Potential IDPrism problem

[meepbear *]

>Fair enough. If you want to give it another shot, the server now pads the 
>encrypted mac key out to 20 bytes before Base64 encoding it.

Sorry about that. It was my understanding that both mac_key and enc_mac_key 
had to be 20 bytes long so I put in a debug assertion to make sure it fails 
if it's not while I'm still testing it.

Beyond Livejournal, IDPrism is the only other implementation of a server I 
know about to test against.

It works fine now by the way and I added padding on my end as well in case 
it's smaller than 20 bytes.