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YANG Groupings for SSH Clients and SSH Servers
draft-ietf-netconf-ssh-client-server-40

Document Type Active Internet-Draft (netconf WG)
Author Kent Watsen
Last updated 2024-09-18 (Latest revision 2024-03-16)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
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Additional resources Yang catalog entry for ietf-ssh-client@2020-08-20.yang
Yang catalog entry for ietf-ssh-common@2020-08-20.yang
Yang catalog entry for ietf-ssh-server@2020-08-20.yang
Yang impact analysis for draft-ietf-netconf-ssh-client-server
Mailing list discussion
Stream WG state Submitted to IESG for Publication
Document shepherd Per Andersson
Shepherd write-up Show Last changed 2022-10-18
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Responsible AD Robert Wilton
Send notices to perander@cisco.com, mjethanandani@gmail.com
IANA IANA review state Version Changed - Review Needed
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IANA expert review state Expert Reviews OK
IANA expert review comments LGTM. I was thrown by the use of both ...:ns:yang:ietf-... and ...:ns:yang:iana-... but the usage at least appears to be consistent.
RFC Editor RFC Editor state AUTH48-DONE
Details
draft-ietf-netconf-ssh-client-server-40
NETCONF Working Group                                          K. Watsen
Internet-Draft                                           Watsen Networks
Intended status: Standards Track                           16 March 2024
Expires: 17 September 2024

             YANG Groupings for SSH Clients and SSH Servers
                draft-ietf-netconf-ssh-client-server-40

Abstract

   This document presents seven YANG 1.1 modules.  Three IETF modules,
   and four supporting IANA modules.

   The three IETF modules are: ietf-ssh-common, ietf-ssh-client, and
   ietf-ssh-server.  The "ietf-ssh-client" and "ietf-ssh-server" modules
   are the primary productions of this work, supporting the
   configuration and monitoring of SSH clients and servers.

   The four IANA modules are: iana-ssh-encryption-algs, iana-ssh-key-
   exchange-algs, iana-ssh-mac-algs, and iana-ssh-public-key-algs.
   These modules each define YANG enumerations providing support for an
   IANA-maintained algorithm registry.

Editorial Note (To be removed by RFC Editor)

   This draft contains placeholder values that need to be replaced with
   finalized values at the time of publication.  This note summarizes
   all of the substitutions that are needed.  No other RFC Editor
   instructions are specified elsewhere in this document.

   Artwork in this document contains shorthand references to drafts in
   progress.  Please apply the following replacements:

   *  AAAA --> the assigned RFC value for draft-ietf-netconf-crypto-
      types

   *  BBBB --> the assigned RFC value for draft-ietf-netconf-trust-
      anchors

   *  CCCC --> the assigned RFC value for draft-ietf-netconf-keystore

   *  DDDD --> the assigned RFC value for draft-ietf-netconf-tcp-client-
      server

   *  EEEE --> the assigned RFC value for this draft

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   Artwork in this document contains placeholder values for the date of
   publication of this draft.  Please apply the following replacement:

   *  2024-03-16 --> the publication date of this draft

   The "Relation to other RFCs" section Section 1.2 contains the text
   "one or more YANG modules" and, later, "modules".  This text is
   sourced from a file in a context where it is unknown how many modules
   a draft defines.  The text is not wrong as is, but it may be improved
   by stating more directly how many modules are defined.

   The "Relation to other RFCs" section Section 1.2 contains a self-
   reference to this draft, along with a corresponding reference in the
   Appendix.  Please replace the self-reference in this section with
   "This RFC" (or similar) and remove the self-reference in the
   "Normative/Informative References" section, whichever it is in.

   Tree-diagrams in this draft may use the '\' line-folding mode defined
   in RFC 8792.  However, nicer-to-the-eye is when the '\\' line-folding
   mode is used.  The AD suggested suggested putting a request here for
   the RFC Editor to help convert "ugly" '\' folded examples to use the
   '\\' folding mode.  "Help convert" may be interpreted as, identify
   what looks ugly and ask the authors to make the adjustment.

   The following Appendix sections are to be removed prior to
   publication:

   *  Appendix A.1.  Initial Module for the "Encryption Algorithm Names"
      Registry

   *  Appendix A.2.  Initial Module for the "MAC Algorithm Names"
      Registry

   *  Appendix A.3.  Initial Module for the "Public Key Algorithm Names"
      Registry

   *  Appendix A.4.  Initial Module for the "Key Exchange Method Names"
      Registry

   *  Appendix B.  Change Log

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   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 17 September 2024.

Copyright Notice

   Copyright (c) 2024 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  . . . . . . . . . . . . . . . . . . . . . . . .   5
     1.1.  Regarding the IETF Modules  . . . . . . . . . . . . . . .   6
     1.2.  Relation to other RFCs  . . . . . . . . . . . . . . . . .   6
     1.3.  Specification Language  . . . . . . . . . . . . . . . . .   8
     1.4.  Adherence to the NMDA . . . . . . . . . . . . . . . . . .   8
     1.5.  Conventions . . . . . . . . . . . . . . . . . . . . . . .   8
   2.  The "ietf-ssh-common" Module  . . . . . . . . . . . . . . . .   9
     2.1.  Data Model Overview . . . . . . . . . . . . . . . . . . .   9
     2.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .  12
     2.3.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .  14
   3.  The "ietf-ssh-client" Module  . . . . . . . . . . . . . . . .  24
     3.1.  Data Model Overview . . . . . . . . . . . . . . . . . . .  24
     3.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .  27
     3.3.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .  31
   4.  The "ietf-ssh-server" Module  . . . . . . . . . . . . . . . .  39
     4.1.  Data Model Overview . . . . . . . . . . . . . . . . . . .  39
     4.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .  41
     4.3.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .  45
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  54

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     5.1.  Considerations for the "iana-ssh-key-exchange-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  54
     5.2.  Considerations for the "iana-ssh-encryption-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  55
     5.3.  Considerations for the "iana-ssh-mac-algs" Module . . . .  56
     5.4.  Considerations for the "iana-ssh-public-key-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  56
     5.5.  Considerations for the "ietf-ssh-common" YANG Module  . .  57
     5.6.  Considerations for the "ietf-ssh-client" YANG Module  . .  57
     5.7.  Considerations for the "ietf-ssh-server" YANG Module  . .  58
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  59
     6.1.  The "IETF XML" Registry . . . . . . . . . . . . . . . . .  59
     6.2.  The "YANG Module Names" Registry  . . . . . . . . . . . .  60
     6.3.  Considerations for the "iana-ssh-encryption-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  61
     6.4.  Considerations for the "iana-ssh-mac-algs" Module . . . .  63
     6.5.  Considerations for the "iana-ssh-public-key-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  64
     6.6.  Considerations for the "iana-ssh-key-exchange-algs"
           Module  . . . . . . . . . . . . . . . . . . . . . . . . .  66
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  68
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  68
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  70
   Appendix A.  Script to Generate IANA-Maintained YANG Modules  . .  73
     A.1.  Initial Module for the "Encryption Algorithm Names"
           Registry  . . . . . . . . . . . . . . . . . . . . . . . .  80
     A.2.  Initial Module for the "MAC Algorithm Names" Registry . .  88
     A.3.  Initial Module for the "Public Key Algorithm Names"
           Registry  . . . . . . . . . . . . . . . . . . . . . . . .  91
     A.4.  Initial Module for the "Key Exchange Method Names"
           Registry  . . . . . . . . . . . . . . . . . . . . . . . .  99
   Appendix B.  Change Log . . . . . . . . . . . . . . . . . . . . . 143
     B.1.  00 to 01  . . . . . . . . . . . . . . . . . . . . . . . . 143
     B.2.  01 to 02  . . . . . . . . . . . . . . . . . . . . . . . . 143
     B.3.  02 to 03  . . . . . . . . . . . . . . . . . . . . . . . . 143
     B.4.  03 to 04  . . . . . . . . . . . . . . . . . . . . . . . . 143
     B.5.  04 to 05  . . . . . . . . . . . . . . . . . . . . . . . . 144
     B.6.  05 to 06  . . . . . . . . . . . . . . . . . . . . . . . . 144
     B.7.  06 to 07  . . . . . . . . . . . . . . . . . . . . . . . . 144
     B.8.  07 to 08  . . . . . . . . . . . . . . . . . . . . . . . . 144
     B.9.  08 to 09  . . . . . . . . . . . . . . . . . . . . . . . . 145
     B.10. 09 to 10  . . . . . . . . . . . . . . . . . . . . . . . . 145
     B.11. 10 to 11  . . . . . . . . . . . . . . . . . . . . . . . . 145
     B.12. 11 to 12  . . . . . . . . . . . . . . . . . . . . . . . . 145
     B.13. 12 to 13  . . . . . . . . . . . . . . . . . . . . . . . . 145
     B.14. 13 to 14  . . . . . . . . . . . . . . . . . . . . . . . . 146
     B.15. 14 to 15  . . . . . . . . . . . . . . . . . . . . . . . . 146
     B.16. 15 to 16  . . . . . . . . . . . . . . . . . . . . . . . . 146

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     B.17. 16 to 17  . . . . . . . . . . . . . . . . . . . . . . . . 146
     B.18. 17 to 18  . . . . . . . . . . . . . . . . . . . . . . . . 146
     B.19. 18 to 19  . . . . . . . . . . . . . . . . . . . . . . . . 147
     B.20. 19 to 20  . . . . . . . . . . . . . . . . . . . . . . . . 147
     B.21. 20 to 21  . . . . . . . . . . . . . . . . . . . . . . . . 148
     B.22. 21 to 22  . . . . . . . . . . . . . . . . . . . . . . . . 148
     B.23. 22 to 23  . . . . . . . . . . . . . . . . . . . . . . . . 148
     B.24. 23 to 24  . . . . . . . . . . . . . . . . . . . . . . . . 148
     B.25. 24 to 25  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.26. 25 to 26  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.27. 26 to 27  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.28. 27 to 28  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.29. 28 to 29  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.30. 29 to 30  . . . . . . . . . . . . . . . . . . . . . . . . 149
     B.31. 30 to 31  . . . . . . . . . . . . . . . . . . . . . . . . 150
     B.32. 31 to 32  . . . . . . . . . . . . . . . . . . . . . . . . 150
     B.33. 32 to 33  . . . . . . . . . . . . . . . . . . . . . . . . 150
     B.34. 33 to 34  . . . . . . . . . . . . . . . . . . . . . . . . 150
     B.35. 34 to 35  . . . . . . . . . . . . . . . . . . . . . . . . 151
     B.36. 35 to 36  . . . . . . . . . . . . . . . . . . . . . . . . 151
     B.37. 36 to 38  . . . . . . . . . . . . . . . . . . . . . . . . 151
     B.38. 38 to 39  . . . . . . . . . . . . . . . . . . . . . . . . 151
     B.39. 39 to 40  . . . . . . . . . . . . . . . . . . . . . . . . 151
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . . 152
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . . 152
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . 152

1.  Introduction

   This document presents seven YANG 1.1 [RFC7950] modules.  Three
   "IETF" modules and four "IANA" modules.

   The three IETF modules are ietf-ssh-common (Section 2), ietf-ssh-
   client (Section 3), and ietf-ssh-server (Section 4).  The "ietf-ssh-
   client" and "ietf-ssh-server" modules are the primary productions of
   this work, supporting the configuration and monitoring of SSH clients
   and servers.

   The groupings defined in this document are expected to be used in
   conjunction with the groupings defined in an underlying transport-
   level module, such as the groupings defined in
   [I-D.ietf-netconf-tcp-client-server].  The transport-level data model
   enables the configuration of transport-level values such as a remote
   address, a remote port, a local address, and a local port.

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   The four IANA modules are: iana-ssh-encryption-algs (Appendix A.1),
   iana-ssh-key-exchange-algs (Appendix A.4), iana-ssh-mac-algs
   (Appendix A.2), and iana-ssh-public-key-algs (Appendix A.3).  These
   modules each define YANG enumerations providing support for an IANA-
   maintained algorithm registry.

   This document assumes that the four IANA modules exist, and presents
   a script in Appendix A that IANA may use to generate the YANG
   modules.  This document does not publish initial versions of these
   four modules.  IANA publishes these modules.

1.1.  Regarding the IETF Modules

   The three IETF modules define features and groupings to model
   "generic" SSH clients and SSH servers, where "generic" should be
   interpreted as "least common denominator" rather than "complete."
   Basic SSH protocol ([RFC4252], [RFC4253], and [RFC4254]) support is
   afforded by these modules, leaving configuration of advance features
   (e.g., multiple channels) to augmentations made by consuming modules.

   It is intended that the YANG groupings will be used by applications
   needing to configure SSH client and server protocol stacks.  For
   instance, these groupings are used to help define the data model for
   NETCONF over SSH [RFC6242] based clients and servers in
   [I-D.ietf-netconf-netconf-client-server].

   The ietf-ssh-client and ietf-ssh-server YANG modules each define one
   grouping, which is focused on just SSH-specific configuration, and
   specifically avoids any transport-level configuration, such as what
   ports to listen on or connect to.  This affords applications the
   opportunity to define their own strategy for how the underlying TCP
   connection is established.  For instance, applications supporting
   NETCONF Call Home [RFC8071] could use the "ssh-server-grouping"
   grouping for the SSH parts it provides, while adding data nodes for
   the TCP-level call-home configuration.

   The modules defined in this document optionally support [RFC6187]
   enabling X.509v3 certificate based host keys and public keys.

1.2.  Relation to other RFCs

   This document presents one or more YANG modules [RFC7950] that are
   part of a collection of RFCs that work together to, ultimately,
   support the configuration of both the clients and servers of both the
   NETCONF [RFC6241] and RESTCONF [RFC8040] protocols.

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   The dependency relationship between the primary YANG groupings
   defined in the various RFCs is presented in the below diagram.  In
   some cases, a draft may define secondary groupings that introduce
   dependencies not illustrated in the diagram.  The labels in the
   diagram are a shorthand name for the defining RFC.  The citation
   reference for shorthand name is provided below the diagram.

   Please note that the arrows in the diagram point from referencer to
   referenced.  For example, the "crypto-types" RFC does not have any
   dependencies, whilst the "keystore" RFC depends on the "crypto-types"
   RFC.

                                  crypto-types
                                    ^      ^
                                   /        \
                                  /          \
                         truststore         keystore
                          ^     ^             ^  ^
                          |     +---------+   |  |
                          |               |   |  |
                          |      +------------+  |
   tcp-client-server      |     /         |      |
      ^    ^        ssh-client-server     |      |
      |    |           ^            tls-client-server
      |    |           |              ^     ^        http-client-server
      |    |           |              |     |                 ^
      |    |           |        +-----+     +---------+       |
      |    |           |        |                     |       |
      |    +-----------|--------|--------------+      |       |
      |                |        |              |      |       |
      +-----------+    |        |              |      |       |
                  |    |        |              |      |       |
                  |    |        |              |      |       |
               netconf-client-server       restconf-client-server

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   +======================+===========================================+
   |Label in Diagram      | Originating RFC                           |
   +======================+===========================================+
   |crypto-types          | [I-D.ietf-netconf-crypto-types]           |
   +----------------------+-------------------------------------------+
   |truststore            | [I-D.ietf-netconf-trust-anchors]          |
   +----------------------+-------------------------------------------+
   |keystore              | [I-D.ietf-netconf-keystore]               |
   +----------------------+-------------------------------------------+
   |tcp-client-server     | [I-D.ietf-netconf-tcp-client-server]      |
   +----------------------+-------------------------------------------+
   |ssh-client-server     | [I-D.ietf-netconf-ssh-client-server]      |
   +----------------------+-------------------------------------------+
   |tls-client-server     | [I-D.ietf-netconf-tls-client-server]      |
   +----------------------+-------------------------------------------+
   |http-client-server    | [I-D.ietf-netconf-http-client-server]     |
   +----------------------+-------------------------------------------+
   |netconf-client-server | [I-D.ietf-netconf-netconf-client-server]  |
   +----------------------+-------------------------------------------+
   |restconf-client-server| [I-D.ietf-netconf-restconf-client-server] |
   +----------------------+-------------------------------------------+

                 Table 1: Label in Diagram to RFC Mapping

1.3.  Specification Language

   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.

1.4.  Adherence to the NMDA

   This document is compliant with the Network Management Datastore
   Architecture (NMDA) [RFC8342].  For instance, as described in
   [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore],
   trust anchors and keys installed during manufacturing are expected to
   appear in <operational> (Section 5.3 of [RFC8342]), and <system>
   [I-D.ietf-netmod-system-config], if implemented.

1.5.  Conventions

   Various examples in this document use "BASE64VALUE=" as a placeholder
   value for binary data that has been base64 encoded (per Section 9.8
   of [RFC7950]).  This placeholder value is used because real base64
   encoded structures are often many lines long and hence distracting to
   the example being presented.

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2.  The "ietf-ssh-common" Module

   The SSH common model presented in this section contains features and
   groupings common to both SSH clients and SSH servers.  The
   "transport-params-grouping" grouping can be used to configure the
   list of SSH transport algorithms permitted by the SSH client or SSH
   server.  The lists of permitted algorithms are in decreasing order of
   usage preference.  The algorithm that appears first in the client
   list that also appears in the server list is the one that is used for
   the SSH transport layer connection.  The ability to restrict the
   algorithms allowed is provided in this grouping for SSH clients and
   SSH servers that are capable of doing so and may serve to make SSH
   clients and SSH servers compliant with security policies.

2.1.  Data Model Overview

   This section provides an overview of the "ietf-ssh-common" module in
   terms of its features, identities, and groupings.

2.1.1.  Features

   The following diagram lists all the "feature" statements defined in
   the "ietf-ssh-common" module:

   Features:
     +-- ssh-x509-certs
     +-- transport-params
     +-- asymmetric-key-pair-generation
     +-- algorithm-discovery

   The diagram above uses syntax that is similar to but not defined in
   [RFC8340].

   Please refer to the YANG module for a description of each feature.

2.1.2.  Groupings

   The "ietf-ssh-common" module defines the following "grouping"
   statement:

   *  transport-params-grouping

   This grouping is presented in the following subsection.

2.1.2.1.  The "transport-params-grouping" Grouping

   The following tree diagram [RFC8340] illustrates the "transport-
   params-grouping" grouping:

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     grouping transport-params-grouping:
       +-- host-key
       |  +-- host-key-alg*   ssh-public-key-algorithm
       +-- key-exchange
       |  +-- key-exchange-alg*   ssh-key-exchange-algorithm
       +-- encryption
       |  +-- encryption-alg*   ssh-encryption-algorithm
       +-- mac
          +-- mac-alg*   ssh-mac-algorithm

   Comments:

   *  This grouping is used by both the "ssh-client-grouping" and the
      "ssh-server-grouping" groupings defined in Section 3.1.2.1 and
      Section 4.1.2.1, respectively.

   *  This grouping enables client and server configurations to specify
      the algorithms that are to be used when establishing SSH sessions.

