Updates to Using the NETCONF Protocol over Transport Layer Security (TLS) with Mutual X.509 Authentication
draft-ietf-netconf-over-tls13-02

Network Configuration                                          S. Turner
Internet-Draft                                                     sn3rd
Updates: 7589 (if approved)                                   R. Housley
Intended status: Standards Track                          Vigil Security
Expires: 11 September 2023                                 10 March 2023

  Updates to Using the NETCONF Protocol over Transport Layer Security
                 (TLS) with Mutual X.509 Authentication
                    draft-ietf-netconf-over-tls13-02

Abstract

   RFC 7589 defines how to protect NETCONF messages with TLS 1.2.  This
   document updates RFC 7589 to address support requirements for TLS 1.2
   and TLS 1.3 and the use of TLS 1.3's early data.

About This Document

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

   The latest revision of this draft can be found at https://netconf-
   wg.github.io/netconf-over-tls13/draft-ietf-netconf-over-tls13.html.
   Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-ietf-netconf-over-tls13/.

   Discussion of this document takes place on the Network Configuration
   Working Group mailing list (mailto:netconf@ietf.org), which is
   archived at https://mailarchive.ietf.org/arch/browse/netconf/.
   Subscribe at https://www.ietf.org/mailman/listinfo/netconf/.

   Source for this draft and an issue tracker can be found at
   https://github.com/netconf-wg/netconf-over-tls13.

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
   working documents as Internet-Drafts.  The list of current Internet-
   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."

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   This Internet-Draft will expire on 11 September 2023.

Copyright Notice

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   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   Please review these documents carefully, as they describe your rights
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  Early Data  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Cipher Suites . . . . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   7.  Normative References  . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   [RFC7589] defines how to protect NETCONF messages [RFC6241] with TLS
   1.2 [RFC5246].  This document updates [RFC7589] to address support
   requirements for TLS 1.2 [RFC5246] and TLS 1.3
   [I-D.ietf-tls-rfc8446bis] and the use of TLS 1.3's early data, which
   is also known as 0-RTT data.  It also updates the "netconf-tls" IANA
   Registered Port Number entry to refer to this document.  All other
   provisions set forth in [RFC7589] are unchanged, including connection
   initiation, message framing, connection closure, certificate
   validation, server identity, and client identity.

      |  Implementations that support TLS 1.3 [I-D.ietf-tls-rfc8446bis]
      |  should refer to TLS 1.3 [I-D.ietf-tls-rfc8446bis] in Sections 4
      |  and 5 of [RFC7589].

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2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  Early Data

   Early data (aka 0-RTT data) is a mechanism defined in TLS 1.3
   [I-D.ietf-tls-rfc8446bis] that allows a client to send data ("early
   data") as part of the first flight of messages to a server.  Note
   that TLS 1.3 can be used without early data as per Appendix F.5 of
   [I-D.ietf-tls-rfc8446bis].  In fact, early data is permitted by TLS
   1.3 only when the client and server share a Pre-Shared Key (PSK),
   either obtained externally or via a previous handshake.  The client
   uses the PSK to authenticate the server and to encrypt the early
   data.

   As noted in Section 2.3 of [I-D.ietf-tls-rfc8446bis], the security
   properties for early data are weaker than those for subsequent TLS-
   protected data.  In particular, early data is not forward secret, and
   there is no protection against the replay of early data between
   connections.  Appendix E.5 of [I-D.ietf-tls-rfc8446bis] requires
   applications not use early data without a profile that defines its
   use.  This document specifies that NETCONF implementations that
   support TLS 1.3 MUST NOT use early data.

4.  Cipher Suites

   Implementations MUST support TLS 1.2 [RFC5246] and are REQUIRED to
   support the TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 cipher suite
   [RFC9325].

   Implementations MAY implement additional TLS 1.2 cipher suites that
   provide mutual authentication [RFC5246] and confidentiality as
   required by NETCONF [RFC6241].

   Implementations SHOULD support TLS 1.3 [I-D.ietf-tls-rfc8446bis] and,
   if implemented, MUST prefer to negotiate TLS 1.3 over earlier
   versions of TLS.

