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<rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="std" consensus="true" ipr="trust200902" submissionType="IETF" docName="draft-ietf-netconf-crypto-types-34" number="9640" obsoletes="" updates="" tocInclude="true" symRefs="true" sortRefs="true" version="3">
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  <front>
    <title abbrev="YANG Data Types and Groupings for Crypto">YANG Data Types and Groupings for Cryptography</title>
    <seriesInfo name="Internet-Draft" value="draft-ietf-netconf-crypto-types-34"/> name="RFC" value="9640"/>
    <author initials="K." surname="Watsen" fullname="Kent Watsen">
      <organization>Watsen Networks</organization>
      <address>
        <email>kent+ietf@watsen.net</email>
      </address>
    </author>
    <date/>
    <area>Operations</area>
    <workgroup>NETCONF Working Group</workgroup>
    <date month="September" year="2024"/>
    <area>OPS</area>
    <workgroup>netconf</workgroup>
    <abstract>
      <t>This document presents a YANG 1.1 (RFC 7950) module defining identities,
          typedefs, and groupings useful to cryptographic applications.</t>
    </abstract>
    <note>
      <name>Editorial Note (To be removed by RFC Editor)</name>
      <t>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.</t>
      <t>Artwork in this document contains shorthand references to drafts in
        progress.  Please apply the following replacements:
      </t>
      <ul spacing="normal">
        <li>
          <tt>AAAA</tt> --&gt; the assigned RFC value for this draft</li>
      </ul>
      <t>Artwork in this document contains placeholder values for the date
        of publication of this draft.  Please apply the following replacement:
      </t>
      <ul spacing="normal">
        <li>
          <tt>2024-03-16</tt> --&gt; the publication date of this draft</li>
      </ul>
      <t>The "Relation to other RFCs" section <xref target="collective-effort"/> 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.</t>
      <t>The "Relation to other RFCs" section <xref target="collective-effort"/> 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.</t>
      <t>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.</t>
      <t>The following Appendix section is to be removed prior to publication:
      </t>
      <ul spacing="normal">
        <li>
          <xref target="change-log"/>.  Change Log</li>
      </ul>
    </note>
  </front>
  <middle>
    <section>
      <name>Introduction</name>
      <t>This document presents a YANG 1.1 <xref target="RFC7950"/>
          module defining identities, typedefs, and groupings useful to
          cryptographic applications.</t>
      <section anchor="collective-effort">
        <name>Relation to other Other RFCs</name>
        <t>This document presents one or more a YANG modules module <xref target="RFC7950"/>
            that are is part of a collection of RFCs that work together
            to, ultimately, support the configuration of both the clients
            and servers of both the NETCONF Network Configuration Protocol (NETCONF) <xref target="RFC6241"/> and
            RESTCONF <xref target="RFC8040"/> protocols.</t> target="RFC8040"/>.</t>
        <t> The dependency relationship between the primary YANG groupings
            defined in the various RFCs is presented in the below diagram.
            In some cases, a draft document may define secondary groupings that
            introduce dependencies not illustrated in the diagram.
            The labels in the diagram are a shorthand name names for the defining
            RFC.
            RFCs.  The citation reference references for the shorthand name is names are provided below
            the diagram.</t>
        <t>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.</t>
        <artwork><![CDATA[
        <artwork align="center"><![CDATA[
                               crypto-types
                                 ^      ^
                                /        \
                               /          \
                      truststore         keystore
                       ^     ^             ^  ^
                       |     +---------+   |  |
                       |               |   |  |
                       |      +------------+  |
tcp-client-server      |     /         |      |
   ^    ^        ssh-client-server     |      |
   |    |           ^            tls-client-server
   |    |           |              ^     ^        http-client-server
   |    |           |              |     |                 ^
   |    |           |        +-----+     +---------+       |
   |    |           |        |                     |       |
   |    +-----------|--------|--------------+      |       |
   |                |        |              |      |       |
   +-----------+    |        |              |      |       |
               |    |        |              |      |       |
               |    |        |              |      |       |
            netconf-client-server       restconf-client-server

]]></artwork>
        <!-- RFC Editor: is there anyway to flush-left the table in PDF/HTML views? -->

