Validation * * By default, a user can upload files without extension limitations, * which can be a security risk if the webserver is not properly secured. * Use {@link setAllowedExtensions()} to limit this list, * and ensure the "assets/" directory does not execute scripts * (see http://doc.silverstripe.org/secure-development#filesystem). * {@link File::$allowed_extensions} provides a good start for a list of "safe" extensions. * * @package framework * @subpackage filesystem * * @todo Allow for non-database uploads */ class Upload extends Controller { private static $allowed_actions = array( 'index', 'load' ); /** * A dataobject (typically {@see File}) which implements {@see AssetContainer} * * @var AssetContainer */ protected $file; /** * Validator for this upload field * * @var Upload_Validator */ protected $validator; /** * Information about the temporary file produced * by the PHP-runtime. * * @var array */ protected $tmpFile; /** * Replace an existing file rather than renaming the new one. * * @var boolean */ protected $replaceFile; /** * Processing errors that can be evaluated, * e.g. by Form-validation. * * @var array */ protected $errors = array(); /** * A foldername relative to /assets, * where all uploaded files are stored by default. * * @config * @var string */ private static $uploads_folder = "Uploads"; /** * A prefix for the version number added to an uploaded file * when a file with the same name already exists. * Example using no prefix: IMG001.jpg becomes IMG2.jpg * Example using '-v' prefix: IMG001.jpg becomes IMG001-v2.jpg * * @config * @var string */ private static $version_prefix = '-v'; public function __construct() { parent::__construct(); $this->validator = Injector::inst()->create('Upload_Validator'); $this->replaceFile = self::config()->replaceFile; } /** * Get current validator * * @return Upload_Validator $validator */ public function getValidator() { return $this->validator; } /** * Set a different instance than {@link Upload_Validator} * for this upload session. * * @param object $validator */ public function setValidator($validator) { $this->validator = $validator; } /** * Get an asset renamer for the given filename. * * @param string $filename Path name * @return AssetNameGenerator */ protected function getNameGenerator($filename){ return Injector::inst()->createWithArgs('AssetNameGenerator', array($filename)); } /** * * @return AssetStore */ protected function getAssetStore() { return Injector::inst()->get('AssetStore'); } /** * Save an file passed from a form post into the AssetStore directly * * @param $tmpFile array Indexed array that PHP generated for every file it uploads. * @param $folderPath string Folder path relative to /assets * @return array|false Either the tuple array, or false if the file could not be saved */ public function load($tmpFile, $folderPath = false) { // Validate filename $filename = $this->getValidFilename($tmpFile, $folderPath); if(!$filename) { return false; } // Save file into backend $result = $this->storeTempFile($tmpFile, $filename, $this->getAssetStore()); //to allow extensions to e.g. create a version after an upload $this->extend('onAfterLoad', $result); return $result; } /** * Save an file passed from a form post into this object. * File names are filtered through {@link FileNameFilter}, see class documentation * on how to influence this behaviour. * * @param array $tmpFile * @param AssetContainer $file * @return bool True if the file was successfully saved into this record */ public function loadIntoFile($tmpFile, $file = null, $folderPath = false) { $this->file = $file; // Validate filename $filename = $this->getValidFilename($tmpFile, $folderPath); if(!$filename) { return false; } $filename = $this->resolveExistingFile($filename); // Save changes to underlying record (if it's a DataObject) $this->storeTempFile($tmpFile, $filename, $this->file); if($this->file instanceof DataObject) { $this->file->write(); } //to allow extensions to e.g. create a version after an upload $this->file->extend('onAfterUpload'); $this->extend('onAfterLoadIntoFile', $this->file); return true; } /** * Assign this temporary file into the given destination * * @param array $tmpFile * @param string $filename * @param AssetContainer|AssetStore $container * @return array */ protected function storeTempFile($tmpFile, $filename, $container) { // Save file into backend $conflictResolution = $this->replaceFile ? AssetStore::CONFLICT_OVERWRITE : AssetStore::CONFLICT_RENAME; $config = array('conflict' => $conflictResolution); return $container->setFromLocalFile($tmpFile['tmp_name'], $filename, null, null, $config); } /** * Given a temporary file and upload path, validate the file and determine the * value of the 'Filename' tuple that should be used to store this asset. * * @param array $tmpFile * @param string $folderPath * @return string|false Value of filename tuple, or false if invalid */ protected function getValidFilename($tmpFile, $folderPath = false) { if(!is_array($tmpFile)) { throw new InvalidArgumentException( "Upload::load() Not passed an array. Most likely, the form hasn't got the right enctype" ); } // Validate $this->clearErrors(); $valid = $this->validate($tmpFile); if(!