<?php
/**
* GNU social - a federating social network
*
* Abstraction for media files
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Media
* @package GNUsocial
* @author Robin Millette <robin@millette.info>
* @author Miguel Dantas <biodantas@gmail.com>
* @author Zach Copley <zach@status.net>
* @author Mikael Nordfeldth <mmn@hethane.se>
* @copyright 2008-2009, 2019 Free Software Foundation http://fsf.org
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link https://www.gnu.org/software/social/
*/
defined('GNUSOCIAL') || die();
/**
* Class responsible for abstracting media files
*/
class MediaFile
{
public $id = null;
public $filepath = null;
public $filename = null;
public $fileRecord = null;
public $fileurl = null;
public $short_fileurl = null;
public $mimetype = null;
/**
* @param string $filepath The path of the file this media refers to. Required
* @param string $mimetype The mimetype of the file. Required
* @param $filehash The hash of the file, if known. Optional
* @param int|null $id The DB id of the file. Int if known, null if not.
* If null, it searches for it. If -1, it skips all DB
* interactions (useful for temporary objects)
* @throws ClientException
* @throws NoResultException
* @throws ServerException
*/
public function __construct(string $filepath, string $mimetype, $filehash = null, $id = null)
{
$this->filepath = $filepath;
$this->filename = basename($this->filepath);
$this->mimetype = $mimetype;
$this->filehash = self::getHashOfFile($this->filepath, $filehash);
$this->id = $id;
// If id is -1, it means we're dealing with a temporary object and don't want to store it in the DB,
// or add redirects
if ($this->id !== -1) {
if (!empty($this->id)) {
// If we have an id, load it
$this->fileRecord = new File();
$this->fileRecord->id = $this->id;
if (!$this->fileRecord->find(true)) {
// If we have set an ID, we need that ID to exist!
throw new NoResultException($this->fileRecord);
}
} else {
// Otherwise, store it
$this->fileRecord = $this->storeFile();
}
$this->fileurl = common_local_url(
'attachment',
array('attachment' => $this->fileRecord->id)
);
$this->short_fileurl = common_shorten_url($this->fileurl);
}
}
public function attachToNotice(Notice $notice)
{
File_to_post::processNew($this->fileRecord, $notice);
}
public function getPath()
{
return File::path($this->filename);
}
public function shortUrl()
{
return $this->short_fileurl;
}
public function getEnclosure()
{
return $this->getFile()->getEnclosure();
}
public function delete()
{
@unlink($this->filepath);
}
public function getFile()
{
if (!$this->fileRecord instanceof File) {
throw new ServerException('File record did not exist for MediaFile');
}
return $this->fileRecord;
}
/**
* Calculate the hash of a file.
*
* This won't work for files >2GiB because PHP uses only 32bit.
* @param string $filepath
* @param string|null $filehash
* @return string
* @throws ServerException
*/
public static function getHashOfFile(string $filepath, $filehash = null)
{
assert(!empty($filepath), __METHOD__ . ": filepath cannot be null");
if ($filehash === null) {
// Calculate if we have an older upload method somewhere (Qvitter) that
// doesn't do this before calling new MediaFile on its local files...
$filehash = hash_file(File::FILEHASH_ALG, $filepath);
if ($filehash === false) {
throw new ServerException('Could not read file for hashing');
}
}
return $filehash;
}
/**
* Retrieve or insert as a file in the DB
*
* @return object File
* @throws ClientException
* @throws ServerException
*/
protected function storeFile()
{
try {
$file = File::getByHash($this->filehash);
// We're done here. Yes. Already. We assume sha256 won't collide on us anytime soon.
return $file;
} catch (NoResultException $e) {
// Well, let's just continue below.
