    Internet Engineering Task Force                                   J. Yao
    Internet-Draft                                                     H. Li
    Intended status: Standards Track                                M. Zhang
    Expires: 03 April  2025                                            CNNIC
                                                                 D. Keathley
                                                                    J. Gould
                                                              VeriSign, Inc.
                                                           30 September 2024

           Extensible Provisioning Protocol (EPP) Transport over QUIC
                             draft-yao-regext-epp-quic-03

    Abstract

       This document describes how an Extensible Provisioning Protocol (EPP)
       session is mapped onto a QUIC connection.  EPP over QUIC (EoQ)
       leverages the performance and security features of the QUIC protocol
       as an EPP transport.

    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."

       This Internet-Draft will expire on 03 April  2025.

    Copyright Notice

       Copyright (c) 2024 IETF Trust and the persons identified as the
       document authors.  All rights reserved.

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       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
       2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
       3.  Session Management  . . . . . . . . . . . . . . . . . . . . .   3
       4.  Message Exchange  . . . . . . . . . . . . . . . . . . . . . .   4
       5.  Data Unit Format  . . . . . . . . . . . . . . . . . . . . . .   6
       6.  EoQ Connection Start Packet . . . . . . . . . . . . . . . . .   6
       7.  Transport Considerations  . . . . . . . . . . . . . . . . . .   7
       8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
         8.1.  Registration of an EoQ Identification String  . . . . . .   7
         8.2.  Registration of Port Number . . . . . . . . . . . . . . .   8
       9.  Implementation Status . . . . . . . . . . . . . . . . . . . .   8
         9.1.  Verisign EPP SDK  . . . . . . . . . . . . . . . . . . . .   9
       10. Security Considerations . . . . . . . . . . . . . . . . . . .   9
       11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
       12. Normative References  . . . . . . . . . . . . . . . . . . . .   9
       Appendix A.  Change History . . . . . . . . . . . . . . . . . . .  10
         A.1.  Change from 00 to 01  . . . . . . . . . . . . . . . . . .  10
       Appendix B.  Change History . . . . . . . . . . . . . . . . . . .  11
         B.1.  Change from 01 to 02  . . . . . . . . . . . . . . . . . .  11
         B.2.  Change from 02 to 03  . . . . . . . . . . . . . . . . . .  11
       Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

    1.  Introduction

       This document describes how the Extensible Provisioning Protocol (EPP
       [RFC5730]) is mapped onto the QUIC transport [RFC9000].  QUIC is a
       network protocol that is based on UDP and incorporates native
       encryption support using TLS [RFC9001].  Though based on UDP, QUIC
       provides connection semantics similar to other stateful protocols.
       This document discusses how EPP implementations can work with this
       and other features of QUIC while preserving the core EPP semantics.

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    2.  Conventions Used in This Document

       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
       [BCP14] when, and only when, they appear in all capitals, as shown
       here.

    3.  Session Management

       Mapping EPP session management facilities onto the QUIC service is
       accomplished with a combination of a QUIC connection and QUIC
       streams.  An EPP session first requires creation of a QUIC connection
       between two peers, one that initiates the connection request and one
       that responds to the connection request.  The initiating peer is
       called the "client", and the responding peer is called the "server".
       An EPP server MUST listen for QUIC connection requests on a standard
       UDP port assigned by IANA.

       A successfully established QUIC connection is automatically secured
       by the native TLS support that QUIC provides.

       Once the QUIC connection is established, the EPP client MUST then
       create a QUIC stream by sending the EoQ Connection Start Packet
       (Section 6).  [RFC9000] states that "streams are created by sending
       data".  Once the EPP server accepts the QUIC stream, it reads the EoQ
       Connection Start Packet (Section 6) and returns an EPP <greeting> to
       the client on same QUIC stream.  After reading the EPP <greeting>
       message, the EPP client sends EPP commands and receives EPP responses
       on the same stream.  A QUIC stream corresponds to an EPP connection,
       which is referred to as a EoQ connection.  An authenticated QUIC
       stream, via a successful EPP <login>, corresponds to an EPP session,
       which is referred to as a EoQ session.

       An EPP session is normally ended by the client issuing an EPP
       <logout> command.  A server receiving an EPP <logout> command MUST
       end the EPP session and close the QUIC stream.  A client MAY end an
       EoQ session by closing the QUIC stream.

