Attested TLS Token Binding
draft-mandyam-tokbind-attest-07

Document Type Active Internet-Draft (individual)
Last updated 2019-01-24
Stream (None)
Intended RFC status (None)
Formats plain text pdf xml html bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
Token Binding Working Group                                   G. Mandyam
Internet-Draft                                Qualcomm Technologies Inc.
Intended status: Standards Track                            L. Lundblade
Expires: July 28, 2019                               Security Theory LLC
                                                                 J. Azen
                                              Qualcomm Technologies Inc.
                                                        January 24, 2019

                       Attested TLS Token Binding
                    draft-mandyam-tokbind-attest-07

Abstract

   Token binding allows HTTP servers to bind bearer tokens to TLS
   connections.  In order to do this, clients or user agents must prove
   possession of a private key.  However, proof-of-possession of a
   private key becomes truly meaningful to a server when accompanied by
   an attestation statement.  This specification describes extensions to
   the existing token binding protocol to allow for attestation
   statements to be sent along with the related token binding messages.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 28, 2019.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents

Mandyam, et al.           Expires July 28, 2019                 [Page 1]
Internet-Draft                TokBindAttest                 January 2019

   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Attestation Enhancement to TLS Token Binding Message  . . . .   3
     2.1.  KeyStore Attestation  . . . . . . . . . . . . . . . . . .   4
       2.1.1.  Verification Procedures . . . . . . . . . . . . . . .   4
     2.2.  TPMv2 Attestation . . . . . . . . . . . . . . . . . . . .   5
       2.2.1.  Verification Procedures . . . . . . . . . . . . . . .   6
   3.  Extension Support Negotiation . . . . . . . . . . . . . . . .   6
     3.1.  Negotiating Token Binding Protocol Extensions . . . . . .   7
   4.  Example - Platform Attestation for Anomaly Detection  . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  TLS Extensions Registry . . . . . . . . . . . . . . . . .   8
     5.2.  Token Binding Extensions for Attestation  . . . . . . . .   8
   6.  Security and Privacy Considerations . . . . . . . . . . . . .   9
     6.1.  Attestation Privacy Considerations  . . . . . . . . . . .   9
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   [RFC8471] and [RFC8472] describe a framework whereby servers can
   leverage cryptographically-bound authentication tokens in part to
   create uniquely-identifiable TLS bindings that can span multiple
   connections between a client and a server.  Once the use of token
   binding is negotiated as part of the TLS handshake, an application
   layer message (the Token Binding message) may be sent from the client
   to the relying party whose primary purpose is to encapsulate a
   signature over a value associated with the current TLS session.  The
   payload used for the signature is the token binding public key (see
   [RFC8471]).  Use of the token binding public key allows for
   generation of the attestation signature once over the lifetime of the
   public key.

   Proof-of-possession of a private key is useful to a relying party,
   but the associated signature in the Token Binding message does not
Show full document text