phpBB

Code Changes

File: includes/functions_download.php

  Unmodified   Added   Modified   Removed
Line 1Line 1
<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/

/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
exit;
}

/**
* A simplified function to deliver avatars
* The argument needs to be checked before calling this function.
*/
function send_avatar_to_browser($file, $browser)
{
global $config, $phpbb_root_path;

$prefix = $config['avatar_salt'] . '_';
$image_dir = $config['avatar_path'];

// Adjust image_dir path (no trailing slash)
if (substr($image_dir, -1, 1) == '/' || substr($image_dir, -1, 1) == '\\')
{
$image_dir = substr($image_dir, 0, -1) . '/';
}
$image_dir = str_replace(array('../', '..\\', './', '.\\'), '', $image_dir);

if ($image_dir && ($image_dir[0] == '/' || $image_dir[0] == '\\'))
{
$image_dir = '';
}
$file_path = $phpbb_root_path . $image_dir . '/' . $prefix . $file;

if ((@file_exists($file_path) && @is_readable($file_path)) && !headers_sent())
{
header('Cache-Control: public');

$image_data = @getimagesize($file_path);
header('Content-Type: ' . image_type_to_mime_type($image_data[2]));

if ((strpos(strtolower($browser), 'msie') !== false) && !phpbb_is_greater_ie_version($browser, 7))
{
header('Content-Disposition: attachment; ' . header_filename($file));

if (strpos(strtolower($browser), 'msie 6.0') !== false)
{
header('Expires: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
}
else
{
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 31536000) . ' GMT');
}
}
else
{
header('Content-Disposition: inline; ' . header_filename($file));
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 31536000) . ' GMT');
}

$size = @filesize($file_path);
if ($size)
{
header("Content-Length: $size");
}

if (@readfile($file_path) == false)
{
$fp = @fopen($file_path, 'rb');

if ($fp !== false)
{
while (!feof($fp))
{
echo fread($fp, 8192);
}
fclose($fp);
}
}

flush();
}
else
{
header('HTTP/1.0 404 Not Found');
}
}

/**
* Wraps an url into a simple html page. Used to display attachments in IE.
* this is a workaround for now; might be moved to template system later
* direct any complaints to 1 Microsoft Way, Redmond
*/
function wrap_img_in_html($src, $title)
{
echo '<!DOCTYPE html>';
echo '<html>';
echo '<head>';
echo '<meta charset="utf-8">';
echo '<meta http-equiv="X-UA-Compatible" content="IE=edge">';
echo '<title>' . $title . '</title>';
echo '</head>';
echo '<body>';
echo '<div>';
echo '<img src="' . $src . '" alt="' . $title . '" />';
echo '</div>';
echo '</body>';
echo '</html>';
}

/**
* Send file to browser
*/
function send_file_to_browser($attachment, $upload_dir, $category)
{
global $user, $db, $config, $phpbb_root_path;

$filename = $phpbb_root_path . $upload_dir . '/' . $attachment['physical_filename'];

if (!@file_exists($filename))
{
send_status_line(404, 'Not Found');
trigger_error('ERROR_NO_ATTACHMENT');
}

// Correct the mime type - we force application/octetstream for all files, except images
// Please do not change this, it is a security precaution
if ($category != ATTACHMENT_CATEGORY_IMAGE || strpos($attachment['mimetype'], 'image') !== 0)
{
$attachment['mimetype'] = (strpos(strtolower($user->browser), 'msie') !== false || strpos(strtolower($user->browser), 'opera') !== false) ? 'application/octetstream' : 'application/octet-stream';
}

if (@ob_get_length())
{
@ob_end_clean();
}

// Now send the File Contents to the Browser
$size = @filesize($filename);

// To correctly display further errors we need to make sure we are using the correct headers for both (unsetting content-length may not work)

// Check if headers already sent or not able to get the file contents.
if (headers_sent() || !@file_exists($filename) || !@is_readable($filename))
{
// PHP track_errors setting On?
if (!empty($php_errormsg))
{
send_status_line(500, 'Internal Server Error');
trigger_error($user->lang['UNABLE_TO_DELIVER_FILE'] . '<br />' . sprintf($user->lang['TRACKED_PHP_ERROR'], $php_errormsg));
}

send_status_line(500, 'Internal Server Error');
trigger_error('UNABLE_TO_DELIVER_FILE');
}

// Make sure the database record for the filesize is correct
if ($size > 0 && $size != $attachment['filesize'] && strpos($attachment['physical_filename'], 'thumb_') === false)
{
// Update database record
$sql = 'UPDATE ' . ATTACHMENTS_TABLE . '
SET filesize = ' . (int) $size . '
WHERE attach_id = ' . (int) $attachment['attach_id'];
$db->sql_query($sql);
}

// Now the tricky part... let's dance
header('Cache-Control: public');