          <table>
          <name>Label
          <name>Labels in Diagram to RFC Mapping</name>
          <tbody>
            <tr>
              <th>Label in Diagram</th>
              <th>Originating RFC</th>
              <th>Reference</th>
            </tr>
            <tr>
              <td>crypto-types</td>
              <td>
                <xref target="I-D.ietf-netconf-crypto-types"/></td>
                RFC 9640</td>
            </tr>
            <tr>
              <td>truststore</td>
              <td>
                <xref target="I-D.ietf-netconf-trust-anchors"/></td> target="RFC9641"/></td>
            </tr>
            <tr>
              <td>keystore</td>
              <td>
                <xref target="I-D.ietf-netconf-keystore"/></td> target="RFC9642"/></td>
            </tr>
            <tr>
              <td>tcp-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-tcp-client-server"/></td> target="RFC9643"/></td>
            </tr>
            <tr>
              <td>ssh-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-ssh-client-server"/></td> target="RFC9644"/></td>
            </tr>
            <tr>
              <td>tls-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-tls-client-server"/></td> target="RFC9645"/></td>
            </tr>
            <tr>
              <td>http-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-http-client-server"/></td>
            </tr>
            <tr>
              <td>netconf-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-netconf-client-server"/></td>
            </tr>
            <tr>
              <td>restconf-client-server</td>
              <td>
                <xref target="I-D.ietf-netconf-restconf-client-server"/></td>
            </tr>
          </tbody>
        </table>
      </section>
      <section>
        <name>Specification Language</name>
        <t>The
        <t>
    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
            NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
            "MAY", "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL
    NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "OPTIONAL" "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
    described in BCP 14 BCP&nbsp;14 <xref target="RFC2119"/> <xref target="RFC8174"/>
    when, and only when, they appear in all capitals, as shown here.</t> here.
        </t>
      </section>
      <section>
        <name>Adherence to the NMDA</name>
        <t>This document is compliant with the Network Management Datastore
            Architecture (NMDA) <xref target="RFC8342"/>. It does not define
            any protocol accessible protocol-accessible nodes that are "config false".</t>
      </section>
      <section>
        <name>Conventions</name>
        <t>Various examples in this document use "BASE64VALUE=" as a
            placeholder value for binary data that has been base64
            encoded (per <xref section="9.8" sectionFormat="of" target="RFC7950"/>).  This
            placeholder value is used because real base64 encoded base64-encoded structures
            are often many lines long and hence distracting to the example
        being presented.</t>
	<t>Various examples in this document use the XML
	<xref target="W3C.REC-xml-20081126"/> encoding. Other encodings, such as JSON <xref target="RFC8259"/>,
  could alternatively be used.</t>
	<t>Various examples in this document contain long lines that may be folded,
   as described in <xref target="RFC8792"/>.</t>
      </section>
    </section>
    <section>
      <name>The "ietf-crypto-types" Module</name>
      <t>This section defines a YANG 1.1 <xref target="RFC7950"/> module called
          "ietf-crypto-types".  A high-level overview of the module is provided in
          <xref target="crypto-types-overview"/>. Examples illustrating the module's use
          are provided in <xref target="crypto-types-examples">Examples</xref>. target="crypto-types-examples"/>. The YANG
          module itself is defined in <xref target="crypto-types-yang-module"/>.</t>
      <section anchor="crypto-types-overview">
        <name>Data Model Overview</name>
        <t>This section provides an overview of the "ietf-crypto-types" module
              in terms of its features, identities, typedefs, and groupings.</t>
        <section anchor="features" toc="exclude">
          <name>Features</name>
          <t>The following diagram lists all the "feature" statements
              defined in the "ietf-crypto-types" module:</t>
          <artwork><![CDATA[
          <sourcecode type="yangtree"><![CDATA[
Features:
  +-- one-symmetric-key-format
  +-- one-asymmetric-key-format
  +-- symmetrically-encrypted-value-format
  +-- asymmetrically-encrypted-value-format
  +-- cms-enveloped-data-format
  +-- cms-encrypted-data-format
  +-- p10-csr-format
  +-- csr-generation
  +-- certificate-expiration-notification
  +-- cleartext-passwords
  +-- encrypted-passwords
  +-- cleartext-symmetric-keys
  +-- hidden-symmetric-keys
  +-- encrypted-symmetric-keys
  +-- cleartext-private-keys
  +-- hidden-private-keys
  +-- encrypted-private-keys
]]></artwork>
          <!--<aside>-->
  ]]></sourcecode>
              <t>The diagram above uses syntax that is similar to but not
                the same as that in <xref target="RFC8340"/>.</t>
          <!--</aside>-->
          </section>
        <section anchor="identities" toc="exclude">
          <name>Identities</name>
          <t>The following diagram illustrates the hierarchical relationship
              amongst the "identity" statements defined in the "ietf-crypto-types"
              module:</t>
          <artwork><![CDATA[
          <sourcecode type="yangtree"><![CDATA[
Identities:
  +-- public-key-format
  |  +-- subject-public-key-info-format
  |  +-- ssh-public-key-format
  +-- private-key-format
  |  +-- rsa-private-key-format
  |  +-- ec-private-key-format
  |  +-- one-asymmetric-key-format
  |            {one-asymmetric-key-format}?
  +-- symmetric-key-format
  |  +-- octet-string-key-format
  |  +-- one-symmetric-key-format
  |            {one-symmetric-key-format}?
  +-- encrypted-value-format
  |  +-- symmetrically-encrypted-value-format
  |  |  |      {symmetrically-encrypted-value-format}?
  |  |  +-- cms-encrypted-data-format
  |  |         {cms-encrypted-data-format}?
  |  +-- asymmetrically-encrypted-value-format
  |     |      {asymmetrically-encrypted-value-format}?
  |     +-- cms-enveloped-data-format
  |            {cms-enveloped-data-format}?
  +-- csr-format
        +-- p10-csr-format {p10-csr-format?}
]]></artwork>
          <!--<aside>-->
]]></sourcecode>
              <t>The diagram above uses syntax that is similar to but not
                the same as that in <xref target="RFC8340"/>.</t>
          <!--</aside>-->
            <t>Comments:</t>
          <ul>
            <li>The diagram shows that there are five base identities.  The
                first three identities are used to indicate the format for the
                key data, while the fourth identity is used to indicate the format
                for encrypted values.  The fifth identity is used to indicate the
                format for a certificate signing request. request (CSR).  The base identities are
                "abstract", in the object oriented programming sense, in that
                they only define a "class" of formats, rather than a specific
                format.</li>
            <li>The various terminal identities define specific encoding
                formats.  The derived identities defined in this document are
                sufficient for the effort described in <xref target="collective-effort"/>
                but, target="collective-effort"/>,
                but by nature of them being identities, additional derived
                identities MAY <bcp14>MAY</bcp14> be defined by future efforts.</li>
            <li>Identities used to specify uncommon formats are enabled by
                "feature" statements, allowing applications to support them
                when needed.</li>
          </ul>
        </section>
        <section anchor="typedefs" toc="exclude">
          <name>Typedefs</name>
          <t>The following diagram illustrates the relationship amongst the
              "typedef" statements defined in the "ietf-crypto-types" module:</t>
          <artwork><![CDATA[
          <sourcecode type="yangtree"><![CDATA[
Typedefs:
  binary
    +-- csr-info
    +-- csr
    +-- x509
    |  +-- trust-anchor-cert-x509
    |  +-- end-entity-cert-x509
    +-- crl
    +-- ocsp-request
    +-- ocsp-response
    +-- cms
       +-- data-content-cms
       +-- signed-data-cms
       |  +-- trust-anchor-cert-cms
       |  +-- end-entity-cert-cms
       +-- enveloped-data-cms
       +-- digested-data-cms
       +-- encrypted-data-cms
       +-- authenticated-data-cms
]]></artwork>
          <!--<aside>-->
]]></sourcecode>
              <t>The diagram above uses syntax that is similar to but not
                the same as that in <xref target="RFC8340"/>.</t>
          <!--</aside>-->
            <t>Comments:</t>
          <ul>
            <li>All the typedefs defined in the "ietf-crypto-types" module
                extend the "binary" type defined in <xref target="RFC7950"/>.</li>
            <li>Additionally, all the typedefs define a type for encoding an ASN.1
                <xref target="ITU.X680.2021"/> structure using DER <xref target="ITU.X690.2021"/>.</li>
            <li>The "trust-anchor-*" and "end-entity-*" typedefs are syntactically
                identical to their base typedefs and only distinguish themselves
                by the expected nature of their content.  These typedefs are
                defined to facilitate common modeling needs.</li>
          </ul>
        </section>
        <section toc="exclude">
          <name>Groupings</name>
          <t>The "ietf-crypto-types" module defines the following "grouping" statements:</t>
          <ul spacing="compact">
            <li>encrypted-value-grouping</li>
            <li>password-grouping</li>
            <li>symmetric-key-grouping</li>
            <li>public-key-grouping</li>
            <li>private-key-grouping</li>
            <li>asymmetric-key-pair-grouping</li>
            <li>certificate-expiration-grouping</li>
            <li>trust-anchor-cert-grouping</li>
            <li>end-entity-cert-grouping</li>
            <li>generate-csr-grouping</li>
            <li>asymmetric-key-pair-with-cert-grouping</li>
            <li>asymmetric-key-pair-with-certs-grouping</li>
          </ul>
          <t>Each of these groupings are presented in the following subsections.</t>
          <section anchor="encrypted-value-grouping">
            <name>The "encrypted-value-grouping" Grouping</name>
            <t>The following tree diagram <xref target="RFC8340"/> illustrates the
                "encrypted-value-grouping" grouping:</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping encrypted-value-grouping:
    +-- encrypted-by
    +-- encrypted-value-format    identityref
    +-- encrypted-value           binary
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>The "encrypted-by" node is an empty container (difficult to
                  see in the diagram) that a consuming module MUST <bcp14>MUST</bcp14> augment key
                  references into.  The "ietf-crypto-types" module is unable to
                  populate this container as the module only defines groupings.
                  <xref target="ct-usage"/> presents an example illustrating
                  a consuming module populating the "encrypted-by" container.</li>
              <li>
                <t>The "encrypted-value" node is the value, value encrypted by the
                    key referenced by the "encrypted-by" node, node and encoded in
                    the format appropriate for the kind of key it was encrypted
                    by.</t>
                <ul>
                  <li>If the value is encrypted by a symmetric key, then the
                      encrypted value is encoded using the format associated with
                      the "symmetrically-encrypted-value-format" identity.</li>
                  <li>If the value is encrypted by an asymmetric key, then the
                      encrypted value is encoded using the format associated with
                      the "asymmetrically-encrypted-value-format" identity.</li>
                </ul>
                <t>See <xref target="identities"/> for information about
                    the "format" identities.</t>
              </li>
            </ul>
          </section>
          <section anchor="password-grouping">
            <name>The "password-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "password-grouping" grouping.  This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping password-grouping:
    +-- (password-type)
       +--:(cleartext-password) {cleartext-passwords}?
       |  +-- cleartext-password?   string
       +--:(encrypted-password) {encrypted-passwords}?
          +-- encrypted-password
             +---u encrypted-value-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>The "password-grouping" enables the configuration of credentials needed to
                  authenticate to a remote system.  The 'ianach:crypt-hash' "ianach:crypt-hash" typedef from
                  <xref target="RFC7317"/> should be used instead when needing to
                  configure a password to authencate authenticate a local account.</li>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "encrypted-value-grouping" grouping is discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
              <li>
                <t>The "choice" statement enables the password data to be cleartext or
                  encrypted, as follows:
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "cleartext-password" node can encode any cleartext value.</li>
                  <li>The "encrypted-password" node's structure node is an instance of the "encrypted-value-grouping" discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
          <section anchor="symmetric-key-grouping">
            <name>The "symmetric-key-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "symmetric-key-grouping" grouping.  This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping symmetric-key-grouping:
    +-- key-format?                      identityref
    +-- (key-type)
       +--:(cleartext-symmetric-key)
       |  +-- cleartext-symmetric-key?   binary
       |          {cleartext-symmetric-keys}?
       +--:(hidden-symmetric-key) {hidden-symmetric-keys}?
