<?php

/*
+--------------------------------------------------------------------------
|   IPB NULL EN
|   =============================================
|   by IPB NULL EN
|   (c) 2001 - 2006 IPB NULL EN, Inc.
|   http://ipb-null.narod.ru/
|   =============================================
|   Web: http://www.ipb-null.narod.ru
|   Licence Info: http://ipb-null.narod.ru/
+---------------------------------------------------------------------------
|   > $Date: 2005-10-10 14:03:20 +0100 (Mon, 10 Oct 2005) $
|   > $Revision: 22 $
|   > $Author: matt $
+---------------------------------------------------------------------------
|
|   > UPLOAD handling methods (KERNEL)
|   > Module written by Matt Mecham
|   > Date started: 15th March 2004
|
|	> Module Version Number: 1.0.0
+--------------------------------------------------------------------------
| ERRORS:
| 1: No upload
| 2: Not valid upload type
| 3: Upload exceeds $max_file_size
| 4: Could not move uploaded file, upload deleted
| 5: File pretending to be an image but isn't (poss XSS attack)
+--------------------------------------------------------------------------
*/

/**
* IPS Kernel Pages: Upload
*
* This class contains all generic functions to handle
* the parsing of $_FILE data.
*
* Example Usage:
* <code>
* $upload = new class_upload();
* $upload->out_file_dir     = './uploads';
* $upload->max_file_size    = '10000000';
* $upload->make_script_safe = 1;
* $upload->allowed_file_ext = array( 'gif', 'jpg', 'jpeg', 'png' );
* $upload->upload_process();
*
* if ( $upload->error_no )
* {
*	  switch( $upload->error_no )
*	  {
*		  case 1:
*			  // No upload
*			  print "No upload"; exit();
*		  case 2:
*		  case 5:
*			  // Invalid file ext
*			   print "Invalid File Extension"; exit();
*		  case 3:
*			  // Too big...
*			   print "File too big"; exit();
*         case 4:
*			  // Cannot move uploaded file
*			   print "Move failed"; exit();
*	  }
*  }
* print $upload->saved_upload_name . " uploaded!";
* </code>
* ERRORS:
* 1: No upload
* 2: Not valid upload type
* 3: Upload exceeds $max_file_size
* 4: Could not move uploaded file, upload deleted
* 5: File pretending to be an image but isn't (poss XSS attack)
*
* @package		IPS_KERNEL
* @author		Matt Mecham
* @copyright	IPB NULL EN, Inc.
* @version		2.1
*/

/**
*
*/

/**
* Upload Class
*
* Methods and functions for handling file uploads
*
* @package	IPS_KERNEL
* @author   Matt Mecham
* @version	2.1
*/
class class_upload
{
	/**
	* Name of upload form field
	*
	* @var string
	*/
	var $upload_form_field = 'FILE_UPLOAD';
	
	/**
	* Out filename *without* extension
	* (Leave blank to retain user filename)
	*
	* @var string
	*/
	var $out_file_name    = '';
	
	/**
	* Out dir (./upload) - no trailing slash
	*
	* @var string
	*/
	var $out_file_dir     = './';
	
	/**
	* maximum file size of this upload
	*
	* @var integer
	*/
	var $max_file_size    = 0;
	
	/**
	* Forces PHP, CGI, etc to text
	*
	* @var integer
	*/
	var $make_script_safe = 1;
	
	/**
	* Force non-img file extenstion (leave blank if not) (ex: 'ibf' makes upload.doc => upload.ibf)
	*
	* @var string
	*/
	var $force_data_ext   = '';
	
	/**
	* Allowed file extensions array( 'gif', 'jpg', 'jpeg'..)
	*
	* @var array
	*/
	var $allowed_file_ext = array();
	
	/**
	* Array of IMAGE file extensions
	*
	* @var array
	*/
	var $image_ext        = array( 'gif', 'jpeg', 'jpg', 'jpe', 'png' );
	
	/**
	* Check to make sure an image is an image
	*
	* @var boolean flag
	*/
	var $image_check      = 1;
	
	/**
	* Returns current file extension	
	*
	* @var string
	*/
	var $file_extension   = '';
	
	/**
	* If force_data_ext == 1, this will return the 'real' extension
	* and $file_extension will return the 'force_data_ext'
	*
	* @var string
	*/
	var $real_file_extension = '';
	
	/**
	* Returns error number	
	*
	* @var integer
	*/
	var $error_no         = 0;
	
	/**
	* Returns if upload is img or not
	*
	* @var integer
	*/
	var $is_image         = 0;
	
	/**
	* Returns file name as was uploaded by user
	*
	* @var string
	*/
	var $original_file_name = "";
	
