lib/private/Files/Type/Detection.php
<?php
/**
* @author Andreas Fischer <bantu@owncloud.com>
* @author Hendrik Leppelsack <hendrik@leppelsack.de>
* @author Jens-Christian Fischer <jens-christian.fischer@switch.ch>
* @author Lukas Reschke <lukas@statuscode.ch>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <icewind@owncloud.com>
* @author Robin McCorkell <robin@mccorkell.me.uk>
* @author Roeland Jago Douma <rullzer@owncloud.com>
* @author Thomas Müller <thomas.mueller@tmit.eu>
* @author Thomas Tanghus <thomas@tanghus.net>
* @author Vincent Petry <pvince81@owncloud.com>
*
* @copyright Copyright (c) 2018, ownCloud GmbH
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
namespace OC\Files\Type;
use OCP\Files\IMimeTypeDetector;
use OCP\IURLGenerator;
/**
* Class Detection
*
* Mimetype detection
*
* @package OC\Files\Type
*/
class Detection implements IMimeTypeDetector {
protected $mimetypes = [];
protected $secureMimeTypes = [];
protected $mimetypeIcons = [];
/** @var string[] */
protected $mimeTypeAlias = [];
/** @var IURLGenerator */
private $urlGenerator;
/** @var string */
private $customConfigDir;
/** @var string */
private $defaultConfigDir;
/**
* @param IURLGenerator $urlGenerator
* @param string $customConfigDir
* @param string $defaultConfigDir
*/
public function __construct(
IURLGenerator $urlGenerator,
$customConfigDir,
$defaultConfigDir
) {
$this->urlGenerator = $urlGenerator;
$this->customConfigDir = $customConfigDir;
$this->defaultConfigDir = $defaultConfigDir;
}
/**
* Add an extension -> mimetype mapping
*
* $mimetype is the assumed correct mime type
* The optional $secureMimeType is an alternative to send to send
* to avoid potential XSS.
*
* @param string $extension
* @param string $mimetype
* @param string|null $secureMimeType
*/
public function registerType(
$extension,
$mimetype,
$secureMimeType = null
) {
$this->mimetypes[$extension] = [$mimetype, $secureMimeType];
$this->secureMimeTypes[$mimetype] = $secureMimeType ?: $mimetype;
}
/**
* Add an array of extension -> mimetype mappings
*
* The mimetype value is in itself an array where the first index is
* the assumed correct mimetype and the second is either a secure alternative
* or null if the correct is considered secure.
*
* @param array $types
*/
public function registerTypeArray($types) {
$this->mimetypes = \array_merge($this->mimetypes, $types);
// Update the alternative mimetypes to avoid having to look them up each time.
foreach ($this->mimetypes as $mimeType) {
$this->secureMimeTypes[$mimeType[0]] = isset($mimeType[1]) ? $mimeType[1]: $mimeType[0];
}
}
/**
* Add the mimetype aliases if they are not yet present
*/
private function loadAliases() {
if (!empty($this->mimeTypeAlias)) {
return;
}
$this->mimeTypeAlias = \json_decode(\file_get_contents($this->defaultConfigDir . '/mimetypealiases.dist.json'), true);
if (\file_exists($this->customConfigDir . '/mimetypealiases.json')) {
$custom = \json_decode(\file_get_contents($this->customConfigDir . '/mimetypealiases.json'), true);
$this->mimeTypeAlias = \array_merge($this->mimeTypeAlias, $custom);
}
}
/**
* @return string[]
*/
public function getAllAliases() {
$this->loadAliases();
return $this->mimeTypeAlias;
}
/**
* Add mimetype mappings if they are not yet present
*/
private function loadMappings() {
if (!empty($this->mimetypes)) {
return;
}
$mimetypeMapping = \json_decode(\file_get_contents($this->defaultConfigDir . '/mimetypemapping.dist.json'), true);
//Check if need to load custom mappings
if (\file_exists($this->customConfigDir . '/mimetypemapping.json')) {
$custom = \json_decode(\file_get_contents($this->customConfigDir . '/mimetypemapping.json'), true);
$mimetypeMapping = \array_merge($mimetypeMapping, $custom);
}
$this->registerTypeArray($mimetypeMapping);
}
/**
* Detect if the file is a shared object file. We detect this file
* with a regex.
*
* @param string $fileName
* @return bool true if file is a shared object else false
*/
private function detectSharedObjFileName($fileName) {
\preg_match("/(.*?)(\.so)([\.]*?.*)/i", $fileName, $match);
/**
* 1. Exactly 4 indexes to match ( check the regex grouping above preg_match )
* 2. Check if the filename has '.so'
* 3. Check if the filename has extension after '.so', say .so.1. or .so.
* That is anything like '.so.*'. This match is made in the 4th index.