   Implementations that support TLS 1.3 [I-D.ietf-tls-rfc8446bis] are
   REQUIRED to support the mandatory-to-implement cipher suites listed
   in Section 9.1 of [I-D.ietf-tls-rfc8446bis].

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   Implementations that support TLS 1.3 MAY implement additional TLS
   cipher suites that provide mutual authentication and confidentiality,
   which are required for NETCONF [RFC6241].

   NETCONF implementations SHOULD follow the recommendations given in
   [RFC9325].

5.  Security Considerations

   The Security Considerations of [RFC6241], [RFC7589], and [RFC9325]
   apply here as well.

   For implementations that support TLS 1.3, the Security Considerations
   of TLS 1.3 [I-D.ietf-tls-rfc8446bis] apply.

   The following considerations from [RFC7589] has been modified to also
   apply to TLS 1.3 [I-D.ietf-tls-rfc8446bis]:

      NETCONF is used to access configuration and state information and
      to modify configuration information.  TLS 1.3 mutual
      authentication is used to ensure that only authorized users and
      systems are able to view the NETCONF server's configuration and
      state or to modify the NETCONF server's configuration.  To this
      end, neither the client nor the server should establish a NETCONF
      over TLS 1.3 connection with an unknown, unexpected, or
      incorrectly identified peer; see Section 7 of [RFC7589].  If
      deployments make use of a trusted list of Certification Authority
      (CA) certificates [RFC5280], then the listed CAs should only issue
      certificates to parties that are authorized to access the NETCONF
      servers.  Doing otherwise will allow certificates that were issued
      for other purposes to be inappropriately accepted by a NETCONF
      server.

   The Security Considerations of [I-D.ietf-uta-rfc6125bis] apply to all
   implementations when the client checks the identity of the server, as
   is required in Section 6 of [RFC7589].

6.  IANA Considerations

   IANA is requested to add a reference to this document in the
   "netconf-tls" entry in the "Registered Port Numbers".  The updated
   registry entry would appear as follows:

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    Service Name:           netconf-tls
    Transport Protocol(s):  TCP
    Assignee:               IESG <iesg@ietf.org>
    Contact:                IETF Chair <chair@ietf.org>
    Description:            NETCONF over TLS
    Reference:              RFC 7589, [THIS RFC]
    Port Number:            6513

7.  Normative References

   [I-D.ietf-tls-rfc8446bis]
              Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", Work in Progress, Internet-Draft, draft-
              ietf-tls-rfc8446bis-05, 24 October 2022,
              <https://datatracker.ietf.org/doc/html/draft-ietf-tls-
              rfc8446bis-05>.

   [I-D.ietf-uta-rfc6125bis]
              Saint-Andre, P. and R. Salz, "Service Identity in TLS",
              Work in Progress, Internet-Draft, draft-ietf-uta-
              rfc6125bis-11, 2 March 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-uta-
              rfc6125bis-11>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <https://www.rfc-editor.org/rfc/rfc5246>.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
              <https://www.rfc-editor.org/rfc/rfc5280>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/rfc/rfc6241>.

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   [RFC7589]  Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
              NETCONF Protocol over Transport Layer Security (TLS) with
              Mutual X.509 Authentication", RFC 7589,
              DOI 10.17487/RFC7589, June 2015,
              <https://www.rfc-editor.org/rfc/rfc7589>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC9325]  Sheffer, Y., Saint-Andre, P., and T. Fossati,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", BCP 195, RFC 9325, DOI 10.17487/RFC9325, November
              2022, <https://www.rfc-editor.org/rfc/rfc9325>.

Acknowledgments

   We would like to thank Per Andersson, Jürgen Schönwälder, Jeff
   Hartley, and Qin Wu for their reviews.

Authors' Addresses

   Sean Turner
   sn3rd
   Email: sean@sn3rd.com

   Russ Housley
   Vigil Security, LLC
   516 Dranesville Road
   Herndon, VA,  20170
   United States of America
   Email: housley@vigilsec.com

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