       |  +-- hidden-symmetric-key?      empty
       +--:(encrypted-symmetric-key) {encrypted-symmetric-keys}?
          +-- encrypted-symmetric-key
             +---u encrypted-value-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "encrypted-value-grouping" grouping is discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
              <li>The "key-format" node is an identity-reference to the "symmetric-key-format"
                  abstract base identity discussed in <xref target="identities"/>,
                    enabling the symmetric key to be encoded using any of the formats
                    defined by the derived identities.</li>
              <li>
                <t>The "choice" statement enables the private key data to be cleartext,
                  encrypted, or hidden, as follows:
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "cleartext-symmetric-key" node can encode any cleartext key value.</li>
                  <li>The "hidden-symmetric-key" node is of type "empty" as the real
                      value cannot be presented via the management interface.</li>
                  <li>The "encrypted-symmetric-key" node's structure is discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
          <section anchor="public-key-grouping">
            <name>The "public-key-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "public-key-grouping" grouping.  This tree diagram does
                not expand any internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping public-key-grouping:
    +-- public-key-format    identityref
    +-- public-key           binary
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>The "public-key-format" node is an identity-reference to the "public-key-format"
                  abstract base identity discussed in <xref target="identities"/>,
                  enabling the public key to be encoded using any of the formats
                  defined by the derived identities.  </li>
              <li>The "public-key" node is the public key data in the selected format.
                  No "choice" statement is used to hide or encrypt the public key data
                  because it is unnecessary to do so for public keys.</li>
            </ul>
          </section>
          <section anchor="private-key-grouping">
            <name>The "private-key-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "private-key-grouping" grouping. This tree diagram does not expand the internally
                used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping private-key-grouping:
    +-- private-key-format?            identityref
    +-- (private-key-type)
       +--:(cleartext-private-key) {cleartext-private-keys}?
       |  +-- cleartext-private-key?   binary
       +--:(hidden-private-key) {hidden-private-keys}?
       |  +-- hidden-private-key?      empty
       +--:(encrypted-private-key) {encrypted-private-keys}?
          +-- encrypted-private-key
             +---u encrypted-value-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "encrypted-value-grouping" grouping is discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
              <li>The "private-key-format" node is an identity-reference to the "private-key-format"
                    abstract base identity discussed in <xref target="identities"/>,
                    enabling the private key to be encoded using any of the formats
                    defined by the derived identities.</li>
              <li>
                <t>The "choice" statement enables the private key data to be cleartext,
                  encrypted, or hidden, as follows:
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "cleartext-private-key" node can encode any cleartext key value.</li>
                  <li>The "hidden-private-key" node is of type "empty" as the real
                      value cannot be presented via the management interface.</li>
                  <li>The "encrypted-private-key" node's structure is discussed in
                      <xref target="encrypted-value-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
          <section anchor="asymmetric-key-pair-grouping">
            <name>The "asymmetric-key-pair-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "asymmetric-key-pair-grouping" grouping. This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping asymmetric-key-pair-grouping:
    +---u public-key-grouping
    +---u private-key-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "public-key-grouping" grouping is discussed in
                      <xref target="public-key-grouping"/>.</li>
                  <li>The "private-key-grouping" grouping is discussed in
                      <xref target="private-key-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
          <section anchor="certificate-expiration-grouping">
            <name>The "certificate-expiration-grouping" Grouping</name>
            <t>The following
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrates illustrating the
                "certificate-expiration-grouping" grouping:</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping certificate-expiration-grouping:
    +---n certificate-expiration
            {certificate-expiration-notification}?
       +-- expiration-date    yang:date-and-time
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>This grouping's only purpose is to define the "certificate-expiration"
                  notification statement, used by the groupings defined in Sections
                  <xref target="trust-anchor-cert-grouping"/> target="trust-anchor-cert-grouping" format="counter"/> and
                  <xref target="end-entity-cert-grouping"/>.</li> target="end-entity-cert-grouping" format="counter"/>.</li>
              <li>The "certificate-expiration" notification enables servers to
                  notify clients when certificates are nearing expiration.</li>
              <li>The "expiration-date" node indicates when the designated
                  certificate will (or did) expire.</li>
              <li>Identification of the certificate that is expiring is built
                  into the notification itself.  For an example, please see
                  <xref target="cert-exp-notif-ex"/>.</li>
            </ul>
          </section>
          <section anchor="trust-anchor-cert-grouping">
            <name>The "trust-anchor-cert-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "trust-anchor-cert-grouping" grouping.  This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping trust-anchor-cert-grouping:
    +-- cert-data?                         trust-anchor-cert-cms
    +---u certificate-expiration-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "certificate-expiration-grouping" grouping is discussed in
                      <xref target="certificate-expiration-grouping"/>.</li>
                </ul>
              </li>
              <li>The "cert-data" node contains a chain of one or more certificates
                  containing at most one self-signed certificates certificate (the "root" certificate),
                  encoded using a "signed-data-cms" typedef discussed in <xref target="typedefs"/>.</li>
            </ul>
          </section>
          <section anchor="end-entity-cert-grouping">
            <name>The "end-entity-cert-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "end-entity-cert-grouping" grouping.  This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping end-entity-cert-grouping:
    +-- cert-data?                         end-entity-cert-cms
    +---u certificate-expiration-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "certificate-expiration-grouping" grouping is discussed in
                      <xref target="certificate-expiration-grouping"/>.</li>
                </ul>
              </li>
              <li>The "cert-data" node contains a chain of one or more certificates
                  containing at most one certificate that is neither not self-signed nor
                  having and does not have
                  Basic constraint "CA true", true" (where "CA" means Certification Authority), encoded using a "signed-data-cms"
                  typedef discussed in <xref target="typedefs"/>.</li>
            </ul>
          </section>
          <section anchor="generate-csr-grouping">
            <name>The "generate-csr-grouping" Grouping</name>
            <t>The following
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrates illustrating the
                "generate-csr-grouping" grouping:</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping generate-csr-grouping:
    +---x generate-csr {csr-generation}?
       +---w input
       |  +---w csr-format    identityref
       |  +---w csr-info      csr-info
       +--ro output
          +--ro (csr-type)
             +--:(p10-csr)
                +--ro p10-csr?   p10-csr
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>This grouping's only purpose is to define the "generate-certificate-signing-request" "generate-csr"
                  action statement, used by the groupings defined in Sections <xref target="asymmetric-key-pair-with-cert-grouping"/> target="asymmetric-key-pair-with-cert-grouping" format="counter"/>
                  and <xref target="asymmetric-key-pair-with-certs-grouping"/>.</li> target="asymmetric-key-pair-with-certs-grouping" format="counter"/>.</li>
              <li>This action takes as two input parameters: a "csr-info" type "csr-info” parameter, for what content should be in the certificate, and returns a
                  "csr" type, both of which “csr-format” parameter, for what CSR format to return.  The action returns the CSR in the specified format.  Both the “csr-info” and “csr” types are discussed in <xref target="typedefs"/>.</li>
              <li>For an example, please see <xref target="gcsr-action"/>.</li>
            </ul>
          </section>
          <section anchor="asymmetric-key-pair-with-cert-grouping">
            <name>The "asymmetric-key-pair-with-cert-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "asymmetric-key-pair-with-cert-grouping" grouping.  This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping asymmetric-key-pair-with-cert-grouping:
    +---u asymmetric-key-pair-grouping
    +---u end-entity-cert-grouping
    +---u generate-csr-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>This grouping defines an asymmetric key with at most one associated
                  certificate, a commonly needed combination in protocol models.</li>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "asymmetric-key-pair-grouping" grouping is discussed in
                      <xref target="asymmetric-key-pair-grouping"/>.</li>
                  <li>The "end-entity-cert-grouping" grouping is discussed in
                      <xref target="end-entity-cert-grouping"/>.</li>
                  <li>The "generate-csr-grouping" grouping is discussed in
                      <xref target="generate-csr-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
          <section anchor="asymmetric-key-pair-with-certs-grouping">
            <name>The "asymmetric-key-pair-with-certs-grouping" Grouping</name>
            <t>This section presents a tree diagram <xref target="RFC8340"/> illustrating the
                "asymmetric-key-pair-with-certs-grouping" grouping. This tree diagram does
                not expand the internally used grouping "grouping" statement(s):</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
  grouping asymmetric-key-pair-with-certs-grouping:
    +---u asymmetric-key-pair-grouping
    +-- certificates
    |  +-- certificate* [name]
    |     +-- name? name                       string
    |     +---u end-entity-cert-grouping
    +---u generate-csr-grouping
]]></artwork>
]]></sourcecode>
            <t>Comments:</t>
            <ul>
              <li>This grouping defines an asymmetric key with one or more
                  associated certificates, a commonly needed combination in
                  configuration models.</li>
              <li>
                <t>For the referenced grouping "grouping" statement(s):
                </t>
                <ul spacing="compact"> spacing="normal">
                  <li>The "asymmetric-key-pair-grouping" grouping is discussed in
                      <xref target="asymmetric-key-pair-grouping"/>.</li>
                  <li>The "end-entity-cert-grouping" grouping is discussed in
                      <xref target="end-entity-cert-grouping"/>.</li>
                  <li>The "generate-csr-grouping" grouping is discussed in
                      <xref target="generate-csr-grouping"/>.</li>
                </ul>
              </li>
            </ul>
          </section>
        </section>
        <section toc="exclude">
          <name>Protocol-accessible
          <name>Protocol-Accessible Nodes</name>
          <t>The "ietf-crypto-types" module does not contain any protocol-accessible nodes,
              but the module needs to be "implemented", as described in <xref section="5.6.5" target="RFC7950"/>, in order for the identities in
              <xref target="identities"/> to be defined.</t>
        </section>
      </section>
      <section anchor="crypto-types-examples">
        <name>Example Usage</name>
        <section anchor="ct-usage" toc="exclude">
          <name>The "symmetric-key-grouping",             "asymmetric-key-pair-with-certs-grouping", and "password-grouping" Groupings</name>
          <t>The following non-normative module is constructed in order to illustrate the
              use of the "symmetric-key-grouping" (<xref target="symmetric-key-grouping"/>), the
              "asymmetric-key-pair-with-certs-grouping" (<xref target="asymmetric-key-pair-with-certs-grouping"/>),
              and the "password-grouping" (<xref target="password-grouping"/>) grouping "grouping" statements.</t>
          <t>Notably, this example module and associated configuration data illustrates that
              a hidden private key (ex-hidden-asymmetric-key)
              has been used to encrypt a symmetric key (ex-encrypted-one-symmetric-based-symmetric-key)
              that has been used to encrypt another private key (ex-encrypted-rsa-based-asymmetric-key).
              Additionally, the symmetric key is also used to encrypt a password (ex-encrypted-password).</t>
          <section toc="exclude">
            <name>Example Module</name>
            <artwork><![CDATA[
            <sourcecode type="yang"><![CDATA[
module ex-crypto-types-usage {
  yang-version 1.1;
  namespace "https://example.com/ns/example-crypto-types-usage";
  prefix ectu;

