protect files download in a folder on server &.htacess visible

Question

I am using a php file code as below to list out the files in a directory from which user will check the required files and download them as a zip file

I have 2 issues

1) How to protect files from Direct download using url i want the files to be downloaded only with form action that is through downloadlist.php (if i keep denyall in .htaccess , the downloaded file is corrupted )

2) this code also shows .htaccess in the list for download ( so i doubt is their a way to only list Docs,xls,pdf's)

i can provide downloadlist.php if required

<?php
function listDir($dirName) 
{  
    ?><form name="filelist" action="downloadList.php" method="POST"><?php echo "\n";
    if ($handle = opendir($dirName)) {
        while (false !== ($file = readdir($handle))) {
            if ($file != "." && $file != "..") { ?>    <input type=checkbox name="file[]" value="<?php  echo "$file";?>"><?php  echo "$file"; ?><br><?php  echo "\n";
            }
        }
    closedir($handle);
    }
    ?><br><input type="submit" name="formSubmit" value="Zip and download" /></form><?php
}
listDir('./fold');  ?>

downloadlist.php

<?php
// function download($file) downloads file provided in $file
function download($file) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename='.basename($file));
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    ob_clean();
    flush();
    readfile($file);
    exit;
}

$files = $_POST['file'];
if(empty($files)) 
{
    echo("You haven't selected any file to download.");
} 
else 
{
    $zip = new ZipArchive();
    $filename = time() . "archive.zip"; //adds timestamp to zip archive so every file has unique filename
    if ($zip->open($filename, ZIPARCHIVE::CREATE)!==TRUE) { // creates new zip archive
            exit("Cannot open <$filename>\n");
    }
    $N = count($files);
    for($i=0; $i < $N; $i++)
    {
      $zip->addFile($files[$i], $files[$i]); //add files to archive
    }
    $numFiles = $zip->numFiles;
    $zip->close();

    $time = 8; //how long in seconds do we wait for files to be archived.
    $found = false;
    for($i=0; $i<$time; $i++){

     if($numFiles == $N){   // check if number of files in zip archive equals number of checked files
        download($filename);
        $found = true;
        break;
     }
     sleep(1); // if not found wait one second before continue looping
 }

 if($found) { }
     else echo "Sorry, this is taking too long";
 } ?>

Answer 1

1. Add this to your htaccess file:

    <FilesMatch "\\.php$"> allow from all </FilesMatch> deny from all 

2. Change

    ($file != "." && $file != "..") 

   To

    ($file != "." && $file != ".." && $file != ".htaccess") 

   Or, if you only want to list files with a certain extension:

    ((substr($file, -strlen(".pdf")) === ".pdf" || (substr($file, -strlen(".xls")) === ".xls" || (substr($file, -strlen(".doc")) === ".doc") 

Answer 2

Add this line in your .htacccess file in fold directory!

deny from all

And edit this line :

  $zip->addFile($files[$i], $files[$i]); //add files to archive

To:

  $zip->addFile('./fold/'.$files[$i], $files[$i]); //add files to archive

And listDir function:

  <?php

function listDir($dirName) 
{  
    $forbidden_files=array('.htaccess','.htpasswd');
    $allow_ext=array('.gif','.png','.bmp','.jpeg','.jpg','.pdf','.doc','.docx','.xls','.xlsx','.php');
    ?><form name="filelist" action="downloadList.php" method="POST"><?php echo "\n";
    if ($handle = opendir($dirName)) {
        while (false !== ($file = readdir($handle))     ) {
            $allowed=(strpos($file,'.')!==false  &&  in_array(substr($file,strpos($file,'.')) ,$allow_ext ));

           if ($file != "." && $file != ".."  && $allowed ) { ?>    <input type=checkbox name="file[]" value="<?php  echo "$file";?>"><?php  echo "$file"; ?><br><?php  echo "\n";
            }
        }
    closedir($handle);
    }
    ?><br><input type="submit" name="formSubmit" value="Zip and download" /></form><?php
}
listDir('./fold');  ?>