   *  Each list is "ordered-by user".

2.1.3.  Protocol-accessible Nodes

   The following tree diagram [RFC8340] lists all the protocol-
   accessible nodes defined in the "ietf-ssh-common" module, without
   expanding the "grouping" statements:

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   module: ietf-ssh-common
     +--ro supported-algorithms {algorithm-discovery}?
        +--ro public-key-algorithms
        |  +--ro supported-algorithm*   ssh-public-key-algorithm
        +--ro encryption-algorithms
        |  +--ro supported-algorithm*   ssh-encryption-algorithm
        +--ro key-exchange-algorithms
        |  +--ro supported-algorithm*   ssh-key-exchange-algorithm
        +--ro mac-algorithms
           +--ro supported-algorithm*   ssh-mac-algorithm

     rpcs:
       +---x generate-asymmetric-key-pair
               {asymmetric-key-pair-generation}?
          +---w input
          |  +---w algorithm               ssh-public-key-algorithm
          |  +---w num-bits?               uint16
          |  +---w private-key-encoding
          |     +---w (private-key-encoding)
          |        +--:(cleartext) {ct:cleartext-private-keys}?
          |        |  +---w cleartext?   empty
          |        +--:(encrypted) {ct:encrypted-private-keys}?
          |        |  +---w encrypted
          |        |     +---w ks:encrypted-by-grouping
          |        +--:(hidden) {ct:hidden-private-keys}?
          |           +---w hidden?      empty
          +--ro output
             +--ro (key-or-hidden)?
                +--:(key)
                |  +---u ct:asymmetric-key-pair-grouping
                +--:(hidden)
                   +--ro location?
                           instance-identifier

   Comments:

   *  Protocol-accessible nodes are those nodes that are accessible when
      the module is "implemented", as described in Section 5.6.5 of
      [RFC7950].

   *  The protocol-accessible nodes for the "ietf-ssh-common" module are
      limited to "supported-algorithms" container, which is constrained
      by the "algorithm-discovery" feature, and the RPC "generate-
      asymmetric-key-pair", which is constrained by the "asymmetric-key-
      pair-generation" feature.

   *  The "encrypted-by-grouping" grouping is discussed in
      Section 2.1.3.1 of [I-D.ietf-netconf-keystore].

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   *  The "asymmetric-key-pair-grouping" grouping is discussed in
      Section 2.1.4.6 of [I-D.ietf-netconf-crypto-types].

2.2.  Example Usage

   The following example illustrates the "transport-params-grouping'
   grouping when populated with some data.

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <!-- The outermost element below doesn't exist in the data model. -->
   <!--  It simulates if the "grouping" were a "container" instead.  -->

   <transport-params
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-common">
     <host-key>
       <host-key-alg>x509v3-rsa2048-sha256</host-key-alg>
       <host-key-alg>ssh-rsa</host-key-alg>
       <host-key-alg>ssh-rsa@openssh.com</host-key-alg>
     </host-key>
     <key-exchange>
       <key-exchange-alg>diffie-hellman-group-exchange-sha256</key-exch\
   ange-alg>
     </key-exchange>
     <encryption>
       <encryption-alg>aes256-ctr</encryption-alg>
       <encryption-alg>aes192-ctr</encryption-alg>
       <encryption-alg>aes128-ctr</encryption-alg>
       <encryption-alg>aes256-gcm@openssh.com</encryption-alg>
     </encryption>
     <mac>
       <mac-alg>hmac-sha2-256</mac-alg>
       <mac-alg>hmac-sha2-512</mac-alg>
     </mac>
   </transport-params>

   The following example illustrates operational state data indicating
   the SSH algorithms supported by the server.

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <supported-algorithms
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-common">
     <encryption-algorithms>
       <supported-algorithm>aes256-ctr</supported-algorithm>
       <supported-algorithm>arcfour256</supported-algorithm>
       <supported-algorithm>serpent256-ctr</supported-algorithm>
       <supported-algorithm>AEAD_AES_128_GCM</supported-algorithm>
       <supported-algorithm>AEAD_AES_256_GCM</supported-algorithm>
       <supported-algorithm>aes256-gcm@openssh.com</supported-algorithm>
     </encryption-algorithms>
     <key-exchange-algorithms>
       <supported-algorithm>ecdh-sha2-nistp256</supported-algorithm>
       <supported-algorithm>rsa2048-sha256</supported-algorithm>
       <supported-algorithm>gss-group14-sha1-nistp256</supported-algori\
   thm>
       <supported-algorithm>gss-gex-sha1-nistp256</supported-algorithm>
       <supported-algorithm>gss-group14-sha256-1.2.840.10045.3.1.1</sup\
   ported-algorithm>
       <supported-algorithm>curve25519-sha256</supported-algorithm>
     </key-exchange-algorithms>
     <mac-algorithms>
       <supported-algorithm>hmac-sha2-256</supported-algorithm>
       <supported-algorithm>hmac-sha2-512</supported-algorithm>
       <supported-algorithm>AEAD_AES_256_GCM</supported-algorithm>
     </mac-algorithms>
     <public-key-algorithms>
       <supported-algorithm>rsa-sha2-256</supported-algorithm>
       <supported-algorithm>rsa-sha2-512</supported-algorithm>
       <supported-algorithm>spki-sign-rsa</supported-algorithm>
       <supported-algorithm>pgp-sign-dss</supported-algorithm>
       <supported-algorithm>x509v3-rsa2048-sha256</supported-algorithm>
       <supported-algorithm>ecdsa-sha2-nistp256</supported-algorithm>
       <supported-algorithm>ecdsa-sha2-1.3.132.0.37</supported-algorith\
   m>
       <supported-algorithm>ssh-ed25519</supported-algorithm>
       <supported-algorithm>ssh-rsa@openssh.com</supported-algorithm>
     </public-key-algorithms>
   </supported-algorithms>

   The following example illustrates the "generate-asymmetric-key-pair"
   RPC.

   REQUEST

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <rpc message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <generate-asymmetric-key-pair
       xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-common">
       <algorithm>ecdsa-sha2-nistp256</algorithm>
       <num-bits>521</num-bits>
       <private-key-encoding>
         <encrypted>
           <asymmetric-key-ref>hidden-asymmetric-key</asymmetric-key-re\
   f>
         </encrypted>
       </private-key-encoding>
     </generate-asymmetric-key-pair>
   </rpc>

   RESPONSE

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <rpc-reply message-id="101"
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types"
     xmlns:sshcmn="urn:ietf:params:xml:ns:yang:ietf-ssh-common">
     <sshcmn:public-key-format>ct:subject-public-key-info-format</sshcm\
   n:public-key-format>
     <sshcmn:public-key>BASE64VALUE=</sshcmn:public-key>
     <sshcmn:private-key-format>ct:ec-private-key-format</sshcmn:privat\
   e-key-format>
     <sshcmn:cleartext-private-key>BASE64VALUE=</sshcmn:cleartext-priva\
   te-key>
   </rpc-reply>

2.3.  YANG Module

   This YANG module has normative references to [RFC4253], [RFC4344],
   [RFC4419], [RFC5656], [RFC6187], [RFC6668], and [FIPS_186-6].

   <CODE BEGINS> file "ietf-ssh-common@2024-03-16.yang"

   module ietf-ssh-common {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-ssh-common";
     prefix sshcmn;

     import iana-ssh-encryption-algs {
       prefix sshea;

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       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     import iana-ssh-key-exchange-algs {
       prefix sshkea;
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     import iana-ssh-mac-algs {
       prefix sshma;
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     import iana-ssh-public-key-algs {
       prefix sshpka;
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     import ietf-crypto-types {
       prefix ct;
       reference
         "RFC AAAA: YANG Data Types and Groupings for Cryptography";
     }

     import ietf-keystore {
       prefix ks;
       reference
         "RFC CCCC: A YANG Data Model for a Keystore";
     }

     organization
       "IETF NETCONF (Network Configuration) Working Group";

     contact
       "WG Web:   https://datatracker.ietf.org/wg/netconf
        WG List:  NETCONF WG list <mailto:netconf@ietf.org>
        Author:   Kent Watsen <mailto:kent+ietf@watsen.net>
        Author:   Gary Wu <mailto:garywu@cisco.com>";

     description
       "This module defines a common features and groupings for
        Secure Shell (SSH).

        Copyright (c) 2024 IETF Trust and the persons identified

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        as authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        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 (RFC 2119)
        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2024-03-16 {
       description
         "Initial version";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     // Features

     feature ssh-x509-certs {
       description
         "X.509v3 certificates are supported for SSH.";
       reference
         "RFC 6187: X.509v3 Certificates for Secure Shell
                    Authentication";
     }

     feature transport-params {
       description
         "SSH transport layer parameters are configurable.";
     }

     feature asymmetric-key-pair-generation {
       description
         "Indicates that the server implements the
          'generate-asymmetric-key-pair' RPC.";
     }

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     feature algorithm-discovery {
       description
         "Indicates that the server implements the
          'supported-algorithms' container.";
     }

     // Typedefs

     typedef ssh-public-key-algorithm {
       type union {
         type sshpka:ssh-public-key-algorithm;
         type string {
           length "1..64" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
           pattern ".*@.*" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
         }
       }
       description
         "A type that enables the public key algorithm to be
          either an IANA-maintained public key algorithm in
          the 'iana-ssh-public-key-algs' YANG module (RFC EEEE),
          or a locally-defined algorithm, per Section 4.6.1
          of RFC 4250.";
       reference
         "RFC 4250: SSH Protocol Assigned Numbers
          RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-key-exchange-algorithm {
       type union {
         type sshkea:ssh-key-exchange-algorithm;
         type string {
           length "1..64" {
             description
               "Non IANA-maintained algorithms must include the

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                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
           pattern ".*@.*" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
         }
       }
       description
         "A type that enables the key exchange algorithm to be
          either an IANA-maintained key exchange algorithm in
          the 'iana-ssh-key-exchange-algs' YANG module (RFC EEEE),
          or a locally-defined algorithm, per Section 4.6.1
          of RFC 4250.";
       reference
         "RFC 4250: SSH Protocol Assigned Numbers
          RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-encryption-algorithm {
       type union {
         type sshea:ssh-encryption-algorithm;
         type string {
           length "1..64" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
           pattern ".*@.*" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
         }
       }

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       description
         "A type that enables the encryption algorithm to be
          either an IANA-maintained encryption algorithm in
          the 'iana-ssh-encryption-algs' YANG module (RFC EEEE),
          or a locally-defined algorithm, per Section 4.6.1
          of RFC 4250.";
       reference
         "RFC 4250: SSH Protocol Assigned Numbers
          RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-mac-algorithm {
       type union {
         type sshma:ssh-mac-algorithm;
         type string {
           length "1..64" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
           pattern ".*@.*" {
             description
               "Non IANA-maintained algorithms must include the
                'at-sign' (@) in them, per Section 4.6.1 of RFC
                4250.";
             reference
               "RFC 4250: SSH Protocol Assigned Numbers";
           }
         }
       }
       description
         "A type that enables the MAC algorithm to be
          either an IANA-maintained MAC algorithm in
          the 'iana-ssh-mac-algs' YANG module (RFC EEEE),
          or a locally-defined algorithm, per Section 4.6.1
          of RFC 4250.";
       reference
         "RFC 4250: SSH Protocol Assigned Numbers
          RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     // Groupings

     grouping transport-params-grouping {
       description

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         "A reusable grouping for SSH transport parameters.";
       reference
         "RFC 4253: The Secure Shell (SSH) Transport Layer Protocol";
       container host-key {
         description
           "Parameters regarding host key.";
         leaf-list host-key-alg {
           type ssh-public-key-algorithm;
           ordered-by user;
           description
             "Acceptable host key algorithms in order of decreasing
              preference.

              If this leaf-list is not configured (has zero elements)
              the acceptable host key algorithms are implementation-
              defined.";
           reference
             "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
         }
       }
       container key-exchange {
         description
           "Parameters regarding key exchange.";
         leaf-list key-exchange-alg {
           type ssh-key-exchange-algorithm;
           ordered-by user;
           description
             "Acceptable key exchange algorithms in order of decreasing
              preference.

              If this leaf-list is not configured (has zero elements)
              the acceptable key exchange algorithms are implementation
              defined.";
         }
       }
       container encryption {
         description
           "Parameters regarding encryption.";
         leaf-list encryption-alg {
           type ssh-encryption-algorithm;
           ordered-by user;
           description
             "Acceptable encryption algorithms in order of decreasing
              preference.

              If this leaf-list is not configured (has zero elements)
              the acceptable encryption algorithms are implementation
              defined.";

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         }
       }
       container mac {
         description
           "Parameters regarding message authentication code (MAC).";
         leaf-list mac-alg {
           type ssh-mac-algorithm;
           ordered-by user;
           description
             "Acceptable MAC algorithms in order of decreasing
              preference.

              If this leaf-list is not configured (has zero elements)
              the acceptable MAC algorithms are implementation-
              defined.";
         }
       }
     }

     // Protocol-accessible Nodes

     container supported-algorithms {
       if-feature "algorithm-discovery";
       config false;
       description
         "Identifies all of the supported algorithms.";
       container public-key-algorithms {
         description
           "A container for a list of public key algorithms
            supported by the server.";
         leaf-list supported-algorithm {
           type ssh-public-key-algorithm;
           description
             "A public key algorithm supported by the server.";
         }
       }
       container encryption-algorithms {
         description
           "A container for a list of encryption algorithms
            supported by the server.";
         leaf-list supported-algorithm {
           type ssh-encryption-algorithm;
           description
             "An encryption algorithm supported by the server.";
         }
       }
       container key-exchange-algorithms {
         config false;

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         description
           "A container for a list of key exchange algorithms
            supported by the server.";
         leaf-list supported-algorithm {
           type ssh-key-exchange-algorithm;
           description
             "A key exchange algorithm supported by the server.";
         }
       }
       container mac-algorithms {
         config false;
         description
           "A container for a list of MAC algorithms
            supported by the server.";
         leaf-list supported-algorithm {
           type ssh-mac-algorithm;
           description
             "A MAC algorithm supported by the server.";
         }
       }
     }

     rpc generate-asymmetric-key-pair {
       if-feature "asymmetric-key-pair-generation";
       description
         "Requests the device to generate a public key using
          the specified key algorithm.";
       input {
         leaf algorithm {
           type ssh-public-key-algorithm;
           mandatory true;
           description
             "The algorithm to be used when generating the key.";
         }
         leaf num-bits {
           type uint16;
           description
             "Specifies the number of bits in the key to create.
              For RSA keys, the minimum size is 1024 bits and
              the default is 3072 bits. Generally, 3072 bits is
              considered sufficient. DSA keys must be exactly 1024
              bits as specified by FIPS 186-6.  For ECDSA keys, the
              'num-bits' value determines the key length by selecting
              from one of three elliptic curve sizes: 256, 384 or
              521 bits. Attempting to use bit lengths other than
              these three values for ECDSA keys will fail. ECDSA-SK,
              Ed25519 and Ed25519-SK keys have a fixed length and
              thus the 'num-bits' value is not specified.";

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           reference
             "FIPS 186-6: Digital Signature Standard (DSS)";
         }
         container private-key-encoding {
           description
             "Indicates how the private key is to be encoded.";
           choice private-key-encoding {
             mandatory true;
             description
               "A choice amongst optional private key handling.";
             case cleartext {
               if-feature "ct:cleartext-private-keys";
               leaf cleartext {
                 type empty;
                 description
                   "Indicates that the private key is to be returned
                    as a cleartext value.";
               }
             }
             case encrypted {
               if-feature "ct:encrypted-private-keys";
               container encrypted {
                 description
                    "Indicates that the private key is to be encrypted
                     using the specified symmetric or asymmetric key.";
                 uses ks:encrypted-by-grouping;
               }
             }
             case hidden {
               if-feature "ct:hidden-private-keys";
               leaf hidden {
                 type empty;
                 description
                   "Indicates that the private key is to be hidden.

                    Unlike the 'cleartext' and 'encrypt' options, the
                    key returned is a placeholder for an internally
                    stored key.  See the 'Support for Built-in Keys'
                    section in RFC CCCC for information about hidden
                    keys.

                    It is expected that the server will instantiate
                    the hidden key in the same location where built-in
                    keys are located.  Rather than return the key,
                    just the key's location is returned in the output.";
               }
             }
           }

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         }
       }
       output {
         choice key-or-hidden {
           case key {
             uses ct:asymmetric-key-pair-grouping;
           }
           case hidden {
             leaf location {
               type instance-identifier;
               description
                 "The location to where a hidden key was created.";
             }
           }
           description
             "The output can be either a key (for cleartext and
              encrypted keys) or the location to where the key
              was created (for hidden keys).";
         }
       }
     } // end generate-asymmetric-key-pair

   }

   <CODE ENDS>

3.  The "ietf-ssh-client" Module

   This section defines a YANG 1.1 [RFC7950] module called "ietf-ssh-
   client".  A high-level overview of the module is provided in
   Section 3.1.  Examples illustrating the module's use are provided in
   Examples (Section 3.2).  The YANG module itself is defined in
   Section 3.3.

3.1.  Data Model Overview

   This section provides an overview of the "ietf-ssh-client" module in
   terms of its features and groupings.

3.1.1.  Features

   The following diagram lists all the "feature" statements defined in
   the "ietf-ssh-client" module:

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   Features:
     +-- ssh-client-keepalives
     +-- client-ident-password
     +-- client-ident-publickey
     +-- client-ident-hostbased
     +-- client-ident-none

   The diagram above uses syntax that is similar to but not defined in
   [RFC8340].

   Please refer to the YANG module for a description of each feature.

3.1.2.  Groupings

   The "ietf-ssh-client" module defines the following "grouping"
   statement:

   *  ssh-client-grouping

   This grouping is presented in the following subsection.

3.1.2.1.  The "ssh-client-grouping" Grouping

   The following tree diagram [RFC8340] illustrates the "ssh-client-
   grouping" grouping:

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

     grouping ssh-client-grouping:
       +-- client-identity
       |  +-- username?      string
       |  +-- public-key! {client-ident-publickey}?
       |  |  +---u ks:inline-or-keystore-asymmetric-key-grouping
       |  +-- password! {client-ident-password}?
       |  |  +---u ct:password-grouping
       |  +-- hostbased! {client-ident-hostbased}?
       |  |  +---u ks:inline-or-keystore-asymmetric-key-grouping
       |  +-- none?          empty {client-ident-none}?
       |  +-- certificate! {sshcmn:ssh-x509-certs}?
       |     +---u ks:inline-or-keystore-end-entity-cert-with-key-group\
   ing
       +-- server-authentication
       |  +-- ssh-host-keys!
       |  |  +---u ts:inline-or-truststore-public-keys-grouping
       |  +-- ca-certs! {sshcmn:ssh-x509-certs}?
       |  |  +---u ts:inline-or-truststore-certs-grouping
       |  +-- ee-certs! {sshcmn:ssh-x509-certs}?
       |     +---u ts:inline-or-truststore-certs-grouping
       +-- transport-params {sshcmn:transport-params}?
       |  +---u sshcmn:transport-params-grouping
       +-- keepalives! {ssh-client-keepalives}?
          +-- max-wait?       uint16
          +-- max-attempts?   uint8

   Comments:

   *  The "client-identity" node configures a "username" and
      authentication methods, each enabled by a "feature" statement
      defined in Section 3.1.1.