       EoQ connections are established as described in the QUIC transport
       specification [RFC9000].  During connection establishment, EoQ
       support is indicated by selecting the Application-Layer Protocol
       Negotiation (ALPN) token "eoq" in the crypto handshake.

       A single QUIC connection may allow multiple QUIC streams.  This means
       that a single QUIC connection may support multiple EoQ sessions.  A
       server MAY limit the life span of an established EoQ session.  EoQ
       sessions that are inactive for more than a server-defined period MAY

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       be ended by a server closing the QUIC stream.  A server MAY close EoQ
       sessions that have been open and active for longer than a server-
       defined limit.  Once the last QUIC stream for a QUIC connection is
       closed, the server MAY end the QUIC connection immediately.

    4.  Message Exchange

       With the exception of the EPP server greeting, EPP messages are
       initiated by the EPP client in the form of EPP commands.  An EPP
       server MUST return an EPP response to an EPP command on the same QUIC
       stream that carried the command.  If the QUIC stream is closed after
       a server receives and successfully processes a command but before the
       response can be returned to the client, the server MAY attempt to
       undo the effects of the command to ensure a consistent state between
       the client and the server.  EPP commands are idempotent, so
       processing a command more than once produces the same net effect on
       the repository as successfully processing the command once.

       An EPP client streams EPP commands to an EPP server on an established
       QUIC stream.  A client MAY establish multiple QUIC streams to support
       multiple EoQ sessions with each EoQ session mapped to a single QUIC
       stream.  A server SHOULD limit a client to a maximum number of QUIC
       streams per QUIC connection based on server capabilities and
       operational load.

       EPP describes client-server interaction as a command-response
       exchange where the client sends one command to the server and the
       server returns one response to the client.

       Each EPP data unit MUST contain a single EPP message.  Commands MUST
       be processed independently.

       A server SHOULD impose a limit on the amount of time required for a
       client to issue a well-formed EPP command to reduce the risk
       associated with a resource exhaustion attack.  A server SHOULD end an
       EoQ session and close the QUIC stream if a well-formed command is not
       received within the time limit.

       A general state machine for an EPP server is described in Section 2
       of [RFC5730].  A general client-server message exchange using QUIC
       transport is illustrated in Figure 1.  It shows the exchange over a
       single QUIC stream of a QUIC connection.  Many QUIC streams may open
       and close during the life of a QUIC connection.

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                              Client                  Server
                         |                                     |
                         |      Successful QUIC Connection     |
                         | <<------------------------------->> |
                         |                                     |
                         |     Successful QUIC Stream with     |
                         |     EoQ Connection Start Packet     |
                         | <<------------------------------->> |
                         |                                     |
                         |             Send Greeting           |
                         | <<-------------------------------<< |
                         |                                     |
                         |             Send <login>            |
                         | >>------------------------------->> |
                         |                                     |
                         |             Send Response           |
                         | <<-------------------------------<< |
                         |                                     |
                         |            Send Command X           |
                         | >>------------------------------->> |
                         |                                     |
                         |            Send Response X          |
                         | <<-------------------------------<< |
                         |                                     |
                         |            Send Command Y           |
                         | >>------------------------------->> |
                         |                                     |
                         |            Send Response Y          |
                         | <<-------------------------------<< |
                         |                  .                  |
                                            .
                                            .
                         |            Send <logout>            |
                         | >>------------------------------->> |
                         |                                     |
                         |            Send Response            |
                         | <<-------------------------------<< |
                         |                                     |
                         |          Close QUIC Stream          |
                         | <<------------------------------->> |
                         |                                     |
                         |        Close QUIC Connection        |
                         | <<------------------------------->> |

                      Figure 1: QUIC Client-Server Message Exchange

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       The EPP server MUST follow the "EPP Server State Machine" procedure
       described in [RFC5730].

    5.  Data Unit Format

       The EPP data unit contains two fields: a 32-bit header that describes
       the total length of the data unit, and the EPP XML instance.  The
       length of the EPP XML instance is determined by subtracting four
       octets from the total length of the data unit.  A receiver must
       successfully read that many octets to retrieve the complete EPP XML
       instance before processing the EPP message.  EPP Data Unit Format
       (one tick mark represents one bit position):

            0                   1                   2                   3
            0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |                           Total Length                        |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |                         EPP XML Instance                      |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+//-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Total Length (32 bits): The total length of the EPP data unit
       measured in octets in network (big endian) byte order.  The octets
       contained in this field MUST be included in the total length
       calculation.  EPP XML Instance (variable length): The EPP XML
       instance carried in the data unit.

