Untitled

<head>
    <title>Testing</title>
    <meta charset="utf-8">
</head>
<body>
<?php

echo '<pre>';

$_SERVER['REDIRECT_SSL_CLIENT_S_DN'] = '../CN=\x00M\x00\xC4\x00,\x00I\x00S\x00,\x004\x000\x003\x001\x002\x000\x000\x002/SN=..';
$pattern = '/CN=(.*)\\/SN=/';
preg_match($pattern, $_SERVER['REDIRECT_SSL_CLIENT_S_DN'], $server_matches);

$string = $server_matches[1];
$string = str_replace('\x00', NULL, $string);

preg_match('/\\\x[A-F0-9]{2}/', $string, $matches);
foreach ($matches as $key => $value) {
    $string = str_replace($value, utf8_encode(chr(hexdec($value))), $string);
}

echo($string);
$splitted = str_split($string);
print_r($splitted);
echo '<input value="'.$string.'">';

/*
results:

String content (CORRECT)
MÄ,IS,40312002

Array content: (STRANGE)
(
    [0] => M
    [1] => �
    [2] => �
    [3] => ,
    [4] => I
    [5] => S
    [6] => ,
    [7] => 4
    [8] => 0
    [9] => 3
    [10] => 1
    [11] => 2
    [12] => 0
    [13] => 0
    [14] => 2
)

Input content: (CORRECT)
MÄ,IS,40312002

*/