Kerberos authentication in libwww?

I'm trying to see if it's possible to implement support for HTTP
Kerberos authentication, as used by Microsoft[1] in libwww.

The questions I'm currently searching for answers to, are:
 1. is the gssapi-data binary chunk mentioned in [1] something that
    can be used directly in the C-binding to GSSAPI[2]?

 2. can the Windows native security API, SSPI, use the gssapi-data
    binary chunk in[1]?

 3. is there a thin GSSAPI wrapper to SSPI available from somwhere?

 4. is it possible to use SASL, rather than GSSAPI to implement[1]?
    (SSPI has an implementation of SASL)

www.google.com hasn't yet brought me any definite answers to these
questions.  Pointers, guesses, and hints, appreciated.

Thanx!


- Steinar


References:
[1] <http://www.ietf.org/internet-drafts/draft-brezak-kerberos-http-00.txt >
[2] <http://www.ietf.org/rfc/rfc1509.txt >