system/libraries/Upload.php
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2019 - 2022, CodeIgniter Foundation
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
* @copyright Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
* @copyright Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 1.0.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* File Uploading Class
*
* @package CodeIgniter
* @subpackage Libraries
* @category Uploads
* @author EllisLab Dev Team
* @link https://codeigniter.com/userguide3/libraries/file_uploading.html
*/
class CI_Upload {
/**
* Maximum file size
*
* @var int
*/
public $max_size = 0;
/**
* Maximum image width
*
* @var int
*/
public $max_width = 0;
/**
* Maximum image height
*
* @var int
*/
public $max_height = 0;
/**
* Minimum image width
*
* @var int
*/
public $min_width = 0;
/**
* Minimum image height
*
* @var int
*/
public $min_height = 0;
/**
* Maximum filename length
*
* @var int
*/
public $max_filename = 0;
/**
* Maximum duplicate filename increment ID
*
* @var int
*/
public $max_filename_increment = 100;
/**
* Allowed file types
*
* @var string
*/
public $allowed_types = '';
/**
* Temporary filename
*
* @var string
*/
public $file_temp = '';
/**
* Filename
*
* @var string
*/
public $file_name = '';
/**
* Original filename
*
* @var string
*/
public $orig_name = '';
/**
* File type
*
* @var string
*/
public $file_type = '';
/**
* File size
*
* @var int
*/
public $file_size = NULL;
/**
* Filename extension
*
* @var string
*/
public $file_ext = '';
/**
* Force filename extension to lowercase
*
* @var string
*/
public $file_ext_tolower = FALSE;
/**
* Upload path
*
* @var string
*/
public $upload_path = '';
/**
* Overwrite flag
*
* @var bool
*/
public $overwrite = FALSE;
/**
* Obfuscate filename flag
*
* @var bool
*/
public $encrypt_name = FALSE;
/**
* Is image flag
*
* @var bool
*/
public $is_image = FALSE;
/**
* Image width
*
* @var int
*/
public $image_width = NULL;
/**
* Image height
*
* @var int
*/
public $image_height = NULL;
/**
* Image type
*
* @var string
*/
public $image_type = '';
/**
* Image size string
*
* @var string
*/
public $image_size_str = '';
/**
* Error messages list
*
* @var array
*/
public $error_msg = array();
/**
* Remove spaces flag
*
* @var bool
*/
public $remove_spaces = TRUE;
/**
* MIME detection flag
*
* @var bool
*/
public $detect_mime = TRUE;
/**
* XSS filter flag
*
* @var bool
*/
public $xss_clean = FALSE;
/**
* Apache mod_mime fix flag
*
* @var bool
*/
public $mod_mime_fix = TRUE;
/**
* Temporary filename prefix
*
* @var string
*/
public $temp_prefix = 'temp_file_';
/**
* Filename sent by the client
*
* @var bool
*/
public $client_name = '';
// --------------------------------------------------------------------
/**
* Filename override
*
* @var string
*/
protected $_file_name_override = '';
/**
* MIME types list
*
* @var array
*/
protected $_mimes = array();
/**
* CI Singleton
*
* @var object
*/
protected $_CI;
// --------------------------------------------------------------------
/**
* Constructor
*
* @param array $config
* @return void
*/
public function __construct($config = array())
{
empty($config) OR $this->initialize($config, FALSE);
$this->_mimes =& get_mimes();
$this->_CI =& get_instance();
log_message('info', 'Upload Class Initialized');
}
// --------------------------------------------------------------------
/**
* Initialize preferences
*
* @param array $config
* @param bool $reset
* @return CI_Upload
*/
public function initialize(array $config = array(), $reset = TRUE)
{
$reflection = new ReflectionClass($this);
if ($reset === TRUE)
{
$defaults = $reflection->getDefaultProperties();
foreach (array_keys($defaults) as $key)
{
if ($key[0] === '_')
{
continue;
}
if (isset($config[$key]))
{
if ($reflection->hasMethod('set_'.$key))
{
$this->{'set_'.$key}($config[$key]);
}
else
{
$this->$key = $config[$key];
}
}
else
{
$this->$key = $defaults[$key];
}
}
}
else
{
foreach ($config as $key => &$value)
{
if ($key[0] !== '_' && $reflection->hasProperty($key))
{
if ($reflection->hasMethod('set_'.$key))
{
$this->{'set_'.$key}($value);
}
else
{
$this->$key = $value;
}
}
}
}
// if a file_name was provided in the config, use it instead of the user input
// supplied file name for all uploads until initialized again
$this->_file_name_override = $this->file_name;
return $this;
}
// --------------------------------------------------------------------
/**
* Perform the file upload
*
* @param string $field
* @return bool
*/
public function do_upload($field = 'userfile')
{
// Is $_FILES[$field] set? If not, no reason to continue.