   *  The "server-authentication" node configures trust anchors for
      authenticating the SSH server, with each option enabled by a
      "feature" statement.

   *  The "transport-params" node, which must be enabled by a feature,
      configures parameters for the SSH sessions established by this
      configuration.

   *  The "keepalives" node, which must be enabled by a feature,
      configures a "presence" container for testing the aliveness of the
      SSH server.  The aliveness-test occurs at the SSH protocol layer.

   *  For the referenced grouping statement(s):

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      -  The "inline-or-keystore-asymmetric-key-grouping" grouping is
         discussed in Section 2.1.3.4 of [I-D.ietf-netconf-keystore].
      -  The "inline-or-keystore-end-entity-cert-with-key-grouping"
         grouping is discussed in Section 2.1.3.6 of
         [I-D.ietf-netconf-keystore].
      -  The "inline-or-truststore-public-keys-grouping" grouping is
         discussed in Section 2.1.3.4 of
         [I-D.ietf-netconf-trust-anchors].
      -  The "inline-or-truststore-certs-grouping" grouping is discussed
         in Section 2.1.3.3 of [I-D.ietf-netconf-trust-anchors].
      -  The "transport-params-grouping" grouping is discussed in
         Section 2.1.2.1 in this document.

3.1.3.  Protocol-accessible Nodes

   The "ietf-ssh-client" module defines only "grouping" statements that
   are used by other modules to instantiate protocol-accessible nodes.
   Thus this module, when implemented, does not itself define any
   protocol-accessible nodes.

3.2.  Example Usage

   This section presents two examples showing the "ssh-client-grouping"
   grouping populated with some data.  These examples are effectively
   the same except the first configures the client identity using a
   inlined key while the second uses a key configured in a keystore.
   Both examples are consistent with the examples presented in
   Section 2.2.1 of [I-D.ietf-netconf-trust-anchors] and Section 2.2.1
   of [I-D.ietf-netconf-keystore].

   The following configuration example uses inline-definitions for the
   client identity and server authentication:

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <!-- The outermost element below doesn't exist in the data model. -->
   <!--  It simulates if the "grouping" were a "container" instead.  -->

   <ssh-client
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-client"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">

     <!-- how this client will authenticate itself to the server -->
     <client-identity>
       <username>foobar</username>
       <public-key>
         <inline-definition>
           <private-key-format>ct:rsa-private-key-format</private-key-f\

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   ormat>
           <cleartext-private-key>BASE64VALUE=</cleartext-private-key>
         </inline-definition>
       </public-key>
     </client-identity>

     <!-- which host keys will this client trust -->
     <server-authentication>
       <ssh-host-keys>
         <inline-definition>
           <public-key>
             <name>corp-fw1</name>
             <public-key-format>ct:ssh-public-key-format</public-key-fo\
   rmat>
             <public-key>BASE64VALUE=</public-key>
           </public-key>
           <public-key>
             <name>corp-fw2</name>
             <public-key-format>ct:ssh-public-key-format</public-key-fo\
   rmat>
             <public-key>BASE64VALUE=</public-key>
           </public-key>
         </inline-definition>
       </ssh-host-keys>
       <ca-certs>
         <inline-definition>
           <certificate>
             <name>Server Cert Issuer #1</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
           <certificate>
             <name>Server Cert Issuer #2</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
         </inline-definition>
       </ca-certs>
       <ee-certs>
         <inline-definition>
           <certificate>
             <name>My Application #1</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
           <certificate>
             <name>My Application #2</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
         </inline-definition>
       </ee-certs>

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     </server-authentication>

     <keepalives>
       <max-wait>30</max-wait>
       <max-attempts>3</max-attempts>
     </keepalives>

   </ssh-client>

   The following configuration example uses central-keystore-references
   for the client identity and central-truststore-references for server
   authentication: from the keystore:

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <!-- The outermost element below doesn't exist in the data model. -->
   <!--  It simulates if the "grouping" were a "container" instead.  -->

   <ssh-client
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-client"
     xmlns:algs="urn:ietf:params:xml:ns:yang:ietf-ssh-common">

     <!-- how this client will authenticate itself to the server -->
     <client-identity>
       <username>foobar</username>
       <public-key>
         <central-keystore-reference>ssh-rsa-key</central-keystore-refe\
   rence>
       </public-key>
       <certificate>
         <central-keystore-reference>
           <asymmetric-key>ssh-rsa-key-with-cert</asymmetric-key>
           <certificate>ex-rsa-cert2</certificate>
         </central-keystore-reference>
       </certificate>
     </client-identity>

     <!-- which host-keys will this client trust -->
     <server-authentication>
       <ssh-host-keys>
         <central-truststore-reference>trusted-ssh-public-keys</central\
   -truststore-reference>
       </ssh-host-keys>
       <ca-certs>
         <central-truststore-reference>trusted-server-ca-certs</central\
   -truststore-reference>
       </ca-certs>
       <ee-certs>
         <central-truststore-reference>trusted-server-ee-certs</central\
   -truststore-reference>
       </ee-certs>
     </server-authentication>

     <keepalives>
       <max-wait>30</max-wait>
       <max-attempts>3</max-attempts>
     </keepalives>

   </ssh-client>

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3.3.  YANG Module

   This YANG module has normative references to [RFC4252], [RFC4254],
   [RFC8341], [I-D.ietf-netconf-crypto-types],
   [I-D.ietf-netconf-trust-anchors], and [I-D.ietf-netconf-keystore].

   <CODE BEGINS> file "ietf-ssh-client@2024-03-16.yang"

   module ietf-ssh-client {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-ssh-client";
     prefix sshc;

     import ietf-netconf-acm {
       prefix nacm;
       reference
         "RFC 8341: Network Configuration Access Control Model";
     }

     import ietf-crypto-types {
       prefix ct;
       reference
         "RFC AAAA: YANG Data Types and Groupings for Cryptography";
     }

     import ietf-truststore {
       prefix ts;
       reference
         "RFC BBBB: A YANG Data Model for a Truststore";
     }

     import ietf-keystore {
       prefix ks;
       reference
         "RFC CCCC: A YANG Data Model for a Keystore";
     }

     import ietf-ssh-common {
       prefix sshcmn;
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     organization
       "IETF NETCONF (Network Configuration) Working Group";

     contact
       "WG Web:   https://datatracker.ietf.org/wg/netconf

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        WG List:  NETCONF WG list <mailto:netconf@ietf.org>
        Author:   Kent Watsen <mailto:kent+ietf@watsen.net>";

     description
       "This module defines a reusable grouping for SSH clients that
        can be used as a basis for specific SSH client instances.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        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 (RFC 2119)
        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2024-03-16 {
       description
         "Initial version";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     // Features

     feature ssh-client-keepalives {
       description
         "Per socket SSH keepalive parameters are configurable for
          SSH clients on the server implementing this feature.";
     }

     feature client-ident-publickey {
       description
         "Indicates that the 'publickey' authentication type, per
          RFC 4252, is supported for client identification.
          The 'publickey' authentication type is required by

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          RFC 4252, but common implementations allow it to
          be disabled.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     feature client-ident-password {
       description
         "Indicates that the 'password' authentication type, per
          RFC 4252, is supported for client identification.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     feature client-ident-hostbased {
       description
         "Indicates that the 'hostbased' authentication type, per
          RFC 4252, is supported for client identification.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     feature client-ident-none {
       description
         "Indicates that the 'none' authentication type, per
          RFC 4252, is supported for client identification.
          It is NOT RECOMMENDED to enable this feature.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     // Groupings

     grouping ssh-client-grouping {
       description
         "A reusable grouping for configuring a SSH client without
          any consideration for how an underlying TCP session is
          established.

          Note that this grouping uses fairly typical descendant
          node names such that a nesting of 'uses' statements will
          have name conflicts.  It is intended that the consuming
          data model will resolve the issue (e.g., by wrapping
          the 'uses' statement in a container called

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          'ssh-client-parameters').  This model purposely does
          not do this itself so as to provide maximum flexibility
          to consuming models.";

       container client-identity {
         nacm:default-deny-write;
         description
           "The username and authentication methods for the client.
            The authentication methods are unordered.  Clients may
            initially send any configured method or, per RFC 4252,
            Section 5.2, send the 'none' method to prompt the server
            to provide a list of productive methods.  Whenever a
            choice amongst methods arises, implementations SHOULD
            use a default ordering that prioritizes automation
            over human-interaction.";
         leaf username {
           type string;
           description
             "The username of this user.  This will be the username
              used, for instance, to log into an SSH server.";
         }
         container public-key {
           if-feature "client-ident-publickey";
           presence
             "Indicates that publickey-based authentication has been
              configured.  This statement is present so the mandatory
              descendant nodes do not imply that this node must be
              configured.";
           description
             "A locally-defined or referenced asymmetric key
              pair to be used for client identification.";
           reference
             "RFC CCCC: A YANG Data Model for a Keystore";
           uses ks:inline-or-keystore-asymmetric-key-grouping {
             refine "inline-or-keystore/inline/inline-definition" {
               must 'not(public-key-format) or derived-from-or-self'
                  + '(public-key-format, "ct:ssh-public-key-format")';
             }
             refine "inline-or-keystore/central-keystore/"
                  + "central-keystore-reference" {
               must 'not(deref(.)/../ks:public-key-format) or derived-'
                  + 'from-or-self(deref(.)/../ks:public-key-format, '
                  + '"ct:ssh-public-key-format")';
             }
           }
         }
         container password {
           if-feature "client-ident-password";

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           presence
             "Indicates that password-based authentication has been
              configured.  This statement is present so the mandatory
              descendant nodes do not imply that this node must be
              configured.";
           description
             "A password to be used to authenticate the client's
              identity.";
           uses ct:password-grouping;
         }
         container hostbased {
           if-feature "client-ident-hostbased";
           presence
             "Indicates that hostbased authentication is configured.
              This statement is present so the mandatory descendant
              nodes do not imply that this node must be configured.";
           description
             "A locally-defined or referenced asymmetric key
              pair to be used for host identification.";
           reference
             "RFC CCCC: A YANG Data Model for a Keystore";
           uses ks:inline-or-keystore-asymmetric-key-grouping {
             refine "inline-or-keystore/inline/inline-definition" {
               must 'not(public-key-format) or derived-from-or-self('
                  + 'public-key-format, "ct:ssh-public-key-format")';
             }
             refine "inline-or-keystore/central-keystore/"
                  + "central-keystore-reference" {
               must 'not(deref(.)/../ks:public-key-format) or derived-'
                  + 'from-or-self(deref(.)/../ks:public-key-format, '
                  + '"ct:ssh-public-key-format")';
             }
           }
         }
         leaf none {
           if-feature "client-ident-none";
           type empty;
           description
             "Indicates that 'none' algorithm is used for client
              identification.";
         }
         container certificate {
           if-feature "sshcmn:ssh-x509-certs";
           presence
             "Indicates that certificate-based authentication has been
              configured.  This statement is present so the mandatory
              descendant nodes do not imply that this node must be
              configured.";

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           description
             "A locally-defined or referenced certificate
              to be used for client identification.";
           reference
             "RFC CCCC: A YANG Data Model for a Keystore";
           uses
             ks:inline-or-keystore-end-entity-cert-with-key-grouping {
             refine "inline-or-keystore/inline/inline-definition" {
               must 'not(public-key-format) or derived-from-or-self('
                  + 'public-key-format, "ct:subject-public-key-info-'
                  + 'format")';
             }
             refine "inline-or-keystore/central-keystore/"
                  + "central-keystore-reference/asymmetric-key" {
               must 'not(deref(.)/../ks:public-key-format) or derived-'
                  + 'from-or-self(deref(.)/../ks:public-key-format, '
                  + '"ct:subject-public-key-info-format")';
             }
           }
         }
       } // container client-identity

       container server-authentication {
         nacm:default-deny-write;
         must 'ssh-host-keys or ca-certs or ee-certs';
         description
           "Specifies how the SSH client can authenticate SSH servers.
            Any combination of authentication methods is additive and
            unordered.";
         container ssh-host-keys {
           presence
             "Indicates that the SSH host key have been configured.
              This statement is present so the mandatory descendant
              nodes do not imply that this node must be configured.";
           description
             "A bag of SSH host keys used by the SSH client to
              authenticate SSH server host keys.  A server host key
              is authenticated if it is an exact match to a
              configured SSH host key.";
           reference
             "RFC BBBB: A YANG Data Model for a Truststore";
           uses ts:inline-or-truststore-public-keys-grouping {
             refine
               "inline-or-truststore/inline/inline-definition/public"
               + "-key" {
               must 'derived-from-or-self(public-key-format,'
                  + ' "ct:ssh-public-key-format")';
             }

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             refine "inline-or-truststore/central-truststore/"
                  + "central-truststore-reference" {
               must 'not(deref(.)/../ts:public-key/ts:public-key-'
                  + 'format[not(derived-from-or-self(., "ct:ssh-'
                  + 'public-key-format"))])';
             }
           }
         }
         container ca-certs {
           if-feature "sshcmn:ssh-x509-certs";
           presence
             "Indicates that the CA certificates have been configured.
              This statement is present so the mandatory descendant
              nodes do not imply that this node must be configured.";
           description
             "A set of certificate authority (CA) certificates used by
              the SSH client to authenticate SSH servers.  A server
              is authenticated if its certificate has a valid chain
              of trust to a configured CA certificate.";
           reference
             "RFC BBBB: A YANG Data Model for a Truststore";
           uses ts:inline-or-truststore-certs-grouping;
         }
         container ee-certs {
           if-feature "sshcmn:ssh-x509-certs";
           presence
             "Indicates that the EE certificates have been configured.
              This statement is present so the mandatory descendant
              nodes do not imply that this node must be configured.";
           description
             "A set of end-entity certificates used by the SSH client
              to authenticate SSH servers.  A server is authenticated
              if its certificate is an exact match to a configured
              end-entity certificate.";
           reference
             "RFC BBBB: A YANG Data Model for a Truststore";
           uses ts:inline-or-truststore-certs-grouping;
         }
       } // container server-authentication

       container transport-params {
         nacm:default-deny-write;
         if-feature "sshcmn:transport-params";
         description
           "Configurable parameters of the SSH transport layer.";
         uses sshcmn:transport-params-grouping;
       } // container transport-parameters

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       container keepalives {
         nacm:default-deny-write;
         if-feature "ssh-client-keepalives";
         presence
           "Indicates that the SSH client proactively tests the
            aliveness of the remote SSH server.";
         description
           "Configures the keep-alive policy, to proactively test
            the aliveness of the SSH server.  An unresponsive SSH
            server is dropped after approximately max-wait *
            max-attempts seconds.  Per Section 4 of RFC 4254,
            the SSH client SHOULD send an SSH_MSG_GLOBAL_REQUEST
            message with a purposely nonexistent 'request name'
            value (e.g., keepalive@ietf.org) and the 'want reply'
            value set to '1'.";
         reference
           "RFC 4254: The Secure Shell (SSH) Connection Protocol";
         leaf max-wait {
           type uint16 {
             range "1..max";
           }
           units "seconds";
           default "30";
           description
             "Sets the amount of time in seconds after which if
              no data has been received from the SSH server, a
              SSH-level message will be sent to test the
              aliveness of the SSH server.";
         }
         leaf max-attempts {
           type uint8;
           default "3";
           description
             "Sets the maximum number of sequential keep-alive
              messages that can fail to obtain a response from
              the SSH server before assuming the SSH server is
              no longer alive.";
         }
       } // container keepalives
     } // grouping ssh-client-grouping

   }

   <CODE ENDS>

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4.  The "ietf-ssh-server" Module

   This section defines a YANG 1.1 module called "ietf-ssh-server".  A
   high-level overview of the module is provided in Section 4.1.
   Examples illustrating the module's use are provided in Examples
   (Section 4.2).  The YANG module itself is defined in Section 4.3.

4.1.  Data Model Overview

   This section provides an overview of the "ietf-ssh-server" module in
   terms of its features and groupings.

4.1.1.  Features

   The following diagram lists all the "feature" statements defined in
   the "ietf-ssh-server" module:

   Features:
     +-- ssh-server-keepalives
     +-- local-users-supported
     +-- local-user-auth-publickey {local-users-supported}?
     +-- local-user-auth-password {local-users-supported}?
     +-- local-user-auth-hostbased {local-users-supported}?
     +-- local-user-auth-none {local-users-supported}?

   The diagram above uses syntax that is similar to but not defined in
   [RFC8340].

   Please refer to the YANG module for a description of each feature.

4.1.2.  Groupings

   The "ietf-ssh-server" module defines the following "grouping"
   statement:

   *  ssh-server-grouping

   This grouping is presented in the following subsection.

4.1.2.1.  The "ssh-server-grouping" Grouping

   The following tree diagram [RFC8340] illustrates the "ssh-server-
   grouping" grouping:

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

     grouping ssh-server-grouping:
       +-- server-identity
       |  +-- host-key* [name]
       |     +-- name?                string
       |     +-- (host-key-type)
       |        +--:(public-key)
       |        |  +-- public-key
       |        |     +---u ks:inline-or-keystore-asymmetric-key-groupi\
   ng
       |        +--:(certificate)
       |           +-- certificate {sshcmn:ssh-x509-certs}?
       |              +---u ks:inline-or-keystore-end-entity-cert-with-\
   key-grouping
       +-- client-authentication
       |  +-- users {local-users-supported}?
       |  |  +-- user* [name]
       |  |     +-- name?          string
       |  |     +-- public-keys! {local-user-auth-publickey}?
       |  |     |  +---u ts:inline-or-truststore-public-keys-grouping
       |  |     +-- password
       |  |     |  +-- hashed-password?   ianach:crypt-hash
       |  |     |  |       {local-user-auth-password}?
       |  |     |  +--ro last-modified?     yang:date-and-time
       |  |     +-- hostbased! {local-user-auth-hostbased}?
       |  |     |  +---u ts:inline-or-truststore-public-keys-grouping
       |  |     +-- none?          empty {local-user-auth-none}?
       |  +-- ca-certs! {sshcmn:ssh-x509-certs}?
       |  |  +---u ts:inline-or-truststore-certs-grouping
       |  +-- ee-certs! {sshcmn:ssh-x509-certs}?
       |     +---u ts:inline-or-truststore-certs-grouping
       +-- transport-params {sshcmn:transport-params}?
       |  +---u sshcmn:transport-params-grouping
       +-- keepalives! {ssh-server-keepalives}?
          +-- max-wait?       uint16
          +-- max-attempts?   uint8

   Comments:

   *  The "server-identity" node configures the authentication methods
      the server can use to identify itself to clients.  The ability to
      use a certificate is enabled by a "feature".

