The Datagram Transport Layer Security (DTLS) Protocol Version 1.3
draft-rescorla-tls-dtls13-00

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Last updated 2016-10-26
Replaced by draft-ietf-tls-dtls13
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TLS                                                          E. Rescorla
Internet-Draft                                                RTFM, Inc.
Obsoletes: 6347 (if approved)                              H. Tschofenig
Intended status: Standards Track                             ARM Limited
Expires: April 29, 2017                                 October 26, 2016

   The Datagram Transport Layer Security (DTLS) Protocol Version 1.3
                      draft-rescorla-tls-dtls13-00

Abstract

   This document specifies Version 1.3 of the Datagram Transport Layer
   Security (DTLS) protocol.  DTLS 1.3 allows client/server applications
   to communicate over the Internet in a way that is designed to prevent
   eavesdropping, tampering, and message forgery.

   The DTLS 1.3 protocol is intentionally based on the Transport Layer
   Security (TLS) 1.3 protocol and provides equivalent security
   guarantees.  Datagram semantics of the underlying transport are
   preserved by the DTLS protocol.

Status of This Memo

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   This Internet-Draft will expire on April 29, 2017.

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   publication of this document.  Please review these documents

Rescorla & Tschofenig    Expires April 29, 2017                 [Page 1]
Internet-Draft                  DTLS 1.3                    October 2016

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
   3.  DTLS Design Rational and Overview . . . . . . . . . . . . . .   4
     3.1.  Packet Loss . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.1.  Reordering  . . . . . . . . . . . . . . . . . . . . .   6
       3.1.2.  Message Size  . . . . . . . . . . . . . . . . . . . .   6
     3.2.  Replay Detection  . . . . . . . . . . . . . . . . . . . .   6
   4.  The DTLS Record Layer . . . . . . . . . . . . . . . . . . . .   7
     4.1.  Transport Layer Mapping . . . . . . . . . . . . . . . . .   8
     4.2.  PMTU Issues . . . . . . . . . . . . . . . . . . . . . . .   9
     4.3.  Record Payload Protection . . . . . . . . . . . . . . . .  11
       4.3.1.  Anti-Replay . . . . . . . . . . . . . . . . . . . . .  11
       4.3.2.  Handling Invalid Records  . . . . . . . . . . . . . .  11
   5.  The DTLS Handshake Protocol . . . . . . . . . . . . . . . . .  12
     5.1.  Denial-of-Service Countermeasures . . . . . . . . . . . .  12
     5.2.  DTLS Handshake Message Format . . . . . . . . . . . . . .  15
     5.3.  ACK Message . . . . . . . . . . . . . . . . . . . . . . .  19
     5.4.  Handshake Message Fragmentation and Reassembly  . . . . .  19
     5.5.  Timeout and Retransmission  . . . . . . . . . . . . . . .  20
       5.5.1.  State Machine . . . . . . . . . . . . . . . . . . . .  24
       5.5.2.  Timer Values  . . . . . . . . . . . . . . . . . . . .  27
     5.6.  CertificateVerify and Finished Messages . . . . . . . . .  28
     5.7.  Alert Messages  . . . . . . . . . . . . . . . . . . . . .  28
     5.8.  Establishing New Associations with Existing Parameters  .  28
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