    6.  EoQ Connection Start Packet

       The EoQ Connection Start Packet is written by the client after
       creating a QUIC stream to signal the server to create the QUIC
       stream.  The server accepts the QUIC stream, reads the EoQ Connection
       Start Packet, and returns the EPP <greeting> to the client on same
       QUIC stream.

       The EoQ Connection Start Packet follows the Data Unit Format
       (Section 5) with two fields: a 32-bit header that describes the total
       length of the data unit, and the constant value of "EoQ Connection
       Start" instead of an "EPP XML Instance".  The length of the data unit
       will be 24 that includes 4 octets for the Total Length and 20 octets
       for the "EoQ Connection Start" constant value.

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    7.  Transport Considerations

       Section 2.1 of [RFC5730] describes considerations to be addressed by
       protocol transport mappings.  This document addresses each of those
       considerations using a combination of features of the QUIC protocol
       itself and features of this document.

       *  Command Order: QUIC guarantees ordered processing of data within
          each stream.  Section 2 of [RFC9000] describes streams in detail.

       *  Session Mapping: EPP session management utilizes QUIC streams and
          is described in Section 3

       *  Stateful Nature: QUIC supports stateful communications between
          endpoints via connection IDs and long-lived streams within each
          connection.  Sections 2 and 5 of [RFC9000] describe these
          features, respectively.

       *  Frame Data Units: QUIC uses frames as one of its units of
          information when sending data over a stream.  Part packets-frames
          of [RFC9000] describes frames, and packets, in detail.

       *  Congestion Avoidance: QUIC provides various mechanisms to help
          achieve congestion avoidance.  [RFC9002] describes these
          mechanisms in detail.

       *  Reliability: QUIC uses message acknowledgement, packet
          retransmission, and other features to ensure reliability.  Part
          packetization of [RFC9000] describes these features in detail.

       *  Pipelining: Pipelining is allowed in EoQ.  QUIC streams support
          sending multiple frames without waiting for responses from the
          other peer.  This does not change the basic single command, single
          response operating mode of the core EPP protocol.

    8.  IANA Considerations

    8.1.  Registration of an EoQ Identification String

       This document creates a new registration for the identification of
       EoQ in the "TLS Application-Layer Protocol Negotiation (ALPN)
       Protocol IDs" registry [RFC7301].

       *  Protocol: EoQ

       *  Identification Sequence: 0x65 0x6F 0x71 ("eoq")

       *  Reference: This document

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    8.2.  Registration of Port Number

       The "Service Name and Transport Protocol Port Number Registry"
       contains an entry for EPP UDP/700 based on [RFC6335].  However, no
       known implementations of EPP over UDP exist.  The entry will be
       reassigned to reference this draft.

       *  Service Name: epp

       *  Port Number: 700

       *  Transport Protocol(s): UDP

       *  Assignee: IESG

       *  Contact: IETF Chair

       *  Description: EPP run over QUIC

       *  Reference: This document

    9.  Implementation Status

       Note to RFC Editor: Please remove this section and the reference to
       RFC 7942 [RFC7942] before publication.

       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 RFC 7942
       [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 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 catalog of available
       implementations or their features.  Readers are advised to note that
       other implementations may exist.

       According to RFC 7942 [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".

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    9.1.  Verisign EPP SDK

       Organization: Verisign Inc.

       Name: Verisign EPP SDK

       Description: The Verisign EPP SDK includes both a full client
       implementation and a full server stub implementation of draft-yao-
       regext-epp-quic.

       Level of maturity: Development

       Coverage: All aspects of the protocol are implemented with QUIC V1.

       Licensing: GNU Lesser General Public License

       Contact: jgould@verisign.com

       URL: https://www.verisign.com/en_US/channel-resources/domain-
       registry-products/epp-sdks

    10.  Security Considerations

       EPP over QUIC provides the similary securtiy with EPP over TCP with
       TLS.  Some related security issues have been discussed in [RFC5734]
       and [RFC9000].

       EoQ servers run the risk of a resource exhaustion attack by allowing
       the creation of unlimited QUIC streams per QUIC connection.  Servers
       SHOULD limit a client to a maximum number of QUIC streams per QUIC
       connection based on server capabilities and operational load.