}
$fileurl = common_local_url('attachment_view', array('filehash' => $this->filehash));
$file = new File;
$file->filename = $this->filename;
$file->urlhash = File::hashurl($fileurl);
$file->url = $fileurl;
$file->filehash = $this->filehash;
$file->size = filesize($this->filepath);
if ($file->size === false) {
throw new ServerException('Could not read file to get its size');
}
$file->date = time();
$file->mimetype = $this->mimetype;
$file_id = $file->insert();
if ($file_id===false) {
common_log_db_error($file, "INSERT", __FILE__);
// TRANS: Client exception thrown when a database error was thrown during a file upload operation.
throw new ClientException(_m('There was a database error while saving your file. Please try again.'));
}
// Set file geometrical properties if available
try {
$image = ImageFile::fromFileObject($file);
$orig = clone($file);
$file->width = $image->width;
$file->height = $image->height;
$file->update($orig);
// We have to cleanup after ImageFile, since it
// may have generated a temporary file from a
// video support plugin or something.
// FIXME: Do this more automagically.
if ($image->getPath() != $file->getPath()) {
$image->unlink();
}
} catch (ServerException $e) {
// We just couldn't make out an image from the file. This
// does not have to be UnsupportedMediaException, as we can
// also get ServerException from files not existing etc.
}
return $file;
}
/**
* The maximum allowed file size, as a string
*/
public static function maxFileSize()
{
$value = self::maxFileSizeInt();
if ($value > 1024 * 1024) {
$value = $value/(1024*1024);
// TRANS: Number of megabytes. %d is the number.
return sprintf(_m('%dMB', '%dMB', $value), $value);
} elseif ($value > 1024) {
$value = $value/1024;
// TRANS: Number of kilobytes. %d is the number.
return sprintf(_m('%dkB', '%dkB', $value), $value);
} else {
// TRANS: Number of bytes. %d is the number.
return sprintf(_m('%dB', '%dB', $value), $value);
}
}
/**
* The maximum allowed file size, as an int
*/
public static function maxFileSizeInt() : int
{
return common_config('attachments', 'file_quota');
}
/**
* Encodes a file name and a file hash in the new file format, which is used to avoid
* having an extension in the file, removing trust in extensions, while keeping the original name
* @throws ClientException
*/
public static function encodeFilename($original_name, string $filehash, $ext = null) : string
{
if (empty($original_name)) {
$original_name = _m('Untitled attachment');
}
// If we're given an extension explicitly, use it, otherwise...
$ext = $ext ?:
// get a replacement extension if configured, returns false if it's blocked,
// null if no extension
File::getSafeExtension($original_name);
if ($ext === false) {
throw new ClientException(_m('Blacklisted file extension.'));
}
if (!empty($ext)) {
// Remove dots if we have them (make sure they're not repeated)
$ext = preg_replace('/^\.+/', '', $ext);
$original_name = preg_replace('/\.+.+$/i', ".{$ext}", $original_name);
}
$enc_name = bin2hex($original_name);
return "{$enc_name}-{$filehash}";
}
/**
* Decode the new filename format
* @return false | null | string on failure, no match (old format) or original file name, respectively
*/
public static function decodeFilename(string $encoded_filename)
{
// Should match:
// hex-hash
// thumb-id-widthxheight-hex-hash
// And return the `hex` part
$ret = preg_match('/^(.*-)?([^-]+)-[^-]+$/', $encoded_filename, $matches);
if ($ret === false) {
return false;
} elseif ($ret === 0 || !ctype_xdigit($matches[2])) {
return null; // No match
} else {
$filename = hex2bin($matches[2]);
// Matches extension
if (preg_match('/^(.+?)\.(.+)$/', $filename, $sub_matches) === 1) {
$ext = $sub_matches[2];
// Previously, there was a blacklisted extension array, which could have an alternative
// extension, such as phps, to replace php. We want to turn it back (this is deprecated,
// as it no longer makes sense, since we don't trust trust files based on extension,
// but keep the feature)
$blacklist = common_config('attachments', 'extblacklist');
if (is_array($blacklist)) {
foreach ($blacklist as $upload_ext => $safe_ext) {
if ($ext === $safe_ext) {
$ext = $upload_ext;
break;
}
}
}
return "{$sub_matches[1]}.{$ext}";
} else {
// No extension, don't bother trying to replace it
return $filename;
}
}
}
/**
* Create a new MediaFile or ImageFile object from an upload
*
* Tries to set the mimetype correctly, using the most secure method available and rejects the file otherwise.
