chamilo-lms2/main/messages/download.php

<?php
/* For licensing terms, see /license.txt */

/**
 * This file is responsible for  passing requested file attachments from messages
 * Html files are parsed to fix a few problems with URLs,
 * but this code will hopefully be replaced soon by an Apache URL
 * rewrite mechanism.
 *
 * @package chamilo.messages
 */
session_cache_limiter('public');

require_once __DIR__.'/../inc/global.inc.php';

$file_url = isset($_GET['file']) ? $_GET['file'] : '';

if (empty($file_url)) {
    api_not_allowed();
}

// IMPORTANT to avoid caching of documents
header('Expires: Wed, 01 Jan 1990 00:00:00 GMT');
header('Cache-Control: public');
header('Pragma: no-cache');

//change the '&' that got rewritten to '///' by mod_rewrite back to '&'
$file_url = str_replace('///', '&', $file_url);
//still a space present? it must be a '+' (that got replaced by mod_rewrite)
$file_url = str_replace(' ', '+', $file_url);
$file_url = str_replace('/..', '', $file_url); //echo $doc_url;

$tbl_messsage = Database::get_main_table(TABLE_MESSAGE);
$tbl_messsage_attachment = Database::get_main_table(TABLE_MESSAGE_ATTACHMENT);

$file_url = Database::escape_string($file_url);
$sql = "SELECT filename, message_id
        FROM $tbl_messsage_attachment
        WHERE path LIKE BINARY '$file_url'";

$result = Database::query($sql);
$row = Database::fetch_array($result, 'ASSOC');
$title = str_replace(' ', '_', $row['filename']);
$message_id = $row['message_id'];

// allow download only for user sender and user receiver
$sql = "SELECT user_sender_id, user_receiver_id, group_id
        FROM $tbl_messsage WHERE id = '$message_id'";
$rs = Database::query($sql);
$row_users = Database::fetch_array($rs, 'ASSOC');
$current_uid = api_get_user_id();

// get message user id for inbox/outbox
$message_uid = '';
$message_type = ['inbox', 'outbox'];
if (in_array($_GET['type'], $message_type)) {
    if ($_GET['type'] == 'inbox') {
        $message_uid = $row_users['user_receiver_id'];
    } else {
        $message_uid = $row_users['user_sender_id'];
    }
}

// allow to the correct user for download this file
$not_allowed_to_edit = false;
$userGroup = new UserGroup();

if (!empty($row_users['group_id'])) {
    $users_group = $userGroup->get_all_users_by_group($row_users['group_id']);
    if (!in_array($current_uid, array_keys($users_group))) {
        $not_allowed_to_edit = true;
    }
} else {
    if ($current_uid != $message_uid) {
        $not_allowed_to_edit = true;
    }
}

if ($not_allowed_to_edit) {
    api_not_allowed(true);
    exit;
}

// set the path directory file
if (!empty($row_users['group_id'])) {
    $path_user_info = $userGroup->get_group_picture_path_by_id(
        $row_users['group_id'],
        'system',
        true
    );
} else {
    $path_user_info['dir'] = UserManager::getUserPathById($message_uid, 'system');
}

$full_file_name = $path_user_info['dir'].'message_attachments/'.$file_url;

if (Security::check_abs_path($full_file_name, $path_user_info['dir'].'message_attachments/')) {
    // launch event
    Event::event_download($file_url);
    $result = DocumentManager::file_send_for_download(
        $full_file_name,
        true,
        $title
    );
    if ($result === false) {
        api_not_allowed(true);
    }
}
exit;