// Send out the Headers. Do not set Content-Disposition to inline please, it is a security measure for users using the Internet Explorer.
header('Content-Type: ' . $attachment['mimetype']);

if (phpbb_is_greater_ie_version($user->browser, 7))
{
header('X-Content-Type-Options: nosniff');
}

if ($category == ATTACHMENT_CATEGORY_FLASH && request_var('view', 0) === 1)
{
// We use content-disposition: inline for flash files and view=1 to let it correctly play with flash player 10 - any other disposition will fail to play inline
header('Content-Disposition: inline');
}
else
{
if (empty($user->browser) || ((strpos(strtolower($user->browser), 'msie') !== false) && !phpbb_is_greater_ie_version($user->browser, 7)))
{
header('Content-Disposition: attachment; ' . header_filename(htmlspecialchars_decode($attachment['real_filename'])));
if (empty($user->browser) || (strpos(strtolower($user->browser), 'msie 6.0') !== false))
{
header('Expires: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
}
}
else
{
header('Content-Disposition: ' . ((strpos($attachment['mimetype'], 'image') === 0) ? 'inline' : 'attachment') . '; ' . header_filename(htmlspecialchars_decode($attachment['real_filename'])));
if (phpbb_is_greater_ie_version($user->browser, 7) && (strpos($attachment['mimetype'], 'image') !== 0))
{
header('X-Download-Options: noopen');
}
}
}

// Close the db connection before sending the file etc.
file_gc(false);

if (!set_modified_headers($attachment['filetime'], $user->browser))
{
// We make sure those have to be enabled manually by defining a constant
// because of the potential disclosure of full attachment path
// in case support for features is absent in the webserver software.
if (defined('PHPBB_ENABLE_X_ACCEL_REDIRECT') && PHPBB_ENABLE_X_ACCEL_REDIRECT)
{
// X-Accel-Redirect - http://wiki.nginx.org/XSendfile
header('X-Accel-Redirect: ' . $user->page['root_script_path'] . $upload_dir . '/' . $attachment['physical_filename']);
exit;
}
else if (defined('PHPBB_ENABLE_X_SENDFILE') && PHPBB_ENABLE_X_SENDFILE && !phpbb_http_byte_range($size))
{
// X-Sendfile - http://blog.lighttpd.net/articles/2006/07/02/x-sendfile
// Lighttpd's X-Sendfile does not support range requests as of 1.4.26
// and always requires an absolute path.
header('X-Sendfile: ' . dirname(__FILE__) . "/../$upload_dir/{$attachment['physical_filename']}");
exit;
}

if ($size)
{
header("Content-Length: $size");
}

// Try to deliver in chunks
@set_time_limit(0);

$fp = @fopen($filename, 'rb');

if ($fp !== false)
{
// Deliver file partially if requested
if ($range = phpbb_http_byte_range($size))
{
fseek($fp, $range['byte_pos_start']);

send_status_line(206, 'Partial Content');
header('Content-Range: bytes ' . $range['byte_pos_start'] . '-' . $range['byte_pos_end'] . '/' . $range['bytes_total']);
header('Content-Length: ' . $range['bytes_requested']);
}

while (!feof($fp))
{
echo fread($fp, 8192);
}
fclose($fp);
}
else
{
@readfile($filename);
}

flush();
}

exit;
}

/**
* Get a browser friendly UTF-8 encoded filename
*/
function header_filename($file)
{
global $request;

$user_agent = $request->header('User-Agent');

// There be dragons here.
// Not many follows the RFC...
if (strpos($user_agent, 'MSIE') !== false || strpos($user_agent, 'Konqueror') !== false)
{
return "filename=" . rawurlencode($file);
}

// follow the RFC for extended filename for the rest
return "filename*=UTF-8''" . rawurlencode($file);
}

/**
* Check if downloading item is allowed
*/
function download_allowed()
{
global $config, $user, $db, $request;

if (!$config['secure_downloads'])
{
return true;
}

$url = htmlspecialchars_decode($request->header('Referer'));

if (!$url)
{
return ($config['secure_allow_empty_referer']) ? true : false;
}

// Split URL into domain and script part
$url = @parse_url($url);

if ($url === false)
{
return ($config['secure_allow_empty_referer']) ? true : false;
}

$hostname = $url['host'];
unset($url);

$allowed = ($config['secure_allow_deny']) ? false : true;
$iplist = array();

if (($ip_ary = @gethostbynamel($hostname)) !== false)
{
foreach ($ip_ary as $ip)
{
if ($ip)
{
$iplist[] = $ip;
}
}
}

// Check for own server...
$server_name = $user->host;

// Forcing server vars is the only way to specify/override the protocol
if ($config['force_server_vars'] || !$server_name)
{
$server_name = $config['server_name'];
}

if (preg_match('#^.*?' . preg_quote($server_name, '#') . '.*?$#i', $hostname))
{
$allowed = true;
}