* In case the upload is an image, this function returns an new ImageFile (which extends MediaFile)
* The filename has a new format:
* bin2hex("{$original_name}.{$ext}")."-{$filehash}"
* This format should be respected. Notice the dash, which is important to distinguish it from the previous
* format ("{$hash}.{$ext}")
*
* @param string $param Form name
* @param Profile|null $scoped
* @return ImageFile|MediaFile
* @throws ClientException
* @throws NoResultException
* @throws NoUploadedMediaException
* @throws ServerException
* @throws UnsupportedMediaException
* @throws UseFileAsThumbnailException
*/
public static function fromUpload(string $param='media', Profile $scoped=null)
{
// The existence of the "error" element means PHP has processed it properly even if it was ok.
if (!(isset($_FILES[$param]) && isset($_FILES[$param]['error']))) {
throw new NoUploadedMediaException($param);
}
switch ($_FILES[$param]['error']) {
case UPLOAD_ERR_OK: // success, jump out
break;
case UPLOAD_ERR_INI_SIZE:
case UPLOAD_ERR_FORM_SIZE:
// TRANS: Exception thrown when too large a file is uploaded.
// TRANS: %s is the maximum file size, for example "500b", "10kB" or "2MB".
throw new ClientException(sprintf(
_m('That file is too big. The maximum file size is %s.'),
self::maxFileSize()
));
case UPLOAD_ERR_PARTIAL:
@unlink($_FILES[$param]['tmp_name']);
// TRANS: Client exception.
throw new ClientException(_m('The uploaded file was only partially uploaded.'));
case UPLOAD_ERR_NO_FILE:
// No file; probably just a non-AJAX submission.
throw new NoUploadedMediaException($param);
case UPLOAD_ERR_NO_TMP_DIR:
// TRANS: Client exception thrown when a temporary folder is not present to store a file upload.
throw new ClientException(_m('Missing a temporary folder.'));
case UPLOAD_ERR_CANT_WRITE:
// TRANS: Client exception thrown when writing to disk is not possible during a file upload operation.
throw new ClientException(_m('Failed to write file to disk.'));
case UPLOAD_ERR_EXTENSION:
// TRANS: Client exception thrown when a file upload operation has been stopped by an extension.
throw new ClientException(_m('File upload stopped by extension.'));
default:
common_log(LOG_ERR, __METHOD__ . ": Unknown upload error " . $_FILES[$param]['error']);
// TRANS: Client exception thrown when a file upload operation has failed with an unknown reason.
throw new ClientException(_m('System error uploading file.'));
}
$filehash = strtolower(self::getHashOfFile($_FILES[$param]['tmp_name']));
try {
$file = File::getByHash($filehash);
// If no exception is thrown the file exists locally, so we'll use that and just add redirections.
// but if the _actual_ locally stored file doesn't exist, getPath will throw FileNotFoundException
$filepath = $file->getPath();
$mimetype = $file->mimetype;
} catch (FileNotFoundException | NoResultException $e) {
// We have to save the upload as a new local file. This is the normal course of action.
if ($scoped instanceof Profile) {
// Throws exception if additional size does not respect quota
// This test is only needed, of course, if we're uploading something new.
File::respectsQuota($scoped, $_FILES[$param]['size']);
}
$mimetype = self::getUploadedMimeType($_FILES[$param]['tmp_name'], $_FILES[$param]['name']);
$media = common_get_mime_media($mimetype);
$basename = basename($_FILES[$param]['name']);
if ($media == 'image') {
// Use -1 for the id to avoid adding this temporary file to the DB
$img = new ImageFile(-1, $_FILES[$param]['tmp_name']);
// Validate the image by re-encoding it. Additionally normalizes old formats to PNG,
// keeping JPEG and GIF untouched
$outpath = $img->resizeTo($img->filepath);
$ext = image_type_to_extension($img->preferredType(), false);
}
$filename = self::encodeFilename($basename, $filehash, isset($ext) ? $ext : File::getSafeExtension($basename));
$filepath = File::path($filename);
if ($media == 'image') {
$result = rename($outpath, $filepath);
} else {
$result = move_uploaded_file($_FILES[$param]['tmp_name'], $filepath);
}
if (!$result) {
// TRANS: Client exception thrown when a file upload operation fails because the file could
// TRANS: not be moved from the temporary folder to the permanent file location.