  import ietf-crypto-types {
    prefix ct;
    reference
      "RFC AAAA: 9640: YANG Data Types and Groupings for Cryptography";
  }

  organization
    "Example Corporation";
  contact
    "YANG Designer <mailto:yang.designer@example.com>";

  description
    "This example module illustrates the 'symmetric-key-grouping'
     and 'asymmetric-key-grouping' groupings defined in the
    'ietf-crypto-types' module defined in RFC AAAA."; 9640.";

  revision 2024-03-16 {
    description
      "Initial version"; version.";
    reference
      "RFC AAAA: Common 9640: YANG Data Types and Groupings for Cryptography";
  }

  container symmetric-keys {
    description
      "A container of symmetric keys.";
    list symmetric-key {
      key "name";
      description
        "A symmetric key"; key.";
      leaf name {
        type string;
        description
          "An arbitrary name for this key.";
      }
      uses ct:symmetric-key-grouping {
        augment "key-type/encrypted-symmetric-key/"
              + "encrypted-symmetric-key/encrypted-by" {
          description
            "Augments in a choice 'choice' statement enabling the
             encrypting key to be any other symmetric or
             asymmetric key.";
          uses encrypted-by-grouping;
        }
      }
    }
  }
  container asymmetric-keys {
    description
      "A container of asymmetric keys.";
    list asymmetric-key {
      key "name";
      leaf name {
        type string;
        description
          "An arbitrary name for this key.";
      }
      uses ct:asymmetric-key-pair-with-certs-grouping {
        augment "private-key-type/encrypted-private-key/"
              + "encrypted-private-key/encrypted-by" {
          description
            "Augments in a choice 'choice' statement enabling the
             encrypting key to be any other symmetric or
             asymmetric key.";
          uses encrypted-by-grouping;
        }
      }
      description
        "An asymmetric key pair with associated certificates.";
    }
  }
  container passwords {
    description
      "A container of passwords.";
    list password {
      key "name";
      leaf name {
        type string;
        description
          "An arbitrary name for this password.";
      }
      uses ct:password-grouping {
        augment "password-type/encrypted-password/"
              + "encrypted-password/encrypted-by" {
          description
            "Augments in a choice 'choice' statement enabling the
             encrypting key to be any symmetric or
             asymmetric key.";
          uses encrypted-by-grouping;
        }
      }
      description
        "A password.";
    }
  }

  grouping encrypted-by-grouping {
    description
      "A grouping that defines a choice enabling references
       to other keys.";
    choice encrypted-by {
      mandatory true;
      description
        "A choice amongst other symmetric or asymmetric keys.";
      case symmetric-key-ref {
        leaf symmetric-key-ref {
          type leafref {
            path "/ectu:symmetric-keys/ectu:symmetric-key/"
               + "ectu:name";
          }
          description
            "Identifies the symmetric key that encrypts this key.";
        }
      }
      case asymmetric-key-ref {
        leaf asymmetric-key-ref {
          type leafref {
            path "/ectu:asymmetric-keys/ectu:asymmetric-key/"
               + "ectu:name";
          }
          description
            "Identifies the asymmetric key that encrypts this key.";
        }
      }
    }
  }
}
]]></artwork>
]]></sourcecode>
          </section>
          <section toc="exclude">
            <name>Tree Diagram for the Example Module</name>
            <t>The tree diagram <xref target="RFC8340"/> for this example module is as follows:</t>
            <artwork><![CDATA[
            <sourcecode type="yangtree"><![CDATA[
module: ex-crypto-types-usage
  +--rw symmetric-keys
  |  +--rw symmetric-key* [name]
  |     +--rw name                             string
  |     +--rw key-format?                      identityref
  |     +--rw (key-type)
  |        +--:(cleartext-symmetric-key)
  |        |  +--rw cleartext-symmetric-key?   binary
  |        |          {cleartext-symmetric-keys}?
  |        +--:(hidden-symmetric-key) {hidden-symmetric-keys}?
  |        |  +--rw hidden-symmetric-key?      empty
  |        +--:(encrypted-symmetric-key) {encrypted-symmetric-keys}?
  |           +--rw encrypted-symmetric-key
  |              +--rw encrypted-by
  |              |  +--rw (encrypted-by)
  |              |     +--:(symmetric-key-ref)
  |              |     |  +--rw symmetric-key-ref?    leafref
  |              |     +--:(asymmetric-key-ref)
  |              |        +--rw asymmetric-key-ref?   leafref
  |              +--rw encrypted-value-format    identityref
  |              +--rw encrypted-value           binary
  +--rw asymmetric-keys
  |  +--rw asymmetric-key* [name]
  |     +--rw name                           string
  |     +--rw public-key-format?             identityref
  |     +--rw public-key?                    binary
  |     +--rw private-key-format?            identityref
  |     +--rw (private-key-type)
  |     |  +--:(cleartext-private-key) {cleartext-private-keys}?
  |     |  |  +--rw cleartext-private-key?   binary
  |     |  +--:(hidden-private-key) {hidden-private-keys}?
  |     |  |  +--rw hidden-private-key?      empty
  |     |  +--:(encrypted-private-key) {encrypted-private-keys}?
  |     |     +--rw encrypted-private-key
  |     |        +--rw encrypted-by
  |     |        |  +--rw (encrypted-by)
  |     |        |     +--:(symmetric-key-ref)
  |     |        |     |  +--rw symmetric-key-ref?    leafref
  |     |        |     +--:(asymmetric-key-ref)
  |     |        |        +--rw asymmetric-key-ref?   leafref
  |     |        +--rw encrypted-value-format    identityref
  |     |        +--rw encrypted-value           binary
  |     +--rw certificates
  |     |  +--rw certificate* [name]
  |     |     +--rw name                      string
  |     |     +--rw cert-data                 end-entity-cert-cms
  |     |     +---n certificate-expiration
  |     |             {certificate-expiration-notification}?
  |     |        +-- expiration-date    yang:date-and-time
  |     +---x generate-csr {csr-generation}?
  |        +---w input
  |        |  +---w csr-format    identityref
  |        |  +---w csr-info      csr-info
  |        +--ro output
  |           +--ro (csr-type)
  |              +--:(p10-csr)
  |                 +--ro p10-csr?   p10-csr
  +--rw passwords
     +--rw password* [name]
        +--rw name                        string
        +--rw (password-type)
           +--:(cleartext-password) {cleartext-passwords}?
           |  +--rw cleartext-password?   string
           +--:(encrypted-password) {encrypted-passwords}?
              +--rw encrypted-password
                 +--rw encrypted-by
                 |  +--rw (encrypted-by)
                 |     +--:(symmetric-key-ref)
                 |     |  +--rw symmetric-key-ref?    leafref
                 |     +--:(asymmetric-key-ref)
                 |        +--rw asymmetric-key-ref?   leafref
                 +--rw encrypted-value-format    identityref
                 +--rw encrypted-value           binary
]]></artwork>
]]></sourcecode>
          </section>
          <section toc="exclude">
            <name>Usage Example for the Example Module</name>
            <t>Finally, the following example illustrates various symmetric and asymmetric keys
            as they might appear in configuration:</t>
            <artwork><![CDATA[ configuration.</t>
            <sourcecode type="xml"><![CDATA[
=============== NOTE: '\' line wrapping per RFC 8792 ================

