Package boltuserdb implements the Katzenpost server user database with a simple boltdb based backend.

Package externuserdb implements the Katzenpost server user database with http calls to a external authorization source (expected to run in localhost).

MaxUsernameSize is the maximum username length in bytes.

ErrNoIdentity is the error returned when the specified user has no identity key set.

ErrNoSuchUser is the error returned when an operation fails due to a non-existent user.

UserDB is the interface provided by all user database implementations.