gnu-social/lib/themeuploader.php

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<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Utilities for theme files and paths
*
* PHP version 5
*
* 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 Paths
* @package StatusNet
* @author Brion Vibber <brion@status.net>
* @copyright 2010 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET') && !defined('LACONICA')) {
exit(1);
}
/**
* Encapsulation of the validation-and-save process when dealing with
* a user-uploaded StatusNet theme archive...
*
* @todo extract theme metadata from css/display.css
* @todo allow saving multiple themes
*/
class ThemeUploader
{
protected $sourceFile;
protected $isUpload;
private $prevErrorReporting;
public function __construct($filename)
{
if (!class_exists('ZipArchive')) {
throw new Exception(_("This server cannot handle theme uploads without ZIP support."));
}
$this->sourceFile = $filename;
}
public static function fromUpload($name)
{
if (!isset($_FILES[$name]['error'])) {
throw new ServerException(_("The theme file is missing or the upload failed."));
}
if ($_FILES[$name]['error'] != UPLOAD_ERR_OK) {
throw new ServerException(_("The theme file is missing or the upload failed."));
}
return new ThemeUploader($_FILES[$name]['tmp_name']);
}
/**
* @param string $destDir
* @throws Exception on bogus files
*/
public function extract($destDir)
{
$zip = $this->openArchive();
// First pass: validate but don't save anything to disk.
// Any errors will trip an exception.
$this->traverseArchive($zip);
// Second pass: now that we know we're good, actually extract!
$tmpDir = $destDir . '.tmp' . getmypid();
$this->traverseArchive($zip, $tmpDir);
$zip->close();
if (file_exists($destDir)) {
$killDir = $tmpDir . '.old';
$this->quiet();
$ok = rename($destDir, $killDir);
$this->loud();
if (!$ok) {
common_log(LOG_ERR, "Could not move old custom theme from $destDir to $killDir");
throw new ServerException(_("Failed saving theme."));
}
} else {
$killDir = false;
}
$this->quiet();
$ok = rename($tmpDir, $destDir);
$this->loud();
if (!$ok) {
common_log(LOG_ERR, "Could not move saved theme from $tmpDir to $destDir");
throw new ServerException(_("Failed saving theme."));
}
if ($killDir) {
$this->recursiveRmdir($killDir);
}
}
/**
*
*/
protected function traverseArchive($zip, $outdir=false)
{
$sizeLimit = 2 * 1024 * 1024; // 2 megabyte space limit?
$blockSize = 4096; // estimated; any entry probably takes this much space
$totalSize = 0;
$hasMain = false;
$commonBaseDir = false;
for ($i = 0; $i < $zip->numFiles; $i++) {
$data = $zip->statIndex($i);
$name = str_replace('\\', '/', $data['name']);
if (substr($name, -1) == '/') {
// A raw directory... skip!
continue;
}
// Is this a safe or skippable file?
$path = pathinfo($name);
if ($this->skippable($path['filename'], $path['extension'])) {
// Documentation and such... booooring
continue;
} else {
$this->validateFile($path['filename'], $path['extension']);
}
// Check the directory structure...
$dirs = explode('/', $path['dirname']);
$baseDir = array_shift($dirs);
if ($commonBaseDir === false) {
$commonBaseDir = $baseDir;
} else {
if ($commonBaseDir != $baseDir) {
throw new ClientException(_("Invalid theme: bad directory structure."));
}
}
foreach ($dirs as $dir) {
$this->validateFileOrFolder($dir);
}
$fullPath = $dirs;
$fullPath[] = $path['basename'];
$localFile = implode('/', $fullPath);
if ($localFile == 'css/display.css') {
$hasMain = true;
}
$size = $data['size'];
$estSize = $blockSize * max(1, intval(ceil($size / $blockSize)));
$totalSize += $estSize;
if ($totalSize > $sizeLimit) {
$msg = sprintf(_("Uploaded theme is too large; " .