   *  The "client-authentication" node configures trust anchors for
      authenticating the SSH client, with each option enabled by a
      "feature" statement.

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   *  The "transport-params" node, which must be enabled by a feature,
      configures parameters for the SSH sessions established by this
      configuration.

   *  The "keepalives" node, which must be enabled by a feature,
      configures a "presence" container for testing the aliveness of the
      SSH client.  The aliveness-test occurs at the SSH protocol layer.

   *  For the referenced grouping statement(s):

      -  The "inline-or-keystore-asymmetric-key-grouping" grouping is
         discussed in Section 2.1.3.4 of [I-D.ietf-netconf-keystore].
      -  The "inline-or-keystore-end-entity-cert-with-key-grouping"
         grouping is discussed in Section 2.1.3.6 of
         [I-D.ietf-netconf-keystore].
      -  The "inline-or-truststore-public-keys-grouping" grouping is
         discussed in Section 2.1.3.4 of
         [I-D.ietf-netconf-trust-anchors].
      -  The "inline-or-truststore-certs-grouping" grouping is discussed
         in Section 2.1.3.3 of [I-D.ietf-netconf-trust-anchors].
      -  The "transport-params-grouping" grouping is discussed in
         Section 2.1.2.1 in this document.

4.1.3.  Protocol-accessible Nodes

   The "ietf-ssh-server" module defines only "grouping" statements that
   are used by other modules to instantiate protocol-accessible nodes.
   Thus this module, when implemented, does not itself define any
   protocol-accessible nodes.

4.2.  Example Usage

   This section presents two examples showing the "ssh-server-grouping"
   grouping populated with some data.  These examples are effectively
   the same except the first configures the server identity using a
   inlined key while the second uses a key configured in a keystore.
   Both examples are consistent with the examples presented in
   Section 2.2.1 of [I-D.ietf-netconf-trust-anchors] and Section 2.2.1
   of [I-D.ietf-netconf-keystore].

   The following configuration example uses inline-definitions for the
   server identity and client authentication:

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <!-- The outermost element below doesn't exist in the data model. -->
   <!--  It simulates if the "grouping" were a "container" instead.  -->

   <ssh-server
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-server"
     xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">

     <!-- the host-key this SSH server will present -->
     <server-identity>
       <host-key>
         <name>my-pubkey-based-host-key</name>
         <public-key>
           <inline-definition>
             <private-key-format>ct:rsa-private-key-format</private-key\
   -format>
             <cleartext-private-key>BASE64VALUE=</cleartext-private-key>
           </inline-definition>
         </public-key>
       </host-key>
       <host-key>
         <name>my-cert-based-host-key</name>
         <certificate>
           <inline-definition>
             <private-key-format>ct:rsa-private-key-format</private-key\
   -format>
             <cleartext-private-key>BASE64VALUE=</cleartext-private-key>
             <cert-data>BASE64VALUE=</cert-data>
           </inline-definition>
         </certificate>
       </host-key>
     </server-identity>

     <!-- the client credentials this SSH server will trust -->
     <client-authentication>
       <users>
         <user>
           <name>mary</name>
           <password>
             <hashed-password>$0$example-secret</hashed-password>
           </password>
           <public-keys>
             <inline-definition>
               <public-key>
                 <name>Mary-Key-1</name>
                 <public-key-format>ct:ssh-public-key-format</public-ke\
   y-format>

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                 <public-key>BASE64VALUE=</public-key>
               </public-key>
               <public-key>
                 <name>Mary-Key-2</name>
                 <public-key-format>ct:ssh-public-key-format</public-ke\
   y-format>
                 <public-key>BASE64VALUE=</public-key>
               </public-key>
             </inline-definition>
           </public-keys>
         </user>
       </users>
       <ca-certs>
         <inline-definition>
           <certificate>
             <name>Identity Cert Issuer #1</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
           <certificate>
             <name>Identity Cert Issuer #2</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
         </inline-definition>
       </ca-certs>
       <ee-certs>
         <inline-definition>
           <certificate>
             <name>Application #1</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
           <certificate>
             <name>Application #2</name>
             <cert-data>BASE64VALUE=</cert-data>
           </certificate>
         </inline-definition>
       </ee-certs>
     </client-authentication>

     <keepalives>
       <max-wait>30</max-wait>
       <max-attempts>3</max-attempts>
     </keepalives>

   </ssh-server>

   The following configuration example uses central-keystore-references
   for the server identity and central-truststore-references for client
   authentication: from the keystore:

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   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <!-- The outermost element below doesn't exist in the data model. -->
   <!--  It simulates if the "grouping" were a "container" instead.  -->

   <ssh-server
     xmlns="urn:ietf:params:xml:ns:yang:ietf-ssh-server">

     <!-- the host-key this SSH server will present -->
     <server-identity>
       <host-key>
         <name>my-pubkey-based-host-key</name>
         <public-key>
           <central-keystore-reference>ssh-rsa-key</central-keystore-re\
   ference>
         </public-key>
       </host-key>
       <host-key>
         <name>my-cert-based-host-key</name>
         <certificate>
           <central-keystore-reference>
             <asymmetric-key>ssh-rsa-key-with-cert</asymmetric-key>
             <certificate>ex-rsa-cert2</certificate>
           </central-keystore-reference>
         </certificate>
       </host-key>
     </server-identity>

     <!-- the client credentials this SSH server will trust -->
     <client-authentication>
       <users>
         <user>
           <name>mary</name>
           <password>
             <hashed-password>$0$example-secret</hashed-password>
           </password>
           <public-keys>
             <central-truststore-reference>SSH Public Keys for Applicat\
   ion A</central-truststore-reference>
           </public-keys>
         </user>
       </users>
       <ca-certs>
         <central-truststore-reference>trusted-client-ca-certs</central\
   -truststore-reference>
       </ca-certs>
       <ee-certs>
         <central-truststore-reference>trusted-client-ee-certs</central\

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   -truststore-reference>
       </ee-certs>
     </client-authentication>

     <keepalives>
       <max-wait>30</max-wait>
       <max-attempts>3</max-attempts>
     </keepalives>

   </ssh-server>

4.3.  YANG Module

   This YANG module has references to [RFC4251], [RFC4252], [RFC4253],
   [RFC4254], [RFC7317], [RFC8341], [I-D.ietf-netconf-crypto-types],
   [I-D.ietf-netconf-trust-anchors], and [I-D.ietf-netconf-keystore].

   <CODE BEGINS> file "ietf-ssh-server@2024-03-16.yang"

   module ietf-ssh-server {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-ssh-server";
     prefix sshs;

     import ietf-yang-types {
       prefix yang;
       reference
         "RFC 6991: Common YANG Data Types";
     }

     import iana-crypt-hash {
       prefix ianach;
       reference
         "RFC 7317: A YANG Data Model for System Management";
     }

     import ietf-netconf-acm {
       prefix nacm;
       reference
         "RFC 8341: Network Configuration Access Control Model";
     }

     import ietf-crypto-types {
       prefix ct;
       reference
         "RFC AAAA: YANG Data Types and Groupings for Cryptography";
     }

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     import ietf-truststore {
       prefix ts;
       reference
         "RFC BBBB: A YANG Data Model for a Truststore";
     }

     import ietf-keystore {
       prefix ks;
       reference
         "RFC CCCC: A YANG Data Model for a Keystore";
     }

     import ietf-ssh-common {
       prefix sshcmn;
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     organization
       "IETF NETCONF (Network Configuration) Working Group";

     contact
       "WG Web:   https://datatracker.ietf.org/wg/netconf
        WG List:  NETCONF WG list <mailto:netconf@ietf.org>
        Author:   Kent Watsen <mailto:kent+ietf@watsen.net>";

     description
       "This module defines a reusable grouping for SSH servers that
        can be used as a basis for specific SSH server instances.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        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 (RFC 2119)

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        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2024-03-16 {
       description
         "Initial version";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     // Features

     feature ssh-server-keepalives {
       description
         "Per socket SSH keepalive parameters are configurable for
          SSH servers on the server implementing this feature.";
     }

     feature local-users-supported {
       description
         "Indicates that the configuration for users can be
          configured herein, as opposed to in an application
          specific location.";
     }

     feature local-user-auth-publickey {
       if-feature "local-users-supported";
       description
         "Indicates that the 'publickey' authentication type,
          per RFC 4252, is supported for locally-defined users.
          The 'publickey' authentication type is required by
          RFC 4252, but common implementations allow it to
          be disabled.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     feature local-user-auth-password {
       if-feature "local-users-supported";
       description
         "Indicates that the 'password' authentication type,
          per RFC 4252, is supported for locally-defined users.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

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     feature local-user-auth-hostbased {
       if-feature "local-users-supported";
       description
         "Indicates that the 'hostbased' authentication type,
          per RFC 4252, is supported for locally-defined users.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     feature local-user-auth-none {
       if-feature "local-users-supported";
       description
         "Indicates that the 'none' authentication type, per
          RFC 4252, is supported.  It is NOT RECOMMENDED to
          enable this feature.";
       reference
         "RFC 4252:
           The Secure Shell (SSH) Authentication Protocol";
     }

     // Groupings

     grouping ssh-server-grouping {
       description
         "A reusable grouping for configuring a SSH server without
          any consideration for how underlying TCP sessions are
          established.

          Note that this grouping uses fairly typical descendant
          node names such that a nesting of 'uses' statements will
          have name conflicts.  It is intended that the consuming
          data model will resolve the issue (e.g., by wrapping
          the 'uses' statement in a container called
          'ssh-server-parameters').  This model purposely does
          not do this itself so as to provide maximum flexibility
          to consuming models.";

       container server-identity {
         nacm:default-deny-write;
         description
           "The list of host keys the SSH server will present when
            establishing a SSH connection.";
         list host-key {
           key "name";
           min-elements 1;
           ordered-by user;
           description

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             "An ordered list of host keys (see RFC 4251) the SSH
              server will use to construct its ordered list of
              algorithms, when sending its SSH_MSG_KEXINIT message,
              as defined in Section 7.1 of RFC 4253.";
           reference
             "RFC 4251: The Secure Shell (SSH) Protocol Architecture
              RFC 4253: The Secure Shell (SSH) Transport Layer
                        Protocol";
           leaf name {
             type string;
             description
               "An arbitrary name for this host key";
           }
           choice host-key-type {
             mandatory true;
             description
               "The type of host key being specified";
             container public-key {
               description
                 "A locally-defined or referenced asymmetric key pair
                  to be used for the SSH server's host key.";
               reference
                 "RFC CCCC: A YANG Data Model for a Keystore";
               uses ks:inline-or-keystore-asymmetric-key-grouping {
                 refine "inline-or-keystore/inline/inline-definition" {
                   must 'not(public-key-format) or derived-from-or-self'
                    + '(public-key-format, "ct:ssh-public-key-format")';

                 }
                 refine "inline-or-keystore/central-keystore/"
                      + "central-keystore-reference" {
                   must 'not(deref(.)/../ks:public-key-format) or '
                      + 'derived-from-or-self(deref(.)/../ks:public-'
                      + 'key-format, "ct:ssh-public-key-format")';
                 }
               }
             }
             container certificate {
               if-feature "sshcmn:ssh-x509-certs";
               description
                 "A locally-defined or referenced end-entity
                  certificate to be used for the SSH server's
                  host key.";
               reference
                 "RFC CCCC: A YANG Data Model for a Keystore";
               uses
               ks:inline-or-keystore-end-entity-cert-with-key-grouping{
                 refine "inline-or-keystore/inline/inline-definition" {

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                   must 'not(public-key-format) or derived-from-or-self'
                      + '(public-key-format, "ct:subject-public-key-'
                      + 'info-format")';
                 }
                 refine "inline-or-keystore/central-keystore/"
                      + "central-keystore-reference/asymmetric-key" {
                   must 'not(deref(.)/../ks:public-key-format) or '
                      + 'derived-from-or-self(deref(.)/../ks:public-key'
                      + '-format, "ct:subject-public-key-info-format")';
                 }
               }
             }
           }
         }
       } // container server-identity

       container client-authentication {
         nacm:default-deny-write;
         description
           "Specifies how the SSH server can be configured to
            authenticate SSH clients.  See RFC 4252 for a general
            discussion about SSH authentication.";
         reference
           "RFC 4252: The Secure Shell (SSH) Transport Layer";
         container users {
           if-feature "local-users-supported";
           description
             "A list of locally configured users.";
           list user {
             key "name";
             description
               "A locally configured user.

                The server SHOULD derive the list of authentication
                'method names' returned to the SSH client from the
                descendant nodes configured herein, per Sections
                5.1 and 5.2 in RFC 4252.

                The authentication methods are unordered.  Clients
                must authenticate to all configured methods.
                Whenever a choice amongst methods arises,
                implementations SHOULD use a default ordering
                that prioritizes automation over human-interaction.";
             leaf name {
               type string;
               description
                 "The 'user name' for the SSH client, as defined in
                  the SSH_MSG_USERAUTH_REQUEST message in RFC 4253.";

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               reference
                 "RFC 4253: The Secure Shell (SSH) Transport Layer
                            Protocol";
             }
             container public-keys {
               if-feature "local-user-auth-publickey";
               presence
                 "Indicates that public keys have been configured.
                  This statement is present so the mandatory descendant
                  nodes do not imply that this node must be
                  configured.";
               description
                 "A set of SSH public keys may be used by the SSH
                  server to authenticate this user.  A user is
                  authenticated if its public key is an exact
                  match to a configured public key.";
               reference
                 "RFC BBBB: A YANG Data Model for a Truststore";
               uses ts:inline-or-truststore-public-keys-grouping {
                 refine "inline-or-truststore/inline/inline-definition/"
                      + "public-key" {
                   must 'derived-from-or-self(public-key-format,'
                      + ' "ct:ssh-public-key-format")';
                 }
                 refine "inline-or-truststore/central-truststore/"
                      + "central-truststore-reference" {
                   must 'not(deref(.)/../ts:public-key/ts:public-key-'
                      + 'format[not(derived-from-or-self(., "ct:ssh-'
                      + 'public-key-format"))])';
                 }
               }
             }
             container password {
               description
                 "A password the SSH server may use to authenticate
                  this user.  A user is authenticated if the hash
                  of the supplied password matches this value.";
               leaf hashed-password {
                 if-feature "local-user-auth-password";
                 type ianach:crypt-hash;
                 description
                   "The password for this user.";
               }
               leaf last-modified {
                 type yang:date-and-time;
                 config false;
                 description
                   "Identifies when the password was last set.";

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               }
             }
             container hostbased {
               if-feature "local-user-auth-hostbased";
               presence
                 "Indicates that hostbased [RFC4252] keys have been
                  configured.  This statement is present so the
                  mandatory descendant nodes do not imply that this
                  node must be configured.";
               description
                 "A set of SSH host keys used by the SSH server to
                  authenticate this user's host.  A user's host is
                  authenticated if its host key is an exact match
                  to a configured host key.";
               reference
                 "RFC 4252: The Secure Shell (SSH) Transport Layer
                  RFC BBBB: A YANG Data Model for a Truststore";
               uses ts:inline-or-truststore-public-keys-grouping {
                 refine "inline-or-truststore/inline/inline-definition/"
                      + "public-key" {
                   must 'derived-from-or-self(public-key-format,'
                      + ' "ct:ssh-public-key-format")';
                 }
                 refine "inline-or-truststore/central-truststore/"
                      + "central-truststore-reference" {
                   must 'not(deref(.)/../ts:public-key/ts:public-key-'
                      + 'format[not(derived-from-or-self(., "ct:ssh-'
                      + 'public-key-format"))])';
                 }
               }
             }
             leaf none {
               if-feature "local-user-auth-none";
               type empty;
               description
                 "Indicates that the 'none' method is configured
                  for this user.";
               reference
                 "RFC 4252: The Secure Shell (SSH) Authentication
                            Protocol.";
             }
           }
         } // users
         container ca-certs {
           if-feature "sshcmn:ssh-x509-certs";
           presence
             "Indicates that CA certificates have been configured.
              This statement is present so the mandatory descendant

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              nodes do not imply this node must be configured.";
           description
             "A set of certificate authority (CA) certificates used by
              the SSH server to authenticate SSH client certificates.
              A client certificate is authenticated if it has a valid
              chain of trust to a configured CA certificate.";
           reference
             "RFC BBBB: A YANG Data Model for a Truststore";
           uses ts:inline-or-truststore-certs-grouping;
         }
         container ee-certs {
           if-feature "sshcmn:ssh-x509-certs";
           presence
             "Indicates that EE certificates have been configured.
              This statement is present so the mandatory descendant
              nodes do not imply this node must be configured.";
           description
             "A set of client certificates (i.e., end entity
              certificates) used by the SSH server to authenticate
              the certificates presented by SSH clients.  A client
              certificate is authenticated if it is an exact match
              to a configured end-entity certificate.";
           reference
             "RFC BBBB: A YANG Data Model for a Truststore";
           uses ts:inline-or-truststore-certs-grouping;
         }
       } // container client-authentication

       container transport-params {
         nacm:default-deny-write;
         if-feature "sshcmn:transport-params";
         description
           "Configurable parameters of the SSH transport layer.";
         uses sshcmn:transport-params-grouping;
       } // container transport-params

       container keepalives {
         nacm:default-deny-write;
         if-feature "ssh-server-keepalives";
         presence
           "Indicates that the SSH server proactively tests the
            aliveness of the remote SSH client.";
         description
           "Configures the keep-alive policy, to proactively test
            the aliveness of the SSH client.  An unresponsive SSH
            client is dropped after approximately max-wait *
            max-attempts seconds.  Per Section 4 of RFC 4254,
            the SSH server SHOULD send an SSH_MSG_GLOBAL_REQUEST

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            message with a purposely nonexistent 'request name'
            value (e.g., keepalive@ietf.org) and the 'want reply'
            value set to '1'.";
         reference
           "RFC 4254: The Secure Shell (SSH) Connection Protocol";
         leaf max-wait {
           type uint16 {
             range "1..max";
           }
           units "seconds";
           default "30";
           description
             "Sets the amount of time in seconds after which
              if no data has been received from the SSH client,
              a SSH-level message will be sent to test the
              aliveness of the SSH client.";
         }
         leaf max-attempts {
           type uint8;
           default "3";
           description
             "Sets the maximum number of sequential keep-alive
              messages that can fail to obtain a response from
              the SSH client before assuming the SSH client is
              no longer alive.";
         }
       }
     } // grouping ssh-server-grouping

   }

   <CODE ENDS>

5.  Security Considerations

   The three IETF YANG modules in this document define groupings and
   will not be deployed as standalone modules.  Their security
   implications may be context dependent based on their use in other
   modules.  The designers of modules which import these grouping must
   conduct their own analysis of the security considerations.

