Initial Import

1 files changed, 585 insertions, 0 deletions

diff --git a/system/libraries/Input.php b/system/libraries/Input.php
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+++ b/system/libraries/Input.php
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+<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * Code Igniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		Rick Ellis
+ * @copyright	Copyright (c) 2006, pMachine, Inc.
+ * @license		http://www.codeignitor.com/user_guide/license.html 
+ * @link		http://www.codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+ 
+// ------------------------------------------------------------------------
+
+/**
+ * Input Class
+ * 
+ * Pre-processes global input data for security
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Input
+ * @author		Rick Ellis
+ * @link		http://www.codeigniter.com/user_guide/libraries/input.html
+ */
+class CI_Input {
+	var $use_xss_clean		= FALSE;
+	var $ip_address			= FALSE;
+	var $user_agent			= FALSE;
+	var $allow_get_array	= FALSE;
+	
+	/**
+	 * Constructor
+	 *
+	 * Sets whether to globally enable the XSS processing
+	 * and whether to allow the $_GET array
+	 *
+	 * @access	public
+	 */	
+	function CI_Input()
+	{	
+		$CFG =& _load_class('CI_Config');
+		$this->use_xss_clean	= ($CFG->item('global_xss_filtering') === TRUE) ? TRUE : FALSE;
+		$this->allow_get_array	= ($CFG->item('enable_query_strings') === TRUE) ? TRUE : FALSE;
+		
+		log_message('debug', "Input Class Initialized");
+		$this->_sanitize_globals();
+	}
+	// END CI_Input()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Sanitize Globals
+	 *
+	 * This function does the folowing:
+	 *
+	 * Unsets $_GET data (if query strings are not enabled)
+	 *
+	 * Unsets all globals if register_globals is enabled
+	 *
+	 * Standardizes newline characters to \n
+	 *
+	 * @access	private
+	 * @return	void
+	 */
+	function _sanitize_globals()
+	{
+		// Unset globals. This is effectively the same as register_globals = off
+		foreach (array($_GET, $_POST, $_COOKIE) as $global)
+		{
+			if ( ! is_array($global))
+			{
+				unset($$global);
+			}
+			else
+			{
+				foreach ($global as $key => $val)
+				{
+					unset($$key);
+				}    
+			}
+		}
+
+		// Is $_GET data allowed?
+		if ($this->allow_get_array == FALSE)
+		{
+			$_GET = array();
+		}
+		
+		// Clean $_POST Data
+		if (is_array($_POST) AND count($_POST) > 0)
+		{
+			foreach($_POST as $key => $val)
+			{                
+				if (is_array($val))
+				{ 	
+					foreach($val as $k => $v)
+					{                    
+						$_POST[$this->_clean_input_keys($key)][$this->_clean_input_keys($k)] = $this->_clean_input_data($v);
+					}
+				}
+				else
+				{
+					$_POST[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
+				}
+			}            
+		}
+	
+		// Clean $_COOKIE Data
+		if (is_array($_COOKIE) AND count($_COOKIE) > 0)
+		{
+			foreach($_COOKIE as $key => $val)
+			{              
+				$_COOKIE[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
+			}    
+		}
+		
+		log_message('debug', "Global POST and COOKIE data sanitized");
+	}	
+	// END _sanitize_globals()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Clean Intput Data
+	 *
+	 * This is a helper function. It escapes data and 
+	 * standardizes newline characters to \n
+	 *
+	 * @access	private
+	 * @param	string
+	 * @return	string
+	 */	
+	function _clean_input_data($str)
+	{
+		if (is_array($str))
+		{
+			$new_array = array();
+			foreach ($str as $key => $val)
+			{
+				$new_array[$key] = $this->_clean_input_data($val);
+			}
+			return $new_array;
+		}
+		
+		if ($this->use_xss_clean === TRUE)
+		{
+			$str = $this->xss_clean($str);
+		}
+		
+		return preg_replace("/\015\012|\015|\012/", "\n", $str);
+	}
+	// END _clean_input_data()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Clean Keys
+	 *
+	 * This is a helper function. To prevent malicious users 
+	 * from trying to exploit keys we make sure that keys are 
+	 * only named with alpha-numeric text and a few other items.