// Get IP's and Hostnames
if (!$allowed)
{
$sql = 'SELECT site_ip, site_hostname, ip_exclude
FROM ' . SITELIST_TABLE;
$result = $db->sql_query($sql);

while ($row = $db->sql_fetchrow($result))
{
$site_ip = trim($row['site_ip']);
$site_hostname = trim($row['site_hostname']);

if ($site_ip)
{
foreach ($iplist as $ip)
{
if (preg_match('#^' . str_replace('\*', '.*?', preg_quote($site_ip, '#')) . '$#i', $ip))
{
if ($row['ip_exclude'])
{
$allowed = ($config['secure_allow_deny']) ? false : true;
break 2;
}
else
{
$allowed = ($config['secure_allow_deny']) ? true : false;
}
}
}
}

if ($site_hostname)
{
if (preg_match('#^' . str_replace('\*', '.*?', preg_quote($site_hostname, '#')) . '$#i', $hostname))
{
if ($row['ip_exclude'])
{
$allowed = ($config['secure_allow_deny']) ? false : true;
break;
}
else
{
$allowed = ($config['secure_allow_deny']) ? true : false;
}
}
}
}
$db->sql_freeresult($result);
}

return $allowed;
}

/**
* Check if the browser has the file already and set the appropriate headers-
* @returns false if a resend is in order.
*/
function set_modified_headers($stamp, $browser)
{
global $request;

// let's see if we have to send the file at all
$last_load = $request->header('If-Modified-Since') ? strtotime(trim($request->header('If-Modified-Since'))) : false;

if (strpos(strtolower($browser), 'msie 6.0') === false && !phpbb_is_greater_ie_version($browser, 7))
{
if ($last_load !== false && $last_load >= $stamp)
{
send_status_line(304, 'Not Modified');
// seems that we need those too ... browsers
header('Cache-Control: public');
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 31536000) . ' GMT');
return true;
}
else
{
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', $stamp) . ' GMT');
}
}
return false;
}

/**
* Garbage Collection
*
* @param bool $exit Whether to die or not.
*
* @return null
*/
function file_gc($exit = true)
{
global $cache, $db;

if (!empty($cache))
{
$cache->unload();
}

$db->sql_close();

if ($exit)
{
exit;
}
}

/**
* HTTP range support (RFC 2616 Section 14.35)
*
* Allows browsers to request partial file content
* in case a download has been interrupted.
*
* @param int $filesize the size of the file in bytes we are about to deliver
*
* @return mixed false if the whole file has to be delivered
* associative array on success
*/
function phpbb_http_byte_range($filesize)
{
// Only call find_range_request() once.
static $request_array;

if (!$filesize)
{
return false;
}

if (!isset($request_array))
{
$request_array = phpbb_find_range_request();
}

return (empty($request_array)) ? false : phpbb_parse_range_request($request_array, $filesize);
}

/**
* Searches for HTTP range request in request headers.
*
* @return mixed false if no request found
* array of strings containing the requested ranges otherwise
* e.g. array(0 => '0-0', 1 => '123-125')
*/
function phpbb_find_range_request()
{
global $request;

$value = $request->header('Range');

// Make sure range request starts with "bytes="
if (strpos($value, 'bytes=') === 0)
{
// Strip leading 'bytes='
// Multiple ranges can be separated by a comma
return explode(',', substr($value, 6));
}

return false;
}

/**
* Analyses a range request array.
*
* A range request can contain multiple ranges,
* we however only handle the first request and
* only support requests from a given byte to the end of the file.
*
* @param array $request_array array of strings containing the requested ranges
* @param int $filesize the full size of the file in bytes that has been requested
*
* @return mixed false if the whole file has to be delivered
* associative array on success
* byte_pos_start the first byte position, can be passed to fseek()
* byte_pos_end the last byte position
* bytes_requested the number of bytes requested
* bytes_total the full size of the file
*/
function phpbb_parse_range_request($request_array, $filesize)
{
// Go through all ranges
foreach ($request_array as $range_string)
{
$range = explode('-', trim($range_string));

// "-" is invalid, "0-0" however is valid and means the very first byte.
if (sizeof($range) != 2 || $range[0] === '' && $range[1] === '')
{
continue;
}

if ($range[0] === '')
{
// Return last $range[1] bytes.

if (!$range[1])
{
continue;
}

if ($range[1] >= $filesize)
{
return false;
}

$first_byte_pos = $filesize - (int) $range[1];
$last_byte_pos = $filesize - 1;
}
else
{
// Return bytes from $range[0] to $range[1]