5.1.  Considerations for the "iana-ssh-key-exchange-algs" Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

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   The "iana-ssh-key-exchange-algs" YANG module defines a data model
   that is designed to be accessed via YANG based management protocols,
   such as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these
   protocols have mandatory-to-implement secure transport layers (e.g.,
   SSH, TLS) with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   This YANG module defines YANG enumerations, for a public IANA-
   maintained registry.

   YANG enumerations are not security-sensitive, as they are statically
   defined in the publicly-accessible YANG module.  IANA MAY deprecate
   and/or obsolete enumerations over time as needed to address security
   issues found in the algorithms.

   This module does not define any writable-nodes, RPCs, actions, or
   notifications, and thus the security consideration for such is not
   provided here.

5.2.  Considerations for the "iana-ssh-encryption-algs" Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

   The "iana-ssh-encryption-algs" YANG module defines a data model that
   is designed to be accessed via YANG based management protocols, such
   as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   This YANG module defines YANG enumerations, for a public IANA-
   maintained registry.

   YANG enumerations are not security-sensitive, as they are statically
   defined in the publicly-accessible YANG module.

   This module does not define any writable-nodes, RPCs, actions, or
   notifications, and thus the security consideration for such is not
   provided here.

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5.3.  Considerations for the "iana-ssh-mac-algs" Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

   The "iana-ssh-mac-algs" YANG module defines a data model that is
   designed to be accessed via YANG based management protocols, such as
   NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   This YANG module defines YANG enumerations, for a public IANA-
   maintained registry.

   YANG enumerations are not security-sensitive, as they are statically
   defined in the publicly-accessible YANG module.

   This module does not define any writable-nodes, RPCs, actions, or
   notifications, and thus the security consideration for such is not
   provided here.

5.4.  Considerations for the "iana-ssh-public-key-algs" Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

   The "iana-ssh-public-key-algs" YANG module defines a data model that
   is designed to be accessed via YANG based management protocols, such
   as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   This YANG module defines YANG enumerations, for a public IANA-
   maintained registry.

   YANG enumerations are not security-sensitive, as they are statically
   defined in the publicly-accessible YANG module.

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   This module does not define any writable-nodes, RPCs, actions, or
   notifications, and thus the security consideration for such is not
   provided here.

5.5.  Considerations for the "ietf-ssh-common" YANG Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

   The "ietf-ssh-common" YANG module defines "grouping" statements that
   are designed to be accessed via YANG based management protocols, such
   as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   Please be aware that this YANG module uses groupings from other YANG
   modules that define nodes that may be considered sensitive or
   vulnerable in network environments.  Please review the Security
   Considerations for dependent YANG modules for information as to which
   nodes may be considered sensitive or vulnerable in network
   environments.

   None of the readable data nodes defined in this YANG module are
   considered sensitive or vulnerable in network environments.  The NACM
   "default-deny-all" extension has not been set for any data nodes
   defined in this module.

   None of the writable data nodes defined in this YANG module are
   considered sensitive or vulnerable in network environments.  The NACM
   "default-deny-write" extension has not been set for any data nodes
   defined in this module.

   This module defines the RPC "generate-asymmetric-key-pair" that may,
   if the "ct:cleartext-private-keys" feature is enabled, and the client
   requests it, return the private clear in cleartext form.  It is NOT
   RECOMMENDED for private keys to pass the server's security perimeter.

   This module does not define any actions or notifications, and thus
   the security consideration for such is not provided here.

5.6.  Considerations for the "ietf-ssh-client" YANG Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

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   The "ietf-ssh-client" YANG module defines "grouping" statements that
   are designed to be accessed via YANG based management protocols, such
   as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   Please be aware that this YANG module uses groupings from other YANG
   modules that define nodes that may be considered sensitive or
   vulnerable in network environments.  Please review the Security
   Considerations for dependent YANG modules for information as to which
   nodes may be considered sensitive or vulnerable in network
   environments.

   One readable data node defined in this YANG module may be considered
   sensitive or vulnerable in some network environments.  This node is
   as follows:

   *  The "client-identity/password" node:

         The cleartext "password" node defined in the "ssh-client-
         grouping" grouping is additionally sensitive to read operations
         such that, in normal use cases, it should never be returned to
         a client.  For this reason, the NACM extension "default-deny-
         all" has been applied to it.

   All the writable data nodes defined by this module may be considered
   sensitive or vulnerable in some network environments.  For instance,
   any modification to a key or reference to a key may dramatically
   alter the implemented security policy.  For this reason, the NACM
   extension "default-deny-write" has been set for all data nodes
   defined in this module.

   This module does not define any RPCs, actions, or notifications, and
   thus the security consideration for such is not provided here.

5.7.  Considerations for the "ietf-ssh-server" YANG Module

   This section follows the template defined in Section 3.7.1 of
   [RFC8407].

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   The "ietf-ssh-server" YANG module defines "grouping" statements that
   are designed to be accessed via YANG based management protocols, such
   as NETCONF [RFC6241] and RESTCONF [RFC8040].  Both of these protocols
   have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
   with mutual authentication.

   The Network Access Control Model (NACM) [RFC8341] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   Please be aware that this YANG module uses groupings from other YANG
   modules that define nodes that may be considered sensitive or
   vulnerable in network environments.  Please review the Security
   Considerations for dependent YANG modules for information as to which
   nodes may be considered sensitive or vulnerable in network
   environments.

   None of the readable data nodes defined in this YANG module are
   considered sensitive or vulnerable in network environments.  The NACM
   "default-deny-all" extension has not been set for any data nodes
   defined in this module.

   All the writable data nodes defined by this module may be considered
   sensitive or vulnerable in some network environments.  For instance,
   the addition or removal of references to keys, certificates, trusted
   anchors, etc., or even the modification of transport or keepalive
   parameters can dramatically alter the implemented security policy.
   For this reason, the NACM extension "default-deny-write" has been set
   for all data nodes defined in this module.

   This module does not define any RPCs, actions, or notifications, and
   thus the security consideration for such is not provided here.

6.  IANA Considerations

6.1.  The "IETF XML" Registry

   This document registers seven URIs in the "ns" subregistry of the
   IETF XML Registry [RFC3688].  Following the format in [RFC3688], the
   following registrations are requested:

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   URI: urn:ietf:params:xml:ns:yang:iana-ssh-key-exchange-algs
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:iana-ssh-encryption-algs
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:iana-ssh-mac-algs
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:iana-ssh-public-key-algs
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:ietf-ssh-common
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:ietf-ssh-client
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

   URI: urn:ietf:params:xml:ns:yang:ietf-ssh-server
   Registrant Contact: The IESG
   XML: N/A, the requested URI is an XML namespace.

6.2.  The "YANG Module Names" Registry

   This document registers seven YANG modules in the YANG Module Names
   registry [RFC6020].  Following the format in [RFC6020], the following
   registrations are requested:

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   name:         iana-ssh-key-exchange-algs
   namespace:    urn:ietf:params:xml:ns:yang:iana-ssh-key-exchange-algs
   prefix:       sshkea
   reference:    RFC EEEE

   name:         iana-ssh-encryption-algs
   namespace:    urn:ietf:params:xml:ns:yang:iana-ssh-encryption-algs
   prefix:       sshea
   reference:    RFC EEEE

   name:         iana-ssh-mac-algs
   namespace:    urn:ietf:params:xml:ns:yang:iana-ssh-mac-algs
   prefix:       sshma
   reference:    RFC EEEE

   name:         iana-ssh-public-key-algs
   namespace:    urn:ietf:params:xml:ns:yang:iana-ssh-public-key-algs
   prefix:       sshpka
   reference:    RFC EEEE

   name:         ietf-ssh-common
   namespace:    urn:ietf:params:xml:ns:yang:ietf-ssh-common
   prefix:       sshcmn
   reference:    RFC EEEE

   name:         ietf-ssh-client
   namespace:    urn:ietf:params:xml:ns:yang:ietf-ssh-client
   prefix:       sshc
   reference:    RFC EEEE

   name:         ietf-ssh-server
   namespace:    urn:ietf:params:xml:ns:yang:ietf-ssh-server
   prefix:       sshs
   reference:    RFC EEEE

6.3.  Considerations for the "iana-ssh-encryption-algs" Module

   This section follows the template defined in Section 4.30.3.1 of
   [I-D.ietf-netmod-rfc8407bis].

   This document presents a script (see Appendix A) for IANA to use to
   generate the IANA-maintained "iana-ssh-encryption-algs" YANG module.
   The most recent version of the YANG module is available from the
   "YANG Parameters" registry [IANA-YANG-PARAMETERS].

   IANA is requested to add the following note to the registry:

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   |  New values must not be directly added to the "iana-ssh-encryption-
   |  algs" YANG module.  They must instead be added to the "Encryption
   |  Algorithm Names" sub-registry of the "Secure Shell (SSH) Protocol
   |  Parameters" registry [IANA-ENC-ALGS].

   When a value is added to the "Encryption Algorithm Names" sub-
   registry, a new "enum" statement must be added to the "iana-ssh-
   encryption-algs" YANG module.  The "enum" statement, and sub-
   statements thereof, should be defined as follows:

   enum
      Replicates a name from the registry.

   value
      Contains the decimal value of the IANA-assigned value.

   status
      Include only if a registration has been deprecated or obsoleted.
      An IANA "Note" containing the word "HISTORIC" maps to YANG status
      "obsolete".  Since the registry is unable to express a "SHOULD
      NOT" recommendation, there is no mapping to YANG status
      "deprecated".

   description
      Contains "Enumeration for the 'foo-bar' algorithm.", where "foo-
      bar" is a placeholder for the algorithm's name (e.g., "3des-cbc").

   reference
      Replicates the reference(s) from the registry with the title of
      the document(s) added.

   Unassigned or reserved values are not present in the module.

   When the "iana-ssh-encryption-algs" YANG module is updated, a new
   "revision" statement with a unique revision date must be added in
   front of the existing revision statements.  The "revision" must have
   a "description" statement explaining why the the update occurred, and
   must have a "reference" substatement that points to the document
   defining the registry update that resulted in this change.  For
   instance:

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   revision 2024-02-02 {
       description
         "This update reflect the update made to the underlying
          Foo Bar registry per RFC XXXX.";
     reference
         "RFC XXXX: Extend the Foo Bars Registry
                    to Support Something Important";
   }

   IANA is requested to add the following note to the "Encryption
   Algorithm Names" sub-registry.

   |  When this registry is modified, the YANG module "iana-ssh-
   |  encryption-algs" [IANA-YANG-PARAMETERS] must be updated as defined
   |  in RFC EEEE.

6.4.  Considerations for the "iana-ssh-mac-algs" Module

   This section follows the template defined in Section 4.30.3.1 of
   [I-D.ietf-netmod-rfc8407bis].

   This document presents a script (see Appendix A) for IANA to use to
   generate the IANA-maintained "iana-ssh-mac-algs" YANG module.  The
   most recent version of the YANG module is available from the "YANG
   Parameters" registry [IANA-YANG-PARAMETERS].

   IANA is requested to add the following note to the registry:

   |  New values must not be directly added to the "iana-ssh-mac-algs"
   |  YANG module.  They must instead be added to the "MAC Algorithm
   |  Names" sub-registry of the "Secure Shell (SSH) Protocol
   |  Parameters" registry [IANA-MAC-ALGS].

   When a value is added to the "MAC Algorithm Names" sub-registry, a
   new "enum" statement must be added to the "iana-ssh-mac-algs" YANG
   module.  The "enum" statement, and sub-statements thereof, should be
   defined as follows:

   enum
      Replicates a name from the registry.

   value
      Contains the decimal value of the IANA-assigned value.

   status
      Include only if a registration has been deprecated or obsoleted.

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   description
      Contains "Enumeration for the 'foo-bar' algorithm.", where "foo-
      bar" is a placeholder for the algorithm's name (e.g., "3des-cbc").

   reference
      Replicates the reference(s) from the registry with the title of
      the document(s) added.

   Unassigned or reserved values are not present in the module.

   When the "iana-ssh-mac-algs" YANG module is updated, a new "revision"
   statement with a unique revision date must be added in front of the
   existing revision statements.  The "revision" must have a
   "description" statement explaining why the the update occurred, and
   must have a "reference" substatement that points to the document
   defining the registry update that resulted in this change.  For
   instance:

   revision 2024-02-02 {
       description
         "This update reflect the update made to the underlying
          Foo Bar registry per RFC XXXX.";
     reference
         "RFC XXXX: Extend the Foo Bars Registry
                    to Support Something Important";
   }

   IANA is requested to add the following note to the "MAC Algorithm
   Names" sub-registry.

   |  When this registry is modified, the YANG module "iana-ssh-mac-
   |  algs" [IANA-YANG-PARAMETERS] must be updated as defined in RFC
   |  EEEE.

6.5.  Considerations for the "iana-ssh-public-key-algs" Module

   This section follows the template defined in Section 4.30.3.1 of
   [I-D.ietf-netmod-rfc8407bis].

   This document presents a script (see Appendix A) for IANA to use to
   generate the IANA-maintained "iana-ssh-public-key-algs" YANG module.
   The most recent version of the YANG module is available from the
   "YANG Parameters" registry [IANA-YANG-PARAMETERS].

   IANA is requested to add the following note to the registry:

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   |  New values must not be directly added to the "iana-ssh-public-key-
   |  algs" YANG module.  They must instead be added to the "Public Key
   |  Algorithm Names" sub-registry of the "Secure Shell (SSH) Protocol
   |  Parameters" registry [IANA-PUBKEY-ALGS].

   When a value is added to the "Public Key Algorithm Names" sub-
   registry, a new "enum" statement must be added to the "iana-ssh-
   public-key-algs" YANG module.  The "enum" statement, and sub-
   statements thereof, should be defined as follows:

   enum
      Replicates a name from the registry.

   value
      Contains the decimal value of the IANA-assigned value.

   status
      Include only if a registration has been deprecated or obsoleted.

   description
      Contains "Enumeration for the 'foo-bar' algorithm.", where "foo-
      bar" is a placeholder for the algorithm's name (e.g., "3des-cbc").

   reference
      Replicates the reference(s) from the registry with the title of
      the document(s) added.

   In the case that the algorithm name ends with "-*", the familiy of
   enumerations must be added.  The familiy of enum algorithm names are
   generated by replacing the '*' character with these strings:
   "nistp256", "nistp384", "nistp521", "1.3.132.0.1",
   "1.2.840.10045.3.1.1", "1.3.132.0.33", "1.3.132.0.26",
   "1.3.132.0.27", "1.3.132.0.16", "1.3.132.0.36", "1.3.132.0.37", and
   "1.3.132.0.38".

   Unassigned or reserved values are not present in the module.

   When the "iana-ssh-public-key-algs" YANG module is updated, a new
   "revision" statement with a unique revision date must be added in
   front of the existing revision statements.  The "revision" must have
   a "description" statement explaining why the the update occurred, and
   must have a "reference" substatement that points to the document
   defining the registry update that resulted in this change.  For
   instance:

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   revision 2024-02-02 {
       description
         "This update reflect the update made to the underlying
          Foo Bar registry per RFC XXXX.";
     reference
         "RFC XXXX: Extend the Foo Bars Registry
                    to Support Something Important";
   }

   IANA is requested to add the following note to the "Public Key
   Algorithm Names" sub-registry.

   |  When this registry is modified, the YANG module "iana-ssh-public-
   |  key-algs" [IANA-YANG-PARAMETERS] must be updated as defined in RFC
   |  EEEE.

6.6.  Considerations for the "iana-ssh-key-exchange-algs" Module

   This section follows the template defined in Section 4.30.3.1 of
   [I-D.ietf-netmod-rfc8407bis].

   This document presents a script (see Appendix A) for IANA to use to
   generate the IANA-maintained "iana-ssh-key-exchange-algs" YANG
   module.  The most recent version of the YANG module is available from
   the "YANG Parameters" registry [IANA-YANG-PARAMETERS].

   IANA is requested to add the following note to the registry:

   |  New values must not be directly added to the "iana-ssh-key-
   |  exchange-algs" YANG module.  They must instead be added to the
   |  "Key Exchange Method Names" sub-registry of the "Secure Shell
   |  (SSH) Protocol Parameters" registry [IANA-KEYEX-ALGS].

   When a value is added to the "Key Exchange Method Names" sub-
   registry, a new "enum" statement must be added to the "iana-ssh-key-
   exchange-algs" YANG module.  The "enum" statement, and sub-statements
   thereof, should be defined as follows:

   enum
      Replicates a name from the registry.

   value
      Contains the decimal value of the IANA-assigned value.

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   status
      Include only if a registration has been deprecated or obsoleted.
      An IANA "OK to Implement" containing "SHOULD NOT" maps to YANG
      status "deprecated".  An IANA "OK to Implement" containing "MUST
      NOT" maps to YANG status "obsolete".

   description
      Contains "Enumeration for the 'foo-bar' algorithm.", where "foo-
      bar" is a placeholder for the algorithm's name (e.g., "3des-cbc").

   reference
      Replicates the reference(s) from the registry with the title of
      the document(s) added.

   In the case that the algorithm name ends with "-*", the familiy of
   enumerations must be added.  The familiy of enum algorithm names are
   generated by replacing the '*' character with these strings:
   "nistp256", "nistp384", "nistp521", "1.3.132.0.1",
   "1.2.840.10045.3.1.1", "1.3.132.0.33", "1.3.132.0.26",
   "1.3.132.0.27", "1.3.132.0.16", "1.3.132.0.36", "1.3.132.0.37", and
   "1.3.132.0.38".

   Unassigned or reserved values are not present in the module.

   When the "iana-ssh-key-exchange-algs" YANG module is updated, a new
   "revision" statement with a unique revision date must be added in
   front of the existing revision statements.  The "revision" must have
   a "description" statement explaining why the the update occurred, and
   must have a "reference" substatement that points to the document
   defining the registry update that resulted in this change.  For
   instance:

   revision 2024-02-02 {
       description
         "This update reflect the update made to the underlying
          Foo Bar registry per RFC XXXX.";
     reference
         "RFC XXXX: Extend the Foo Bars Registry
                    to Support Something Important";
   }

   IANA is requested to add the following note to the "Key Exchange
   Method Names" sub-registry.

   |  When this registry is modified, the YANG module "iana-ssh-key-
   |  exchange-algs" [IANA-YANG-PARAMETERS] must be updated as defined
   |  in RFC EEEE.

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7.  References

7.1.  Normative References

   [I-D.ietf-netconf-crypto-types]
              Watsen, K., "YANG Data Types and Groupings for
              Cryptography", Work in Progress, Internet-Draft, draft-
              ietf-netconf-crypto-types-33, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              crypto-types-33>.

   [I-D.ietf-netconf-keystore]
              Watsen, K., "A YANG Data Model for a Keystore and Keystore
              Operations", Work in Progress, Internet-Draft, draft-ietf-
              netconf-keystore-34, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              keystore-34>.

