The Datagram Transport Layer Security (DTLS) Protocol Version 1.3
draft-ietf-tls-dtls13-41
TLS E. Rescorla
Internet-Draft RTFM, Inc.
Obsoletes: 6347 (if approved) H. Tschofenig
Intended status: Standards Track Arm Limited
Expires: 11 August 2021 N. Modadugu
Google, Inc.
7 February 2021
The Datagram Transport Layer Security (DTLS) Protocol Version 1.3
draft-ietf-tls-dtls13-41
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 with the exception of order protection/non-replayability.
Datagram semantics of the underlying transport are preserved by the
DTLS protocol.
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 11 August 2021.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
Rescorla, et al. Expires 11 August 2021 [Page 1]
Internet-Draft DTLS 1.3 February 2021
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4
3. DTLS Design Rationale and Overview . . . . . . . . . . . . . 6
3.1. Packet Loss . . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Reordering . . . . . . . . . . . . . . . . . . . . . . . 7
3.3. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 8
3.4. Replay Detection . . . . . . . . . . . . . . . . . . . . 8
4. The DTLS Record Layer . . . . . . . . . . . . . . . . . . . . 8
4.1. Demultiplexing DTLS Records . . . . . . . . . . . . . . . 12
4.2. Sequence Number and Epoch . . . . . . . . . . . . . . . . 13
4.2.1. Processing Guidelines . . . . . . . . . . . . . . . . 14
4.2.2. Reconstructing the Sequence Number and Epoch . . . . 14
4.2.3. Record Number Encryption . . . . . . . . . . . . . . 15
4.3. Transport Layer Mapping . . . . . . . . . . . . . . . . . 16
4.4. PMTU Issues . . . . . . . . . . . . . . . . . . . . . . . 17
4.5. Record Payload Protection . . . . . . . . . . . . . . . . 18
4.5.1. Anti-Replay . . . . . . . . . . . . . . . . . . . . . 18
4.5.2. Handling Invalid Records . . . . . . . . . . . . . . 19
4.5.3. AEAD Limits . . . . . . . . . . . . . . . . . . . . . 20
5. The DTLS Handshake Protocol . . . . . . . . . . . . . . . . . 21
5.1. Denial-of-Service Countermeasures . . . . . . . . . . . . 22
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