"must be less than %d bytes uncompressed."),
$sizeLimit);
throw new ClientException($msg);
}
if ($outdir) {
$this->extractFile($zip, $data['name'], "$outdir/$localFile");
}
}
if (!$hasMain) {
throw new ClientException(_("Invalid theme archive: " .
"missing file css/display.css"));
}
}
/**
* @fixme Probably most unrecognized files should just be skipped...
*/
protected function skippable($filename, $ext)
{
$skip = array('txt', 'html', 'rtf', 'doc', 'docx', 'odt', 'xcf');
if (strtolower($filename) == 'readme') {
return true;
}
if (in_array(strtolower($ext), $skip)) {
return true;
}
return false;
}
protected function validateFile($filename, $ext)
{
$this->validateFileOrFolder($filename);
$this->validateExtension($ext);
// @fixme validate content
}
protected function validateFileOrFolder($name)
{
if (!preg_match('/^[a-z0-9_\.-]+$/i', $name)) {
$msg = _("Theme contains invalid file or folder name. " .
"Stick with ASCII letters, digits, underscore, and minus sign.");
throw new ClientException($msg);
}
if (preg_match('/\.(php|cgi|asp|aspx|js|vb)\w/i', $name)) {
$msg = _("Theme contains unsafe file extension names; may be unsafe.");
throw new ClientException($msg);
}
return true;
}
protected function validateExtension($ext)
{
$allowed = array('css', // CSS may need validation
'png', 'gif', 'jpg', 'jpeg',
'svg', // SVG images/fonts may need validation
'ttf', 'eot', 'woff');
if (!in_array(strtolower($ext), $allowed)) {
$msg = sprintf(_("Theme contains file of type '.%s', " .
"which is not allowed."),
$ext);
throw new ClientException($msg);
}
return true;
}
/**
* @return ZipArchive
*/
protected function openArchive()
{
$zip = new ZipArchive;
$ok = $zip->open($this->sourceFile);
if ($ok !== true) {
common_log(LOG_ERR, "Error opening theme zip archive: " .
"{$this->sourceFile} code: {$ok}");
throw new Exception(_("Error opening theme archive."));
}
return $zip;
}
/**
* @param ZipArchive $zip
* @param string $from original path inside ZIP archive
* @param string $to final destination path in filesystem
*/
protected function extractFile($zip, $from, $to)
{
$dir = dirname($to);
if (!file_exists($dir)) {
$this->quiet();
$ok = mkdir($dir, 0755, true);
$this->loud();
if (!$ok) {
common_log(LOG_ERR, "Failed to mkdir $dir while uploading theme");
throw new ServerException(_("Failed saving theme."));
}
} else if (!is_dir($dir)) {
common_log(LOG_ERR, "Output directory $dir not a directory while uploading theme");
throw new ServerException(_("Failed saving theme."));
}
// ZipArchive::extractTo would be easier, but won't let us alter
// the directory structure.
$in = $zip->getStream($from);
if (!$in) {
common_log(LOG_ERR, "Couldn't open archived file $from while uploading theme");
throw new ServerException(_("Failed saving theme."));
}
$this->quiet();
$out = fopen($to, "wb");
$this->loud();
if (!$out) {
common_log(LOG_ERR, "Couldn't open output file $to while uploading theme");
throw new ServerException(_("Failed saving theme."));
}
while (!feof($in)) {
$buffer = fread($in, 65536);
fwrite($out, $buffer);
}
fclose($in);
fclose($out);
}
private function quiet()
{
$this->prevErrorReporting = error_reporting();
error_reporting($this->prevErrorReporting & ~E_WARNING);
}
private function loud()
{
error_reporting($this->prevErrorReporting);
}
private function recursiveRmdir($dir)
{
$list = dir($dir);
while (($file = $list->read()) !== false) {
if ($file == '.' || $file == '..') {
continue;
}
$full = "$dir/$file";
if (is_dir($full)) {
$this->recursiveRmdir($full);
} else {
unlink($full);
}
}
$list->close();
rmdir($dir);
}
}