1<?php
2/**
3 * Functions used by lib/exe/fetch.php
4 * (not included by other parts of dokuwiki)
5 */
6
7/**
8 * Set headers and send the file to the client
9 *
10 * The $cache parameter influences how long files may be kept in caches, the $public parameter
11 * influences if this caching may happen in public proxis or in the browser cache only FS#2734
12 *
13 * This function will abort the current script when a 304 is sent or file sending is handled
14 * through x-sendfile
15 *
16 * @param string $file local file to send
17 * @param string $mime mime type of the file
18 * @param bool $dl set to true to force a browser download
19 * @param int $cache remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
20 * @param bool $public is this a public ressource or a private one?
21 * @param string $orig original file to send - the file name will be used for the Content-Disposition
22 * @param array $csp The ContentSecurityPolicy to send
23 * @author Andreas Gohr <andi@splitbrain.org>
24 * @author Ben Coburn <btcoburn@silicodon.net>
25 * @author Gerry Weissbach <dokuwiki@gammaproduction.de>
26 *
27 */
28function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null, $csp=[]) {
29    global $conf;
30    // send mime headers
31    header("Content-Type: $mime");
32
33    // send security policy if given
34    if (!empty($csp)) dokuwiki\HTTP\Headers::contentSecurityPolicy($csp);
35
36    // calculate cache times
37    if($cache == -1) {
38        $maxage  = max($conf['cachetime'], 3600); // cachetime or one hour
39        $expires = time() + $maxage;
40    } else if($cache > 0) {
41        $maxage  = $cache; // given time
42        $expires = time() + $maxage;
43    } else { // $cache == 0
44        $maxage  = 0;
45        $expires = 0; // 1970-01-01
46    }
47
48    // smart http caching headers
49    if($maxage) {
50        if($public) {
51            // cache publically
52            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
53            header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
54        } else {
55            // cache in browser
56            header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
57            header('Cache-Control: private, no-transform, max-age='.$maxage);
58        }
59    } else {
60        // no cache at all
61        header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
62        header('Cache-Control: no-cache, no-transform');
63    }
64
65    //send important headers first, script stops here if '304 Not Modified' response
66    $fmtime = @filemtime($file);
67    http_conditionalRequest($fmtime);
68
69    // Use the current $file if is $orig is not set.
70    if ( $orig == null ) {
71        $orig = $file;
72    }
73
74    //download or display?
75    if ($dl) {
76        header('Content-Disposition: attachment;' . rfc2231_encode(
77                'filename', \dokuwiki\Utf8\PhpString::basename($orig)) . ';'
78        );
79    } else {
80        header('Content-Disposition: inline;' . rfc2231_encode(
81                'filename', \dokuwiki\Utf8\PhpString::basename($orig)) . ';'
82        );
83    }
84
85    //use x-sendfile header to pass the delivery to compatible webservers
86    http_sendfile($file);
87
88    // send file contents
89    $fp = @fopen($file, "rb");
90    if($fp) {
91        http_rangeRequest($fp, filesize($file), $mime);
92    } else {
93        http_status(500);
94        print "Could not read $file - bad permissions?";
95    }
96}
97
98/**
99 * Try an rfc2231 compatible encoding. This ensures correct
100 * interpretation of filenames outside of the ASCII set.
101 * This seems to be needed for file names with e.g. umlauts that
102 * would otherwise decode wrongly in IE.
103 *
104 * There is no additional checking, just the encoding and setting the key=value for usage in headers
105 *
106 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
107 * @param string $name      name of the field to be set in the header() call
108 * @param string $value     value of the field to be set in the header() call
109 * @param string $charset   used charset for the encoding of value
110 * @param string $lang      language used.
111 * @return string           in the format " name=value" for values WITHOUT special characters
112 * @return string           in the format " name*=charset'lang'value" for values WITH special characters
113 */
114function rfc2231_encode($name, $value, $charset='utf-8', $lang='en') {
115    $internal = preg_replace_callback(
116        '/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/',
117        function ($match) {
118            return rawurlencode($match[0]);
119        },
120        $value
121    );
122    if ( $value != $internal ) {
123        return ' '.$name.'*='.$charset."'".$lang."'".$internal;
124    } else {
125        return ' '.$name.'="'.$value.'"';
126    }
127}
128
129/**
130 * Check for media for preconditions and return correct status code
131 *
132 * READ: MEDIA, MIME, EXT, CACHE
133 * WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
134 *
135 * @author Gerry Weissbach <gerry.w@gammaproduction.de>
136 *
137 * @param string $media  reference to the media id
138 * @param string $file   reference to the file variable
139 * @param string $rev
140 * @param int    $width
141 * @param int    $height
142 * @return array as array(STATUS, STATUSMESSAGE)
143 */
144function checkFileStatus(&$media, &$file, $rev = '', $width=0, $height=0) {
145    global $MIME, $EXT, $CACHE, $INPUT;
146
147    //media to local file
148    if(media_isexternal($media)) {
149        //check token for external image and additional for resized and cached images
150        if(media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
151            return array(412, 'Precondition Failed');
152        }
153        //handle external images
154        if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
155        if(!$file) {
156            //download failed - redirect to original URL
157            return array(302, $media);
158        }
159    } else {
160        $media = cleanID($media);
161        if(empty($media)) {
162            return array(400, 'Bad request');
163        }
164        // check token for resized images
165        if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
166            return array(412, 'Precondition Failed');
167        }
168
169        //check permissions (namespace only)
170        if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
171            return array(403, 'Forbidden');
172        }
173        $file = mediaFN($media, $rev);
174    }
175
176    //check file existance
177    if(!file_exists($file)) {
178        return array(404, 'Not Found');
179    }
180
181    return array(200, null);
182}
183
184/**
185 * Returns the wanted cachetime in seconds
186 *
187 * Resolves named constants
188 *
189 * @author  Andreas Gohr <andi@splitbrain.org>
190 *
191 * @param string $cache
192 * @return int cachetime in seconds
193 */
194function calc_cache($cache) {
195    global $conf;
196
197    if(strtolower($cache) == 'nocache') return 0; //never cache
198    if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
199    return -1; //cache endless
200}
201