Path Computation Element

Internet Engineering Task Force (IETF)                          D. Dhody
Internet-Draft
Request for Comments: 9916                                        Huawei
Updates: 8253 (if approved)                                                  S. Turner
Intended status:
Category: Standards Track                                          sn3rd
Expires: 12 July 2024
ISSN: 2070-1721                                               R. Housley
                                                          Vigil Security
                                                          9
                                                            January 2024 2026

 Updates for PCEPS: to the Usage of TLS Connection Establishment Restrictions
                     draft-ietf-pce-pceps-tls13-04 to Provide a Secure Transport for the Path
           Computation Element Communication Protocol (PCEP)

Abstract

   Section 3.4 of RFC 8253 specifies TLS connection establishment
   restrictions for PCEPS; PCEPS refers to usage of TLS to provide a
   secure transport for PCEP (Path the Path Computation Element Communication
   Protocol).
   Protocol (PCEP).  This document adds restrictions to specify what
   PCEPS implementations do if they support more than one version of the
   TLS protocol and to restrict the use of TLS 1.3's early data.

About This Document

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

   Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-ietf-pce-pceps-tls13/.

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

   Source for this draft and an issue tracker can be found at
   https://github.com/ietf-wg-pce/draft-ietf-pce-pceps-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 an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list  It represents the consensus of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid the IETF community.  It has
   received public review and has been approved for a maximum publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of six months RFC 7841.

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   This Internet-Draft will expire on 12 July 2024.
   https://www.rfc-editor.org/info/rfc9916.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  TLS Connection Establishment Restrictions . . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Implementation Status . . . . . . . . . . . . . . . . . . . .   4
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     7.1.
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     7.2.
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Section 3.4 of [RFC8253] specifies TLS connection establishment
   restrictions for PCEPS; PCEPS refers to usage of TLS to provide a
   secure transport for PCEP (Path the Path Computation Element Communication
   Protocol)
   Protocol (PCEP) [RFC5440].  This document adds restrictions to
   specify what PCEPS implementations do if they support more than one
   version of the TLS protocol, e.g., TLS 1.2 [RFC5246] and TLS 1.3
   [I-D.ietf-tls-rfc8446bis],
   [RFC9846], and to restrict the use of TLS 1.3's early data, which is
   also known as 0-RTT data.  All other provisions set forth in
   [RFC8253] are unchanged, including connection initiation, message
   framing, connection closure, certificate validation, peer identity,
   and failure handling.

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.  TLS Connection Establishment Restrictions

   Step 1 in Section 3.4 of [RFC8253] Step 1 includes restrictions on PCEPS TLS
   connection establishment.  This document adds the following
   restrictions:

   *  Implementations that support multiple versions of the TLS protocol
      MUST prefer to negotiate the latest version of the TLS protocol;
      see Section 4.2.1 of [I-D.ietf-tls-rfc8446bis]. [RFC9846].

   *  PCEPS implementations that support TLS 1.3 or later MUST NOT use
      early data.

      |  NOTE: Early data (aka 0-RTT data) is a mechanism defined in TLS
      |  1.3
      [I-D.ietf-tls-rfc8446bis] [RFC9846] 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].
      |  [RFC9846].  In fact, early data is permitted by TLS 1.3 only
      |  when the client and server share a Pre-
      Shared 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.

      |  NOTE: As noted in Section 2.3 of [I-D.ietf-tls-rfc8446bis], [RFC9846], the security
      |  properties for early data are weaker than those for subsequent TLS- protected
      |  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] [RFC9846] requires
      |  applications not use early data without a profile that defines
      |  its use.

4.  Security Considerations

   The Security Considerations security considerations of PCEP [RFC5440], [RFC8231], [RFC8253],
   [RFC8281], and [RFC8283]; [RFC5440] [RFC8231] [RFC8253]
   [RFC8281] [RFC8283], TLS 1.2 [RFC5246]; [RFC5246], TLS 1.3
   [I-D.ietf-tls-rfc8446bis], and; [RFC9846], and TLS/
   DTLS recommendations [RFC9325] apply here as well.

5.  IANA Considerations

   There are no IANA considerations.

6.  Implementation Status

      |  Note to the RFC Editor - remove this section before
      |  publication, as well as remove the reference to RFC 7942.

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description of implementations in this section is intended to
   assist the IETF in its decision processes in progressing drafts to
   RFCs.  Please note that the listing of any individual implementation
   here does not imply endorsement by the IETF.  Furthermore, no effort document has been spent to verify the information presented here that was
   supplied by IETF contributors.  This is not intended as, and must not
   be construed to be, a catalogue of available implementations or their
   features.  Readers are advised to note that other implementations may
   exist.

   According to [RFC7942], "this will allow reviewers and working groups
   to assign due consideration to documents that have the benefit of
   running code, which may serve as evidence of valuable experimentation
   and feedback that have made the implemented protocols more mature.
   It is up to the individual working groups to use this information as
   they see fit".

   At the time of posting the -04 version of this document, there are no
   known implementations of this mechanism.  It is believed that one
   vendor has implementation, but these plans are too vague to make any
   further assertions.

7. IANA actions.

6.  References

7.1.

6.1.  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-09, 7 July 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-tls-
              rfc8446bis-09>.

   [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>.
              <https://www.rfc-editor.org/info/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>.
              <https://www.rfc-editor.org/info/rfc5246>.

   [RFC5440]  Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
              Element (PCE) Communication Protocol (PCEP)", RFC 5440,
              DOI 10.17487/RFC5440, March 2009,
              <https://www.rfc-editor.org/rfc/rfc5440>.
              <https://www.rfc-editor.org/info/rfc5440>.

   [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>. <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8253]  Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
              "PCEPS: Usage of TLS to Provide a Secure Transport for the
              Path Computation Element Communication Protocol (PCEP)",
              RFC 8253, DOI 10.17487/RFC8253, October 2017,
              <https://www.rfc-editor.org/rfc/rfc8253>.
              <https://www.rfc-editor.org/info/rfc8253>.

   [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>.

7.2.  Informative References

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205, <https://www.rfc-editor.org/info/rfc9325>.

   [RFC9846]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 7942, 9846, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/rfc/rfc7942>. 10.17487/RFC9846, January
              2026, <https://www.rfc-editor.org/info/rfc9846>.

6.2.  Informative References

   [RFC8231]  Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for Stateful PCE", RFC 8231,
              DOI 10.17487/RFC8231, September 2017,
              <https://www.rfc-editor.org/rfc/rfc8231>.
              <https://www.rfc-editor.org/info/rfc8231>.

   [RFC8281]  Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for PCE-Initiated LSP Setup in a Stateful PCE
              Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8281>.
              <https://www.rfc-editor.org/info/rfc8281>.

   [RFC8283]  Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
              Architecture for Use of PCE and the PCE Communication
              Protocol (PCEP) in a Network with Central Control",
              RFC 8283, DOI 10.17487/RFC8283, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8283>.
              <https://www.rfc-editor.org/info/rfc8283>.

Acknowledgments

   We would like to thank Adrian Farrel, Stephane Litkowski, Cheng Li,
   and Andrew Stone for their review.

Authors' Addresses

   Dhruv Dhody
   Huawei
   Email: dhruv.ietf@gmail.com

   Sean Turner
   sn3rd
   Email: sean@sn3rd.com

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