1<?php
2
3/**
4 +-----------------------------------------------------------------------+
5 | This file is part of the Roundcube Webmail client                     |
6 |                                                                       |
7 | Copyright (C) The Roundcube Dev Team                                  |
8 |                                                                       |
9 | Licensed under the GNU General Public License version 3 or            |
10 | any later version with exceptions for skins & plugins.                |
11 | See the README file for a full license statement.                     |
12 |                                                                       |
13 | PURPOSE:                                                              |
14 |   Delivering a specific uploaded file or mail message attachment      |
15 +-----------------------------------------------------------------------+
16 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
17 | Author: Aleksander Machniak <alec@alec.pl>                            |
18 +-----------------------------------------------------------------------+
19*/
20
21class rcmail_action_mail_get extends rcmail_action_mail_index
22{
23    protected static $attachment;
24
25    /**
26     * Request handler.
27     *
28     * @param array $args Arguments from the previous step(s)
29     */
30    public function run($args = [])
31    {
32        $rcmail = rcmail::get_instance();
33
34        // This resets X-Frame-Options for framed output (#6688)
35        $rcmail->output->page_headers();
36
37        // show loading page
38        if (!empty($_GET['_preload'])) {
39            unset($_GET['_preload']);
40            unset($_GET['_safe']);
41
42            $url     = $rcmail->url($_GET + ['_mimewarning' => 1, '_embed' => 1]);
43            $message = $rcmail->gettext('loadingdata');
44
45            header('Content-Type: text/html; charset=' . RCUBE_CHARSET);
46            print "<html>\n<head>\n"
47                . '<meta http-equiv="refresh" content="0; url='.rcube::Q($url).'">' . "\n"
48                . '<meta http-equiv="content-type" content="text/html; charset=' . RCUBE_CHARSET . '">' . "\n"
49                . "</head>\n<body>\n$message\n</body>\n</html>";
50            exit;
51        }
52
53        $attachment = new rcmail_attachment_handler;
54        $mimetype = $attachment->mimetype;
55        $filename = $attachment->filename;
56
57        self::$attachment = $attachment;
58
59        // show part page
60        if (!empty($_GET['_frame'])) {
61            $rcmail->output->set_pagetitle($filename);
62
63            // register UI objects
64            $rcmail->output->add_handlers([
65                    'messagepartframe'    => [$this, 'message_part_frame'],
66                    'messagepartcontrols' => [$this, 'message_part_controls'],
67            ]);
68
69            $part_id = rcube_utils::get_input_value('_part', rcube_utils::INPUT_GET);
70            $uid     = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_GET);
71
72            // message/rfc822 preview (Note: handle also multipart/ parts, they can
73            // come from Enigma, which replaces message/rfc822 with real mimetype)
74            if ($part_id && ($mimetype == 'message/rfc822' || strpos($mimetype, 'multipart/') === 0)) {
75                $uid = preg_replace('/\.[0-9.]+/', '', $uid);
76                $uid .= '.' . $part_id;
77
78                $rcmail->output->set_env('is_message', true);
79            }
80
81            $rcmail->output->set_env('mailbox', $rcmail->storage->get_folder());
82            $rcmail->output->set_env('uid', $uid);
83            $rcmail->output->set_env('part', $part_id);
84            $rcmail->output->set_env('filename', $filename);
85            $rcmail->output->set_env('mimetype', $mimetype);
86
87            $rcmail->output->send('messagepart');
88        }
89
90        // render thumbnail of an image attachment
91        if (!empty($_GET['_thumb']) && $attachment->is_valid()) {
92            $thumbnail_size = $rcmail->config->get('image_thumbnail_size', 240);
93            $file_ident     = $attachment->ident;
94            $thumb_name     = 'thumb' . md5($file_ident . ':' . $rcmail->user->ID . ':' . $thumbnail_size);
95            $cache_file     = rcube_utils::temp_filename($thumb_name, false, false);
96
97            // render thumbnail image if not done yet
98            if (!is_file($cache_file) && $attachment->body_to_file($orig_name = $cache_file . '.tmp')) {
99                $image = new rcube_image($orig_name);
100
101                if ($imgtype = $image->resize($thumbnail_size, $cache_file, true)) {
102                    $mimetype = 'image/' . $imgtype;
103                }
104                else {
105                    // Resize failed, we need to check the file mimetype
