kses5

Complexity

Total Complexity

115

Size/Duplication

Total Lines	1056
Duplicated Lines	0 %

Importance

Changes

0

<?php
		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("kses5::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("kses5::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("kses5::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("kses5::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("kses5::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("kses5::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("kses5::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 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("kses5::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("kses5::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("kses5::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 PHP5 OOP 1.0.2
			 */
			public 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 PHP5 OOP 1.0.2
			 */
			public 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 $attribs Associative array of allowed attributes - key => attribute name - value => attribute parameter
			 *	@return bool Status of Adding (X)HTML and attributes.
			 *	@since PHP4 OOP 0.0.1
			 */
			public function AddHTML($tag = "", $attribs = array())
			{
				if(!is_string($tag))
				{
					trigger_error("kses5::AddHTML() requires the tag to be a string", E_USER_WARNING);
					return false;
				}

				$tag = strtolower(trim($tag));
				if($tag == "")
				{
					trigger_error("kses5::AddHTML() tried to add an empty/NULL tag", E_USER_WARNING);
					return false;
				}

				if(!is_array($attribs))
				{
					trigger_error("kses5::AddHTML() requires an array (even an empty one) of attributes for '$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 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);
				return $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 $string
			 *	@return string String with normalized entities
			 *	@since PHP4 OOP 0.0.1
			 */
			private function normalizeEntities($string)
			{
				# Disarm all entities by converting & to &amp;
				$string = str_replace('&', '&amp;', $string);

				#	TODO: Change back (Keep?) the allowed entities in our entity white list

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

				#	Change numeric entities to valid 16 bit values

				$string = preg_replace(
					'/&amp;#0*([0-9]{1,5});/e',
					'\$this->normalizeEntities16bit("\\1")',
					$string
				);

				#	Change &XHHHHHHH (Hex digits) to 16 bit hex values
				$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 $i
			 *	@return string Normalized numeric entity
			 *	@see normalizeEntities()
			 *	@since PHP4 OOP 0.0.1
			 */
			private function normalizeEntities16bit($i)
			{
			  return (($i > 65535) ? "&amp;#$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 '&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)]))
				{
					#	Found an HTML element not in the white list
					return '';
				}

				if ($slash != '')
				{
					return "<$slash$elem>";
				}
				# No attributes are allowed for closing elements

				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);
				$string = preg_replace('/\xad+/', '', $string); # deals with Opera "feature"
				$string2 = $string . 'a';

				$string2 = preg_split('/:|&#58;|&#x3a;/i', $string, 2);
				if(isset($string2[1]) && !preg_match('%/\?%',$string2[0]))
				{
					$string = $this->filterProtocols($string2[0]).trim($string2[1]);
				}
				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 = preg_replace('/\xad+/', '', $string2); # deals with Opera "feature"
				$string = strtolower($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 (&#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 $value The entitiy to be decoded.
			 *	@return string Decoded entity
			 *	@since PHP4 OOP 0.0.1
			 */
			private function decodeEntities($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 1.0.2';
			}
?>