<symmetric-keys
  xmlns="https://example.com/ns/example-crypto-types-usage"
  xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
  <symmetric-key>
    <name>ex-hidden-symmetric-key</name>
    <hidden-symmetric-key/>
  </symmetric-key>
  <symmetric-key>
    <name>ex-octet-string-based-symmetric-key</name>
    <key-format>ct:octet-string-key-format</key-format>
    <cleartext-symmetric-key>BASE64VALUE=</cleartext-symmetric-key>
  </symmetric-key>
  <symmetric-key>
    <name>ex-one-symmetric-based-symmetric-key</name>
    <key-format>ct:one-symmetric-key-format</key-format>
    <cleartext-symmetric-key>BASE64VALUE=</cleartext-symmetric-key>
  </symmetric-key>
  <symmetric-key>
    <name>ex-encrypted-one-symmetric-based-symmetric-key</name>
    <key-format>ct:one-symmetric-key-format</key-format>
    <encrypted-symmetric-key>
      <encrypted-by>
        <asymmetric-key-ref>ex-hidden-asymmetric-key</asymmetric-key\
-ref>
      </encrypted-by>
      <encrypted-value-format>ct:cms-enveloped-data-format</encrypte\
d-value-format>
      <encrypted-value>BASE64VALUE=</encrypted-value>
    </encrypted-symmetric-key>
  </symmetric-key>
</symmetric-keys>

<asymmetric-keys
  xmlns="https://example.com/ns/example-crypto-types-usage"
  xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
  <asymmetric-key>
    <name>ex-hidden-asymmetric-key</name>
    <public-key-format>ct:subject-public-key-info-format</public-key\
-format>
    <public-key>BASE64VALUE=</public-key>
    <hidden-private-key/>
    <certificates>
      <certificate>
        <name>ex-hidden-asymmetric-key-cert</name>
        <cert-data>BASE64VALUE=</cert-data>
      </certificate>
    </certificates>
  </asymmetric-key>
  <asymmetric-key>
    <name>ex-rsa-based-asymmetric-key</name>
    <public-key-format>ct:subject-public-key-info-format</public-key\
-format>
    <public-key>BASE64VALUE=</public-key>
    <private-key-format>ct:rsa-private-key-format</private-key-forma\
t>
    <cleartext-private-key>BASE64VALUE=</cleartext-private-key>
    <certificates>
      <certificate>
        <name>ex-cert</name>
        <cert-data>BASE64VALUE=</cert-data>
      </certificate>
    </certificates>
  </asymmetric-key>
  <asymmetric-key>
    <name>ex-one-asymmetric-based-asymmetric-key</name>
    <public-key-format>ct:subject-public-key-info-format</public-key\
-format>
    <public-key>BASE64VALUE=</public-key>
    <private-key-format>ct:one-asymmetric-key-format</private-key-fo\
rmat>
    <cleartext-private-key>BASE64VALUE=</cleartext-private-key>
  </asymmetric-key>
  <asymmetric-key>
    <name>ex-encrypted-rsa-based-asymmetric-key</name>
    <public-key-format>ct:subject-public-key-info-format</public-key\
-format>
    <public-key>BASE64VALUE=</public-key>
    <private-key-format>ct:rsa-private-key-format</private-key-forma\
t>
    <encrypted-private-key>
      <encrypted-by>
        <symmetric-key-ref>ex-encrypted-one-symmetric-based-symmetri\
c-key</symmetric-key-ref>
      </encrypted-by>
      <encrypted-value-format>ct:cms-encrypted-data-format</encrypte\
d-value-format>
      <encrypted-value>BASE64VALUE=</encrypted-value>
    </encrypted-private-key>
  </asymmetric-key>
</asymmetric-keys>

<passwords
  xmlns="https://example.com/ns/example-crypto-types-usage"
  xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
  <password>
    <name>ex-cleartext-password</name>
    <cleartext-password>super-secret</cleartext-password>
  </password>
  <password>
    <name>ex-encrypted-password</name>
    <encrypted-password>
      <encrypted-by>
        <symmetric-key-ref>ex-encrypted-one-symmetric-based-symmetri\
c-key</symmetric-key-ref>
      </encrypted-by>
      <encrypted-value-format>ct:cms-encrypted-data-format</encrypte\
d-value-format>
      <encrypted-value>BASE64VALUE=</encrypted-value>
    </encrypted-password>
  </password>
</passwords>
]]></artwork>
]]></sourcecode>
          </section>
        </section>
        <section anchor="gcsr-action" toc="exclude">
          <name>The "generate-certificate-signing-request" "generate-csr" Action</name>
          <t>The following example illustrates the "generate-certificate-signing-request" "generate-csr"
          action, discussed in <xref target="generate-csr-grouping"/>, with the NETCONF protocol.</t>
          <t keepWithNext="true">REQUEST</t>
          <artwork><![CDATA[
          <sourcecode type="xml"><![CDATA[
<rpc message-id="101"
  xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
  xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
  <action xmlns="urn:ietf:params:xml:ns:yang:1">
    <asymmetric-keys
      xmlns="https://example.com/ns/example-crypto-types-usage">
      <asymmetric-key>
        <name>ex-hidden-asymmetric-key</name>
        <generate-csr>
          <csr-format>ct:p10-csr-format</csr-format>
          <csr-info>BASE64VALUE=</csr-info>
        </generate-csr>
      </asymmetric-key>
    </asymmetric-keys>
  </action>
</rpc>
]]></artwork>
]]></sourcecode>
          <t keepWithNext="true">RESPONSE</t>
          <artwork><![CDATA[
          <sourcecode type="xml"><![CDATA[
=============== NOTE: '\' line wrapping per RFC 8792 ================

<rpc-reply message-id="101"
  xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <p10-csr xmlns="https://example.com/ns/example-crypto-types-usage"\
>BASE64VALUE=</p10-csr>
</rpc-reply>
]]></artwork>
]]></sourcecode>
        </section>
        <section anchor="cert-exp-notif-ex" toc="exclude">
          <name>The "certificate-expiration" Notification</name>
          <t>The following example illustrates the "certificate-expiration"
              notification, discussed in <xref target="certificate-expiration-grouping"/>,
          with the NETCONF protocol.</t>
          <artwork><![CDATA[
          <sourcecode type="xml"><![CDATA[
=============== NOTE: '\' line wrapping per RFC 8792 ================

<notification
  xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
  <eventTime>2018-05-25T00:01:00Z</eventTime>
  <asymmetric-keys xmlns="https://example.com/ns/example-crypto-type\
s-usage">
    <asymmetric-key>
      <name>ex-hidden-asymmetric-key</name>
      <certificates>
        <certificate>
          <name>ex-hidden-asymmetric-key-cert</name>
          <certificate-expiration>
            <expiration-date>2018-08-05T14:18:53-05:00</expiration-d\
ate>
          </certificate-expiration>
        </certificate>
      </certificates>
    </asymmetric-key>
  </asymmetric-keys>
</notification>
]]></artwork>
]]></sourcecode>
        </section>
      </section>
      <section anchor="crypto-types-yang-module">
        <name>YANG Module</name>
        <t>This module has normative references to <xref target="RFC2119"/>,
          <xref target="RFC2986"/>, <xref target="RFC4253"/>, <xref target="RFC5280"/>,
          <xref target="RFC5652"/>, <xref target="RFC5915"/>, <xref target="RFC5958"/>,
          <xref target="RFC6031"/>, <xref target="RFC6960"/>,
          <xref target="RFC6991"/>, <xref target="RFC7093"/>, <xref target="RFC8017"/>,
          <xref target="RFC8174"/>, <xref target="RFC8341"/>,
          and <xref target="ITU.X690.2021"/>.</t>
        <t keepWithNext="true">&lt;CODE BEGINS&gt; file "ietf-crypto-types@2024-03-16.yang"</t>
        <artwork><![CDATA[
        <sourcecode name="ietf-crypto-types@2024-03-16.yang" type="yang" markers="true"><![CDATA[
module ietf-crypto-types {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-crypto-types";
  prefix ct;

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

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

  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 common YANG types for cryptographic
     applications.

     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.