    11.  Acknowledgements

       The authors wish to thank the following persons for their feedback
       and suggestions: Scott Hollenbeck.

    12.  Normative References

       [BCP14]    Best Current Practice 14,
                  <https://www.rfc-editor.org/info/bcp14>.
                  At the time of writing, this BCP comprises the following:

                  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>.

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                  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>.

       [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
                  STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
                  <https://www.rfc-editor.org/info/rfc5730>.

       [RFC5734]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
                  Transport over TCP", STD 69, RFC 5734,
                  DOI 10.17487/RFC5734, August 2009,
                  <https://www.rfc-editor.org/info/rfc5734>.

       [RFC6335]  Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S.
                  Cheshire, "Internet Assigned Numbers Authority (IANA)
                  Procedures for the Management of the Service Name and
                  Transport Protocol Port Number Registry", BCP 165,
                  RFC 6335, DOI 10.17487/RFC6335, August 2011,
                  <https://www.rfc-editor.org/info/rfc6335>.

       [RFC7301]  Friedl, S., Popov, A., Langley, A., and E. Stephan,
                  "Transport Layer Security (TLS) Application-Layer Protocol
                  Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
                  July 2014, <https://www.rfc-editor.org/info/rfc7301>.

       [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
                  Code: The Implementation Status Section", BCP 205,
                  RFC 7942, DOI 10.17487/RFC7942, July 2016,
                  <https://www.rfc-editor.org/info/rfc7942>.

       [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
                  Multiplexed and Secure Transport", RFC 9000,
                  DOI 10.17487/RFC9000, May 2021,
                  <https://www.rfc-editor.org/info/rfc9000>.

       [RFC9001]  Thomson, M., Ed. and S. Turner, Ed., "Using TLS to Secure
                  QUIC", RFC 9001, DOI 10.17487/RFC9001, May 2021,
                  <https://www.rfc-editor.org/info/rfc9001>.

       [RFC9002]  Iyengar, J., Ed. and I. Swett, Ed., "QUIC Loss Detection
                  and Congestion Control", RFC 9002, DOI 10.17487/RFC9002,
                  May 2021, <https://www.rfc-editor.org/info/rfc9002>.

    Appendix A.  Change History

    A.1.  Change from 00 to 01

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       1.  Added Dan Keathley and James Gould as co-authors and aligned the
           draft with EPP RFC 5734.

    Appendix B.  Change History

    B.1.  Change from 01 to 02

       1.  Make the clear distinction between an EPP connection and an EPP
           session for EoQ in the Session Management section.
       2.  Align the handling of the EPP <logout> command with RFC 5734, by
           including "A client MAY end an EoQ session by closing the QUIC
           stream" in the Session Management section.
       3.  Ensure that the relationship of the EoQ connection and the EoQ
           stream is maintained with the sentence "This means that a single
           QUIC connection may support multiple EoQ sessions" in the Session
           Management section.
       4.  Leverage the EoQ session in place of the more generic EPP session
           in the Message Exchange section.

    B.2.  Change from 02 to 03

       1.  Added the definition and use of the EoQ Connection Start Packet
           to explicitly trigger the creation of the QUIC stream and the EoQ
           connection to the server.
       2.  Added the Implementation Status section with the Verisign EPP SDK
           implementation.

    Authors' Addresses

       Jiankang Yao
       CNNIC
       4 South 4th Street,Zhongguancun,Haidian District
       Beijing
       Beijing, 100190
       China
       Phone: +86 10 5881 3007
       Email: yaojk@cnnic.cn

       Hongtao Li
       CNNIC
       4 South 4th Street,Zhongguancun,Haidian District
       Beijing
       Beijing, 100190
       China
       Email: lihongtao@cnnic.cn

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       Man Zhang
       CNNIC
       4 South 4th Street,Zhongguancun,Haidian District
       Beijing
       Beijing, 100190
       China
       Email: zhangman@cnnic.cn

       Daniel Keathley
       VeriSign, Inc.
       12061 Bluemont Way
       Reston, VA 20190
       United States of America
       Email: dkeathley@verisign.com
       URI:   http://www.verisigninc.com

       James Gould
       VeriSign, Inc.
       12061 Bluemont Way
       Reston, VA 20190
       United States of America
       Email: jgould@verisign.com
       URI:   http://www.verisigninc.com

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