$valid) { return false; } // Clean filename if(!$folderPath) { $folderPath = $this->config()->uploads_folder; } $nameFilter = FileNameFilter::create(); $file = $nameFilter->filter($tmpFile['name']); $filename = basename($file); if($folderPath) { $filename = File::join_paths($folderPath, $filename); } return $filename; } /** * Given a file and filename, ensure that file renaming / replacing rules are satisfied * * If replacing, this method may replace $this->file with an existing record to overwrite. * If renaming, a new value for $filename may be returned * * @param string $filename * @return string $filename A filename safe to write to */ protected function resolveExistingFile($filename) { // Create a new file record (or try to retrieve an existing one) if(!$this->file) { $fileClass = File::get_class_for_file_extension( File::get_file_extension($filename) ); $this->file = $fileClass::create(); } // Skip this step if not writing File dataobjects if(! ($this->file instanceof File) ) { return $filename; } // Check there is if existing file $existing = File::find($filename); // If replacing (or no file exists) confirm this filename is safe if($this->replaceFile || !$existing) { // If replacing files, make sure to update the OwnerID if(!$this->file->ID && $this->replaceFile && $existing) { $this->file = $existing; $this->file->OwnerID = Member::currentUserID(); } // Filename won't change if replacing return $filename; } // if filename already exists, version the filename (e.g. test.gif to test-v2.gif, test-v2.gif to test-v3.gif) $renamer = $this->getNameGenerator($filename); foreach($renamer as $newName) { if(!File::find($newName)) { return $newName; } } // Fail $tries = $renamer->getMaxTries(); throw new Exception("Could not rename {$filename} with {$tries} tries"); } /** * @return Boolean */ public function setReplaceFile($bool) { $this->replaceFile = $bool; } /** * @return Boolean */ public function getReplaceFile() { return $this->replaceFile; } /** * Container for all validation on the file * (e.g. size and extension restrictions). * Is NOT connected to the {Validator} classes, * please have a look at {FileField->validate()} * for an example implementation of external validation. * * @param array $tmpFile * @return boolean */ public function validate($tmpFile) { $validator = $this->validator; $validator->setTmpFile($tmpFile); $isValid = $validator->validate(); if($validator->getErrors()) { $this->errors = array_merge($this->errors, $validator->getErrors()); } return $isValid; } /** * Get file-object, either generated from {load()}, * or manually set. * * @return AssetContainer */ public function getFile() { return $this->file; } /** * Set a file-object (similiar to {loadIntoFile()}) * * @param AssetContainer $file */ public function setFile(AssetContainer $file) { $this->file = $file; } /** * Clear out all errors (mostly set by {loadUploaded()}) * including the validator's errors */ public function clearErrors() { $this->errors = array(); $this->validator->clearErrors(); } /** * Determines wether previous operations caused an error. * * @return boolean */ public function isError() { return (count($this->errors)); } /** * Return all errors that occurred while processing so far * (mostly set by {loadUploaded()}) * * @return array */ public function getErrors() { return $this->errors; } } /** * @package framework * @subpackage filesystem */ class Upload_Validator { /** * Contains a list of the max file sizes shared by * all upload fields. This is then duplicated into the * "allowedMaxFileSize" instance property on construct. * * @config * @var array */ private static $default_max_file_size = array(); /** * Information about the temporary file produced * by the PHP-runtime. * * @var array */ protected $tmpFile; protected $errors = array(); /** * Restrict filesize for either all filetypes * or a specific extension, with extension-name * as array-key and the size-restriction in bytes as array-value. * * @var array */ public $allowedMaxFileSize = array(); /** * @var array Collection of extensions. * Extension-names are treated case-insensitive. * * Example: * * array("jpg","GIF") * */ public $allowedExtensions = array(); /** * Return all errors that occurred while validating * the temporary file. * * @return array */ public function getErrors() { return $this->errors; } /** * Clear out all errors */ public function clearErrors() { $this->errors = array(); } /** * Set information about temporary file produced by PHP. * @param array $tmpFile */ public function setTmpFile($tmpFile) { $this->tmpFile = $tmpFile; } /** * Get maximum file size for all or specified file extension. * * @param string $ext * @return int Filesize in bytes */ public function getAllowedMaxFileSize($ext = null) { // Check