Connection Identifier for DTLS 1.2
RFC 9146



Internet Engineering Task Force (IETF)                  E. Rescorla, Ed.
Request for Comments: 9146                                       Mozilla
Updates: 6347                                         H. Tschofenig, Ed.
Category: Standards Track                                     T. Fossati
ISSN: 2070-1721                                              Arm Limited
                                                                A. Kraus
                                                           Bosch.IO GmbH
                                                              March 2022

                   Connection Identifier for DTLS 1.2

Abstract

   This document specifies the Connection ID (CID) construct for the
   Datagram Transport Layer Security (DTLS) protocol version 1.2.

   A CID is an identifier carried in the record layer header that gives
   the recipient additional information for selecting the appropriate
   security association.  In "classical" DTLS, selecting a security
   association of an incoming DTLS record is accomplished with the help
   of the 5-tuple.  If the source IP address and/or source port changes
   during the lifetime of an ongoing DTLS session, then the receiver
   will be unable to locate the correct security context.

   The new ciphertext record format with the CID also provides content
   type encryption and record layer padding.

   This document updates RFC 6347.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc9146.

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Table of Contents

   1.  Introduction
   2.  Conventions and Terminology
   3.  The "connection_id" Extension
   4.  Record Layer Extensions
   5.  Record Payload