+	 *
+	 * @access	private
+	 * @param	string
+	 * @return	string
+	 */
+	function _clean_input_keys($str)
+	{    
+		 if ( ! preg_match("/^[a-z0-9:_\/-]+$/i", $str))
+		 { 
+			exit('Disallowed Key Characters: '.$str);
+		 }
+	
+		if ( ! get_magic_quotes_gpc())
+		{
+		   return addslashes($str);
+		}
+		
+		return $str;
+	}
+	// END _clean_input_keys()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Fetch an item from the POST array
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function post($index = '', $xss_clean = FALSE)
+	{		
+		if ( ! isset($_POST[$index]))
+		{
+			return FALSE;
+		}
+		else
+		{
+			if ($xss_clean === TRUE)
+			{
+				return $this->xss_clean($_POST[$index]);
+			}
+			else
+			{
+				return $_POST[$index];
+			}
+		}
+	}
+	// END post()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Fetch an item from the COOKIE array
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function cookie($index = '', $xss_clean = FALSE)
+	{
+		if ( ! isset($_COOKIE[$index]))
+		{
+			return FALSE;
+		}
+		else
+		{
+			if ($xss_clean === TRUE)
+			{
+				return $this->xss_clean($_COOKIE[$index]);
+			}
+			else
+			{
+				return $_COOKIE[$index];
+			}
+		}
+	}
+	// END cookie()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Fetch the IP Address
+	 *
+	 * @access	public
+	 * @return	string
+	 */
+	function ip_address()
+	{
+		if ($this->ip_address !== FALSE)
+		{
+			return $this->ip_address;
+		}
+	
+		$cip = (isset($_SERVER['HTTP_CLIENT_IP']) AND $_SERVER['HTTP_CLIENT_IP'] != "") ? $_SERVER['HTTP_CLIENT_IP'] : FALSE;
+		$rip = (isset($_SERVER['REMOTE_ADDR']) AND $_SERVER['REMOTE_ADDR'] != "") ? $_SERVER['REMOTE_ADDR'] : FALSE;
+		$fip = (isset($_SERVER['HTTP_X_FORWARDED_FOR']) AND $_SERVER['HTTP_X_FORWARDED_FOR'] != "") ? $_SERVER['HTTP_X_FORWARDED_FOR'] : FALSE;
+					
+		if ($cip && $rip)	$this->ip_address = $cip;	
+		elseif ($rip)		$this->ip_address = $rip;
+		elseif ($cip)		$this->ip_address = $cip;
+		elseif ($fip)		$this->ip_address = $fip;
+		
+		if (strstr($this->ip_address, ','))
+		{
+			$x = explode(',', $this->ip_address);
+			$this->ip_address = end($x);
+		}
+		
+		if ( ! $this->valid_ip($this->ip_address))
+		{
+			$this->ip_address = '0.0.0.0';
+		}
+		
+		unset($cip);
+		unset($rip);
+		unset($fip);
+		
+		return $this->ip_address;
+	}
+	// END ip_address()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Validate IP Address
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function valid_ip($ip)
+	{
+		return ( ! preg_match( "/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/", $ip)) ? FALSE : TRUE;
+	}
+	// END valid_ip()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * User Agent
+	 *
+	 * @access	public
+	 * @return	string
+	 */
+	function user_agent()
+	{
+		if ($this->user_agent !== FALSE)
+		{
+			return $this->user_agent;
+		}
+	
+		$this->user_agent = ( ! isset($_SERVER['HTTP_USER_AGENT'])) ? FALSE : $_SERVER['HTTP_USER_AGENT'];
+		
+		return $this->user_agent;
+	}
+	// END user_agent()
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * XSS Clean
+	 *
+	 * Sanitizes data so that Cross Site Scripting Hacks can be
+	 * prevented.Ê This function does a fair amount of work but
+	 * it is extremely thorough, designed to prevent even the
+	 * most obscure XSS attempts.Ê Nothing is ever 100% foolproof,
+	 * of course, but I haven't been able to get anything passed
+	 * the filter.
+	 *
+	 * Note: This function should only be used to deal with data
+	 * upon submission.Ê It's not something that should
+	 * be used for general runtime processing.
+	 *
+	 * This function was based in part on some code and ideas I
+	 * got from Bitflux: http://blog.bitflux.ch/wiki/XSS_Prevention
+	 *
+	 * To help develop this script I used this great list of
+	 * vulnerabilities along with a few other hacks I've 
+	 * harvested from examining vulnerabilities in other programs:
+	 * http://ha.ckers.org/xss.html
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function xss_clean($str, $charset = 'ISO-8859-1')
+	{	
+		/*
+		 * Remove Null Characters
+		 *
+		 * This prevents sandwiching null characters
+		 * between ascii characters, like Java\0script.
