php4.class.kses.php

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			 *	@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&T", ":" to ":", "&#XYZZY;" to "&#XYZZY;" and so on.
			 *
			 *	@access private
			 *	@param string $string
			 *	@return string String with normalized entities
			 *	@since PHP4 OOP 0.0.1
			 */
			function _normalize_entities($string)
			{
				# Disarm all entities by converting & to &
			  $string = str_replace('&', '&', $string);

				# Change back the allowed entities in our entity white list

			  $string = preg_replace('/&([A-Za-z][A-Za-z0-9]{0,19});/', '&\\1;', $string);
			  $string = preg_replace('/&#0*([0-9]{1,5});/e', '\$this->_normalize_entities2("\\1")', $string);
			  $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 $i
			 *	@return string Normalized numeric entity
			 *	@see _normalize_entities()
			 *	@since PHP4 OOP 0.0.1
			 */
			function _normalize_entities2($i)
			{
			  return (($i > 65535) ? "&#$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.
			 *