags, no matter how malformed.  It also

         * matches stray ">" characters.

         *

         * @access private

         * @param string $string

         * @return string HTML tags

         * @since PHP4 OOP 0.0.1

         */

        function _split($string)

        {

            return preg_replace('%(<' . # EITHER: <

'[^>]*' . # things that aren't >

'(>|$)' . # > or end of string

'|>)%e', # OR: just a >

"\$this->_split2('\\1')", $string);

        }



        /**

         * 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

         */

        function _split2($string)

        {

            $string = $this->_stripslashes($string);

            

            if (substr($string, 0, 1) != '<')

            {

                # It matched a ">" character

                return '&gt;';

            }

            

            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)]))

            {

                # They are using a not allowed HTML element

                return '';

            }

            

            if ($slash != '')

            {

                return "<$slash$elem>";

            }

            # No attributes are allowed for closing elements

            



            return $this->_attr("$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 $this->_hair() to split them further, and then it

         * builds up new HTML code from the data that $this->_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.

         *

         * @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 _hair()

         * @since PHP4 OOP 0.0.1

         */

        function _attr($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 = $this->_hair($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 ($current == '')

                    {

                        # the attribute is not allowed

                        continue;

                    }

                    

                    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 (! $this->_check_attr_val($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

         */

        function _hair($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 = $this->_bad_protocol($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 = $this->_bad_protocol($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 = $this->_bad_protocol($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 = $this->_html_error($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

         */

        function _bad_protocol($string)

        {

            $string = $this->_no_null($string);

            $string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"

            $string2 = $string . 'a';

            

            while ($string != $string2)

            {

                $string2 = $string;

                $string = $this->_bad_protocol_once($string);

            } # while

            



            return $string;

        }



        /**

         * Helper method used by _bad_protocol()

         *

         * This function searches for URL protocols at the beginning of $string, while

         * handling whitespace and HTML entities.

         *

         * @access private

         * @param string $string String to check for protocols

         * @return string String with removed protocols

         * @see _bad_protocol()

         * @since PHP4 OOP 0.0.1

         */

        function _bad_protocol_once($string)

        {

            return preg_replace('/^((&[^;]*;|[\sA-Za-z0-9])*)' . '(:|&#58;|&#[Xx]3[Aa];)\s*/e', '\$this->_bad_protocol_once2("\\1")', $string);

        }



        /**

         * Helper method used by _bad_protocol_once() regex

         *

         * 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 _bad_protocol()

         * @see _bad_protocol_once()

         * @since PHP4 OOP 0.0.1

         */

        function _bad_protocol_once2($string)

        {

            $string = $this->_decode_entities($string);

            $string = preg_replace('/\s/', '', $string);

            $string = $this->_no_null($string);

            $string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"

            $string = strtolower($string);

            

            $allowed = false;

            if (is_array($this->allowed_protocols) && count($this->allowed_protocols) > 0)

            {

                foreach ($this->allowed_protocols as $one_protocol)

                {

                    if (strtolower($one_protocol) == $string)

                    {

                        $allowed = true;

                        break;

                    }

                }

            }

            

            if ($allowed)

            {

                return "$string:";

            }

            else

            {

                return '';

            }

        }



        /**

         * 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.

         *

         * @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 PHP4 OOP 0.0.1

         */

        function _check_attr_val($value, $vless, $checkname, $checkvalue)

        {

            $ok = true;

            

            switch (strtolower($checkname))

            {

                /**

                 * 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.

                 */

                case 'maxlen' :

                    if (strlen($value) > $checkvalue)

                    {

                        $ok = false;

                    }

                    break;

                

                /**

                 * The minlen check makes sure that the attribute value has a length not

                 * smaller than the given value.

                 */

                case 'minlen' :

                    if (strlen($value) < $checkvalue)

                    {

                        $ok = false;

                    }

                    break;

                

                /**

                 * 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.

                 */

                case 'maxval' :

                    if (! preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))

                    {

                        $ok = false;

                    }

                    if ($value > $checkvalue)

                    {

                        $ok = false;

                    }

                    break;

                

                /**

                 * The minval check checks that the attribute value is a positive integer,

                 * and that it is not smaller than the given value.

                 */

                case 'minval' :

                    if (! preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))

                    {

                        $ok = false;

                    }

                    if ($value < $checkvalue)

                    {

                        $ok = false;

                    }

                    break;

                

                /**

                 * 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.

                 */

                case 'valueless' :

                    if (strtolower($checkvalue) != $vless)

                    {

                        $ok = false;

                    }

                    break;

            

            }

            

            return $ok;

        }



        /**

         * Changes \" to "

         *

         * 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.

         *

         * @access private

         * @param string $string The string to be stripped.

         * @return string string stripped of \"

         * @since PHP4 OOP 0.0.1

         */

        function _stripslashes($string)

        {

            return preg_replace('%\\\\"%', '"', $string);

        }



        /**

         * helper method for _hair()

         *

         * This function deals with parsing errors in _hair(). The general plan is

         * to remove everything to and including some whitespace, but it deals with

         * quotes and apostrophes as well.

         *

         * @access private

         * @param string $string The string to be stripped.

         * @return string string stripped of whitespace

         * @see _hair()

         * @since PHP4 OOP 0.0.1

         */

        function _html_error($string)

        {

            return preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $string);

        }



        /**

         * Decodes numeric HTML entities

         *

         * This method decodes numeric HTML entities (&#65; and &#x41;). It doesn't

         * do anything with other entities like &auml;, 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

         */

        function _decode_entities($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 PHP4 OOP version # of kses.

         *

         * Since this class has been refactored and documented and proven to work,

         * I'm syncing the version number to procedural kses.

         *

         * @access public

         * @return string Version number

         * @since PHP4 OOP 0.0.1

         */

        function _version()

        {

            return 'PHP4 0.2.2 (OOP fork of procedural kses 0.2.2)';

        }

    }



}

?>