     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 AAAA
     (https://www.rfc-editor.org/info/rfcAAAA); 9640
     (https://www.rfc-editor.org/info/rfc9640); 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."; notices.";

  revision 2024-03-16 {
    description
      "Initial version"; version.";
    reference
      "RFC AAAA: 9640: YANG Data Types and Groupings for Cryptography";
  }

  /****************/
  /*   Features   */
  /****************/

  feature one-symmetric-key-format {
    description
      "Indicates that the server supports the
       'one-symmetric-key-format' identity.";
  }

  feature one-asymmetric-key-format {
    description
      "Indicates that the server supports the
       'one-asymmetric-key-format' identity.";
  }

  feature symmetrically-encrypted-value-format {
    description
      "Indicates that the server supports the
       'symmetrically-encrypted-value-format' identity.";
  }

  feature asymmetrically-encrypted-value-format {
    description
      "Indicates that the server supports the
       'asymmetrically-encrypted-value-format' identity.";
  }

  feature cms-enveloped-data-format {
    description
      "Indicates that the server supports the
       'cms-enveloped-data-format' identity.";
  }

  feature cms-encrypted-data-format {
    description
      "Indicates that the server supports the
       'cms-encrypted-data-format' identity.";
  }

  feature p10-csr-format {
    description
      "Indicates that the server implements support
       for generating P10-based CSRs, as defined
       in RFC 2986.";
    reference
      "RFC 2986: PKCS #10: Certification Request Syntax
                 Specification Version 1.7";
  }

  feature csr-generation {
    description
      "Indicates that the server implements the
       'generate-csr' action.";
  }

  feature certificate-expiration-notification {
    description
      "Indicates that the server implements the
       'certificate-expiration' notification.";
  }

  feature cleartext-passwords {
    description
      "Indicates that the server supports cleartext
       passwords.";
  }

  feature encrypted-passwords {
    description
      "Indicates that the server supports password
       encryption.";
  }

  feature cleartext-symmetric-keys {
    description
      "Indicates that the server supports cleartext
       symmetric keys.";
  }

  feature hidden-symmetric-keys {
    description
      "Indicates that the server supports hidden keys.";
  }

  feature encrypted-symmetric-keys {
    description
      "Indicates that the server supports encryption
       of symmetric keys.";
  }

  feature cleartext-private-keys {
    description
      "Indicates that the server supports cleartext
       private keys.";
  }

  feature hidden-private-keys {
    description
      "Indicates that the server supports hidden keys.";
  }

  feature encrypted-private-keys {
    description
      "Indicates that the server supports encryption
       of private keys.";
  }

  /*************************************************/
  /*   Base Identities for Key Format Structures   */
  /*************************************************/

  identity symmetric-key-format {
    description
      "Base key-format identity for symmetric keys.";
  }

  identity public-key-format {
    description
      "Base key-format identity for public keys.";
  }

  identity private-key-format {
    description
      "Base key-format identity for private keys.";
  }

  /****************************************************/
  /*   Identities for Private Key Format Structures   */
  /****************************************************/

  identity rsa-private-key-format {
    base private-key-format;
    description
      "Indicates that the private key value is encoded as
       an RSAPrivateKey (from RFC 8017), encoded using ASN.1
       distinguished encoding rules (DER), as specified in
       ITU-T X.690.";
    reference
      "RFC 8017:
         PKCS #1: RSA Cryptography Specifications Version 2.2
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  identity ec-private-key-format {
    base private-key-format;
    description
      "Indicates that the private key value is encoded as
       an ECPrivateKey (from RFC 5915), encoded using ASN.1
       distinguished encoding rules (DER), as specified in
       ITU-T X.690.";
    reference
      "RFC 5915:
         Elliptic Curve Private Key Structure
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  identity one-asymmetric-key-format {
    if-feature "one-asymmetric-key-format";
    base private-key-format;
    description
      "Indicates that the private key value is a CMS
       Cryptographic Message Syntax (CMS) OneAsymmetricKey
       structure, as defined in RFC 5958, encoded using
       ASN.1 distinguished encoding rules (DER), as
       specified in ITU-T X.690.";
    reference
      "RFC 5958:
         Asymmetric Key Packages
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /***************************************************/
  /*   Identities for Public Key Format Structures   */
  /***************************************************/

  identity ssh-public-key-format {
    base public-key-format;
    description
      "Indicates that the public key value is an SSH a Secure Shell (SSH)
       public key, as specified by in RFC 4253, Section 6.6, i.e.:

         string    certificate or public key format
                   identifier
         byte[n]   key/certificate data.";
    reference
      "RFC 4253: The Secure Shell (SSH) Transport Layer Protocol";
  }

  identity subject-public-key-info-format {
    base public-key-format;
    description
      "Indicates that the public key value is a SubjectPublicKeyInfo
       structure, as described in RFC 5280 5280, encoded using ASN.1
       distinguished encoding rules (DER), as specified in
       ITU-T X.690.";
    reference
      "RFC 5280:
         Internet X.509 Public Key Infrastructure Certificate
         and Certificate Revocation List (CRL) Profile
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /******************************************************/
  /*   Identities for Symmetric Key Format Structures   */
  /******************************************************/

  identity octet-string-key-format {
    base symmetric-key-format;
    description
      "Indicates that the key is encoded as a raw octet string.
       The length of the octet string MUST be appropriate for
       the associated algorithm's block size.

       The identity of the associated algorithm is outside the
       scope of this specification.  This is also true when
       the octet string has been encrypted.";
  }

  identity one-symmetric-key-format {
    if-feature "one-symmetric-key-format";
    base symmetric-key-format;
    description
      "Indicates that the private key value is a CMS
       OneSymmetricKey structure, as defined in RFC 6031,
       encoded using ASN.1 distinguished encoding rules
       (DER), as specified in ITU-T X.690.";
    reference
      "RFC 6031:
         Cryptographic Message Syntax (CMS)
         Symmetric Key Package Content Type
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /*************************************************/
  /*   Identities for Encrypted Value Structures   */
  /*************************************************/

  identity encrypted-value-format {
    description
      "Base format identity for encrypted values.";
  }

  identity symmetrically-encrypted-value-format {
    if-feature "symmetrically-encrypted-value-format";
    base encrypted-value-format;
    description
      "Base format identity for symmetrically encrypted
       values.";
  }

  identity asymmetrically-encrypted-value-format {
    if-feature "asymmetrically-encrypted-value-format";
    base encrypted-value-format;
    description
      "Base format identity for asymmetrically encrypted
       values.";
  }

  identity cms-encrypted-data-format {
    if-feature "cms-encrypted-data-format";
    base symmetrically-encrypted-value-format;
    description
      "Indicates that the encrypted value conforms to
       the 'encrypted-data-cms' type with the constraint
       that the 'unprotectedAttrs' value is not set.";
    reference
      "RFC 5652:
         Cryptographic Message Syntax (CMS)
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  identity cms-enveloped-data-format {
    if-feature "cms-enveloped-data-format";
    base asymmetrically-encrypted-value-format;
    description
      "Indicates that the encrypted value conforms to the
       'enveloped-data-cms' type with the following constraints:

       The EnvelopedData structure MUST have exactly one
       'RecipientInfo'.

       If the asymmetric key supports public key cryptography
       (e.g., RSA), then the 'RecipientInfo' must be a
       'KeyTransRecipientInfo' with the 'RecipientIdentifier'
       using a 'subjectKeyIdentifier' with the value set using
       'method 1' in RFC 7093 over the recipient's public key.

       Otherwise, if the asymmetric key supports key agreement
       (e.g., ECC), Elliptic Curve Cryptography (ECC)), then the
       'RecipientInfo' must be a 'KeyAgreeRecipientInfo'.  The
       'OriginatorIdentifierOrKey' value must use the
       'OriginatorPublicKey' alternative.  The
       'UserKeyingMaterial' value must not be present.  There
       must be exactly one 'RecipientEncryptedKeys' value
       having the 'KeyAgreeRecipientIdentifier' set to 'rKeyId'
       with the value set using 'method 1' in RFC 7093 over the
       recipient's public key.";
    reference
      "RFC 5652:
         Cryptographic Message Syntax (CMS)
       RFC 7093:
         Additional Methods for Generating Key
         Identifiers Values
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /*********************************************************/
  /*   Identities for Certificate Signing Request Formats  */
  /*********************************************************/

  identity csr-format {
    description
      "A base identity for the certificate signing request
       formats.  Additional derived identities MAY be defined
       by future efforts.";
  }

  identity p10-csr-format {
    if-feature "p10-csr-format";
    base csr-format;
    description
      "Indicates the 'CertificationRequest' CertificationRequest structure
       defined in RFC 2986.";
    reference
      "RFC 2986: PKCS #10: Certification Request Syntax
                 Specification Version 1.7";
  }