if (isset($_FILES[$field]))
{
$_file = $_FILES[$field];
}
// Does the field name contain array notation?
elseif (($c = preg_match_all('/(?:^[^\[]+)|\[[^]]*\]/', $field, $matches)) > 1)
{
$_file = $_FILES;
for ($i = 0; $i < $c; $i++)
{
// We can't track numeric iterations, only full field names are accepted
if (($field = trim($matches[0][$i], '[]')) === '' OR ! isset($_file[$field]))
{
$_file = NULL;
break;
}
$_file = $_file[$field];
}
}
if ( ! isset($_file))
{
$this->set_error('upload_no_file_selected', 'debug');
return FALSE;
}
// Is the upload path valid?
if ( ! $this->validate_upload_path())
{
// errors will already be set by validate_upload_path() so just return FALSE
return FALSE;
}
// Was the file able to be uploaded? If not, determine the reason why.
if ( ! is_uploaded_file($_file['tmp_name']))
{
$error = isset($_file['error']) ? $_file['error'] : 4;
switch ($error)
{
case UPLOAD_ERR_INI_SIZE:
$this->set_error('upload_file_exceeds_limit', 'info');
break;
case UPLOAD_ERR_FORM_SIZE:
$this->set_error('upload_file_exceeds_form_limit', 'info');
break;
case UPLOAD_ERR_PARTIAL:
$this->set_error('upload_file_partial', 'debug');
break;
case UPLOAD_ERR_NO_FILE:
$this->set_error('upload_no_file_selected', 'debug');
break;
case UPLOAD_ERR_NO_TMP_DIR:
$this->set_error('upload_no_temp_directory', 'error');
break;
case UPLOAD_ERR_CANT_WRITE:
$this->set_error('upload_unable_to_write_file', 'error');
break;
case UPLOAD_ERR_EXTENSION:
$this->set_error('upload_stopped_by_extension', 'debug');
break;
default:
$this->set_error('upload_no_file_selected', 'debug');
break;
}
return FALSE;
}
// Set the uploaded data as class variables
$this->file_temp = $_file['tmp_name'];
$this->file_size = $_file['size'];
// Skip MIME type detection?
if ($this->detect_mime !== FALSE)
{
$this->_file_mime_type($_file);
}
$this->file_type = preg_replace('/^(.+?);.*$/', '\\1', $this->file_type);
$this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));
$this->file_name = $this->_prep_filename($_file['name']);
$this->file_ext = $this->get_extension($this->file_name);
$this->client_name = $this->file_name;
// Is the file type allowed to be uploaded?
if ( ! $this->is_allowed_filetype())
{
$this->set_error('upload_invalid_filetype', 'debug');
return FALSE;
}
// if we're overriding, let's now make sure the new name and type is allowed
if ($this->_file_name_override !== '')
{
$this->file_name = $this->_prep_filename($this->_file_name_override);
// If no extension was provided in the file_name config item, use the uploaded one
if (strpos($this->_file_name_override, '.') === FALSE)
{
$this->file_name .= $this->file_ext;
}
else
{
// An extension was provided, let's have it!
