Network Time Security for the Network Time Protocol
draft-ietf-ntp-using-nts-for-ntp-08

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Last updated 2017-03-13
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NTP Working Group                                              D. Franke
Internet-Draft                                                    Akamai
Intended status: Standards Track                               D. Sibold
Expires: September 14, 2017                                   K. Teichel
                                                                     PTB
                                                          March 13, 2017

          Network Time Security for the Network Time Protocol
                  draft-ietf-ntp-using-nts-for-ntp-08

Abstract

   This memo specifies Network Time Security (NTS), a mechanism for
   using Transport Layer Security (TLS) and Authenticated Encryption
   with Associated Data (AEAD) to provide cryptographic security for the
   Network Time Protocol.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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 http://datatracker.ietf.org/drafts/current/.

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   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 September 14, 2017.

Copyright Notice

   Copyright (c) 2017 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

Franke, et al.         Expires September 14, 2017               [Page 1]
Internet-Draft                   NTS4NTP                      March 2017

   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terms and Abbreviations . . . . . . . . . . . . . . . . . . .   3
   3.  Objectives  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Overview of NTS-Secured NTP . . . . . . . . . . . . . . . . .   4
     4.1.  Client-Server Mode  . . . . . . . . . . . . . . . . . . .   5
     4.2.  Symmetric/Peer Mode and Control Modes . . . . . . . . . .   5
   5.  Employing (D)TLS for NTP Security . . . . . . . . . . . . . .   5
     5.1.  TLS profile for Network Time Security . . . . . . . . . .   6
     5.2.  The NTS-encapsulated NTPv4 protocol . . . . . . . . . . .   7
     5.3.  The NTS Key Establishment protocol  . . . . . . . . . . .   7
       5.3.1.  NTS-KE record types . . . . . . . . . . . . . . . . .   9
       5.3.2.  Key Extraction (generally)  . . . . . . . . . . . . .  11
     5.4.  NTS Extensions for NTPv4  . . . . . . . . . . . . . . . .  11
       5.4.1.  Key Extraction (for NTPv4)  . . . . . . . . . . . . .  11
       5.4.2.  Packet structure overview . . . . . . . . . . . . . .  12
       5.4.3.  The Unique Identifier extension . . . . . . . . . . .  13
       5.4.4.  The NTS Cookie extension  . . . . . . . . . . . . . .  13
       5.4.5.  The NTS Cookie Placeholder extension  . . . . . . . .  14
       5.4.6.  The NTS Authenticator and Encrypted Extensions
               extension . . . . . . . . . . . . . . . . . . . . . .  14
       5.4.7.  Protocol details  . . . . . . . . . . . . . . . . . .  15
     5.5.  Recommended format for NTS cookies  . . . . . . . . . . .  17
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  22
     7.1.  Random Number Generation  . . . . . . . . . . . . . . . .  23
     7.2.  Usage of NTP Pools  . . . . . . . . . . . . . . . . . . .  23
     7.3.  Initial Verification of the Server Certificates . . . . .  23
     7.4.  Treatment of Initial Messages . . . . . . . . . . . . . .  23
     7.5.  DTLS-Related Issues . . . . . . . . . . . . . . . . . . .  23
     7.6.  Delay Attack  . . . . . . . . . . . . . . . . . . . . . .  23
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