106                    // So, we do not exit here, but goto generic file body handler below
107                    $_GET['_thumb']     = 0;
108                    $_REQUEST['_embed'] = 1;
109                }
110            }
111
112            if (!empty($_GET['_thumb'])) {
113                if (is_file($cache_file)) {
114                    $rcmail->output->future_expire_header(3600);
115                    header('Content-Type: ' . $mimetype);
116                    header('Content-Length: ' . filesize($cache_file));
117                    readfile($cache_file);
118                }
119
120                exit;
121            }
122        }
123
124        // Handle attachment body (display or download)
125        if (empty($_GET['_thumb']) && $attachment->is_valid()) {
126            // require CSRF protected url for downloads
127            if (!empty($_GET['_download'])) {
128                $rcmail->request_security_check(rcube_utils::INPUT_GET);
129            }
130
131            $extensions = rcube_mime::get_mime_extensions($mimetype);
132
133            // compare file mimetype with the stated content-type headers and file extension to avoid malicious operations
134            if (!empty($_REQUEST['_embed']) && empty($_REQUEST['_nocheck'])) {
135                $file_extension = strtolower(pathinfo($filename, PATHINFO_EXTENSION));
136
137                // 1. compare filename suffix with expected suffix derived from mimetype
138                $valid = $file_extension && in_array($file_extension, (array)$extensions)
139                    || empty($extensions)
140                    || !empty($_REQUEST['_mimeclass']);
141
142                // 2. detect the real mimetype of the attachment part and compare it with the stated mimetype and filename extension
143                if ($valid || !$file_extension || $mimetype == 'application/octet-stream' || stripos($mimetype, 'text/') === 0) {
144                    $tmp_body = $attachment->body(2048);
145
146                    // detect message part mimetype
147                    $real_mimetype = rcube_mime::file_content_type($tmp_body, $filename, $mimetype, true, true);
148                    list($real_ctype_primary, $real_ctype_secondary) = explode('/', $real_mimetype);
149
150                    // accept text/plain with any extension
151                    if ($real_mimetype == 'text/plain' && self::mimetype_compare($real_mimetype, $mimetype)) {
152                        $valid_extension = true;
153                    }
154                    // ignore differences in text/* mimetypes. Filetype detection isn't very reliable here
155                    else if ($real_ctype_primary == 'text' && strpos($mimetype, $real_ctype_primary) === 0) {
156                        $real_mimetype   = $mimetype;
157                        $valid_extension = true;
158                    }
159                    // ignore filename extension if mimeclass matches (#1489029)
160                    else if (!empty($_REQUEST['_mimeclass']) && $real_ctype_primary == $_REQUEST['_mimeclass']) {
161                        $valid_extension = true;
162                    }
163                    else {
164                        // get valid file extensions
165                        $extensions      = rcube_mime::get_mime_extensions($real_mimetype);
166                        $valid_extension = !$file_extension || empty($extensions) || in_array($file_extension, (array)$extensions);
167                    }
168
169                    if (
170                        // fix mimetype for files wrongly declared as octet-stream
171                        ($mimetype == 'application/octet-stream' && $valid_extension)
172                        // force detected mimetype for images (#8158)
173                        || (strpos($real_mimetype, 'image/') === 0)
174                    ) {
175                        $mimetype = $real_mimetype;
176                    }
177
178                    // "fix" real mimetype the same way the original is before comparison
179                    $real_mimetype = rcube_mime::fix_mimetype($real_mimetype);
180
181                    $valid = $valid_extension && self::mimetype_compare($real_mimetype, $mimetype);
182                }
183                else {
184                    $real_mimetype = $mimetype;
185                }
186
187                // show warning if validity checks failed
188                if (!$valid) {
189                    // send blocked.gif for expected images
190                    if (empty($_REQUEST['_mimewarning']) && strpos($mimetype, 'image/') === 0) {
191                        // Do not cache. Failure might be the result of a misconfiguration,
192                        // thus real content should be returned once fixed.
