Anarchy Online Key Exchange PHP module.

The purpose of this module is to perform the Diffie-Hellman key-exchange and
login info encryption using the TEA cipher.  Those are the algorithms used
by Anarchy Online chat servers.

It used to be possible to implement all this in PHP, using either BCmath or
GMP extensions as provided by PHP, but unfortunately PHP 5.0.2 introduced a
change in double-to-long conversion that broke the TEA implementation.

The module should be quite straightforward, it only has one function,
aokex_login_key($serverseed, $username, $password) which should be called in
place of AOChat.php's AOChat::generate_login_key(..) function.

There are two DH implementation at the moment, one using GMP and one using
OpenSSL, both of them should work, and provide an example of how to
implement DH with other libraries, or perhaps purely in C for maximum
portability.

// Oskari Saarenmaa / 'Auno' / 2005-Jan-07