// UX: too specific
throw new ClientException(_m('File could not be moved to destination directory.'));
}
if ($media == 'image') {
return new ImageFile(null, $filepath);
}
}
return new MediaFile($filepath, $mimetype, $filehash);
}
public static function fromFilehandle($fh, Profile $scoped=null)
{
$stream = stream_get_meta_data($fh);
// So far we're only handling filehandles originating from tmpfile(),
// so we can always do hash_file on $stream['uri'] as far as I can tell!
$filehash = hash_file(File::FILEHASH_ALG, $stream['uri']);
try {
$file = File::getByHash($filehash);
// Already have it, so let's reuse the locally stored File
// by using getPath we also check whether the file exists
// and throw a FileNotFoundException with the path if it doesn't.
$filename = basename($file->getPath());
$mimetype = $file->mimetype;
} catch (FileNotFoundException $e) {
// This happens if the file we have uploaded has disappeared
// from the local filesystem for some reason. Since we got the
// File object from a sha256 check in fromFilehandle, it's safe
// to just copy the uploaded data to disk!
fseek($fh, 0); // just to be sure, go to the beginning
// dump the contents of our filehandle to the path from our exception
// and report error if it failed.
if (false === file_put_contents($e->path, fread($fh, filesize($stream['uri'])))) {
// TRANS: Client exception thrown when a file upload operation fails because the file could
// TRANS: not be moved from the temporary folder to the permanent file location.
throw new ClientException(_m('File could not be moved to destination directory.'));
}
if (!chmod($e->path, 0664)) {
common_log(LOG_ERR, 'Could not chmod uploaded file: '._ve($e->path));
}
$filename = basename($file->getPath());
$mimetype = $file->mimetype;
} catch (NoResultException $e) {
if ($scoped instanceof Profile) {
File::respectsQuota($scoped, filesize($stream['uri']));
}
$mimetype = self::getUploadedMimeType($stream['uri']);
$filename = strtolower($filehash) . '.' . File::guessMimeExtension($mimetype);
$filepath = File::path($filename);
$result = copy($stream['uri'], $filepath) && chmod($filepath, 0664);
if (!$result) {
common_log(LOG_ERR, 'File could not be moved (or chmodded) from '._ve($stream['uri']) . ' to ' . _ve($filepath));
// TRANS: Client exception thrown when a file upload operation fails because the file could
// TRANS: not be moved from the temporary folder to the permanent file location.
throw new ClientException(_m('File could not be moved to destination directory.'));
}
}
return new MediaFile($filename, $mimetype, $filehash);
}
/**
* Attempt to identify the content type of a given file.