$this->file_ext = $this->get_extension($this->_file_name_override);
}
if ( ! $this->is_allowed_filetype(TRUE))
{
$this->set_error('upload_invalid_filetype', 'debug');
return FALSE;
}
}
// Convert the file size to kilobytes
if ($this->file_size > 0)
{
$this->file_size = round($this->file_size/1024, 2);
}
// Is the file size within the allowed maximum?
if ( ! $this->is_allowed_filesize())
{
$this->set_error('upload_invalid_filesize', 'info');
return FALSE;
}
// Are the image dimensions within the allowed size?
// Note: This can fail if the server has an open_basedir restriction.
if ( ! $this->is_allowed_dimensions())
{
$this->set_error('upload_invalid_dimensions', 'info');
return FALSE;
}
// Sanitize the file name for security
$this->file_name = $this->_CI->security->sanitize_filename($this->file_name);
// Truncate the file name if it's too long
if ($this->max_filename > 0)
{
$this->file_name = $this->limit_filename_length($this->file_name, $this->max_filename);
}
// Remove white spaces in the name
if ($this->remove_spaces === TRUE)
{
$this->file_name = preg_replace('/\s+/', '_', $this->file_name);
}
if ($this->file_ext_tolower && ($ext_length = strlen($this->file_ext)))
{
// file_ext was previously lower-cased by a get_extension() call
$this->file_name = substr($this->file_name, 0, -$ext_length).$this->file_ext;
}
/*
* Validate the file name
* This function appends an number onto the end of
* the file if one with the same name already exists.
* If it returns false there was a problem.
*/
$this->orig_name = $this->file_name;
if (FALSE === ($this->file_name = $this->set_filename($this->upload_path, $this->file_name)))
{
return FALSE;
}
/*
* Run the file through the XSS hacking filter
* This helps prevent malicious code from being
* embedded within a file. Scripts can easily
* be disguised as images or other file types.
*/
if ($this->xss_clean && $this->do_xss_clean() === FALSE)
{
$this->set_error('upload_unable_to_write_file', 'error');
return FALSE;
}
/*
* Move the file to the final destination
* To deal with different server configurations
* we'll attempt to use copy() first. If that fails
* we'll use move_uploaded_file(). One of the two should
* reliably work in most environments
*/
if ( ! @copy($this->file_temp, $this->upload_path.$this->file_name))
{
if ( ! @move_uploaded_file($this->file_temp, $this->upload_path.$this->file_name))
{
$this->set_error('upload_destination_error', 'error');
return FALSE;
}
}
/*
* Set the finalized image dimensions
* This sets the image width/height (assuming the
* file was an image). We use this information
* in the "data" function.
*/
$this->set_image_properties($this->upload_path.$this->file_name);
return TRUE;
}
// --------------------------------------------------------------------
/**
* Finalized Data Array
*
* Returns an associative array containing all of the information
* related to the upload, allowing the developer easy access in one array.
*
* @param string $index
* @return mixed
*/
public function data($index = NULL)
{
$data = array(
'file_name' => $this->file_name,
'file_type' => $this->file_type,
'file_path' => $this->upload_path,
'full_path' => $this->upload_path.$this->file_name,
'raw_name' => substr($this->file_name, 0, -strlen($this->file_ext)),
'orig_name' => $this->orig_name,
'client_name' => $this->client_name,
'file_ext' => $this->file_ext,
'file_size' => $this->file_size,
'is_image' => $this->is_image(),
'image_width' => $this->image_width,
'image_height' => $this->image_height,
'image_type' => $this->image_type,
'image_size_str' => $this->image_size_str,
);
if ( ! empty($index))
{
return isset($data[$index]) ? $data[$index] : NULL;
}
return $data;
}
// --------------------------------------------------------------------
/**
* Set Upload Path
*
* @param string $path
* @return CI_Upload
*/
public function set_upload_path($path)
{
// Make sure it has a trailing slash
$this->upload_path = rtrim($path, '/').'/';
return $this;
}
// --------------------------------------------------------------------
/**
* Set the file name
*
* This function takes a filename/path as input and looks for the
* existence of a file with the same name. If found, it will append a
* number to the end of the filename to avoid overwriting a pre-existing file.
