GSS-API based Authentication and Key Establishment in TLS

1
GSS-API based Authentication and Key
Establishment in TLS

• Stefan Santesson
• Microsoft

2
Current status

• Subject presented at last IETF
• First individual draft submitted
• http//www.ietf.org/internet-drafts/draft-santesso
  n-tls-gssapi-01.txt
• Discussion on TLS list raised concerns

3
Design goals

• Replacing RFC 2712
• Allow primary Kerberos over a generic GSS-API
  based exchange
• Obtain channel binding between authentication and
  the encrypted channel.
• Allow certificate less TLS
• Transparency for applications using TLS as means
  of client authentication.
• Protocol efficiency

4
Protocol design

• Alternative design proposals discussed
• Proposal by Pasi places GSS-negotiation after the
  TLS handshake.
• Channel binding performed after completed channel
  setup
• Does not provide certificate less TLS
• Does provide encryption protection of the GSS
  exchange
• Problem for applications requiring client
  authentication to be obtained through the TLS
  handshake

5
Way forward

• Openness toward different technical solutions
  that provide adequate functionality in a way that
  the community can accept
• Recognition of the importance of enbaling
  alternative authentication methods over TLS
• Acceptance by the TLS working group to work on an
  appropriate solution using current draft as a
  starting point for the work.