+		 *
+		 */
+		$str = preg_replace('/\0+/', '', $str);
+		$str = preg_replace('/(\\\\0)+/', '', $str);
+
+		/*
+		 * Validate standard character entites
+		 *
+		 * Add a semicolon if missing.  We do this to enable
+		 * the conversion of entities to ASCII later.
+		 *
+		 */
+		$str = preg_replace('#(&\#*\w+)[\x00-\x20]+;#u',"\\1;",$str);
+		
+		/*
+		 * Validate UTF16 two byte encodeing (x00) 
+		 *
+		 * Just as above, adds a semicolon if missing.
+		 *
+		 */
+		$str = preg_replace('#(&\#x*)([0-9A-F]+);*#iu',"\\1\\2;",$str);
+
+		/*
+		 * URL Decode
+		 *
+		 * Just in case stuff like this is submitted:
+		 *
+		 * <a href="http://%77%77%77%2E%67%6F%6F%67%6C%65%2E%63%6F%6D">Google</a>
+		 *
+		 * Note: Normally urldecode() would be easier but it removes plus signs
+		 *
+		 */	
+		$str = preg_replace("/%u0([a-z0-9]{3})/i", "&#x\\1;", $str);
+		$str = preg_replace("/%([a-z0-9]{2})/i", "&#x\\1;", $str);        
+        		
+		/*
+		 * Convert character entities to ASCII 
+		 *
+		 * This permits our tests below to work reliably.
+		 * We only convert entities that are within tags since
+		 * these are the ones that will pose security problems.
+		 *
+		 */
+		 
+        if (preg_match_all("/<(.+?)>/si", $str, $matches))
+        {        
+			for ($i = 0; $i < count($matches['0']); $i++)
+			{
+				$str = str_replace($matches['1'][$i], 
+									$this->_html_entity_decode($matches['1'][$i], $charset), 
+									$str);
+			}
+		}
+	
+		/*
+		 * Convert all tabs to spaces
+		 *
+		 * This prevents strings like this: ja	vascript
+		 * Note: we deal with spaces between characters later.
+		 *
+		 */		
+		$str = preg_replace("#\t+#", " ", $str);
+	
+		/*
+		 * Makes PHP tags safe
+		 *
+		 *  Note: XML tags are inadvertently replaced too:
+		 *
+		 *	<?xml
+		 *
+		 * But it doesn't seem to pose a problem.
+		 *
+		 */		
+		$str = str_replace(array('<?php', '<?PHP', '<?', '?>'),  array('&lt;?php', '&lt;?PHP', '&lt;?', '?&gt;'), $str); // <?php BBEdit bug fix
+	
+		/*
+		 * Compact any exploded words
+		 *
+		 * This corrects words like:  j a v a s c r i p t
+		 * These words are compacted back to their correct state.
+		 *
+		 */		
+		$words = array('javascript', 'vbscript', 'script', 'applet', 'alert', 'document', 'write', 'cookie', 'window');
+		foreach ($words as $word)
+		{
+			$temp = '';
+			for ($i = 0; $i < strlen($word); $i++)
+			{
+				$temp .= substr($word, $i, 1)."\s*";
+			}
+			
+			$temp = substr($temp, 0, -3);
+			$str = preg_replace('#'.$temp.'#s', $word, $str);
+			$str = preg_replace('#'.ucfirst($temp).'#s', ucfirst($word), $str);
+		}
+	
+		/*
+		 * Remove disallowed Javascript in links or img tags
+		 */		
+		 $str = preg_replace("#<a.+?href=.*?(alert\(|alert&\#40;|javascript\:|window\.|document\.|\.cookie|<script|<xss).*?\>.*?</a>#si", "", $str);
+		 $str = preg_replace("#<img.+?src=.*?(alert\(|alert&\#40;|javascript\:|window\.|document\.|\.cookie|<script|<xss).*?\>#si", "", $str);
+		 $str = preg_replace("#<(script|xss).*?\>#si", "", $str);
+
+		/*
+		 * Remove JavaScript Event Handlers
+		 *
+		 * Note: This code is a little blunt.  It removes
+		 * the event handler and anything up to the closing >, 
+		 * but it's unlkely to be a problem.
