barnacles: authd

An authentication HTTP server that does the insane Rails
PBKDF2-then-verify-then-decrypt, which by the way is named
"decrypt_and_verify" (which makes it sound like it's doing decryption
and THEN verifcation, which makes your heart stop a little bit until you
read the source code), and then reverse-proxies the actual data we
want (the DB session token) onto a
yet-to-be-determined-but-hopefully-Haskell backend.