*
* @param string $path
* @param string $filename
* @return string
*/
public function set_filename($path, $filename)
{
if ($this->encrypt_name === TRUE)
{
$filename = md5(uniqid(mt_rand())).$this->file_ext;
}
if ($this->overwrite === TRUE OR ! file_exists($path.$filename))
{
return $filename;
}
$filename = str_replace($this->file_ext, '', $filename);
$new_filename = '';
for ($i = 1; $i < $this->max_filename_increment; $i++)
{
if ( ! file_exists($path.$filename.$i.$this->file_ext))
{
$new_filename = $filename.$i.$this->file_ext;
break;
}
}
if ($new_filename === '')
{
$this->set_error('upload_bad_filename', 'debug');
return FALSE;
}
return $new_filename;
}
// --------------------------------------------------------------------
/**
* Set Maximum File Size
*
* @param int $n
* @return CI_Upload
*/
public function set_max_filesize($n)
{
$this->max_size = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set Maximum File Size
*
* An internal alias to set_max_filesize() to help with configuration
* as initialize() will look for a set_<property_name>() method ...
*
* @param int $n
* @return CI_Upload
*/
protected function set_max_size($n)
{
return $this->set_max_filesize($n);
}
// --------------------------------------------------------------------
/**
* Set Maximum File Name Length
*
* @param int $n
* @return CI_Upload
*/
public function set_max_filename($n)
{
$this->max_filename = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set Maximum Image Width
*
* @param int $n
* @return CI_Upload
*/
public function set_max_width($n)
{
$this->max_width = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set Maximum Image Height
*
* @param int $n
* @return CI_Upload
*/
public function set_max_height($n)
{
$this->max_height = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set minimum image width
*
* @param int $n
* @return CI_Upload
*/
public function set_min_width($n)
{
$this->min_width = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set minimum image height
*
* @param int $n
* @return CI_Upload
*/
public function set_min_height($n)
{
$this->min_height = ($n < 0) ? 0 : (int) $n;
return $this;
}
// --------------------------------------------------------------------
/**
* Set Allowed File Types
*
* @param mixed $types
* @return CI_Upload
*/
public function set_allowed_types($types)
{
$this->allowed_types = (is_array($types) OR $types === '*')
? $types
: explode('|', $types);
return $this;
}
// --------------------------------------------------------------------
/**
* Set Image Properties
*
* Uses GD to determine the width/height/type of image
*
* @param string $path
* @return CI_Upload
*/
public function set_image_properties($path = '')
{
if ($this->is_image() && function_exists('getimagesize'))
{
if (FALSE !== ($D = @getimagesize($path)))
{
$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
$this->image_width = $D[0];
$this->image_height = $D[1];
$this->image_type = isset($types[$D[2]]) ? $types[$D[2]] : 'unknown';
$this->image_size_str = $D[3]; // string containing height and width
}
}
return $this;
}
// --------------------------------------------------------------------
/**
* Set XSS Clean
*
* Enables the XSS flag so that the file that was uploaded
* will be run through the XSS filter.
*
* @param bool $flag
* @return CI_Upload
*/
public function set_xss_clean($flag = FALSE)
{
$this->xss_clean = ($flag === TRUE);
return $this;
}
// --------------------------------------------------------------------
/**
* Validate the image
*
* @return bool
*/
public function is_image()
{
// IE will sometimes return odd mime-types during upload, so here we just standardize all
// jpegs or pngs to the same file type.