+		 *
+		 */		
+		 $str = preg_replace('#(<[^>]+.*?)(onblur|onchange|onclick|onfocus|onload|onmouseover|onmouseup|onmousedown|onselect|onsubmit|onunload|onkeypress|onkeydown|onkeyup|onresize)[^>]*>#iU',"\\1>",$str);
+	
+		/*
+		 * Sanitize naughty HTML elements
+		 *
+		 * If a tag containing any of the words in the list 
+		 * below is found, the tag gets converted to entities.
+		 *
+		 * So this: <blink>
+		 * Becomes: &lt;blink&gt;
+		 *
+		 */		
+		$str = preg_replace('#<(/*\s*)(alert|applet|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|layer|link|meta|object|plaintext|style|script|textarea|title|xml|xss)([^>]*)>#is', "&lt;\\1\\2\\3&gt;", $str);
+		
+		/*
+		 * Sanitize naughty scripting elements
+		 *
+		 * Similar to above, only instead of looking for
+		 * tags it looks for PHP and JavaScript commands
+		 * that are disallowed.  Rather than removing the
+		 * code, it simply converts the parenthesis to entities
+		 * rendering the code unexecutable.
+		 *
+		 * For example:	eval('some code')
+		 * Becomes:		eval&#40;'some code'&#41;
+		 *
+		 */
+		$str = preg_replace('#(alert|cmd|passthru|eval|exec|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si', "\\1\\2&#40;\\3&#41;", $str);
+						
+		/*
+		 * Final clean up
+		 *
+		 * This adds a bit of extra precaution in case
+		 * something got through the above filters
+		 *
+		 */	
+		$bad = array(
+						'document.cookie'	=> '',
+						'document.write'	=> '',
+						'window.location'	=> '',
+						"javascript\s*:"	=> '',
+						"Redirect\s+302"	=> '',
+						'<!--'				=> '&lt;!--',
+						'-->'				=> '--&gt;'
+					);
+	
+		foreach ($bad as $key => $val)
+		{
+			$str = preg_replace("#".$key."#i", $val, $str);   
+		}
+		
+                        
+		log_message('debug', "XSS Filtering completed");
+		return $str;
+	}
+	// END xss_clean()
+
+
+	/**
+	 * HTML Entities Decode
+	 *
+	 * This function is a replacement for html_entity_decode()
+	 *
+	 * In some versions of PHP the native function does not work
+	 * when UTF-8 is the specified character set, so this gives us
+	 * a work-around.  More info here:
+	 * http://bugs.php.net/bug.php?id=25670
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	/* -------------------------------------------------
+    /*  Replacement for html_entity_decode()
+    /* -------------------------------------------------*/
+    
+    /*
+    NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the 
+    character set, and the PHP developers said they were not back porting the
+    fix to versions other than PHP 5.x.
+    */
+	function _html_entity_decode($str, $charset='ISO-8859-1') 
+	{
+		if (stristr($str, '&') === FALSE) return $str;
+	
+		// The reason we are not using html_entity_decode() by itself is because
+		// while it is not technically correct to leave out the semicolon
+		// at the end of an entity most browsers will still interpret the entity
+		// correctly.  html_entity_decode() does not convert entities without
+		// semicolons, so we are left with our own little solution here. Bummer.
+	
+		if (function_exists('html_entity_decode') && (strtolower($charset) != 'utf-8' OR version_compare(phpversion(), '5.0.0', '>=')))
+		{
+			$str = html_entity_decode($str, ENT_COMPAT, $charset);
+			$str = preg_replace('~&#x([0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str);
+			return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str);
+		}
+		
+		// Numeric Entities
+		$str = preg_replace('~&#x([0-9a-f]{2,5});{0,1}~ei', 'chr(hexdec("\\1"))', $str);
+		$str = preg_replace('~&#([0-9]{2,4});{0,1}~e', 'chr(\\1)', $str);
+	
+		// Literal Entities - Slightly slow so we do another check
+		if (stristr($str, '&') === FALSE)
+		{
+			$str = strtr($str, array_flip(get_html_translation_table(HTML_ENTITIES)));
+		}
+		
+		return $str;
+	}
+
+}
+// END Input class
+?>
\ No newline at end of file