	/**
	* Returns final file name as is saved on disk. (no path info)
	*
	* @var string
	*/
	var $parsed_file_name = "";
	
	/**
	* Returns final file name with path info
	*
	* @var string
	*/
	var $saved_upload_name = "";
	
	/*-------------------------------------------------------------------------*/
	// CONSTRUCTOR
	/*-------------------------------------------------------------------------*/
	
	function class_upload()
	{
		
	}
	
	
	/*-------------------------------------------------------------------------*/
	// PROCESS THE UPLOAD
	/*-------------------------------------------------------------------------*/
	
	/**
	* Processes the upload
	*
	*/
	
	function upload_process()
	{
		$this->_clean_paths();
		
		//-------------------------------------------------
		// Check for getimagesize
		//-------------------------------------------------
		
		if ( ! function_exists( 'getimagesize' ) )
		{
			$this->image_check = 0;
		}
		
		//-------------------------------------------------
		// Set up some variables to stop carpals developing
		//-------------------------------------------------
		
		$FILE_NAME = isset($_FILES[ $this->upload_form_field ]['name']) ? $_FILES[ $this->upload_form_field ]['name'] : '';
		$FILE_SIZE = isset($_FILES[ $this->upload_form_field ]['size']) ? $_FILES[ $this->upload_form_field ]['size'] : '';
		$FILE_TYPE = isset($_FILES[ $this->upload_form_field ]['type']) ? $_FILES[ $this->upload_form_field ]['type'] : '';
		
		//-------------------------------------------------
		// Naughty Opera adds the filename on the end of the
		// mime type - we don't want this.
		//-------------------------------------------------
		
		$FILE_TYPE = preg_replace( "/^(.+?);.*$/", "\\1", $FILE_TYPE );
		
		//-------------------------------------------------
		// Naughty Mozilla likes to use "none" to indicate an empty upload field.
		// I love universal languages that aren't universal.
		//-------------------------------------------------
		
		if ( !isset($_FILES[ $this->upload_form_field ]['name'])
		or $_FILES[ $this->upload_form_field ]['name'] == ""
		or !$_FILES[ $this->upload_form_field ]['name']
		or !$_FILES[ $this->upload_form_field ]['size']
		or ($_FILES[ $this->upload_form_field ]['name'] == "none") )
		{
			$this->error_no = 1;
			return;
		}
		
		if( !is_uploaded_file($_FILES[ $this->upload_form_field ]['tmp_name']) )
		{
			$this->error_no = 1;
			return;
		}
		
		//-------------------------------------------------
		// De we have allowed file_extensions?
		//-------------------------------------------------
		
		if ( ! is_array( $this->allowed_file_ext ) or ! count( $this->allowed_file_ext ) )
		{
			$this->error_no = 2;
			return;
		}
		
		//-------------------------------------------------
		// Get file extension
		//-------------------------------------------------
		
		$this->file_extension = $this->_get_file_extension( $FILE_NAME );

		if ( ! $this->file_extension )
		{
			$this->error_no = 2;
			return;
		}
		
		$this->real_file_extension = $this->file_extension;
		
		//-------------------------------------------------
		// Valid extension?
		//-------------------------------------------------
		
		if ( ! in_array( $this->file_extension, $this->allowed_file_ext ) )
		{
			$this->error_no = 2;
			return;
		}
		
		//-------------------------------------------------
		// Check the file size
		//-------------------------------------------------
		
		if ( ( $this->max_file_size ) and ( $FILE_SIZE > $this->max_file_size ) )
		{
			$this->error_no = 3;
			return;
		}
		
		//-------------------------------------------------
		// Make the uploaded file safe
		//-------------------------------------------------
		
		$FILE_NAME = preg_replace( "/[^\w\.]/", "_", $FILE_NAME );
		
		$this->original_file_name = $FILE_NAME;
		
		//-------------------------------------------------
		// Convert file name?
		// In any case, file name is WITHOUT extension
		//-------------------------------------------------
		
		if ( $this->out_file_name )
		{
			$this->parsed_file_name = $this->out_file_name;
		}
		else
		{
			$this->parsed_file_name = str_replace( '.'.$this->file_extension, "", $FILE_NAME );
		}
		
		//-------------------------------------------------
		// Make safe?
		//-------------------------------------------------
		
		$renamed = 0;
		
		if ( $this->make_script_safe )
		{
			if ( preg_match( "/\.(cgi|pl|js|asp|php|html|htm|jsp|jar)(\.|$)/i", $FILE_NAME ) )
			{
				$FILE_TYPE                 = 'text/plain';
				$this->file_extension      = 'txt';
				$this->parsed_file_name	   = preg_replace( "/\.(cgi|pl|js|asp|php|html|htm|jsp|jar)(\.|$)/i", "$2", $this->parsed_file_name );
				