  /***************************************************/
  /*   Typedefs for ASN.1 structures from RFC 2986   */
  /***************************************************/

  typedef csr-info {
    type binary;
    description
      "A CertificationRequestInfo structure, as defined in
       RFC 2986, encoded using ASN.1 distinguished encoding
       rules (DER), as specified in ITU-T X.690.";
    reference
      "RFC 2986:
         PKCS #10: Certification Request Syntax
         Specification Version 1.7
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  typedef p10-csr {
    type binary;
    description
      "A CertificationRequest structure, as specified in
       RFC 2986, encoded using ASN.1 distinguished encoding
       rules (DER), as specified in ITU-T X.690.";
    reference
      "RFC 2986:
         PKCS #10: Certification Request Syntax Specification
         Version 1.7
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /***************************************************/
  /*   Typedefs for ASN.1 structures from RFC 5280   */
  /***************************************************/

  typedef x509 {
    type binary;
    description
      "A Certificate structure, as specified in RFC 5280,
       encoded using ASN.1 distinguished encoding rules (DER),
       as specified in ITU-T X.690.";
    reference
      "RFC 5280:
         Internet X.509 Public Key Infrastructure Certificate
         and Certificate Revocation List (CRL) Profile
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  typedef crl {
    type binary;
    description
      "A CertificateList structure, as specified in RFC 5280,
       encoded using ASN.1 distinguished encoding rules (DER),
       as specified in ITU-T X.690.";
    reference
      "RFC 5280:
         Internet X.509 Public Key Infrastructure Certificate
         and Certificate Revocation List (CRL) Profile
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /***************************************************/
  /*   Typedefs for ASN.1 structures from RFC 6960   */
  /***************************************************/

  typedef oscp-request {
    type binary;
    description
      "A OCSPRequest structure, as specified in RFC 6960,
       encoded using ASN.1 distinguished encoding rules
       (DER), as specified in ITU-T X.690.";
    reference
      "RFC 6960:
         X.509 Internet Public Key Infrastructure Online
         Certificate Status Protocol - OCSP
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  typedef oscp-response {
    type binary;
    description
      "A OCSPResponse structure, as specified in RFC 6960,
       encoded using ASN.1 distinguished encoding rules
       (DER), as specified in ITU-T X.690.";
    reference
      "RFC 6960:
         X.509 Internet Public Key Infrastructure Online
         Certificate Status Protocol - OCSP
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  /***********************************************/
  /*   Typedefs for ASN.1 structures from 5652   */
  /***********************************************/

  typedef cms {
    type binary;
    description
      "A ContentInfo structure, as specified in RFC 5652,
       encoded using ASN.1 distinguished encoding rules (DER),
       as specified in ITU-T X.690.";
    reference
      "RFC 5652:
         Cryptographic Message Syntax (CMS)
       ITU-T X.690:
         Information technology - ASN.1 encoding rules:
         Specification of Basic Encoding Rules (BER),
         Canonical Encoding Rules (CER) and Distinguished
         Encoding Rules (DER) 02/2021."; 02/2021";
  }

  typedef data-content-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       data content type, as described by in Section 4 in of RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  typedef signed-data-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       signed-data content type, as described by in Section 5 in of
       RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  typedef enveloped-data-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       enveloped-data content type, as described by in Section 6
       in
       of RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  typedef digested-data-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       digested-data content type, as described by in Section 7
       in
       of RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  typedef encrypted-data-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       encrypted-data content type, as described by in Section 8
       in
       of RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  typedef authenticated-data-cms {
    type cms;
    description
      "A CMS structure whose top-most content type MUST be the
       authenticated-data content type, as described by in Section 9
       in
       of RFC 5652.";
    reference
      "RFC 5652: Cryptographic Message Syntax (CMS)";
  }

  /*********************************************************/
  /*   Typedefs for ASN.1 structures related to RFC 5280   */
  /*********************************************************/

  typedef trust-anchor-cert-x509 {
    type x509;
    description
      "A Certificate structure that MUST encode a self-signed
       root certificate.";
  }

  typedef end-entity-cert-x509 {
    type x509;
    description
      "A Certificate structure that MUST encode a certificate
       that is neither self-signed nor having has Basic constraint
       CA true.";
  }

  /*********************************************************/
  /*   Typedefs for ASN.1 structures related to RFC 5652   */
  /*********************************************************/

  typedef trust-anchor-cert-cms {
    type signed-data-cms;
    description
      "A CMS SignedData structure that MUST contain the chain of
       X.509 certificates needed to authenticate the certificate
       presented by a client or end-entity. end entity.

       The CMS MUST contain only a single chain of certificates.
       The client or end-entity certificate MUST only authenticate
       to the last intermediate CA certificate listed in the chain.

       In all cases, the chain MUST include a self-signed root
       certificate.  In the case where the root certificate is
       itself the issuer of the client or end-entity certificate,
       only one certificate is present.

       This CMS structure MAY (as applicable where this type is
       used) also contain suitably fresh (as defined by local
       policy) revocation objects with which the device can
       verify the revocation status of the certificates.

       This CMS encodes the degenerate form of the SignedData
       structure (RFC 5652, Section 5.2) that is commonly used
       to disseminate X.509 certificates and revocation objects
       (RFC 5280).";
    reference
      "RFC 5280:
         Internet X.509 Public Key Infrastructure Certificate
         and Certificate Revocation List (CRL) Profile. Profile
       RFC 5652:
         Cryptographic Message Syntax (CMS)";
  }

  typedef end-entity-cert-cms {
    type signed-data-cms;
    description
      "A CMS SignedData structure that MUST contain the end
       entity end-entity
       certificate itself, itself and MAY contain any number
       of intermediate certificates leading up to a trust
       anchor certificate.  The trust anchor certificate
       MAY be included as well.

       The CMS MUST contain a single end entity end-entity certificate.
       The CMS MUST NOT contain any spurious certificates.

       This CMS structure MAY (as applicable where this type is
       used) also contain suitably fresh (as defined by local
       policy) revocation objects with which the device can
       verify the revocation status of the certificates.

       This CMS encodes the degenerate form of the SignedData
       structure (RFC 5652, Section 5.2) that is commonly
       used to disseminate X.509 certificates and revocation
       objects (RFC 5280).";

    reference
      "RFC 5280:
         Internet X.509 Public Key Infrastructure Certificate
         and Certificate Revocation List (CRL) Profile. Profile
       RFC 5652:
         Cryptographic Message Syntax (CMS)";
  }

  /*****************/
  /*   Groupings   */
  /*****************/

  grouping encrypted-value-grouping {
    description
      "A reusable grouping for a value that has been encrypted by
       a referenced symmetric or asymmetric key.";
    container encrypted-by {
      nacm:default-deny-write;
      description
        "An empty container enabling a reference to the key that
         encrypted the value to be augmented in.  The referenced
         key MUST be a symmetric key or an asymmetric key.

         A symmetric key MUST be referenced via a leaf node called
         'symmetric-key-ref'.  An asymmetric key MUST be referenced
         via a leaf node called 'asymmetric-key-ref'.

         The leaf nodes MUST be direct descendants in the data tree, tree
         and MAY be direct descendants in the schema tree (e.g.,
         choice/case
         'choice'/'case' statements are allowed, allowed but not a
         container).";
    }
    leaf encrypted-value-format {
      type identityref {
        base encrypted-value-format;
      }
      mandatory true;
      description
        "Identifies the format of the 'encrypted-value' leaf.

         If 'encrypted-by' points to a symmetric key, then a
         'symmetrically-encrypted-value-format' based an
         identity based on 'symmetrically-encrypted-value-format'
         MUST be set (e.g., cms-encrypted-data-format). 'cms-encrypted-data-format').

         If 'encrypted-by' points to an asymmetric key, then an
         'asymmetrically-encrypted-value-format' based
         identity based on 'asymmetrically-encrypted-value-format'
         MUST be set (e.g., cms-enveloped-data-format)."; 'cms-enveloped-data-format').";
    }
    leaf encrypted-value {
      nacm:default-deny-write;
      type binary;
      must '../encrypted-by';
      mandatory true;
      description
        "The value, encrypted using the referenced symmetric
         or asymmetric key.  The value MUST be encoded using
         the format associated with the 'encrypted-value-format'
         leaf.";
    }
  }

  grouping password-grouping {
    description
      "A password used for authenticating to a remote system.

       The 'ianach:crypt-hash' typedef from RFC 7317 should be
       used instead when needing a password to authencate authenticate a
       local account.";
    choice password-type {
      nacm:default-deny-write;
      mandatory true;
      description
        "Choice between password types.";
      case cleartext-password {
        if-feature "cleartext-passwords";
        leaf cleartext-password {
          nacm:default-deny-all;
          type string;
          description
            "The cleartext value of the password.";
        }
      }
      case encrypted-password {
        if-feature "encrypted-passwords";
        container encrypted-password {
          description
            "A container for the encrypted password value.";
          uses encrypted-value-grouping;
        }
      }
    }
  }

  grouping symmetric-key-grouping {
    description
      "A symmetric key.";
    leaf key-format {
      nacm:default-deny-write;
      type identityref {
        base symmetric-key-format;
      }
      description
        "Identifies the symmetric key's format.  Implementations
         SHOULD ensure that the incoming symmetric key value is
         encoded in the specified format.

