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./othercms/phpBB3/includes/functions_download.php
<?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, $phpbb_dispatcher, $phpbb_root_path, $request;

   
$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);

   
/**
    * Event to alter attachment before it is sent to browser.
    *
    * @event core.send_file_to_browser_before
    * @var    array    attachment    Attachment data
    * @var    string    upload_dir    Relative path of upload directory
    * @var    int        category    Attachment category
    * @var    string    filename    Path to file, including filename
    * @var    int        size        File size
    * @since 3.1.11-RC1
    */
   
$vars = array(
       
'attachment',
       
'upload_dir',
       
'category',
       
'filename',
       
'size',
    );
   
extract($phpbb_dispatcher->trigger_event('core.send_file_to_browser_before', compact($vars)));

   
// 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: private');

   
// 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 (empty(
$user->browser) || ((strpos(strtolower($user->browser), 'msie') !== false) && !phpbb_is_greater_ie_version($user->browser, 7)))
    {
       
header('Content-Disposition: attachment; ' . header_filename(html_entity_decode($attachment['real_filename'], ENT_COMPAT)));
        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($attachment['mimetype'], 'image') === 0) ? 'inline' : 'attachment') . '; ' . header_filename(html_entity_decode($attachment['real_filename'], ENT_COMPAT)));
        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: ' . __DIR__ . "/../$upload_dir/{$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']);

               
// First read chunks
               
while (!feof($fp) && ftell($fp) < $range['byte_pos_end'] - 8192)
                {
                    echo
fread($fp, 8192);
                }
               
// Then, read the remainder
               
echo fread($fp, $range['bytes_requested'] % 8192);
            }
            else
            {
                while (!
feof($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;
    }

   
$url = html_entity_decode($request->header('Referer'), ENT_COMPAT);

    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: private');
           
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)
{
   
$first_byte_pos    = -1;
   
$last_byte_pos    = -1;

   
// 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 (count($range) != 2 || $range[0] === '' && $range[1] === '')
        {
            continue;
        }

       
// Substitute defaults
       
if ($range[0] === '')
        {
           
$range[0] = 0;
        }

        if (
$range[1] === '')
        {
           
$range[1] = $filesize - 1;
        }

        if (
$last_byte_pos >= 0 && $last_byte_pos + 1 != $range[0])
        {
           
// We only support contiguous ranges, no multipart stuff :(
           
return false;
        }

        if (
$range[1] && $range[1] < $range[0])
        {
           
// The requested range contains 0 bytes.
           
continue;
        }

       
// Return bytes from $range[0] to $range[1]
       
if ($first_byte_pos < 0)
        {
           
$first_byte_pos    = (int) $range[0];
        }

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

        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;
        }
    }

    if (
$first_byte_pos < 0 || $last_byte_pos < 0)
    {
        return
false;
    }

    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)
{
    global
$phpbb_container;

   
$sql_array = [
       
'SELECT'    => 't.forum_id, t.topic_poster, t.topic_visibility, f.forum_name, f.forum_password, f.parent_id',
       
'FROM'        => [
           
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);

   
$phpbb_content_visibility = $phpbb_container->get('content.visibility');

    if (
$row && !$phpbb_content_visibility->is_visible('topic', $row['forum_id'], $row))
    {
       
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)
{
    global
$phpbb_dispatcher;

    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);

   
/**
    * Event to modify PM attachments download auth
    *
    * @event core.modify_pm_attach_download_auth
    * @var    bool    allowed        Whether the user is allowed to download from that PM or not
    * @var    int        msg_id        The id of the PM to download from
    * @var    int        user_id        The user id for auth check
    * @since 3.1.11-RC1
    */
   
$vars = array('allowed', 'msg_id', 'user_id');
   
extract($phpbb_dispatcher->trigger_event('core.modify_pm_attach_download_auth', compact($vars)));

    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;
    }
}