如何解码十六进制内容？

Question

I have $_SERVER['REDIRECT_SSL_CLIENT_S_DN'] content that has somekind of hex data. How can i decode it?

$_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'], $server_matches);
print_r($server_matches[1]);

The result is:

\x00M\x00\xC4\x00,\x00I\x00S\x00,\x004\x000\x003\x001\x002\x000\x000\x002

The result i need is:

MÄ,IS,40312002

I tried to decode it with chr(hexdec($value)); and it almost works, but in html input i see lot of question marks.

EDIT: Additional test with results. Not yet perfect. Array reveals some errors: http://pastebin.com/BC4xxqmE

Answer 1

After using utf8_encode, you now have a multibyte string. This means you need to use PHP's multibyte (mb_) functions.

So, str_split won't work anymore. You need to use either mb_split or preg_split with the u flag.

$splitted = preg_split('//u', $string);

Here's a demo showing that your code is now working: http://ideone.com/nqeC0U