$png_mimes = array('image/x-png');
$jpeg_mimes = array('image/jpg', 'image/jpe', 'image/jpeg', 'image/pjpeg');
if (in_array($this->file_type, $png_mimes))
{
$this->file_type = 'image/png';
}
elseif (in_array($this->file_type, $jpeg_mimes))
{
$this->file_type = 'image/jpeg';
}
$img_mimes = array('image/gif', 'image/jpeg', 'image/png', 'image/webp');
return in_array($this->file_type, $img_mimes, TRUE);
}
// --------------------------------------------------------------------
/**
* Verify that the filetype is allowed
*
* @param bool $ignore_mime
* @return bool
*/
public function is_allowed_filetype($ignore_mime = FALSE)
{
if ($this->allowed_types === '*')
{
return TRUE;
}
if (empty($this->allowed_types) OR ! is_array($this->allowed_types))
{
$this->set_error('upload_no_file_types', 'debug');
return FALSE;
}
$ext = strtolower(ltrim($this->file_ext, '.'));
if ( ! in_array($ext, $this->allowed_types, TRUE))
{
return FALSE;
}
// Images get some additional checks
if (in_array($ext, array('gif', 'jpg', 'jpeg', 'jpe', 'png', 'webp'), TRUE) && @getimagesize($this->file_temp) === FALSE)
{
return FALSE;
}
if ($ignore_mime === TRUE)
{
return TRUE;
}
if (isset($this->_mimes[$ext]))
{
return is_array($this->_mimes[$ext])
? in_array($this->file_type, $this->_mimes[$ext], TRUE)
: ($this->_mimes[$ext] === $this->file_type);
}
return FALSE;
}
// --------------------------------------------------------------------
/**
* Verify that the file is within the allowed size
*
* @return bool
*/
public function is_allowed_filesize()
{
return ($this->max_size === 0 OR $this->max_size > $this->file_size);
}
// --------------------------------------------------------------------
/**
* Verify that the image is within the allowed width/height
*
* @return bool
*/
public function is_allowed_dimensions()
{
if ( ! $this->is_image())
{
return TRUE;
}
if (function_exists('getimagesize'))
{
$D = @getimagesize($this->file_temp);
if ($this->max_width > 0 && $D[0] > $this->max_width)
{
return FALSE;
}
if ($this->max_height > 0 && $D[1] > $this->max_height)
{
return FALSE;
}
if ($this->min_width > 0 && $D[0] < $this->min_width)
{
return FALSE;
}
if ($this->min_height > 0 && $D[1] < $this->min_height)
{
return FALSE;
}
}
return TRUE;
}
// --------------------------------------------------------------------
/**
* Validate Upload Path
*
* Verifies that it is a valid upload path with proper permissions.
*
* @return bool
*/
public function validate_upload_path()
{
if ($this->upload_path === '')
{
$this->set_error('upload_no_filepath', 'error');
return FALSE;
}
if (realpath($this->upload_path) !== FALSE)
{
$this->upload_path = str_replace('\\', '/', realpath($this->upload_path));
}
if ( ! is_dir($this->upload_path))
{
$this->set_error('upload_no_filepath', 'error');
return FALSE;
}
if ( ! is_really_writable($this->upload_path))
{
$this->set_error('upload_not_writable', 'error');
return FALSE;
}
$this->upload_path = preg_replace('/(.+?)\/*$/', '\\1/', $this->upload_path);
return TRUE;
}
// --------------------------------------------------------------------
/**
* Extract the file extension
*
* @param string $filename
* @return string
*/
public function get_extension($filename)
{
$x = explode('.', $filename);
if (count($x) === 1)
{
return '';
}
$ext = ($this->file_ext_tolower) ? strtolower(end($x)) : end($x);
return '.'.$ext;
}
// --------------------------------------------------------------------
/**
* Limit the File Name Length
*
* @param string $filename
* @param int $length
* @return string
*/
public function limit_filename_length($filename, $length)
{
if (strlen($filename) < $length)
{
return $filename;
}
$ext = '';
if (strpos($filename, '.') !== FALSE)
{
$parts = explode('.', $filename);
$ext = '.'.array_pop($parts);
$filename = implode('.', $parts);
}
return substr($filename, 0, ($length - strlen($ext))).$ext;
}
// --------------------------------------------------------------------
/**
* Runs the file through the XSS clean function
*
* This prevents people from embedding malicious code in their files.