   [I-D.ietf-netconf-trust-anchors]
              Watsen, K., "A YANG Data Model for a Truststore", Work in
              Progress, Internet-Draft, draft-ietf-netconf-trust-
              anchors-27, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              trust-anchors-27>.

   [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>.

   [RFC4251]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Protocol Architecture", RFC 4251, DOI 10.17487/RFC4251,
              January 2006, <https://www.rfc-editor.org/info/rfc4251>.

   [RFC4252]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
              January 2006, <https://www.rfc-editor.org/info/rfc4252>.

   [RFC4253]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Transport Layer Protocol", RFC 4253, DOI 10.17487/RFC4253,
              January 2006, <https://www.rfc-editor.org/info/rfc4253>.

   [RFC4254]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Connection Protocol", RFC 4254, DOI 10.17487/RFC4254,
              January 2006, <https://www.rfc-editor.org/info/rfc4254>.

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   [RFC4344]  Bellare, M., Kohno, T., and C. Namprempre, "The Secure
              Shell (SSH) Transport Layer Encryption Modes", RFC 4344,
              DOI 10.17487/RFC4344, January 2006,
              <https://www.rfc-editor.org/info/rfc4344>.

   [RFC4419]  Friedl, M., Provos, N., and W. Simpson, "Diffie-Hellman
              Group Exchange for the Secure Shell (SSH) Transport Layer
              Protocol", RFC 4419, DOI 10.17487/RFC4419, March 2006,
              <https://www.rfc-editor.org/info/rfc4419>.

   [RFC4432]  Harris, B., "RSA Key Exchange for the Secure Shell (SSH)
              Transport Layer Protocol", RFC 4432, DOI 10.17487/RFC4432,
              March 2006, <https://www.rfc-editor.org/info/rfc4432>.

   [RFC4462]  Hutzelman, J., Salowey, J., Galbraith, J., and V. Welch,
              "Generic Security Service Application Program Interface
              (GSS-API) Authentication and Key Exchange for the Secure
              Shell (SSH) Protocol", RFC 4462, DOI 10.17487/RFC4462, May
              2006, <https://www.rfc-editor.org/info/rfc4462>.

   [RFC5647]  Igoe, K. and J. Solinas, "AES Galois Counter Mode for the
              Secure Shell Transport Layer Protocol", RFC 5647,
              DOI 10.17487/RFC5647, August 2009,
              <https://www.rfc-editor.org/info/rfc5647>.

   [RFC5656]  Stebila, D. and J. Green, "Elliptic Curve Algorithm
              Integration in the Secure Shell Transport Layer",
              RFC 5656, DOI 10.17487/RFC5656, December 2009,
              <https://www.rfc-editor.org/info/rfc5656>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC6187]  Igoe, K. and D. Stebila, "X.509v3 Certificates for Secure
              Shell Authentication", RFC 6187, DOI 10.17487/RFC6187,
              March 2011, <https://www.rfc-editor.org/info/rfc6187>.

   [RFC6668]  Bider, D. and M. Baushke, "SHA-2 Data Integrity
              Verification for the Secure Shell (SSH) Transport Layer
              Protocol", RFC 6668, DOI 10.17487/RFC6668, July 2012,
              <https://www.rfc-editor.org/info/rfc6668>.

   [RFC7317]  Bierman, A. and M. Bjorklund, "A YANG Data Model for
              System Management", RFC 7317, DOI 10.17487/RFC7317, August
              2014, <https://www.rfc-editor.org/info/rfc7317>.

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   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [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>.

   [RFC8268]  Baushke, M., "More Modular Exponentiation (MODP) Diffie-
              Hellman (DH) Key Exchange (KEX) Groups for Secure Shell
              (SSH)", RFC 8268, DOI 10.17487/RFC8268, December 2017,
              <https://www.rfc-editor.org/info/rfc8268>.

   [RFC8308]  Bider, D., "Extension Negotiation in the Secure Shell
              (SSH) Protocol", RFC 8308, DOI 10.17487/RFC8308, March
              2018, <https://www.rfc-editor.org/info/rfc8308>.

   [RFC8332]  Bider, D., "Use of RSA Keys with SHA-256 and SHA-512 in
              the Secure Shell (SSH) Protocol", RFC 8332,
              DOI 10.17487/RFC8332, March 2018,
              <https://www.rfc-editor.org/info/rfc8332>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8709]  Harris, B. and L. Velvindron, "Ed25519 and Ed448 Public
              Key Algorithms for the Secure Shell (SSH) Protocol",
              RFC 8709, DOI 10.17487/RFC8709, February 2020,
              <https://www.rfc-editor.org/info/rfc8709>.

   [RFC8731]  Adamantiadis, A., Josefsson, S., and M. Baushke, "Secure
              Shell (SSH) Key Exchange Method Using Curve25519 and
              Curve448", RFC 8731, DOI 10.17487/RFC8731, February 2020,
              <https://www.rfc-editor.org/info/rfc8731>.

   [RFC8732]  Sorce, S. and H. Kario, "Generic Security Service
              Application Program Interface (GSS-API) Key Exchange with
              SHA-2", RFC 8732, DOI 10.17487/RFC8732, February 2020,
              <https://www.rfc-editor.org/info/rfc8732>.

   [RFC8758]  Velvindron, L., "Deprecating RC4 in Secure Shell (SSH)",
              BCP 227, RFC 8758, DOI 10.17487/RFC8758, April 2020,
              <https://www.rfc-editor.org/info/rfc8758>.

7.2.  Informative References

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   [FIPS_186-6]
              (NIST), T. N. I. F. S. A. T., "Digital Signature Standard
              (DSS)",
              <https://csrc.nist.gov/publications/detail/fips/186/5/
              draft>.

   [I-D.ietf-netconf-http-client-server]
              Watsen, K., "YANG Groupings for HTTP Clients and HTTP
              Servers", Work in Progress, Internet-Draft, draft-ietf-
              netconf-http-client-server-19, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              http-client-server-19>.

   [I-D.ietf-netconf-netconf-client-server]
              Watsen, K., "NETCONF Client and Server Models", Work in
              Progress, Internet-Draft, draft-ietf-netconf-netconf-
              client-server-35, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              netconf-client-server-35>.

   [I-D.ietf-netconf-restconf-client-server]
              Watsen, K., "RESTCONF Client and Server Models", Work in
              Progress, Internet-Draft, draft-ietf-netconf-restconf-
              client-server-35, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              restconf-client-server-35>.

   [I-D.ietf-netconf-ssh-client-server]
              Watsen, K., "YANG Groupings for SSH Clients and SSH
              Servers", Work in Progress, Internet-Draft, draft-ietf-
              netconf-ssh-client-server-39, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              ssh-client-server-39>.

   [I-D.ietf-netconf-tcp-client-server]
              Watsen, K. and M. Scharf, "YANG Groupings for TCP Clients
              and TCP Servers", Work in Progress, Internet-Draft, draft-
              ietf-netconf-tcp-client-server-23, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              tcp-client-server-23>.

   [I-D.ietf-netconf-tls-client-server]
              Watsen, K., "YANG Groupings for TLS Clients and TLS
              Servers", Work in Progress, Internet-Draft, draft-ietf-
              netconf-tls-client-server-40, 1 March 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
              tls-client-server-40>.

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   [I-D.ietf-netmod-rfc8407bis]
              Bierman, A., Boucadair, M., and Q. Wu, "Guidelines for
              Authors and Reviewers of Documents Containing YANG Data
              Models", Work in Progress, Internet-Draft, draft-ietf-
              netmod-rfc8407bis-09, 28 February 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
              rfc8407bis-09>.

   [I-D.ietf-netmod-system-config]
              Ma, Q., Wu, Q., and C. Feng, "System-defined
              Configuration", Work in Progress, Internet-Draft, draft-
              ietf-netmod-system-config-05, 21 February 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
              system-config-05>.

   [IANA-ENC-ALGS]
              (IANA), I. A. N. A., "IANA "Encryption Algorithm Names"
              Sub-registry of the "Secure Shell (SSH) Protocol
              Parameters" Registry", <https://www.iana.org/assignments/
              ssh-parameters/ssh-parameters.xhtml#ssh-parameters-17>.

   [IANA-KEYEX-ALGS]
              (IANA), I. A. N. A., "IANA "Key Exchange Method Names"
              Sub-registry of the "Secure Shell (SSH) Protocol
              Parameters" Registry", <https://www.iana.org/assignments/
              ssh-parameters/ssh-parameters.xhtml#ssh-parameters-16>.

   [IANA-MAC-ALGS]
              (IANA), I. A. N. A., "IANA "MAC Algorithm Names" Sub-
              registry of the "Secure Shell (SSH) Protocol Parameters"
              Registry", <https://www.iana.org/assignments/ssh-
              parameters/ssh-parameters.xhtml#ssh-parameters-18>.

   [IANA-PUBKEY-ALGS]
              (IANA), I. A. N. A., "IANA "Public Key Algorithm Names"
              Sub-registry of the "Secure Shell (SSH) Protocol
              Parameters" Registry", <https://www.iana.org/assignments/
              ssh-parameters/ssh-parameters.xhtml#ssh-parameters-19>.

   [IANA-YANG-PARAMETERS]
              "YANG Parameters", n.d.,
              <https://www.iana.org/assignments/yang-parameters>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

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   [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/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8071]  Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
              RFC 8071, DOI 10.17487/RFC8071, February 2017,
              <https://www.rfc-editor.org/info/rfc8071>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8407]  Bierman, A., "Guidelines for Authors and Reviewers of
              Documents Containing YANG Data Models", BCP 216, RFC 8407,
              DOI 10.17487/RFC8407, October 2018,
              <https://www.rfc-editor.org/info/rfc8407>.

Appendix A.  Script to Generate IANA-Maintained YANG Modules

   This section is not Normative.

   The Python https://www.python.org script contained in this section
   will create the four IANA-maintained modules described in this
   document.

   Run the script using the command `python gen-yang-modules.py`, to
   produce four YANG module files in the current directory.

   Be aware that the script does not attempt to copy the "revision"
   statements from the previous/current YANG module.  Copying the
   revision statements must be done manually.

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   <CODE BEGINS>
   =============== NOTE: '\' line wrapping per RFC 8792 ================

   import re
   import csv
   import textwrap
   import requests
   import requests_cache
   from io import StringIO
   from datetime import datetime

   # Metadata for the four YANG modules produced by this script
   MODULES = [
       {
           "csv_url": "https://www.iana.org/assignments/ssh-parameters/\
   ssh-parameters-17.csv",
           "spaced_name": "encryption",
           "hypenated_name": "encryption",
           "prefix": "sshea",
           "description": """    "This module defines enumerations for \
   the encryption algorithms
        defined in the 'Encryption Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA.""",
       },
       {
           "csv_url": "https://www.iana.org/assignments/ssh-parameters/\
   ssh-parameters-19.csv",
           "spaced_name": "public key",
           "hypenated_name": "public-key",
           "prefix": "sshpka",
           "description": """    "This module defines enumerations for \
   the public key algorithms
        defined in the 'Public Key Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA."""
       },
       {
           "csv_url": "https://www.iana.org/assignments/ssh-parameters/\
   ssh-parameters-18.csv",
           "spaced_name": "mac",
           "hypenated_name": "mac",
           "prefix": "sshma",
           "description": """    "This module defines enumerations for \
   the MAC algorithms
        defined in the 'MAC Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA."""

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       },
       {
           "csv_url": "https://www.iana.org/assignments/ssh-parameters/\
   ssh-parameters-16.csv",
           "spaced_name": "key exchange",
           "hypenated_name": "key-exchange",
           "prefix": "sshkea",
           "description": """    "This module defines enumerations for \
   the key exchange algorithms
        defined in the 'Key Exchange Method Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA."""
       },
   ]

   def create_module_begin(module, f):

       # Define template for all four modules
       PREAMBLE_TEMPLATE="""
   module iana-ssh-HNAME-algs {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-ssh-HNAME-algs";
     prefix PREFIX;

     organization
       "Internet Assigned Numbers Authority (IANA)";

     contact
       "Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America
        Tel:    +1 310 301 5800
        Email:  iana@iana.org";

     description
   DESCRIPTION

        Copyright (c) YEAR IETF Trust and the persons identified as
        authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's

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        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        All versions of this module are published by IANA at
        https://www.iana.org/assignments/yang-parameters.";

     revision DATE {
       description
         "This initial version of the module was created using
          the script defined in RFC EEEE to reflect the contents
          of the SNAME algorithms registry maintained by IANA.";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-HNAME-algorithm {
       type enumeration {
   """
       # Replacements
       rep = {
         "DATE": datetime.today().strftime('%Y-%m-%d'),
         "YEAR": datetime.today().strftime('%Y'),
         "SNAME": module["spaced_name"],
         "HNAME": module["hypenated_name"],
         "PREFIX": module["prefix"],
         "DESCRIPTION": module["description"]
       }

       # Do the replacement
       rep = dict((re.escape(k), v) for k, v in rep.items())
       pattern = re.compile("|".join(rep.keys()))
       text = pattern.sub(lambda m: rep[re.escape(m.group(0))], PREAMBL\
   E_TEMPLATE)

       # Write preamble into the file
       f.write(text)

   def create_module_body(module, f):

       # Fetch the current CSV file from IANA
       r = requests.get(module["csv_url"])
       assert(r.status_code == 200)

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       # Ascertain the first CSV column's name
       with StringIO(r.text) as csv_file:
           csv_reader = csv.reader(csv_file)
           for row in csv_reader:
               first_colname = row[0]
               break

       # Parse each CSV line
       with StringIO(r.text) as csv_file:
           csv_reader = csv.DictReader(csv_file)
           for row in csv_reader:

               # Extract just the ref
               refs = row["Reference"][1:-1]  # remove the '[' and ']' \
   chars
               refs = refs.split("][")

               # There may be more than one ref
               titles = []
               for ref in refs:

                   # Ascertain the ref's title
                   if ref.startswith("RFC"):

                       # Fetch the current BIBTEX entry
                       bibtex_url="https://datatracker.ietf.org/doc/"+ \
   ref.lower() + "/bibtex/"
                       r = requests.get(bibtex_url)
                       assert r.status_code == 200, "Could not GET " + \
   bibtex_url

                       # Append to 'titles' value from the "title" line
                       for item in r.text.split("\n"):
                           if "title =" in item:
                               titles.append(re.sub('.*{{(.*)}}.*', r'\\
   g<1>', item))
                               break
                       else:
                           raise Exception("RFC title not found")

                       # Insert a space: "RFCXXXX" --> "RFC XXXX"
                       index = refs.index(ref)
                       refs[index] = "RFC " + ref[3:]

                   elif ref.startswith("FIPS"):
                       # Special case for FIPS, since no bibtex to fetch
                       if ref == "FIPS 46-3" or ref == "FIPS-46-3":

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                           titles.append("Data Encryption Standard (DES\
   )")
                       else:
                           raise Exception("FIPS ref not found")

                   else:
                       raise Exception("ref not found")

               # Function used below
               def write_enumeration(alg):
                   f.write('\n')
                   f.write(f'      enum {alg} {{\n')
                   if "HISTORIC" in row["Note"]:
                       f.write(f'        status obsolete;\n')
                   elif "OK to Implement" in row:
                       if "MUST NOT" in row["OK to Implement"]:
                           f.write(f'        status obsolete;\n')
                       elif "SHOULD NOT" in row["OK to Implement"]:
                           f.write(f'        status deprecated;\n')
                   f.write(f'        description\n')
                   description = f'          "Enumeration for the \'{al\
   g}\' algorithm.'
                   if "Section" in row["Note"]:
                       description += " " + row["Note"]
                   description += '";'
                   description = textwrap.fill(description, width=69, s\
   ubsequent_indent="           ")
                   f.write(f'{description}\n')
                   f.write('        reference\n')
                   f.write('          "')
                   if row["Reference"] == "":
                       f.write('    Missing in IANA registry.')
                   else:
                       ref_len = len(refs)
                       for i in range(ref_len):
                           ref = refs[i]
                           f.write(f'{ref}:\n')
                           title = "             " + titles[i]
                           if i == ref_len - 1:
                               title += '";'
                           title = textwrap.fill(title, width=67, subse\
   quent_indent="             ")
                           f.write(f'{title}')
                           if i != ref_len - 1:
                               f.write('\n       ')
                   f.write('\n')
                   f.write('      }\n')

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               # Write one or more "enumeration" statements
               if not row[first_colname].endswith("-*"): # just one enu\
   meration
                   # Avoid duplicate entries caused by the "ecdh-sha2-*\
   " family expansion
                   if not row[first_colname].startswith("ecdh-sha2-nist\
   p"):
                       write_enumeration(row[first_colname])
               else: # a family of enumerations
                   curve_ids = [
                       "nistp256",
                       "nistp384",
                       "nistp521",
                       "1.3.132.0.1",
                       "1.2.840.10045.3.1.1",
                       "1.3.132.0.33",
                       "1.3.132.0.26",
                       "1.3.132.0.27",
                       "1.3.132.0.16",
                       "1.3.132.0.36",
                       "1.3.132.0.37",
                       "1.3.132.0.38",
                   ]
                   for curve_id in curve_ids:
                       write_enumeration(row[first_colname][:-1] + curv\
   e_id)

   def create_module_end(module, f):

       # Close out the enumeration, typedef, and module
       f.write("    }\n")
       f.write("    description\n")
       f.write(f'      "An enumeration for SSH {module["spaced_name"]} \
   algorithms.";\n')
       f.write("  }\n")
       f.write('\n')
       f.write('}\n')

   def create_module(module):

       # Install cache for 8x speedup
       requests_cache.install_cache()

       # ascertain yang module's name
       yang_module_name = "iana-ssh-" + module["hypenated_name"] + "-al\
   gs.yang"

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       # create yang module file
       with open(yang_module_name, "w") as f:
           create_module_begin(module, f)
           create_module_body(module, f)
           create_module_end(module, f)

   def main():
       for module in MODULES:
           create_module(module)

   if __name__ == "__main__":
       main()
   <CODE ENDS>

A.1.  Initial Module for the "Encryption Algorithm Names" Registry

   Following are the complete contents to the initial IANA-maintained
   YANG module.  Please note that the date "2024-03-16" reflects the day
   on which the extraction occurred.  Applications SHOULD use the IANA-
   maintained module, not the module defined in this draft.

   This YANG module has normative references to [FIPS 46-3], [RFC4253],
   [RFC4344], [RFC5647], and [RFC8758].

