SAML Enhanced Client SASL and GSS-API Mechanisms
draft-ietf-kitten-sasl-saml-ec-12

Network Working Group                                          S. Cantor
Internet-Draft                                     Shibboleth Consortium
Intended status: Standards Track                            S. Josefsson
Expires: July 2, 2015                                             SJD AB
                                                       December 29, 2014

            SAML Enhanced Client SASL and GSS-API Mechanisms
                 draft-ietf-kitten-sasl-saml-ec-12.txt

Abstract

   Security Assertion Markup Language (SAML) 2.0 is a generalized
   framework for the exchange of security-related information between
   asserting and relying parties.  Simple Authentication and Security
   Layer (SASL) and the Generic Security Service Application Program
   Interface (GSS-API) are application frameworks to facilitate an
   extensible authentication model.  This document specifies a SASL and
   GSS-API mechanism for SAML 2.0 that leverages the capabilities of a
   SAML-aware "enhanced client" to address significant barriers to
   federated authentication in a manner that encourages reuse of
   existing SAML bindings and profiles designed for non-browser
   scenarios.

Status of this Memo

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   This document is subject to BCP 78 and the IETF Trust's Legal
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Cantor & Josefsson        Expires July 2, 2015                  [Page 1]
Internet-Draft     SAML ECP SASL & GSS-API Mechanisms      December 2014

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  6
   3.  Applicability for Non-HTTP Use Cases . . . . . . . . . . . . .  7
   4.  SAML SASL Mechanism Specification  . . . . . . . . . . . . . . 10
     4.1.  Advertisement  . . . . . . . . . . . . . . . . . . . . . . 10
     4.2.  Initiation . . . . . . . . . . . . . . . . . . . . . . . . 10
     4.3.  Server Response  . . . . . . . . . . . . . . . . . . . . . 11
     4.4.  User Authentication with Identity Provider . . . . . . . . 11
     4.5.  Client Response  . . . . . . . . . . . . . . . . . . . . . 11
     4.6.  Outcome  . . . . . . . . . . . . . . . . . . . . . . . . . 11
     4.7.  Additional Notes . . . . . . . . . . . . . . . . . . . . . 11
   5.  SAML EC GSS-API Mechanism Specification  . . . . . . . . . . . 13
     5.1.  GSS-API Credential Delegation  . . . . . . . . . . . . . . 13
     5.2.  GSS-API Channel Binding  . . . . . . . . . . . . . . . . . 14
     5.3.  Session Key Derivation . . . . . . . . . . . . . . . . . . 15
       5.3.1.  Generated by Identity Provider . . . . . . . . . . . . 15
       5.3.2.  Alternate Key Derivation Mechanisms  . . . . . . . . . 16
     5.4.  Per-Message Tokens . . . . . . . . . . . . . . . . . . . . 17
     5.5.  Pseudo-Random Function (PRF) . . . . . . . . . . . . . . . 17
     5.6.  GSS-API Principal Name Types for SAML EC . . . . . . . . . 17
       5.6.1.  User Naming Considerations . . . . . . . . . . . . . . 18
       5.6.2.  Service Naming Considerations  . . . . . . . . . . . . 19
   6.  Example  . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 28
     7.1.  Risks Left Unaddressed . . . . . . . . . . . . . . . . . . 28
     7.2.  User Privacy . . . . . . . . . . . . . . . . . . . . . . . 28
     7.3.  Collusion between RPs  . . . . . . . . . . . . . . . . . . 29
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 30
     8.1.  GSS-API and SASL Mechanism Registration  . . . . . . . . . 30