193                        $content = self::get_resource_content('blocked.gif');
194                        $rcmail->output->nocacheing_headers();
195                        header("Content-Type: image/gif");
196                        header("Content-Transfer-Encoding: binary");
197                        header("Content-Length: " . strlen($content));
198                        echo $content;
199                    }
200                    // html warning with a button to load the file anyway
201                    else {
202                        $rcmail->output = new rcmail_html_page();
203                        $rcmail->output->register_inline_warning(
204                            $rcmail->gettext([
205                                    'name' => 'attachmentvalidationerror',
206                                    'vars' => [
207                                        'expected' => $mimetype . (!empty($file_extension) ? rcube::Q(" (.{$file_extension})") : ''),
208                                        'detected' => $real_mimetype . (!empty($extensions[0]) ? " (.{$extensions[0]})" : ''),
209                                    ]
210                            ]),
211                            $rcmail->gettext('showanyway'),
212                            $rcmail->url(array_merge($_GET, ['_nocheck' => 1]))
213                        );
214
215                        $rcmail->output->write();
216                    }
217
218                    exit;
219                }
220            }
221
222            // TIFF/WEBP to JPEG conversion, if needed
223            foreach (['tiff', 'webp'] as $type) {
224                $img_support = !empty($_SESSION['browser_caps']) && !empty($_SESSION['browser_caps'][$type]);
225                if (
226                    !empty($_REQUEST['_embed'])
227                    && !$img_support
228                    && $attachment->image_type() == 'image/' . $type
229                    && rcube_image::is_convertable('image/' . $type)
230                ) {
231                    $convert2jpeg = true;
232                    $mimetype     = 'image/jpeg';
233                    break;
234                }
235            }
236
237            // deliver part content
238            if ($mimetype == 'text/html' && empty($_GET['_download'])) {
239                $rcmail->output = new rcmail_html_page();
240                $out = '';
241
242                // Check if we have enough memory to handle the message in it
243                // #1487424: we need up to 10x more memory than the body
244                if (!rcube_utils::mem_check($attachment->size * 10)) {
245                    $rcmail->output->register_inline_warning(
246                        $rcmail->gettext('messagetoobig'),
247                        $rcmail->gettext('download'),
248                        $rcmail->url(array_merge($_GET, ['_download' => 1]))
249                    );
250                }
251                else {
252                    // render HTML body
253                    $out = $attachment->html();
254
255                    // insert remote objects warning into HTML body
256                    if (self::$REMOTE_OBJECTS) {
257                        $rcmail->output->register_inline_warning(
258                            $rcmail->gettext('blockedresources'),
259                            $rcmail->gettext('allow'),
260                            $rcmail->url(array_merge($_GET, ['_safe' => 1]))
261                        );
262                    }
263                }
264
265                $rcmail->output->write($out);
266                exit;
267            }
268
269            // add filename extension if missing
270            if (!pathinfo($filename, PATHINFO_EXTENSION) && ($extensions = rcube_mime::get_mime_extensions($mimetype))) {
271                $filename .= '.' . $extensions[0];
272            }
273
274            $rcmail->output->download_headers($filename, [
275                    'type'         => $mimetype,
276                    'type_charset' => $attachment->charset,
277                    'disposition'  => !empty($_GET['_download']) ? 'attachment' : 'inline',
278            ]);
279
280            // handle tiff to jpeg conversion
281            if (!empty($convert2jpeg)) {
282                $file_path = rcube_utils::temp_filename('attmnt');
283
284                // convert image to jpeg and send it to the browser
285                if ($attachment->body_to_file($file_path)) {
286                    $image = new rcube_image($file_path);
287                    if ($image->convert(rcube_image::TYPE_JPG, $file_path)) {
288                        header("Content-Length: " . filesize($file_path));
289                        readfile($file_path);
290                    }
291                }
292            }
293            else {
294                $attachment->output($mimetype);
295            }
296
297            exit;
298        }
299
300        // if we arrive here, the requested part was not found
301        header('HTTP/1.1 404 Not Found');
302        exit;
303    }
304
305    /**
306     * Compares two mimetype strings with making sure that
307     * e.g. image/bmp and image/x-ms-bmp are treated as equal.
308     */
309    public static function mimetype_compare($type1, $type2)
310    {
311        $regexp = '~/(x-ms-|x-)~';
312        $type1  = preg_replace($regexp, '/', $type1);
313        $type2  = preg_replace($regexp, '/', $type2);
314
315        return $type1 === $type2;
316    }
317
318    /**
319     * Attachment properties table
320     */
321    public static function message_part_controls($attrib)
322    {
323        if (!self::$attachment->is_valid()) {
324            return '';
325        }
326
327        $rcmail = rcmail::get_instance();
328        $table  = new html_table(['cols' => 2]);
329
330        $table->add('title', rcube::Q($rcmail->gettext('namex')).':');
331        $table->add('header', rcube::Q(self::$attachment->filename));
332
333        $table->add('title', rcube::Q($rcmail->gettext('type')).':');
334        $table->add('header', rcube::Q(self::$attachment->mimetype));
335
336        $table->add('title', rcube::Q($rcmail->gettext('size')).':');
337        $table->add('header', rcube::Q(self::$attachment->size()));
338
339        return $table->show($attrib);
340    }
341
342    /**
343     * Attachment preview frame
344     */
345    public static function message_part_frame($attrib)
346    {
347        $rcmail = rcmail::get_instance();
348
349        if ($rcmail->output->get_env('is_message')) {
350            $url = [
351                'task'   => 'mail',
352                'action' => 'preview',
353                'uid'    => $rcmail->output->get_env('uid'),
354                'mbox'   => $rcmail->output->get_env('mailbox'),
355            ];
356        }
357        else {
358            $mimetype = $rcmail->output->get_env('mimetype');
359            $url      = $_GET;
360            $url[strpos($mimetype, 'text/') === 0 ? '_embed' : '_preload'] = 1;
361            unset($url['_frame']);
362        }
363
364        $url['_framed'] = 1; // For proper X-Frame-Options:deny handling
365
366        $attrib['src'] = $rcmail->url($url);
367
368        $rcmail->output->add_gui_object('messagepartframe', $attrib['id']);
369
370        return html::iframe($attrib);
371    }
372}
373