DES and 3DES

Hello, I am am trying to write a bit of php code that can take a file containing usernames and encrypted passwords and using the php crypt() function compare them against a user supplied password string. The problem is, that the encrypted passwords come in two different formats. About halfway through the file the encryption method changes from normal DES encryption to 3DES encryption and the php crypt() function does not seem to like this.. I had thought of using mcrypt, but cannot devise a way to switch between the two types automaticly... any ideas ? Michael Slater slaterm@tnet.com.au