				$renamed = 1;
			}
		}
		
		//-------------------------------------------------
		// Is it an image?
		//-------------------------------------------------

		if ( is_array( $this->image_ext ) and count( $this->image_ext ) )
		{
			if ( in_array( $this->real_file_extension, $this->image_ext ) )
			{
				$this->is_image = 1;
			}
		}

		//-------------------------------------------------
		// Add on the extension...
		//-------------------------------------------------
		
		if ( $this->force_data_ext and ! $this->is_image )
		{
			$this->file_extension = str_replace( ".", "", $this->force_data_ext ); 
		}
		
		$this->parsed_file_name .= '.'.$this->file_extension;
		
		//-------------------------------------------------
		// Copy the upload to the uploads directory
		// ^^ We need to do this before checking the img
		//    size for the openbasedir restriction peeps
		//    We'll just unlink if it doesn't checkout
		//-------------------------------------------------
		
		$this->saved_upload_name = $this->out_file_dir.'/'.$this->parsed_file_name;
		
		if ( ! @move_uploaded_file( $_FILES[ $this->upload_form_field ]['tmp_name'], $this->saved_upload_name) )
		{
			$this->error_no = 4;
			return;
		}
		else
		{
			@chmod( $this->saved_upload_name, 0777 );
		}
		
		if( !$renamed )
		{
			$this->check_xss_infile();
			
			if( $this->error_no )
			{
				return;
			}
		}
		
		//-------------------------------------------------
		// Is it an image?
		//-------------------------------------------------
		
		if ( $this->is_image )
		{
			//-------------------------------------------------
			// Are we making sure its an image?
			//-------------------------------------------------
			
			if ( $this->image_check )
			{
				$img_attributes = @getimagesize( $this->saved_upload_name );
				
				if ( ! is_array( $img_attributes ) or ! count( $img_attributes ) )
				{
					// Unlink the file first
					@unlink( $this->saved_upload_name );
					$this->error_no = 5;
					return;
				}
				else if ( ! $img_attributes[2] )
				{
					// Unlink the file first
					@unlink( $this->saved_upload_name );
					$this->error_no = 5;
					return;
				}
				else if ( $img_attributes[2] == 1 AND ( $this->file_extension == 'jpg' OR $this->file_extension == 'jpeg' ) )
				{
					// Potential XSS attack with a fake GIF header in a JPEG
					@unlink( $this->saved_upload_name );
					$this->error_no = 5;
					return;
				}
			}
		}
		
		//-------------------------------------------------
		// If filesize and $_FILES['size'] don't match then
		// either file is corrupt, or there was funny
		// business between when it hit tmp and was moved
		//-------------------------------------------------
		
		if( filesize($this->saved_upload_name) != $_FILES[ $this->upload_form_field ]['size'] )
		{
			@unlink( $this->saved_upload_name );
			
			$this->error_no = 1;
			return;
		}
	}
	
	
	/*-------------------------------------------------------------------------*/
	// INTERNAL: Check for XSS inside file
	/*-------------------------------------------------------------------------*/
	
	/**
	* Checks for XSS inside file.  If found, sets error_no to 5 and returns
	*
	* @param void
	*/
	
	function check_xss_infile()
	{
		// HTML added inside an inline file is not good in IE...
		
		$fh = fopen( $this->saved_upload_name, 'rb' );
		
		$file_check = fread( $fh, 512 );
		
		fclose( $fh );
		
		if( !$file_check )
		{
			@unlink( $this->saved_upload_name );
			$this->error_no = 5;
			return;
		}
		
		# Thanks to Nicolas Grekas from comments at www.splitbrain.org for helping to identify all vulnerable HTML tags
		
		else if( preg_match( "#<script|<html|<head|<title|<body|<pre|<table|<a\s+href|<img|<plaintext|<cross\-domain\-policy#si", $file_check ) )
		{
			@unlink( $this->saved_upload_name );
			$this->error_no = 5;
			return;
		}
	}
	
	/*-------------------------------------------------------------------------*/
	// INTERNAL: Get file extension
	/*-------------------------------------------------------------------------*/
	
	/**
	* Returns the file extension of the current filename
	*
	* @param string Filename
	*/
	
	function _get_file_extension($file)
	{
		return strtolower( str_replace( ".", "", substr( $file, strrpos( $file, '.' ) ) ) );
	}
	
	/*-------------------------------------------------------------------------*/
	// INTERNAL: Clean paths
	/*-------------------------------------------------------------------------*/
	
	/**
	* Trims off trailing slashes
	*
	*/
	
	function _clean_paths()
	{
		$this->out_file_dir = preg_replace( "#/$#", "", $this->out_file_dir );
	}

	
	
}

?>