Semi-Static Diffie-Hellman Key Establishment for TLS 1.3
draft-ietf-tls-semistatic-dh-01
TLS Working Group E. Rescorla
Internet-Draft Mozilla
Intended status: Standards Track N. Sullivan
Expires: 8 September 2020 Cloudflare
C.A. Wood
Apple Inc.
7 March 2020
Semi-Static Diffie-Hellman Key Establishment for TLS 1.3
draft-ietf-tls-semistatic-dh-01
Abstract
TLS 1.3 [RFC8446] specifies a signed Diffie-Hellman exchange modelled
after SIGMA [SIGMA]. This design is suitable for endpoints whose
certified credential is a signing key, which is the common situation
for current TLS servers. This document describes a mode of TLS 1.3
in which one or both endpoints have a certified DH key which is used
to authenticate the exchange.
Note to Readers
Source for this draft and an issue tracker can be found at
https://github.com/ekr/draft-rescorla-tls13-semistatic-dh
(https://github.com/ekr/draft-rescorla-tls13-semistatic-dh).
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 8 September 2020.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 3
3. Negotiation . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Certificate Format . . . . . . . . . . . . . . . . . . . . . 5
5. Certificate Verify Computation . . . . . . . . . . . . . . . 5
6. Client Authentication . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
DISCLAIMER: This is a work-in-progress draft and has not yet seen
significant security analysis. Thus, this draft should not be used
as a basis for building production systems.
TLS 1.3 [RFC8446] specifies a signed Diffie-Hellman (DH) exchange
modeled after SIGMA [SIGMA]. This design is suitable for endpoints
whose certified credential is a signing key, which is the common
situation for current TLS servers, which is why it was selected for
TLS 1.3.
However, it is also possible - although currently rare - for
endpoints to have a credential which is an (EC)DH key. This can
happen in one of two ways:
* They may be issued a certificate with an (EC)DH key, as specified
for instance in [I-D.ietf-curdle-pkix]
* They may have a signing key which they use to generate a delegated
credential [I-D.ietf-tls-subcerts] containing an (EC)DH key.
In these situations, a signed DH exchange is not appropriate, and
instead a design in which the endpoint authenticates via its long-
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term (EC)DH key is suitable. This document describes such a design
modeled on that described in OPTLS [KW16].
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