RFC 9916 PROPOSED STANDARD SECURITY · TLS · PCEP
PCEPS TLS version rules: Updates to the Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)
Two extra TLS rules for secure PCEP: prefer the newest TLS version, and never use TLS 1.3 early data.
RFC EDITOR
Dhody, D., Turner, S., and R. Housley, "Updates to the Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)", RFC 9916, DOI 10.17487/RFC9916, July 2026, <https://www.rfc-editor.org/info/rfc9916>.
BIBTEX
@misc{rfc9916,
series = {Request for Comments},
number = 9916,
howpublished = {RFC 9916},
publisher = {RFC Editor},
doi = {10.17487/RFC9916},
url = {https://www.rfc-editor.org/info/rfc9916},
author = {D. Dhody and S. Turner and R. Housley},
title = {{Updates to the Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)}},
pagetotal = 5,
year = 2026,
month = jul,
} LINEAGE · FROM THE RFC INDEXOpen full graph →
RFC text
Contents
Internet Engineering Task Force (IETF) D. Dhody
Request for Comments: 9916 Huawei
Updates: 8253 S. Turner
Category: Standards Track sn3rd
ISSN: 2070-1721 R. Housley
Vigil Security
July 2026
Updates to the Usage of TLS 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 the Path Computation Element Communication
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.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9916.
Copyright Notice
Copyright (c) 2026 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.
Table of Contents
1. Introduction
2. Conventions
3. TLS Connection Establishment Restrictions
4. Security Considerations
5. IANA Considerations
6. References
6.1. Normative References
6.2. Informative References
Acknowledgments
Authors' Addresses
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 the Path Computation Element Communication
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
[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
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] 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 [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 [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
| [RFC9846]. 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.
| NOTE: As noted in Section 2.3 of [RFC9846], 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 [RFC9846] requires
| applications not use early data without a profile that defines
| its use.
4. Security Considerations
The security considerations of PCEP [RFC5440] [RFC8231] [RFC8253]
[RFC8281] [RFC8283], TLS 1.2 [RFC5246], TLS 1.3 [RFC9846], and
TLS/DTLS recommendations [RFC9325] apply here as well.
5. IANA Considerations
This document has no IANA actions.
6. References
6.1. Normative References
[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/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/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/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/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/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/info/rfc9325>.
[RFC9846] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 9846, DOI 10.17487/RFC9846, July 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/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/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/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 20170
United States of America
Email: housley@vigilsec.com
AI ELI5
On this page
PROBLEMRFC 8253 describes how to run PCEP over TLS (PCEPS), but it does not say what to do when an implementation supports several TLS versions, or whether TLS 1.3 early data may be used.
MECHANISMThis document adds two rules to the TLS connection establishment restrictions: implementations that support multiple TLS versions MUST prefer the latest one, and PCEPS implementations that support TLS 1.3 or later MUST NOT use early data.
WHY IT MATTERSIt updates RFC 8253 and changes nothing else in it. Connection initiation, message framing, closure, certificate validation, peer identity and failure handling stay as RFC 8253 defines them.
§1What This Update Changes
PCEPS is the name for using TLS as a secure transport for the Path Computation Element Communication Protocol (PCEP). RFC 8253 defines it and, in its Section 3.4, lists restrictions on how the TLS connection is established.
This document adds two restrictions to that list. It states that all other provisions of RFC 8253 are unchanged, including connection initiation, message framing, connection closure, certificate validation, peer identity and failure handling.
There is already a rulebook for locking PCEP messages in a safe box. This note adds two small rules to it and leaves the rest alone.
§3Preferring the Latest TLS Version
The first new rule applies to implementations that support more than one version of TLS, for example TLS 1.2 and TLS 1.3. They MUST prefer to negotiate the latest version of the TLS protocol.
The RFC points to Section 4.2.1 of RFC 9846 for how that version negotiation works.
If both sides know old and new versions of the secret code, they must pick the newest one they share.
§3No Early Data
The second rule says that PCEPS implementations that support TLS 1.3 or later MUST NOT use early data. Early data, also called 0-RTT data, lets a TLS 1.3 client send data in the first flight of messages to a server.
The RFC explains why. Early data is permitted by TLS 1.3 only when client and server share a Pre-Shared Key (PSK). Its security properties are weaker than those of later TLS-protected data: it is not forward secret, and nothing protects against replay of early data between connections. TLS 1.3 can be used without early data.
The Security Considerations section adds that the security considerations of PCEP, TLS 1.2, TLS 1.3 and the TLS/DTLS recommendations in RFC 9325 apply as well.
Sending your message before the secret handshake is done is risky, because someone could copy it and send it again. So PCEPS may not do that.
§4References
[RFC8253]RFC 8253Lopez, 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, October 2017.October 2017[RFC5440]RFC 5440Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, March 2009.March 2009[RFC9846]RFC 9846Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 9846, July 2026.July 2026[RFC9325]RFC 9325Sheffer, 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, November 2022.November 2022