我尝试使用互联网上提供的 SmartFile 下载提供的代码。在代码中，我使用登录 ID 检查文件名，以避免用户直接在 URL 中提供不同的文件名。（他很容易猜到，因为文件名的第一部分是来自登录 ID）。我在代码中检查它是否相等，然后它允许 pdf 下载，否则显示访问冲突。到目前为止一切都很好。但下载后我收到文件已损坏或文件已损坏的消息（它作为电子邮件附件发送且未正确解码）。我无法弄清楚问题出在哪里。任何帮助表示赞赏。谢谢
<?php
session_start();
include_once('header.php');
if(!$_SESSION['username'])
{
header("Location: index.php");//redirect to login page to secure the welcome page without login access.
}
else
{
$user = $_SESSION['username'];
// Allow direct file download (hotlinking)?
// Empty - allow hotlinking
// If set to nonempty value (Example: example.com) will only allow downloads when referrer contains this text
define('ALLOWED_REFERRER', '');
// Download folder, i.e. folder where you keep all files for download.
// MUST end with slash (i.e. "/" )
define('BASE_DIR','../../downloads/');
// log downloads? true/false
define('LOG_DOWNLOADS',true);
// log file name
define('LOG_FILE','downloads.log');
// Allowed extensions list in format 'extension' => 'mime type'
// If myme type is set to empty string then script will try to detect mime type
// itself, which would only work if you have Mimetype or Fileinfo extensions
// installed on server.
$allowed_ext = array (
// documents
'pdf' => 'application/pdf'
);
####################################################################
### DO NOT CHANGE BELOW
####################################################################
// If hotlinking not allowed then make hackers think there are some server problems
if (ALLOWED_REFERRER !== ''
&& (!isset($_SERVER['HTTP_REFERER']) || strpos(strtoupper($_SERVER['HTTP_REFERER']),strtoupper(ALLOWED_REFERRER)) === false)
) {
die("Internal server error. Please contact system administrator.");
}
// Make sure program execution doesn't time out
// Set maximum script execution time in seconds (0 means no limit)
//set_time_limit(0);
if (!isset($_GET['f']) || empty($_GET['f'])) {
die("Please specify file name for download.");
}
// Nullbyte hack fix
if (strpos($_GET['f'], "\0") !== FALSE) die('');
// Get real file name.
// Remove any path info to avoid hacking by adding relative path, etc.
$fname = basename($_GET['f']);
if ($fname == $user."IN".".pdf")
{
// Check if the file exists
// Check in subfolders too
function find_file ($dirname, $fname, &$file_path) {
$dir = opendir($dirname);
while ($file = readdir($dir)) {
if (empty($file_path) && $file != '.' && $file != '..') {
if (is_dir($dirname.'/'.$file)) {
find_file($dirname.'/'.$file, $fname, $file_path);
}
else {
if (file_exists($dirname.'/'.$fname)) {
$file_path = $dirname.'/'.$fname;
return;
}
}
}
}
} // find_file
// get full file path (including subfolders)
$file_path = '';
find_file(BASE_DIR, $fname, $file_path);
if (!is_file($file_path)) {
die("File does not exist. Make sure you specified correct file name.");
}
// file size in bytes
$fsize = filesize($file_path);
// file extension
$fext = strtolower(substr(strrchr($fname,"."),1));
// check if allowed extension
if (!array_key_exists($fext, $allowed_ext)) {
die("Not allowed file type.");
}
// get mime type
if ($allowed_ext[$fext] == '') {
$mtype = '';
// mime type is not set, get from server settings
if (function_exists('mime_content_type')) {
$mtype = mime_content_type($file_path);
}
else if (function_exists('finfo_file')) {
$finfo = finfo_open(FILEINFO_MIME); // return mime type
$mtype = finfo_file($finfo, $file_path);
finfo_close($finfo);
}
if ($mtype == '') {
$mtype = "application/force-download";
}
}
else {
// get mime type defined by admin
$mtype = $allowed_ext[$fext];
}
// Browser will try to save file with this filename, regardless original filename.
// You can override it if needed.
if (!isset($_GET['fc']) || empty($_GET['fc'])) {
$asfname = $fname;
}
else {
// remove some bad chars
$asfname = str_replace(array('"',"'",'\\','/'), '', $_GET['fc']);
if ($asfname === '') $asfname = 'NoName';
}
// set headers
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: public");
header("Content-Description: File Transfer");
header("Content-Type: $mtype");
header("Content-Disposition: attachment; filename=\"$asfname\"");
header("Content-Transfer-Encoding: binary");
header("Content-Length: " . $fsize);
// download
// @readfile($file_path);
$file = @fopen($file_path,"rb");
if ($file) {
while(!feof($file)) {
print(@fread($file, 1024*8));
flush();
if (connection_status()!=0) {
@fclose($file);
die();
}
}
@fclose($file);
}
// log downloads
if (!LOG_DOWNLOADS) die();
$f = @fopen(LOG_FILE, 'a+');
if ($f) {
@fputs($f, date("m.d.Y g:ia")." ".$_SERVER['REMOTE_ADDR']." ".$fname."\n");
@fclose($f);
}
}
else
{
echo '<script type="text/javascript">alert("Access Violation !")header("Location: index.php");</script>';
}
}
?>