   <CODE BEGINS> file "iana-ssh-encryption-algs@2024-03-16.yang"

   module iana-ssh-encryption-algs {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-ssh-encryption-algs";
     prefix sshea;

     organization
       "Internet Assigned Numbers Authority (IANA)";

     contact
       "Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America
        Tel:    +1 310 301 5800
        Email:  iana@iana.org";

     description
       "This module defines enumerations for the encryption algorithms
        defined in the 'Encryption Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained

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        by IANA.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        All versions of this module are published by IANA at
        https://www.iana.org/assignments/yang-parameters.";

     revision 2024-03-16 {
       description
         "This initial version of the module was created using
          the script defined in RFC EEEE to reflect the contents
          of the encryption algorithms registry maintained by IANA.";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-encryption-algorithm {
       type enumeration {

         enum 3des-cbc {
           description
             "Enumeration for the '3des-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum blowfish-cbc {
           description
             "Enumeration for the 'blowfish-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

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         enum twofish256-cbc {
           description
             "Enumeration for the 'twofish256-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum twofish-cbc {
           description
             "Enumeration for the 'twofish-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum twofish192-cbc {
           description
             "Enumeration for the 'twofish192-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum twofish128-cbc {
           description
             "Enumeration for the 'twofish128-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum aes256-cbc {
           description
             "Enumeration for the 'aes256-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum aes192-cbc {
           description
             "Enumeration for the 'aes192-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:

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                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum aes128-cbc {
           description
             "Enumeration for the 'aes128-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum serpent256-cbc {
           description
             "Enumeration for the 'serpent256-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum serpent192-cbc {
           description
             "Enumeration for the 'serpent192-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum serpent128-cbc {
           description
             "Enumeration for the 'serpent128-cbc' algorithm. Section
              6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum arcfour {
           status obsolete;
           description
             "Enumeration for the 'arcfour' algorithm.";
           reference
             "RFC 8758:
                Deprecating RC4 in Secure Shell (SSH)";
         }

         enum idea-cbc {

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           description
             "Enumeration for the 'idea-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum cast128-cbc {
           description
             "Enumeration for the 'cast128-cbc' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum none {
           description
             "Enumeration for the 'none' algorithm. Section 6.3";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum des-cbc {
           status obsolete;
           description
             "Enumeration for the 'des-cbc' algorithm.";
           reference
             "FIPS-46-3:
                Data Encryption Standard (DES)";
         }

         enum arcfour128 {
           status obsolete;
           description
             "Enumeration for the 'arcfour128' algorithm.";
           reference
             "RFC 8758:
                Deprecating RC4 in Secure Shell (SSH)";
         }

         enum arcfour256 {
           status obsolete;
           description
             "Enumeration for the 'arcfour256' algorithm.";
           reference
             "RFC 8758:
                Deprecating RC4 in Secure Shell (SSH)";

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         }

         enum aes128-ctr {
           description
             "Enumeration for the 'aes128-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum aes192-ctr {
           description
             "Enumeration for the 'aes192-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum aes256-ctr {
           description
             "Enumeration for the 'aes256-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum 3des-ctr {
           description
             "Enumeration for the '3des-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum blowfish-ctr {
           description
             "Enumeration for the 'blowfish-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum twofish128-ctr {

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           description
             "Enumeration for the 'twofish128-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum twofish192-ctr {
           description
             "Enumeration for the 'twofish192-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum twofish256-ctr {
           description
             "Enumeration for the 'twofish256-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum serpent128-ctr {
           description
             "Enumeration for the 'serpent128-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum serpent192-ctr {
           description
             "Enumeration for the 'serpent192-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum serpent256-ctr {
           description
             "Enumeration for the 'serpent256-ctr' algorithm.";
           reference

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             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum idea-ctr {
           description
             "Enumeration for the 'idea-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum cast128-ctr {
           description
             "Enumeration for the 'cast128-ctr' algorithm.";
           reference
             "RFC 4344:
                The Secure Shell (SSH) Transport Layer Encryption
                Modes";
         }

         enum AEAD_AES_128_GCM {
           description
             "Enumeration for the 'AEAD_AES_128_GCM' algorithm. Section
              6.1";
           reference
             "RFC 5647:
                AES Galois Counter Mode for the Secure Shell Transport
                Layer Protocol";
         }

         enum AEAD_AES_256_GCM {
           description
             "Enumeration for the 'AEAD_AES_256_GCM' algorithm. Section
              6.2";
           reference
             "RFC 5647:
                AES Galois Counter Mode for the Secure Shell Transport
                Layer Protocol";
         }
       }
       description
         "An enumeration for SSH encryption algorithms.";
     }

   }

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   <CODE ENDS>

A.2.  Initial Module for the "MAC Algorithm Names" Registry

   Following are the complete contents to the initial IANA-maintained
   YANG module.  Please note that the date "2024-03-16" reflects the day
   on which the extraction occurred.  Applications SHOULD use the IANA-
   maintained module, not the module defined in this draft.

   This YANG module has normative references [RFC4253], [RFC5647], and
   [RFC6668].

   <CODE BEGINS> file "iana-ssh-mac-algs@2024-03-16.yang"

   module iana-ssh-mac-algs {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-ssh-mac-algs";
     prefix sshma;

     organization
       "Internet Assigned Numbers Authority (IANA)";

     contact
       "Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America
        Tel:    +1 310 301 5800
        Email:  iana@iana.org";

     description
       "This module defines enumerations for the MAC algorithms
        defined in the 'MAC Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC

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        itself for full legal notices.

        All versions of this module are published by IANA at
        https://www.iana.org/assignments/yang-parameters.";

     revision 2024-03-16 {
       description
         "This initial version of the module was created using
          the script defined in RFC EEEE to reflect the contents
          of the mac algorithms registry maintained by IANA.";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-mac-algorithm {
       type enumeration {

         enum hmac-sha1 {
           description
             "Enumeration for the 'hmac-sha1' algorithm. Section 6.4";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum hmac-sha1-96 {
           description
             "Enumeration for the 'hmac-sha1-96' algorithm. Section
              6.4";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum hmac-md5 {
           description
             "Enumeration for the 'hmac-md5' algorithm. Section 6.4";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum hmac-md5-96 {
           description
             "Enumeration for the 'hmac-md5-96' algorithm. Section 6.4";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";

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         }

         enum none {
           description
             "Enumeration for the 'none' algorithm. Section 6.4";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum AEAD_AES_128_GCM {
           description
             "Enumeration for the 'AEAD_AES_128_GCM' algorithm. Section
              6.1";
           reference
             "RFC 5647:
                AES Galois Counter Mode for the Secure Shell Transport
                Layer Protocol";
         }

         enum AEAD_AES_256_GCM {
           description
             "Enumeration for the 'AEAD_AES_256_GCM' algorithm. Section
              6.2";
           reference
             "RFC 5647:
                AES Galois Counter Mode for the Secure Shell Transport
                Layer Protocol";
         }

         enum hmac-sha2-256 {
           description
             "Enumeration for the 'hmac-sha2-256' algorithm. Section 2";
           reference
             "RFC 6668:
                SHA-2 Data Integrity Verification for the Secure Shell
                (SSH) Transport Layer Protocol";
         }

         enum hmac-sha2-512 {
           description
             "Enumeration for the 'hmac-sha2-512' algorithm. Section 2";
           reference
             "RFC 6668:
                SHA-2 Data Integrity Verification for the Secure Shell
                (SSH) Transport Layer Protocol";
         }
       }

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       description
         "An enumeration for SSH mac algorithms.";
     }

   }

   <CODE ENDS>

A.3.  Initial Module for the "Public Key Algorithm Names" Registry

   Following are the complete contents to the initial IANA-maintained
   YANG module.  Please note that the date "2024-03-16" reflects the day
   on which the extraction occurred.  Applications SHOULD use the IANA-
   maintained module, not the module defined in this draft.

   This YANG module has normative references [RFC4253], [RFC4462],
   [RFC5656], [RFC6187], [RFC8332], and [RFC8709].

   <CODE BEGINS> file "iana-ssh-public-key-algs@2024-03-16.yang"

   module iana-ssh-public-key-algs {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-ssh-public-key-algs";
     prefix sshpka;

     organization
       "Internet Assigned Numbers Authority (IANA)";

     contact
       "Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America
        Tel:    +1 310 301 5800
        Email:  iana@iana.org";

     description
       "This module defines enumerations for the public key algorithms
        defined in the 'Public Key Algorithm Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised

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        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        All versions of this module are published by IANA at
        https://www.iana.org/assignments/yang-parameters.";

     revision 2024-03-16 {
       description
         "This initial version of the module was created using
          the script defined in RFC EEEE to reflect the contents
          of the public key algorithms registry maintained by IANA.";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

     typedef ssh-public-key-algorithm {
       type enumeration {

         enum ssh-dss {
           description
             "Enumeration for the 'ssh-dss' algorithm. Section 6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum ssh-rsa {
           description
             "Enumeration for the 'ssh-rsa' algorithm. Section 6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum rsa-sha2-256 {
           description
             "Enumeration for the 'rsa-sha2-256' algorithm. Section 3";
           reference
             "RFC 8332:
                Use of RSA Keys with SHA-256 and SHA-512 in the Secure
                Shell (SSH) Protocol";
         }

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         enum rsa-sha2-512 {
           description
             "Enumeration for the 'rsa-sha2-512' algorithm. Section 3";
           reference
             "RFC 8332:
                Use of RSA Keys with SHA-256 and SHA-512 in the Secure
                Shell (SSH) Protocol";
         }

         enum spki-sign-rsa {
           description
             "Enumeration for the 'spki-sign-rsa' algorithm. Section
              6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum spki-sign-dss {
           description
             "Enumeration for the 'spki-sign-dss' algorithm. Section
              6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum pgp-sign-rsa {
           description
             "Enumeration for the 'pgp-sign-rsa' algorithm. Section
              6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum pgp-sign-dss {
           description
             "Enumeration for the 'pgp-sign-dss' algorithm. Section
              6.6";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum null {
           description
             "Enumeration for the 'null' algorithm. Section 5";

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           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol";
         }

         enum ecdsa-sha2-nistp256 {
           description
             "Enumeration for the 'ecdsa-sha2-nistp256' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-nistp384 {
           description
             "Enumeration for the 'ecdsa-sha2-nistp384' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-nistp521 {
           description
             "Enumeration for the 'ecdsa-sha2-nistp521' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.1 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.1' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'ecdsa-sha2-1.2.840.10045.3.1.1'
              algorithm.";
           reference

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             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.33 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.33' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.26 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.26' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.27 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.27' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.16 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.16' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.36 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.36' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";

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         }

         enum ecdsa-sha2-1.3.132.0.37 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.37' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdsa-sha2-1.3.132.0.38 {
           description
             "Enumeration for the 'ecdsa-sha2-1.3.132.0.38' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum x509v3-ssh-dss {
           description
             "Enumeration for the 'x509v3-ssh-dss' algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ssh-rsa {
           description
             "Enumeration for the 'x509v3-ssh-rsa' algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-rsa2048-sha256 {
           description
             "Enumeration for the 'x509v3-rsa2048-sha256' algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-nistp256 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-nistp256'
              algorithm.";

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           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-nistp384 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-nistp384'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-nistp521 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-nistp521'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.1 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'x509v3-ecdsa-
              sha2-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.33 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";

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         }

         enum x509v3-ecdsa-sha2-1.3.132.0.26 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.27 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.16 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.36 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.37 {
           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum x509v3-ecdsa-sha2-1.3.132.0.38 {

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           description
             "Enumeration for the 'x509v3-ecdsa-sha2-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 6187:
                X.509v3 Certificates for Secure Shell Authentication";
         }

         enum ssh-ed25519 {
           description
             "Enumeration for the 'ssh-ed25519' algorithm.";
           reference
             "RFC 8709:
                Ed25519 and Ed448 Public Key Algorithms for the Secure
                Shell (SSH) Protocol";
         }

         enum ssh-ed448 {
           description
             "Enumeration for the 'ssh-ed448' algorithm.";
           reference
             "RFC 8709:
                Ed25519 and Ed448 Public Key Algorithms for the Secure
                Shell (SSH) Protocol";
         }
       }
       description
         "An enumeration for SSH public key algorithms.";
     }

   }

   <CODE ENDS>

A.4.  Initial Module for the "Key Exchange Method Names" Registry

   Following are the complete contents to the initial IANA-maintained
   YANG module.  Please note that the date "2024-03-16" reflects the day
   on which the extraction occurred.  Applications SHOULD use the IANA-
   maintained module, not the module defined in this draft.

   This YANG module has normative references to [RFC4419], [RFC4432],
   [RFC5656], [RFC8268], [RFC8308], [RFC8731], [RFC8732].

   <CODE BEGINS> file "iana-ssh-key-exchange-algs@2024-03-16.yang"

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   module iana-ssh-key-exchange-algs {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:iana-ssh-key-exchange-algs";
     prefix sshkea;

     organization
       "Internet Assigned Numbers Authority (IANA)";

     contact
       "Postal: ICANN
                12025 Waterfront Drive, Suite 300
                Los Angeles, CA  90094-2536
                United States of America
        Tel:    +1 310 301 5800
        Email:  iana@iana.org";

     description
       "This module defines enumerations for the key exchange algorithms
        defined in the 'Key Exchange Method Names' sub-registry of the
        'Secure Shell (SSH) Protocol Parameters' registry maintained
        by IANA.

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

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        The initial version of this YANG module is part of RFC EEEE
        (https://www.rfc-editor.org/info/rfcEEEE); see the RFC
        itself for full legal notices.

        All versions of this module are published by IANA at
        https://www.iana.org/assignments/yang-parameters.";

     revision 2024-03-16 {
       description
         "This initial version of the module was created using
          the script defined in RFC EEEE to reflect the contents
          of the key exchange algorithms registry maintained by IANA.";
       reference
         "RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
     }

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     typedef ssh-key-exchange-algorithm {
       type enumeration {

         enum diffie-hellman-group-exchange-sha1 {
           status deprecated;
           description
             "Enumeration for the 'diffie-hellman-group-exchange-sha1'
              algorithm. Section 4.1";
           reference
             "RFC 4419:
                Diffie-Hellman Group Exchange for the Secure Shell
                (SSH) Transport Layer Protocol
          RFC 8270:
                Increase the Secure Shell Minimum Recommended Diffie-
                Hellman Modulus Size to 2048 Bits";
         }

         enum diffie-hellman-group-exchange-sha256 {
           description
             "Enumeration for the 'diffie-hellman-group-exchange-sha256'
              algorithm. Section 4.2";
           reference
             "RFC 4419:
                Diffie-Hellman Group Exchange for the Secure Shell
                (SSH) Transport Layer Protocol
          RFC 8270:
                Increase the Secure Shell Minimum Recommended Diffie-
                Hellman Modulus Size to 2048 Bits";
         }

         enum diffie-hellman-group1-sha1 {
           status deprecated;
           description
             "Enumeration for the 'diffie-hellman-group1-sha1'
              algorithm. Section 8.1";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

         enum diffie-hellman-group14-sha1 {
           description
             "Enumeration for the 'diffie-hellman-group14-sha1'
              algorithm. Section 8.2";
           reference
             "RFC 4253:
                The Secure Shell (SSH) Transport Layer Protocol";
         }

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         enum diffie-hellman-group14-sha256 {
           description
             "Enumeration for the 'diffie-hellman-group14-sha256'
              algorithm.";
           reference
             "RFC 8268:
                More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                Key Exchange (KEX) Groups for Secure Shell (SSH)";
         }

         enum diffie-hellman-group15-sha512 {
           description
             "Enumeration for the 'diffie-hellman-group15-sha512'
              algorithm.";
           reference
             "RFC 8268:
                More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                Key Exchange (KEX) Groups for Secure Shell (SSH)";
         }

         enum diffie-hellman-group16-sha512 {
           description
             "Enumeration for the 'diffie-hellman-group16-sha512'
              algorithm.";
           reference
             "RFC 8268:
                More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                Key Exchange (KEX) Groups for Secure Shell (SSH)";
         }

         enum diffie-hellman-group17-sha512 {
           description
             "Enumeration for the 'diffie-hellman-group17-sha512'
              algorithm.";
           reference
             "RFC 8268:
                More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                Key Exchange (KEX) Groups for Secure Shell (SSH)";
         }

         enum diffie-hellman-group18-sha512 {
           description
             "Enumeration for the 'diffie-hellman-group18-sha512'
              algorithm.";
           reference
             "RFC 8268:
                More Modular Exponentiation (MODP) Diffie-Hellman (DH)
                Key Exchange (KEX) Groups for Secure Shell (SSH)";

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         }

         enum ecdh-sha2-nistp256 {
           description
             "Enumeration for the 'ecdh-sha2-nistp256' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-nistp384 {
           description
             "Enumeration for the 'ecdh-sha2-nistp384' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-nistp521 {
           description
             "Enumeration for the 'ecdh-sha2-nistp521' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.1 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.1' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'ecdh-sha2-1.2.840.10045.3.1.1'
              algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

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         enum ecdh-sha2-1.3.132.0.33 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.33' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.26 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.26' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.27 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.27' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.16 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.16' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.36 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.36' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.37 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.37' algorithm.";

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           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecdh-sha2-1.3.132.0.38 {
           description
             "Enumeration for the 'ecdh-sha2-1.3.132.0.38' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum ecmqv-sha2 {
           description
             "Enumeration for the 'ecmqv-sha2' algorithm.";
           reference
             "RFC 5656:
                Elliptic Curve Algorithm Integration in the Secure
                Shell Transport Layer";
         }

         enum gss-group1-sha1-nistp256 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-nistp256'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-nistp384 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-nistp384'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the

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                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-nistp521 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-nistp521'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.2.840.10045.3.1.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.2.840.10045.3.1.1'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface

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                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.33 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.26 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.27 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-group1-sha1-1.3.132.0.16 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.36 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.37 {
           status deprecated;
           description
             "Enumeration for the 'gss-group1-sha1-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group1-sha1-1.3.132.0.38 {
           status deprecated;
           description

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             "Enumeration for the 'gss-group1-sha1-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-nistp256 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-nistp256'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-nistp384 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-nistp384'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-nistp521 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-nistp521'
              algorithm.";
           reference

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             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.2.840.10045.3.1.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.2.840.10045.3.1.1'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.33 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the

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                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.26 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.27 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.16 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface

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                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.36 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.37 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha1-1.3.132.0.38 {
           status deprecated;
           description
             "Enumeration for the 'gss-group14-sha1-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-gex-sha1-nistp256 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-nistp256' algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-nistp384 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-nistp384' algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-nistp521 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-nistp521' algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.1'
              algorithm.";
           reference

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             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.2.840.10045.3.1.1 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.2.840.10045.3.1.1'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.33 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.26 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the

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                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.27 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.16 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.36 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface

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                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.37 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-gex-sha1-1.3.132.0.38 {
           status deprecated;
           description
             "Enumeration for the 'gss-gex-sha1-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol
          RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss- {
           description
             "Enumeration for the 'gss-' algorithm. Section 2.6";
           reference
             "RFC 4462:
                Generic Security Service Application Program Interface
                (GSS-API) Authentication and Key Exchange for the
                Secure Shell (SSH) Protocol";
         }

         enum rsa1024-sha1 {
           status obsolete;
           description
             "Enumeration for the 'rsa1024-sha1' algorithm.";
           reference

