<?php
use dokuwiki\HTTP\Headers;
use dokuwiki\Utf8\PhpString;
/**
* Functions used by lib/exe/fetch.php
* (not included by other parts of dokuwiki)
*/
/**
* Set headers and send the file to the client
*
* The $cache parameter influences how long files may be kept in caches, the $public parameter
* influences if this caching may happen in public proxis or in the browser cache only FS#2734
*
* This function will abort the current script when a 304 is sent or file sending is handled
* through x-sendfile
*
* @param string $file local file to send
* @param string $mime mime type of the file
* @param bool $dl set to true to force a browser download
* @param int $cache remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
* @param bool $public is this a public ressource or a private one?
* @param string $orig original file to send - the file name will be used for the Content-Disposition
* @param array $csp The ContentSecurityPolicy to send
* @author Andreas Gohr <andi@splitbrain.org>
* @author Ben Coburn <btcoburn@silicodon.net>
* @author Gerry Weissbach <dokuwiki@gammaproduction.de>
*
*/
function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null, $csp = [])
{
global $conf;
// send mime headers
header("Content-Type: $mime");
// send security policy if given
if (!empty($csp)) Headers::contentSecurityPolicy($csp);
// calculate cache times
if ($cache == -1) {
$maxage = max($conf['cachetime'], 3600); // cachetime or one hour
$expires = time() + $maxage;
} elseif ($cache > 0) {
$maxage = $cache; // given time
$expires = time() + $maxage;
} else { // $cache == 0
$maxage = 0;
$expires = 0; // 1970-01-01
}
// smart http caching headers
if ($maxage) {
if ($public) {
// cache publically
header('Expires: ' . gmdate("D, d M Y H:i:s", $expires) . ' GMT');
header('Cache-Control: public, proxy-revalidate, no-transform, max-age=' . $maxage);
} else {
// cache in browser
header('Expires: ' . gmdate("D, d M Y H:i:s", $expires) . ' GMT');
header('Cache-Control: private, no-transform, max-age=' . $maxage);
}
} else {
// no cache at all
header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
header('Cache-Control: no-cache, no-transform');
}
//send important headers first, script stops here if '304 Not Modified' response
$fmtime = @filemtime($file);
http_conditionalRequest($fmtime);
// Use the current $file if is $orig is not set.
if ($orig == null) {
$orig = $file;
}
//download or display?
if ($dl) {
header('Content-Disposition: attachment;' . rfc2231_encode(
'filename',
PhpString::basename($orig)
) . ';');
} else {
header('Content-Disposition: inline;' . rfc2231_encode(
'filename',
PhpString::basename($orig)
) . ';');
}
//use x-sendfile header to pass the delivery to compatible webservers
http_sendfile($file);
// send file contents
$fp = @fopen($file, "rb");
if ($fp) {
http_rangeRequest($fp, filesize($file), $mime);
} else {
http_status(500);
echo "Could not read $file - bad permissions?";
}
}
/**
* Try an rfc2231 compatible encoding. This ensures correct
* interpretation of filenames outside of the ASCII set.
* This seems to be needed for file names with e.g. umlauts that
* would otherwise decode wrongly in IE.
*
* There is no additional checking, just the encoding and setting the key=value for usage in headers
*
* @author Gerry Weissbach <gerry.w@gammaproduction.de>
* @param string $name name of the field to be set in the header() call
* @param string $value value of the field to be set in the header() call
* @param string $charset used charset for the encoding of value
* @param string $lang language used.
* @return string in the format " name=value" for values WITHOUT special characters
* @return string in the format " name*=charset'lang'value" for values WITH special characters
*/
function rfc2231_encode($name, $value, $charset = 'utf-8', $lang = 'en')
{
$internal = preg_replace_callback(
'/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/',
static fn($match) => rawurlencode($match[0]),
$value
);
if ($value != $internal) {
return ' ' . $name . '*=' . $charset . "'" . $lang . "'" . $internal;
} else {
return ' ' . $name . '="' . $value . '"';
}
}
/**
* Check for media for preconditions and return correct status code
*
* READ: MEDIA, MIME, EXT, CACHE
* WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
*
* @author Gerry Weissbach <gerry.w@gammaproduction.de>
*
* @param string $media reference to the media id
* @param string $file reference to the file variable
* @param string $rev
* @param int $width
* @param int $height
* @return array as array(STATUS, STATUSMESSAGE)
*/
function checkFileStatus(&$media, &$file, $rev = '', $width = 0, $height = 0)
{
global $MIME, $EXT, $CACHE, $INPUT;
//media to local file
if (media_isexternal($media)) {
//check token for external image and additional for resized and cached images
if (media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
return [412, 'Precondition Failed'];
}
//handle external images
if (str_starts_with($MIME, 'image/')) $file = media_get_from_URL($media, $EXT, $CACHE);
if (!$file) {
//download failed - redirect to original URL
return [302, $media];
}
} else {
$media = cleanID($media);
if (empty($media)) {
return [400, 'Bad request'];
}
// check token for resized images
if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
return [412, 'Precondition Failed'];
}
//check permissions (namespace only)
if (auth_quickaclcheck(getNS($media) . ':X') < AUTH_READ) {
return [403, 'Forbidden'];
}
$file = mediaFN($media, $rev);
}
//check file existance
if (!file_exists($file)) {
return [404, 'Not Found'];
}
return [200, null];
}
/**
* Returns the wanted cachetime in seconds
*
* Resolves named constants
*
* @author Andreas Gohr <andi@splitbrain.org>
*
* @param string $cache
* @return int cachetime in seconds
*/
function calc_cache($cache)
{
global $conf;
if (strtolower($cache) == 'nocache') return 0; //never cache
if (strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
return -1; //cache endless
}