*
* @param string $filepath filesystem path as string (file must exist)
* @param bool $originalFilename (optional) for extension-based detection
* @return string
*
* @throws ClientException if type is known, but not supported for local uploads
* @throws ServerException
* @fixme this seems to tie a front-end error message in, kinda confusing
*
*/
public static function getUploadedMimeType(string $filepath, $originalFilename=false)
{
// We only accept filenames to existing files
$mimetype = null;
// From CodeIgniter
// 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')) {
$finfo = @finfo_open(FILEINFO_MIME);
// It is possible that a FALSE value is returned, if there is no magic MIME database
// file found on the system
if (is_resource($finfo)) {
$mime = @finfo_file($finfo, $filepath);
finfo_close($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)) {
$mimetype = $matches[1];
}
}
}
/* 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 !== '\\') {
$cmd = 'file --brief --mime '.escapeshellarg($filepath).' 2>&1';
if (empty($mimetype) && function_exists('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)) {
$mimetype = $matches[1];
}
}
if (empty($mimetype) && function_exists('shell_exec')) {
$mime = @shell_exec($cmd);
if (strlen($mime) > 0) {
$mime = explode("\n", trim($mime));
if (preg_match($regexp, $mime[(count($mime) - 1)], $matches)) {
$mimetype = $matches[1];
}
}
}
if (empty($mimetype) && function_exists('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)) {
$mimetype = $matches[1];
}
}
}
}
}
// Fall back to mime_content_type(), if available (still better than $_FILES[$field]['type'])
if (empty($mimetype) && function_exists('mime_content_type')) {
$mimetype = @mime_content_type($filepath);
// It's possible that mime_content_type() returns FALSE or an empty string
if ($mimetype == false && strlen($mimetype) > 0) {
throw new ServerException(_m('Could not determine file\'s MIME type.'));
}
}
// Unclear types are such that we can't really tell by the auto
// detect what they are (.bin, .exe etc. are just "octet-stream")
$unclearTypes = array('application/octet-stream',
'application/vnd.ms-office',
'application/zip',
'text/plain',
'text/html', // Ironically, Wikimedia Commons' SVG_logo.svg is identified as text/html
// TODO: for XML we could do better content-based sniffing too
'text/xml');
$supported = common_config('attachments', 'supported');
// If we didn't match, or it is an unclear match
if ($originalFilename && (!$mimetype || in_array($mimetype, $unclearTypes))) {
try {
$type = common_supported_filename_to_mime($originalFilename);
return $type;
} catch (UnknownExtensionMimeException $e) {
// FIXME: I think we should keep the file extension here (supported should be === true here)
} catch (Exception $e) {
// Extension parsed but no connected mimetype, so $mimetype is our best guess
}
}
// If $config['attachments']['supported'] equals boolean true, accept any mimetype
if ($supported === true || array_key_exists($mimetype, $supported)) {
// FIXME: Don't know if it always has a mimetype here because
// finfo->file CAN return false on error: http://php.net/finfo_file
// so if $supported === true, this may return something unexpected.
return $mimetype;
}
// We can conclude that we have failed to get the MIME type
$media = common_get_mime_media($mimetype);
if ('application' !== $media) {
// TRANS: Client exception thrown trying to upload a forbidden MIME type.
// TRANS: %1$s is the file type that was denied, %2$s is the application part of
// TRANS: the MIME type that was denied.
$hint = sprintf(_m('"%1$s" is not a supported file type on this server. ' .
'Try using another %2$s format.'), $mimetype, $media);
} else {
// TRANS: Client exception thrown trying to upload a forbidden MIME type.
// TRANS: %s is the file type that was denied.
$hint = sprintf(_m('"%s" is not a supported file type on this server.'), $mimetype);
}
throw new ClientException($hint);
}
/**
* Title for a file, to display in the interface (if there's no better title) and
* for download filenames
* @param $file File object
* @returns string
*/
public static function getDisplayName(File $file) : string {
if (empty($file->filename)) {
return _m('Untitled attachment');
}
// New file name format is "{bin2hex(original_name.ext)}-{$hash}"
$filename = self::decodeFilename($file->filename);
// If there was an error in the match, something's wrong with some piece
// of code (could be a file with utf8 chars in the name)
$log_error_msg = "Invalid file name for File with id={$file->id} " .
"({$file->filename}). Some plugin probably did something wrong.";
if ($filename === false) {
common_log(LOG_ERR, $log_error_msg);
} elseif ($filename === null) {
// The old file name format was "{hash}.{ext}" so we didn't have a name
// This extracts the extension
$ret = preg_match('/^.+?\.+?(.+)$/', $file->filename, $matches);
if ($ret !== 1) {
common_log(LOG_ERR, $log_error_msg);
return _m('Untitled attachment');
}
$ext = $matches[1];
// There's a blacklisted extension array, which could have an alternative
// extension, such as phps, to replace php. We want to turn it back
// (currently defaulted to empty, but let's keep the feature)
$blacklist = common_config('attachments', 'extblacklist');
if (is_array($blacklist)) {
foreach ($blacklist as $upload_ext => $safe_ext) {
if ($ext === $safe_ext) {
$ext = $upload_ext;
break;
}
}
}
$filename = "untitled.{$ext}";
}
return $filename;
}
}