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             "RFC 4432:
                RSA Key Exchange for the Secure Shell (SSH) Transport
                Layer Protocol";
         }

         enum rsa2048-sha256 {
           description
             "Enumeration for the 'rsa2048-sha256' algorithm.";
           reference
             "RFC 4432:
                RSA Key Exchange for the Secure Shell (SSH) Transport
                Layer Protocol";
         }

         enum ext-info-s {
           description
             "Enumeration for the 'ext-info-s' algorithm. Section 2";
           reference
             "RFC 8308:
                Extension Negotiation in the Secure Shell (SSH)
                Protocol";
         }

         enum ext-info-c {
           description
             "Enumeration for the 'ext-info-c' algorithm. Section 2";
           reference
             "RFC 8308:
                Extension Negotiation in the Secure Shell (SSH)
                Protocol";
         }

         enum gss-group14-sha256-nistp256 {
           description
             "Enumeration for the 'gss-group14-sha256-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-nistp384 {
           description
             "Enumeration for the 'gss-group14-sha256-nistp384'
              algorithm.";
           reference
             "RFC 8732:

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                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-nistp521 {
           description
             "Enumeration for the 'gss-group14-sha256-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              group14-sha256-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.26'
              algorithm.";

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           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-group14-sha256-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group14-sha256-1.3.132.0.38 {
           description

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             "Enumeration for the 'gss-group14-sha256-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-nistp256 {
           description
             "Enumeration for the 'gss-group15-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-nistp384 {
           description
             "Enumeration for the 'gss-group15-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-nistp521 {
           description
             "Enumeration for the 'gss-group15-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-group15-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              group15-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";

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         }

         enum gss-group15-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group15-sha512-1.3.132.0.38 {
           description
             "Enumeration for the 'gss-group15-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-nistp256 {
           description
             "Enumeration for the 'gss-group16-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-nistp384 {
           description
             "Enumeration for the 'gss-group16-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:

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                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-nistp521 {
           description
             "Enumeration for the 'gss-group16-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              group16-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.26'
              algorithm.";

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           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-group16-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group16-sha512-1.3.132.0.38 {
           description

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             "Enumeration for the 'gss-group16-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-nistp256 {
           description
             "Enumeration for the 'gss-group17-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-nistp384 {
           description
             "Enumeration for the 'gss-group17-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-nistp521 {
           description
             "Enumeration for the 'gss-group17-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-group17-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              group17-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";

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         }

         enum gss-group17-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group17-sha512-1.3.132.0.38 {
           description
             "Enumeration for the 'gss-group17-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-nistp256 {
           description
             "Enumeration for the 'gss-group18-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-nistp384 {
           description
             "Enumeration for the 'gss-group18-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:

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                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-nistp521 {
           description
             "Enumeration for the 'gss-group18-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              group18-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.26'
              algorithm.";

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           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-group18-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-group18-sha512-1.3.132.0.38 {
           description

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             "Enumeration for the 'gss-group18-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-nistp256 {
           description
             "Enumeration for the 'gss-nistp256-sha256-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-nistp384 {
           description
             "Enumeration for the 'gss-nistp256-sha256-nistp384'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-nistp521 {
           description
             "Enumeration for the 'gss-nistp256-sha256-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-nistp256-sha256-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              nistp256-sha256-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";

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         }

         enum gss-nistp256-sha256-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp256-sha256-1.3.132.0.38 {
           description
             "Enumeration for the 'gss-nistp256-sha256-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-nistp256 {
           description
             "Enumeration for the 'gss-nistp384-sha384-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-nistp384 {
           description
             "Enumeration for the 'gss-nistp384-sha384-nistp384'
              algorithm.";
           reference
             "RFC 8732:

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                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-nistp521 {
           description
             "Enumeration for the 'gss-nistp384-sha384-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              nistp384-sha384-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.26'
              algorithm.";

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           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp384-sha384-1.3.132.0.38 {
           description

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             "Enumeration for the 'gss-nistp384-sha384-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-nistp256 {
           description
             "Enumeration for the 'gss-nistp521-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-nistp384 {
           description
             "Enumeration for the 'gss-nistp521-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-nistp521 {
           description
             "Enumeration for the 'gss-nistp521-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-nistp521-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              nistp521-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";

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         }

         enum gss-nistp521-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-nistp521-sha512-1.3.132.0.38 {
           description
             "Enumeration for the 'gss-nistp521-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-nistp256 {
           description
             "Enumeration for the 'gss-curve25519-sha256-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-nistp384 {
           description
             "Enumeration for the 'gss-curve25519-sha256-nistp384'
              algorithm.";
           reference
             "RFC 8732:

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                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-nistp521 {
           description
             "Enumeration for the 'gss-curve25519-sha256-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              curve25519-sha256-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.26'
              algorithm.";

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           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve25519-sha256-1.3.132.0.38 {
           description

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             "Enumeration for the 'gss-curve25519-sha256-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-nistp256 {
           description
             "Enumeration for the 'gss-curve448-sha512-nistp256'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-nistp384 {
           description
             "Enumeration for the 'gss-curve448-sha512-nistp384'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-nistp521 {
           description
             "Enumeration for the 'gss-curve448-sha512-nistp521'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.1 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.1'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

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         enum gss-curve448-sha512-1.2.840.10045.3.1.1 {
           description
             "Enumeration for the 'gss-
              curve448-sha512-1.2.840.10045.3.1.1' algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.33 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.33'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.26 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.26'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.27 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.27'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.16 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.16'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";

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         }

         enum gss-curve448-sha512-1.3.132.0.36 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.36'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.37 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.37'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum gss-curve448-sha512-1.3.132.0.38 {
           description
             "Enumeration for the 'gss-curve448-sha512-1.3.132.0.38'
              algorithm.";
           reference
             "RFC 8732:
                Generic Security Service Application Program Interface
                (GSS-API) Key Exchange with SHA-2";
         }

         enum curve25519-sha256 {
           description
             "Enumeration for the 'curve25519-sha256' algorithm.";
           reference
             "RFC 8731:
                Secure Shell (SSH) Key Exchange Method Using
                Curve25519 and Curve448";
         }

         enum curve448-sha512 {
           description
             "Enumeration for the 'curve448-sha512' algorithm.";
           reference
             "RFC 8731:
                Secure Shell (SSH) Key Exchange Method Using
                Curve25519 and Curve448";

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         }
       }
       description
         "An enumeration for SSH key exchange algorithms.";
     }

   }

   <CODE ENDS>

Appendix B.  Change Log

B.1.  00 to 01

   *  Noted that '0.0.0.0' and '::' might have special meanings.

   *  Renamed "keychain" to "keystore".

B.2.  01 to 02

   *  Removed the groupings 'listening-ssh-client-grouping' and
      'listening-ssh-server-grouping'.  Now modules only contain the
      transport-independent groupings.

   *  Simplified the "client-auth" part in the ietf-ssh-client module.
      It now inlines what it used to point to keystore for.

   *  Added cipher suites for various algorithms into new 'ietf-ssh-
      common' module.

B.3.  02 to 03

   *  Removed 'RESTRICTED' enum from 'password' leaf type.

   *  Added a 'must' statement to container 'server-auth' asserting that
      at least one of the various auth mechanisms must be specified.

   *  Fixed description statement for leaf 'trusted-ca-certs'.

B.4.  03 to 04

   *  Change title to "YANG Groupings for SSH Clients and SSH Servers"

   *  Added reference to RFC 6668

   *  Added RFC 8174 to Requirements Language Section.

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   *  Enhanced description statement for ietf-ssh-server's "trusted-ca-
      certs" leaf.

   *  Added mandatory true to ietf-ssh-client's "client-auth" 'choice'
      statement.

   *  Changed the YANG prefix for module ietf-ssh-common from 'sshcom'
      to 'sshcmn'.

   *  Removed the compression algorithms as they are not commonly
      configurable in vendors' implementations.

   *  Updating descriptions in transport-params-grouping and the
      servers's usage of it.

   *  Now tree diagrams reference ietf-netmod-yang-tree-diagrams

   *  Updated YANG to use typedefs around leafrefs to common keystore
      paths

   *  Now inlines key and certificates (no longer a leafref to keystore)

B.5.  04 to 05

   *  Merged changes from co-author.

B.6.  05 to 06

   *  Updated to use trust anchors from trust-anchors draft (was
      keystore draft)

   *  Now uses new keystore grouping enabling asymmetric key to be
      either locally defined or a reference to the keystore.

B.7.  06 to 07

   *  factored the ssh-[client|server]-groupings into more reusable
      groupings.

   *  added if-feature statements for the new "ssh-host-keys" and
      "x509-certificates" features defined in draft-ietf-netconf-trust-
      anchors.

B.8.  07 to 08

   *  Added a number of compatibility matrices to Section 5 (thanks
      Frank!)

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   *  Clarified that any configured "host-key-alg" values need to be
      compatible with the configured private key.

B.9.  08 to 09

   *  Updated examples to reflect update to groupings defined in the
      keystore -09 draft.

   *  Add SSH keepalives features and groupings.

   *  Prefixed top-level SSH grouping nodes with 'ssh-' and support
      mashups.

   *  Updated copyright date, boilerplate template, affiliation, and
      folding algorithm.

B.10.  09 to 10

   *  Reformatted the YANG modules.

B.11.  10 to 11

   *  Reformatted lines causing folding to occur.

B.12.  11 to 12

   *  Collapsed all the inner groupings into the top-level grouping.

   *  Added a top-level "demux container" inside the top-level grouping.

   *  Added NACM statements and updated the Security Considerations
      section.

   *  Added "presence" statements on the "keepalive" containers, as was
      needed to address a validation error that appeared after adding
      the "must" statements into the NETCONF/RESTCONF client/server
      modules.

   *  Updated the boilerplate text in module-level "description"
      statement to match copyeditor convention.

B.13.  12 to 13

   *  Removed the "demux containers", floating the nacm:default-deny-
      write to each descendant node, and adding a note to model
      designers regarding the potential need to add their own demux
      containers.

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   *  Fixed a couple references (section 2 --> section 3)

   *  In the server model, replaced <client-cert-auth> with <client-
      authentication> and introduced 'inline-or-external' choice.

B.14.  13 to 14

   *  Updated to reflect changes in trust-anchors drafts (e.g., s/trust-
      anchors/truststore/g + s/pinned.//)

B.15.  14 to 15

   *  Updated examples to reflect ietf-crypto-types change (e.g.,
      identities --> enumerations)

   *  Updated "server-authentication" and "client-authentication" nodes
      from being a leaf of type "ts:host-keys-ref" or "ts:certificates-
      ref" to a container that uses "ts:inline-or-truststore-host-keys-
      grouping" or "ts:inline-or-truststore-certs-grouping".

B.16.  15 to 16

   *  Removed unnecessary if-feature statements in the -client and
      -server modules.

   *  Cleaned up some description statements in the -client and -server
      modules.

   *  Fixed a canonical ordering issue in ietf-ssh-common detected by
      new pyang.

B.17.  16 to 17

   *  Removed choice inline-or-external by removing the 'external' case
      and flattening the 'local' case and adding a "local-users-
      supported" feature.

   *  Updated examples to include the "*-key-format" nodes.

   *  Augmented-in "must" expressions ensuring that locally-defined
      public-key-format are "ct:ssh-public-key-format" (must expr for
      ref'ed keys are TBD).

B.18.  17 to 18

   *  Removed leaf-list 'other' from ietf-ssh-server.

   *  Removed unused 'external-client-auth-supported' feature.

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   *  Added features client-auth-password, client-auth-hostbased, and
      client-auth-none.

   *  Renamed 'host-key' to 'public-key' for when refering to
      'publickey' based auth.

   *  Added new feature-protected 'hostbased' and 'none' to the 'user'
      node's config.

   *  Added new feature-protected 'hostbased' and 'none' to the 'client-
      identity' node's config.

   *  Updated examples to reflect new "bag" addition to truststore.

   *  Refined truststore/keystore groupings to ensure the key formats
      "must" be particular values.

   *  Switched to using truststore's new "public-key" bag (instead of
      separate "ssh-public-key" and "raw-public-key" bags.

   *  Updated client/server examples to cover ALL cases (local/ref x
      cert/raw-key/psk).

B.19.  18 to 19

   *  Updated the "keepalives" containers to address Michal Vasko's
      request to align with RFC 8071.

   *  Removed algorithm-mapping tables from the "SSH Common Model"
      section

   *  Removed 'algorithm' node from examples.

   *  Added feature "userauth-publickey"

   *  Removed "choice auth-type", as auth-types are not exclusive.

   *  Renamed both "client-certs" and "server-certs" to "ee-certs"

   *  Switch "must" to assert the public-key-format is "subject-public-
      key-info-format" when certificates are used.

   *  Added a "Note to Reviewers" note to first page.

B.20.  19 to 20

   *  Added a "must 'public-key or password or hostbased or none or
      certificate'" statement to the "user" node in ietf-ssh-client

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   *  Expanded "Data Model Overview section(s) [remove "wall" of tree
      diagrams].

   *  Moved the "ietf-ssh-common" module section to proceed the other
      two module sections.

   *  Updated the Security Considerations section.

B.21.  20 to 21

   *  Updated examples to reflect new "cleartext-" prefix in the crypto-
      types draft.

B.22.  21 to 22

   *  Cleaned up the SSH-client examples (i.e., removing FIXMEs)

   *  Fixed issues found by the SecDir review of the "keystore" draft.

   *  Updated the "ietf-ssh-client" module to use the new "password-
      grouping" grouping from the "crypto-types" module.

B.23.  22 to 23

   *  Addressed comments raised by YANG Doctor in the ct/ts/ks drafts.

B.24.  23 to 24

   *  Removed the 'supported-authentication-methods' from {grouping ssh-
      server-grouping}/client-authentication.

   *  Added XML-comment above examples explaining the reason for the
      unexepected top-most element's presence.

   *  Added RFC-references to various 'feature' statements.

   *  Renamed "credentials" to "authentication methods"

   *  Renamed "client-auth-*" to "userauth-*"

   *  Renamed "client-identity-*" to "userauth-*"

   *  Fixed nits found by YANG Doctor reviews.

   *  Aligned modules with `pyang -f` formatting.

   *  Added a 'Contributors' section.

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B.25.  24 to 25

   *  Moved algorithms in ietf-ssh-common (plus more) to IANA-maintained
      modules

   *  Added "config false" lists for algorithms supported by the server.

   *  Renamed "{ietf-ssh-client}userauth-*" to "client-ident-*"

   *  Renamed "{ietf-ssh-server}userauth-*" to "local-user-auth-*"

   *  Fixed issues found during YANG Doctor review.

   *  Fixed issues found during Secdir review.

B.26.  25 to 26

   *  Replaced "base64encodedvalue==" with "BASE64VALUE=" in examples.

   *  Minor editorial nits

B.27.  26 to 27

   *  Fixed up the 'WG Web' and 'WG List' lines in YANG module(s)

   *  Fixed up copyright (i.e., s/Simplified/Revised/) in YANG module(s)

   *  Created identityref-based typedefs for each of the four IANA alg
      identity bases.

   *  Added ietf-ssh-common:generate-asymmetric-key-pair() RPC for
      discussion.

B.28.  27 to 28

   *  Fixed example to not have line-returns around "identity" values.

   *  Fixed examples to not include "xmlns:algs".

   *  Added an example for the "generate-asymmetric-key-pair" RPC.

B.29.  28 to 29

   *  Updated modules to IANA-maintained modules in Appendix A to
      2022-06-16.

B.30.  29 to 30

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   *  Fixed 'must' expressions.

   *  Added missing 'revision' statement.

B.31.  30 to 31

   *  Updated per Shepherd reviews impacting the suite of drafts.

B.32.  31 to 32

   *  Updated per Shepherd reviews impacting the suite of drafts.

B.33.  32 to 33

   *  Updated per Tom Petch review.

   *  Updated Intro to clarify what "generic" means.

   *  Added RPC-reply for 'generate-asymmetric-key-pair' example.

   *  Added references to RFC 4251 and FIPS 186-6.

   *  Added "if-feature ct:encrypted-private-keys" for "case cleartext".

B.34.  33 to 34

   *  Addresses AD review comments.

   *  Added note to Editor to fix line foldings.

   *  Introduction now more clearly identifies the "ietf-" and "iana-"
      modules defined.

   *  Clarified that the modules, when implemented, do not define any
      protocol-accessible nodes.

   *  Clarified that IANA may deprecate and/or obsolete identities over
      time.

   *  Added Security Consideration for the "generate-asymmetric-key-
      pair" RPC.

   *  Added Security Considerations text to also look a SC-section from
      imported modules.

   *  Fixed private-key "must" expressions to not require public-key
      nodes to be present.

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   *  Renamed leaf from "bits" to "num-bits".

   *  Renamed leaf from "hide" to "hidden".

   *  Added container "private-key-encoding" to wrap existing choice.

   *  Removed "public-key-format" and "public-key" nodes from examples.

B.35.  34 to 35

   *  Addresses AD review by Rob Wilton.

B.36.  35 to 36

   *  Addresses 1st-round of IESG reviews.

B.37.  36 to 38

   *  Addresses issues found in OpsDir review of the ssh-client-server
      draft.

   *  Replaced identities with enums in the IANA modules.

   *  Updated per Elwyn Davies' Gen-ART review.

   *  Updated Introduction to read more like the Abstract

   *  Add refs to where the 'operational' and 'system' datastores are
      defined.

   *  Updated Editor-notes to NOT remove the script (just remove the
      initial IANA modules)

   *  Renamed Security Considerations section s/Template for/
      Considerations for/

   *  s/defines/presents/ in a few places.

   *  Renamed script from 'gen-identities.py' to 'gen-yang-modules.py'

   *  Removed the removeInRFC="true" attribute in Appendix sections

B.38.  38 to 39

   *  Address IESG review comments.

B.39.  39 to 40

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   *  Updated to reflect comments from Paul Wouters.

   *  Fixed the "generate-asymmetric-key-pair" RPC to return the
      location to where hidden keys are created.

Acknowledgements

   The authors would like to thank the following for lively discussions
   on list and in the halls (ordered by first name): Alan Luchuk, Andy
   Bierman, Balázs Kovács, Barry Leiba, Benoit Claise, Bert Wijnen,
   David Lamparter, Elwyn Davies, Gary Wu, Jürgen Schönwälder, Ladislav
   Lhotka, Liang Xia, Martin Björklund, Martin Thomson, Mehmet Ersue,
   Michal Vaško, Murray Kucherawy, Paul Wouters, Per Andersson, Phil
   Shafer, Qin Wun, Radek Krejci, Rob Wilton, Roman Danyliw, Russ
   Housley, Sean Turner, Tom Petch, Thomas Martin, and Warren Kumari.

Contributors

   Special acknowledgement goes to Gary Wu for his work on the "ietf-
   ssh-common" module.

Author's Address

   Kent Watsen
   Watsen Networks
   Email: kent+ietf@watsen.net

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