* I'm not sure that it won't negatively affect certain files in unexpected ways,
* but so far I haven't found that it causes trouble.
*
* @return string
*/
public function do_xss_clean()
{
$file = $this->file_temp;
if (filesize($file) == 0)
{
return FALSE;
}
if (memory_get_usage() && ($memory_limit = ini_get('memory_limit')) > 0)
{
$memory_limit = str_split($memory_limit, strspn($memory_limit, '1234567890'));
if ( ! empty($memory_limit[1]))
{
switch ($memory_limit[1][0])
{
case 'g':
case 'G':
$memory_limit[0] *= 1024 * 1024 * 1024;
break;
case 'm':
case 'M':
$memory_limit[0] *= 1024 * 1024;
break;
default:
break;
}
}
$memory_limit = (int) ceil(filesize($file) + $memory_limit[0]);
ini_set('memory_limit', $memory_limit); // When an integer is used, the value is measured in bytes. - PHP.net
}
// If the file being uploaded is an image, then we should have no problem with XSS attacks (in theory), but
// IE can be fooled into mime-type detecting a malformed image as an html file, thus executing an XSS attack on anyone
// using IE who looks at the image. It does this by inspecting the first 255 bytes of an image. To get around this
// CI will itself look at the first 255 bytes of an image to determine its relative safety. This can save a lot of
// processor power and time if it is actually a clean image, as it will be in nearly all instances _except_ an
// attempted XSS attack.
if (function_exists('getimagesize') && @getimagesize($file) !== FALSE)
{
if (($file = @fopen($file, 'rb')) === FALSE) // "b" to force binary
{
return FALSE; // Couldn't open the file, return FALSE
}
$opening_bytes = fread($file, 256);
fclose($file);
// These are known to throw IE into mime-type detection chaos
// <a, <body, <head, <html, <img, <plaintext, <pre, <script, <table, <title
// title is basically just in SVG, but we filter it anyhow
// if it's an image or no "triggers" detected in the first 256 bytes - we're good
return ! preg_match('/<(a|body|head|html|img|plaintext|pre|script|table|title)[\s>]/i', $opening_bytes);
}
if (($data = @file_get_contents($file)) === FALSE)
{
return FALSE;
}
return $this->_CI->security->xss_clean($data, TRUE);
}
// --------------------------------------------------------------------
/**
* Set an error message
*
* @param string $msg
* @return CI_Upload
*/
public function set_error($msg, $log_level = 'error')
{
$this->_CI->lang->load('upload');
is_array($msg) OR $msg = array($msg);
foreach ($msg as $val)
{
$msg = ($this->_CI->lang->line($val) === FALSE) ? $val : $this->_CI->lang->line($val);
$this->error_msg[] = $msg;
log_message($log_level, $msg);
}
return $this;
}
// --------------------------------------------------------------------
/**
* Display the error message
*
* @param string $open
* @param string $close
* @return string
*/
public function display_errors($open = '<p>', $close = '</p>')
{
return (count($this->error_msg) > 0) ? $open.implode($close.$open, $this->error_msg).$close : '';
}
// --------------------------------------------------------------------
/**
* Prep Filename
*
* Prevents possible script execution from Apache's handling
* of files' multiple extensions.
