<?php
function md5_apr($password) {
  $salt = substr(str_shuffle("abcdefghijklmnopqrstuvwxyz0123456789"), 0, 8);
  $len = strlen($password);
  $text = $password.'$apr1$'.$salt;
  $bin = pack('H32', md5($password.$salt.$password));
  for($i=$len; $i>0; $i-=16) $text .= substr($bin, 0, min(16, $i));
  for($i=$len; $i>0; $i>>=1) $text .= ($i&1)?chr(0):$password{0};
  $bin = pack('H32', md5($text));
  for($i=0; $i<1000; $i++) {
    $new = ($i&1)?$password:$bin;
    if($i%3) $new .= $salt;
    if($i%7) $new .= $password;
    $new .= ($i&1)?$bin:$password;
    $bin = pack('H32', md5($new));
 } 
 $tmp = '';
 for($i=0; $i<5; $i++) {
    $k = $i + 6;
    $j = $i + 12;
    if($j==16) $j = 5;
    $tmp = $bin[$i].$bin[$k].$bin[$j].$tmp;
  }
  $tmp = chr(0).chr(0).$bin[11].$tmp;
  $tmp = strtr(
      strrev(substr(base64_encode($tmp),2)), 
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/", 
      "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
  );
  return '$apr1$'.$salt.'$'.$tmp;
}