if there is any defined instance max file sizes if (empty($this->allowedMaxFileSize)) { // Set default max file sizes if there isn't $fileSize = Config::inst()->get('Upload_Validator', 'default_max_file_size'); if (isset($fileSize)) { $this->setAllowedMaxFileSize($fileSize); } else { // When no default is present, use maximum set by PHP $maxUpload = File::ini2bytes(ini_get('upload_max_filesize')); $maxPost = File::ini2bytes(ini_get('post_max_size')); $this->setAllowedMaxFileSize(min($maxUpload, $maxPost)); } } $ext = strtolower($ext); if ($ext) { if (isset($this->allowedMaxFileSize[$ext])) { return $this->allowedMaxFileSize[$ext]; } $category = File::get_app_category($ext); if ($category && isset($this->allowedMaxFileSize['[' . $category . ']'])) { return $this->allowedMaxFileSize['[' . $category . ']']; } return false; } else { return (isset($this->allowedMaxFileSize['*'])) ? $this->allowedMaxFileSize['*'] : false; } } /** * Set filesize maximums (in bytes or INI format). * Automatically converts extensions to lowercase * for easier matching. * * Example: * * array('*' => 200, 'jpg' => 1000, '[doc]' => '5m') * * * @param array|int $rules */ public function setAllowedMaxFileSize($rules) { if(is_array($rules) && count($rules)) { // make sure all extensions are lowercase $rules = array_change_key_case($rules, CASE_LOWER); $finalRules = array(); $tmpSize = 0; foreach ($rules as $rule => $value) { if (is_numeric($value)) { $tmpSize = $value; } else { $tmpSize = File::ini2bytes($value); } $finalRules[$rule] = (int)$tmpSize; } $this->allowedMaxFileSize = $finalRules; } elseif(is_string($rules)) { $this->allowedMaxFileSize['*'] = File::ini2bytes($rules); } elseif((int) $rules > 0) { $this->allowedMaxFileSize['*'] = (int)$rules; } } /** * @return array */ public function getAllowedExtensions() { return $this->allowedExtensions; } /** * Limit allowed file extensions. Empty by default, allowing all extensions. * To allow files without an extension, use an empty string. * See {@link File::$allowed_extensions} to get a good standard set of * extensions that are typically not harmful in a webserver context. * See {@link setAllowedMaxFileSize()} to limit file size by extension. * * @param array $rules List of extensions */ public function setAllowedExtensions($rules) { if(!is_array($rules)) return false; // make sure all rules are lowercase foreach($rules as &$rule) $rule = strtolower($rule); $this->allowedExtensions = $rules; } /** * Determines if the bytesize of an uploaded * file is valid - can be defined on an * extension-by-extension basis in {@link $allowedMaxFileSize} * * @return boolean */ public function isValidSize() { $pathInfo = pathinfo($this->tmpFile['name']); $extension = isset($pathInfo['extension']) ? strtolower($pathInfo['extension']) : null; $maxSize = $this->getAllowedMaxFileSize($extension); return (!$this->tmpFile['size'] || !$maxSize || (int) $this->tmpFile['size'] < $maxSize); } /** * Determines if the temporary file has a valid extension * An empty string in the validation map indicates files without an extension. * @return boolean */ public function isValidExtension() { $pathInfo = pathinfo($this->tmpFile['name']); // Special case for filenames without an extension if(!isset($pathInfo['extension'])) { return in_array('', $this->allowedExtensions, true); } else { return (!count($this->allowedExtensions) || in_array(strtolower($pathInfo['extension']), $this->allowedExtensions)); } } /** * Run through the rules for this validator checking against * the temporary file set by {@link setTmpFile()} to see if * the file is deemed valid or not. * * @return boolean */ public function validate() { // we don't validate for empty upload fields yet if(empty($this->tmpFile['name']) || empty($this->tmpFile['tmp_name'])) { return true; } $isRunningTests = (class_exists('SapphireTest', false) && SapphireTest::is_running_test()); if(isset($this->tmpFile['tmp_name']) && !is_uploaded_file($this->tmpFile['tmp_name']) && !$isRunningTests) { $this->errors[] = _t('File.NOVALIDUPLOAD', 'File is not a valid upload'); return false; } // Check file isn't empty if(empty($this->tmpFile['size']) || !filesize($this->tmpFile['tmp_name'])) { $this->errors[] = _t('File.NOFILESIZE', 'Filesize is zero bytes.'); return false; } $pathInfo = pathinfo($this->tmpFile['name']); // filesize validation if(!$this->isValidSize()) { $ext = (isset($pathInfo['extension'])) ? $pathInfo['extension'] : ''; $arg = File::format_size($this->getAllowedMaxFileSize($ext)); $this->errors[] = _t( 'File.TOOLARGE', 'Filesize is too large, maximum {size} allowed', 'Argument 1: Filesize (e.g. 1MB)', array('size' => $arg) ); return false; } // extension validation if(!$this->isValidExtension()) { $this->errors[] = _t( 'File.INVALIDEXTENSION', 'Extension is not allowed (valid: {extensions})', 'Argument 1: Comma-separated list of valid extensions', array('extensions' => wordwrap(implode(', ', $this->allowedExtensions))) ); return false; } return true; } }