* No extension after '.so' is considered to be shared object file
*/
return (\count($match) === 4) && ($match[2] === '.so')
&& ($match[3] === '' || ($match[3] !== '' && \strpos($match[3], '.') === 0));
}
/**
* @return array
*/
public function getAllMappings() {
$this->loadMappings();
return $this->mimetypes;
}
/**
* detect mimetype only based on filename, content of file is not used
*
* @param string $path
* @return string
*/
public function detectPath($path) {
$this->loadMappings();
$fileName = \basename($path);
# let's eat the first char if it is a .
$fileName = ltrim($fileName, ".");
//try to guess the type by the file extension
if ($this->detectSharedObjFileName($fileName)) {
$extension = 'so';
} else {
$extension = \strtolower(\strrchr($fileName, '.'));
$extension = \substr($extension, 1); //remove leading .
}
return (isset($this->mimetypes[$extension], $this->mimetypes[$extension][0]))
? $this->mimetypes[$extension][0]
: 'application/octet-stream';
}
/**
* detect mimetype based on both filename and content
*
* @param string $path
* @return string
*/
public function detect($path) {
$this->loadMappings();
if (@\is_dir($path)) {
// directories are easy
return "httpd/unix-directory";
}
$mimeType = $this->detectPath($path);
if ($mimeType === 'application/octet-stream' and \function_exists('finfo_open')
and \function_exists('finfo_file') and $finfo = \finfo_open(FILEINFO_MIME)
) {
$info = @\strtolower(\finfo_file($finfo, $path));
\finfo_close($finfo);
if ($info) {
$mimeType = \substr($info, 0, \strpos($info, ';'));
return empty($mimeType) ? 'application/octet-stream' : $mimeType;
}
}
$isWrapped = (\strpos($path, '://') !== false) and (\substr($path, 0, 7) === 'file://');
if (!$isWrapped and $mimeType === 'application/octet-stream' && \function_exists("mime_content_type")) {
// use mime magic extension if available
$mimeType = \mime_content_type($path);
}
if (!$isWrapped and $mimeType === 'application/octet-stream' && \OC_Helper::canExecute("file")) {
// it looks like we have a 'file' command,
// lets see if it does have mime support
$path = \escapeshellarg($path);
$fp = \popen("file -b --mime-type $path 2>/dev/null", "r");
$reply = \fgets($fp);
\pclose($fp);
//trim the newline
$mimeType = \trim($reply);
if (empty($mimeType)) {
$mimeType = 'application/octet-stream';
}
}
return $mimeType;
}
/**
* detect mimetype based on the content of a string
*
* @param string $data
* @return string
*/
public function detectString($data) {
if (\function_exists('finfo_open') and \function_exists('finfo_file')) {
$finfo = \finfo_open(FILEINFO_MIME);
return \finfo_buffer($finfo, $data);
} else {
$tmpFile = \OC::$server->getTempManager()->getTemporaryFile();
$fh = \fopen($tmpFile, 'wb');
\fwrite($fh, $data, 8024);
\fclose($fh);
$mime = $this->detect($tmpFile);
unset($tmpFile);
return $mime;
}
}
/**
* Get a secure mimetype that won't expose potential XSS.
*
* @param string $mimeType
* @return string
*/
public function getSecureMimeType($mimeType) {
$this->loadMappings();
return isset($this->secureMimeTypes[$mimeType])
? $this->secureMimeTypes[$mimeType]
: 'application/octet-stream';
}
/**
* Get path to the icon of a file type
* @param string $mimetype the MIME type
* @return string the url
*/
public function mimeTypeIcon($mimetype) {
$this->loadAliases();
while (isset($this->mimeTypeAlias[$mimetype])) {
$mimetype = $this->mimeTypeAlias[$mimetype];
}
if (isset($this->mimetypeIcons[$mimetype])) {
return $this->mimetypeIcons[$mimetype];
}
// Replace slash and backslash with a minus
$icon = \str_replace('/', '-', $mimetype);
$icon = \str_replace('\\', '-', $icon);
// Is it a dir?
if ($mimetype === 'dir') {
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/folder.svg');
return $this->mimetypeIcons[$mimetype];
}
if ($mimetype === 'dir-shared') {
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/folder-shared.svg');
return $this->mimetypeIcons[$mimetype];
}
if ($mimetype === 'dir-external') {
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/folder-external.svg');
return $this->mimetypeIcons[$mimetype];
}
// Icon exists?
try {
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/' . $icon . '.svg');
return $this->mimetypeIcons[$mimetype];
} catch (\RuntimeException $e) {
// Specified image not found
}
// Try only the first part of the filetype
$mimePart = \substr($icon, 0, \strpos($icon, '-'));
try {
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/' . $mimePart . '.svg');
return $this->mimetypeIcons[$mimetype];
} catch (\RuntimeException $e) {
// Image for the first part of the mimetype not found
}
$this->mimetypeIcons[$mimetype] = $this->urlGenerator->imagePath('core', 'filetypes/file.svg');
return $this->mimetypeIcons[$mimetype];
}
}