$first_byte_pos = (int) $range[0];
$last_byte_pos = (int) $range[1];

if ($last_byte_pos && $last_byte_pos < $first_byte_pos)
{
// The requested range contains 0 bytes.
continue;
}

if ($first_byte_pos >= $filesize)
{
// Requested range not satisfiable
return false;
}

// Adjust last-byte-pos if it is absent or greater than the content.
if ($range[1] === '' || $last_byte_pos >= $filesize)
{
$last_byte_pos = $filesize - 1;
}
}

// We currently do not support range requests that end before the end of the file
if ($last_byte_pos != $filesize - 1)
{
continue;
}

return array(
'byte_pos_start' => $first_byte_pos,
'byte_pos_end' => $last_byte_pos,
'bytes_requested' => $last_byte_pos - $first_byte_pos + 1,
'bytes_total' => $filesize,
);
}
}

/**
* Increments the download count of all provided attachments
*
* @param \phpbb\db\driver\driver_interface $db The database object
* @param array|int $ids The attach_id of each attachment
*
* @return null
*/
function phpbb_increment_downloads($db, $ids)
{
if (!is_array($ids))
{
$ids = array($ids);
}

$sql = 'UPDATE ' . ATTACHMENTS_TABLE . '
SET download_count = download_count + 1
WHERE ' . $db->sql_in_set('attach_id', $ids);
$db->sql_query($sql);
}

/**
* Handles authentication when downloading attachments from a post or topic
*
* @param \phpbb\db\driver\driver_interface $db The database object
* @param \phpbb\auth\auth $auth The authentication object
* @param int $topic_id The id of the topic that we are downloading from
*
* @return null
*/
function phpbb_download_handle_forum_auth($db, $auth, $topic_id)
{
$sql_array = array(
'SELECT' => 't.topic_visibility, t.forum_id, f.forum_name, f.forum_password, f.parent_id',
'FROM' => array(
TOPICS_TABLE => 't',
FORUMS_TABLE => 'f',
),
'WHERE' => 't.topic_id = ' . (int) $topic_id . '
AND t.forum_id = f.forum_id',
);

$sql = $db->sql_build_query('SELECT', $sql_array);
$result = $db->sql_query($sql);
$row = $db->sql_fetchrow($result);
$db->sql_freeresult($result);

if ($row && $row['topic_visibility'] != ITEM_APPROVED && !$auth->acl_get('m_approve', $row['forum_id']))
{
send_status_line(404, 'Not Found');
trigger_error('ERROR_NO_ATTACHMENT');
}
else if ($row && $auth->acl_get('u_download') && $auth->acl_get('f_download', $row['forum_id']))
{
if ($row['forum_password'])
{
// Do something else ... ?
login_forum_box($row);
}
}
else
{
send_status_line(403, 'Forbidden');
trigger_error('SORRY_AUTH_VIEW_ATTACH');
}
}

/**
* Handles authentication when downloading attachments from PMs
*
* @param \phpbb\db\driver\driver_interface $db The database object
* @param \phpbb\auth\auth $auth The authentication object
* @param int $user_id The user id
* @param int $msg_id The id of the PM that we are downloading from
*
* @return null
*/
function phpbb_download_handle_pm_auth($db, $auth, $user_id, $msg_id)
{
if (!$auth->acl_get('u_pm_download'))
{
send_status_line(403, 'Forbidden');
trigger_error('SORRY_AUTH_VIEW_ATTACH');
}

$allowed = phpbb_download_check_pm_auth($db, $user_id, $msg_id);

if (!$allowed)
{
send_status_line(403, 'Forbidden');
trigger_error('ERROR_NO_ATTACHMENT');
}
}

/**
* Checks whether a user can download from a particular PM
*
* @param \phpbb\db\driver\driver_interface $db The database object
* @param int $user_id The user id
* @param int $msg_id The id of the PM that we are downloading from
*
* @return bool Whether the user is allowed to download from that PM or not
*/
function phpbb_download_check_pm_auth($db, $user_id, $msg_id)
{
// Check if the attachment is within the users scope...
$sql = 'SELECT msg_id
FROM ' . PRIVMSGS_TO_TABLE . '
WHERE msg_id = ' . (int) $msg_id . '
AND (
user_id = ' . (int) $user_id . '
OR author_id = ' . (int) $user_id . '
)';
$result = $db->sql_query_limit($sql, 1);
$allowed = (bool) $db->sql_fetchfield('msg_id');
$db->sql_freeresult($result);

return $allowed;
}

/**
* Check if the browser is internet explorer version 7+
*
* @param string $user_agent User agent HTTP header
* @param int $version IE version to check against
*
* @return bool true if internet explorer version is greater than $version
*/
function phpbb_is_greater_ie_version($user_agent, $version)
{
if (preg_match('/msie (\d+)/', strtolower($user_agent), $matches))
{
$ie_version = (int) $matches[1];
return ($ie_version > $version);
}
else
{
return false;
}
}