*
* @link https://httpd.apache.org/docs/1.3/mod/mod_mime.html#multipleext
*
* @param string $filename
* @return string
*/
protected function _prep_filename($filename)
{
if ($this->mod_mime_fix === FALSE OR $this->allowed_types === '*' OR ($ext_pos = strrpos($filename, '.')) === FALSE)
{
return $filename;
}
$ext = substr($filename, $ext_pos);
$filename = substr($filename, 0, $ext_pos);
return str_replace('.', '_', $filename).$ext;
}
// --------------------------------------------------------------------
/**
* File MIME type
*
* Detects the (actual) MIME type of the uploaded file, if possible.
* The input array is expected to be $_FILES[$field]
*
* @param array $file
* @return void
*/
protected function _file_mime_type($file)
{
// We'll need this to validate the MIME info string (e.g. text/plain; charset=us-ascii)
$regexp = '/^([a-z\-]+\/[a-z0-9\-\.\+]+)(;\s.+)?$/';
/**
* Fileinfo extension - most reliable method
*
* Apparently XAMPP, CentOS, cPanel and who knows what
* other PHP distribution channels EXPLICITLY DISABLE
* ext/fileinfo, which is otherwise enabled by default
* since PHP 5.3 ...
*/
if (function_exists('finfo_file'))
{
$finfo = @finfo_open(FILEINFO_MIME);
if ($finfo !== FALSE) // It is possible that a FALSE value is returned, if there is no magic MIME database file found on the system
{
$mime = @finfo_file($finfo, $file['tmp_name']);
finfo_close($finfo);
/* According to the comments section of the PHP manual page,
* it is possible that this function returns an empty string
* for some files (e.g. if they don't exist in the magic MIME database)
*/
if (is_string($mime) && preg_match($regexp, $mime, $matches))
{
$this->file_type = $matches[1];
return;
}
}
}
/* This is an ugly hack, but UNIX-type systems provide a "native" way to detect the file type,
* which is still more secure than depending on the value of $_FILES[$field]['type'], and as it
* was reported in issue #750 (https://github.com/EllisLab/CodeIgniter/issues/750) - it's better
* than mime_content_type() as well, hence the attempts to try calling the command line with
* three different functions.
*
* Notes:
* - the DIRECTORY_SEPARATOR comparison ensures that we're not on a Windows system
* - many system admins would disable the exec(), shell_exec(), popen() and similar functions
* due to security concerns, hence the function_usable() checks
*/
if (DIRECTORY_SEPARATOR !== '\\')
{
$cmd = 'file --brief --mime '.escapeshellarg($file['tmp_name']).' 2>&1';
if (function_usable('exec'))
{
/* This might look confusing, as $mime is being populated with all of the output when set in the second parameter.
* However, we only need the last line, which is the actual return value of exec(), and as such - it overwrites
* anything that could already be set for $mime previously. This effectively makes the second parameter a dummy
* value, which is only put to allow us to get the return status code.
*/
$mime = @exec($cmd, $mime, $return_status);
if ($return_status === 0 && is_string($mime) && preg_match($regexp, $mime, $matches))
{
$this->file_type = $matches[1];
return;
}
}
if (function_usable('shell_exec'))
{
$mime = @shell_exec($cmd);
if (strlen($mime) > 0)
{
$mime = explode("\n", trim($mime));
if (preg_match($regexp, $mime[(count($mime) - 1)], $matches))
{
$this->file_type = $matches[1];
return;
}
}
}
if (function_usable('popen'))
{
$proc = @popen($cmd, 'r');
if (is_resource($proc))
{
$mime = @fread($proc, 512);
@pclose($proc);
if ($mime !== FALSE)
{
$mime = explode("\n", trim($mime));
if (preg_match($regexp, $mime[(count($mime) - 1)], $matches))
{
$this->file_type = $matches[1];
return;
}
}
}
}
}
// Fall back to mime_content_type(), if available (still better than $_FILES[$field]['type'])
if (function_exists('mime_content_type'))
{
$this->file_type = @mime_content_type($file['tmp_name']);
if (strlen($this->file_type) > 0) // It's possible that mime_content_type() returns FALSE or an empty string
{
return;
}
}
$this->file_type = $file['type'];
}
}