It's not obvious how to turn authentication off after
using it, so I recommend using custom handles with
authentication.
Usage
authenticate(user, password, type = "any")
Arguments
user
user name
password
password
type
type of HTTP authentication. Should be one
of the following types supported by Curl: basic, digest,
digest_ie, gssnegotiate, ntlm, ntlm_vn, any. It defaults
to any.