'@type magic: L{bytes}
@param magic: The challenge string used to encrypt the password.
@type username: L{bytes}
@param username: The username associated with these credentials.
@type digest: L{bytes}
@param digest: An encrypted version of the user\'s password.  Should be
generated as an MD5 hash of the challenge string concatenated with
the plaintext password.'

def __init__(self, magic, username, digest):

    self.magic = magic
    self.username = username
    self.digest = digest
