Transport Layer Security (TLS) Resumption across Server Names
draft-vvv-tls-cross-sni-resumption-00

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TLS Working Group                                            V. Vasiliev
Internet-Draft                                                    Google
Intended status: Standards Track                            12 July 2020
Expires: 13 January 2021

     Transport Layer Security (TLS) Resumption across Server Names
                 draft-vvv-tls-cross-sni-resumption-00

Abstract

   This document specifies a way for the parties in the Transport Layer
   Security (TLS) protocol to indicate that an individual session ticket
   can be used to perform resumption even if the Server Name of the new
   connection does not match the Server Name of the original.

Discussion Venues

   This note is to be removed before publishing as an RFC.

   Discussion of this document takes place on the TLS Working Group
   mailing list (tls@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/tls/
   (https://mailarchive.ietf.org/arch/browse/tls/).

   Source for this draft and an issue tracker can be found at
   https://github.com/vasilvv/tls-cross-sni-resumption
   (https://github.com/vasilvv/tls-cross-sni-resumption).

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
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   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 13 January 2021.

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Copyright Notice

   Copyright (c) 2020 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 carefully, as they describe your rights
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   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  The Extension . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   Transport Layer Security protocol [RFC8446] allows the clients to use
   an abbreviated handshake in cases where the client has previously
   established a secure session with the same server.  This mechanism is
   known as "session resumption", and its positive impact on performance
   makes it desirable to be able to use it as frequently as possible.

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   Modern application-level protocols, HTTP in particular, often require
   accessing multiple servers within a single workflow.  Since the
   identity of the server is established through its certificate, in the
   ideal case, the resumption would be possible to all of the domains
   for which the certificate is valid (see [PERF] for a survey of
   potential practical impact of such approach).  TLS, starting with
   version 1.3, defines the SNI value to be a property of an individual
   connection that is not retained across sessions ([RFC8446],
   Section 4.2.11).  However, in the absence of additional signals, it
   discourages using a session ticket when the SNI value does not match
   ([RFC8446], Section 4.6.1), as there is normally no reason to assume
   that all servers sharing the same certificate would also share the
   same session keys.  The extension defined in this document allows the
   server to provide such a signal in-band.

2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",