         For encrypted keys, the value is the decrypted key's
         format (i.e., the 'encrypted-value-format' conveys the
         encrypted key's format."; format).";
    }
    choice key-type {
      nacm:default-deny-write;
      mandatory true;
      description
        "Choice between key types.";
      case cleartext-symmetric-key {
        leaf cleartext-symmetric-key {
          if-feature "cleartext-symmetric-keys";
          nacm:default-deny-all;
          type binary;
          must '../key-format';
          description
            "The binary value of the key.  The interpretation of
             the value is defined by the 'key-format' field.";
        }
      }
      case hidden-symmetric-key {
        if-feature "hidden-symmetric-keys";
        leaf hidden-symmetric-key {
          type empty;
          must 'not(../key-format)';
          description
            "A hidden key is not exportable, exportable and not extractable,
             and extractable;
             therefore, it is of type 'empty' as its value is
             inaccessible via management interfaces.  Though hidden
             to users, such keys are not hidden to the server and
             may be referenced by configuration to indicate which
             key a server should use for a cryptographic operation.
             How such keys are created is outside the scope of this
             module.";
        }
      }
      case encrypted-symmetric-key {
        if-feature "encrypted-symmetric-keys";
        container encrypted-symmetric-key {
          must '../key-format';
          description
            "A container for the encrypted symmetric key value.
             The interpretation of the 'encrypted-value' node
             is via the 'key-format' node";
          uses encrypted-value-grouping;
        }
      }
    }
  }

  grouping public-key-grouping {
    description
      "A public key.";
    leaf public-key-format {
      nacm:default-deny-write;
      type identityref {
        base public-key-format;
      }
      mandatory true;
      description
        "Identifies the public key's format.  Implementations SHOULD
         ensure that the incoming public key value is encoded in the
         specified format.";
    }
    leaf public-key {
      nacm:default-deny-write;
      type binary;
      mandatory true;
      description
        "The binary value of the public key.  The interpretation
         of the value is defined by the 'public-key-format' field.";
    }
  }

  grouping private-key-grouping {
    description
      "A private key.";
    leaf private-key-format {
      nacm:default-deny-write;
      type identityref {
        base private-key-format;
      }
      description
        "Identifies the private key's format.  Implementations SHOULD
         ensure that the incoming private key value is encoded in the
         specified format.

         For encrypted keys, the value is the decrypted key's
         format (i.e., the 'encrypted-value-format' conveys the
         encrypted key's format."; format).";
    }
    choice private-key-type {
      nacm:default-deny-write;
      mandatory true;
      description
        "Choice between key types.";
      case cleartext-private-key {
        if-feature "cleartext-private-keys";
        leaf cleartext-private-key {
          nacm:default-deny-all;
          type binary;
          must '../private-key-format';
          description
            "The value of the binary key key.  The key's value is
             interpreted by the 'private-key-format' field.";
        }
      }
      case hidden-private-key {
        if-feature "hidden-private-keys";
        leaf hidden-private-key {
          type empty;
          must 'not(../private-key-format)';
          description
            "A hidden key.  It is of type 'empty' as its value is
             inaccessible via management interfaces.  Though hidden
             to users, such keys are not hidden to the server and
             and
             may be referenced by configuration to indicate which
             key a server should use for a cryptographic operation.
             How such keys are created is outside the scope of this
             module.";
        }
      }
      case encrypted-private-key {
        if-feature "encrypted-private-keys";
        container encrypted-private-key {
          must '../private-key-format';
          description
            "A container for the encrypted asymmetric private key
             value.  The interpretation of the 'encrypted-value'
             node is via the 'private-key-format' node";
          uses encrypted-value-grouping;
        }
      }
    }
  }

  grouping asymmetric-key-pair-grouping {
    description
      "A private key and, optionally, its associated public key.
       Implementations MUST ensure that the two keys, when both
       are specified, are a matching pair.";
    uses public-key-grouping {
      refine public-key-format "public-key-format" {
        mandatory false;
      }
      refine public-key "public-key" {
        mandatory false;
      }
    }
    uses private-key-grouping;
  }

  grouping certificate-expiration-grouping {
    description
      "A notification for when a certificate is about to, to expire or
       has already has, expired.";
    notification certificate-expiration {
      if-feature "certificate-expiration-notification";
      description
        "A notification indicating that the configured certificate
         is either about to expire or has already expired.  When to
         send notifications is an implementation specific implementation-specific decision,
         but it is RECOMMENDED that a notification be sent once a
         month for 3 months, then once a week for four weeks, and
         then once a day thereafter until the issue is resolved.

         If the certificate's Issuer issuer maintains a Certificate
         Revocation List (CRL), the expiration notification MAY
         be sent if the CRL is about to expire.";
      leaf expiration-date {
        type yang:date-and-time;
        mandatory true;
        description
          "Identifies the expiration date on the certificate.";
      }
    }
  }

  grouping trust-anchor-cert-grouping {
    description
      "A trust anchor certificate, certificate and a notification for when
       it is about to (or expire or has already has) expire."; expired.";
    leaf cert-data {
      nacm:default-deny-all;
      type trust-anchor-cert-cms;
      description
        "The binary certificate data for this certificate.";
    }
    uses certificate-expiration-grouping;
  }

  grouping end-entity-cert-grouping {
    description
      "An end entity certificate, end-entity certificate and a notification for when
       it is about to (or expire or has already has) expire. expired.  Implementations
       SHOULD assert that, where used, the end entity end-entity certificate
       contains the expected public key.";
    leaf cert-data {
      nacm:default-deny-all;
      type end-entity-cert-cms;
      description
        "The binary certificate data for this certificate.";
    }
    uses certificate-expiration-grouping;
  }

  grouping generate-csr-grouping {
    description
      "Defines the 'generate-csr' action.";
    action generate-csr {
      if-feature "csr-generation";
      nacm:default-deny-all;
      description
        "Generates a certificate signing request structure for
         the associated asymmetric key using the passed subject
         and attribute values.

         This action 'action' statement is only available when the
         associated 'public-key-format' node's value is
         'subject-public-key-info-format'.";
      input {
        leaf csr-format {
          type identityref {
            base csr-format;
          }
          mandatory true;
          description
            "Specifies the format for the returned certificate.";
        }
        leaf csr-info {
          type csr-info;
          mandatory true;
          description
            "A CertificationRequestInfo structure, as defined in
             RFC 2986.

             Enables the client to provide a fully-populated fully populated
             CertificationRequestInfo structure that the server
             only needs to sign in order to generate the complete
             'CertificationRequest'
             CertificationRequest structure to return in the
             'output'.

             The 'AlgorithmIdentifier' field contained inside
             the 'SubjectPublicKeyInfo' field MUST be one known
             to be supported by the device.";
          reference
            "RFC 2986:
               PKCS #10: Certification Request Syntax Specification
             RFC AAAA: 9640:
               YANG Data Types and Groupings for Cryptography";
        }
      }
      output {
        choice csr-type {
          mandatory true;
          description
            "A choice amongst certificate signing request formats.
             Additional formats MAY be augmented into this 'choice'
             statement by future efforts.";
          case p10-csr {
            leaf p10-csr {
              type p10-csr;
              description
                "A CertificationRequest, as defined in RFC 2986.";
            }
            description
              "A CertificationRequest, as defined in RFC 2986.";
            reference
              "RFC 2986:
                 PKCS #10: Certification Request Syntax Specification
               RFC AAAA: 9640:
                 YANG Data Types and Groupings for Cryptography";
          }
        }
      }
    }
  } // generate-csr-grouping

  grouping asymmetric-key-pair-with-cert-grouping {
    description
      "A private/public key pair and an associated certificate.
       Implementations MUST assert that the certificate contains
       the matching public key.";
    uses asymmetric-key-pair-grouping;
    uses end-entity-cert-grouping;
    uses generate-csr-grouping;
  } // asymmetric-key-pair-with-cert-grouping

  grouping asymmetric-key-pair-with-certs-grouping {
    description
      "A private/public key pair and a list of associated
       certificates.  Implementations MUST assert that
       certificates contain the matching public key.";
    uses asymmetric-key-pair-grouping;
    container certificates {
      nacm:default-deny-write;
      description
        "Certificates associated with this asymmetric key.";
      list certificate {
        key "name";
        description
          "A certificate for this asymmetric key.";
        leaf name {
          type string;
          description
            "An arbitrary name for the certificate.";
        }
        uses end-entity-cert-grouping {
          refine "cert-data" {
            mandatory true;
          }
        }
      }
    }
    uses generate-csr-grouping;
  } // asymmetric-key-pair-with-certs-grouping

}
]]></artwork>
        <t keepWithPrevious="true">&lt;CODE ENDS&gt;</t>
]]></sourcecode>
      </section>
    </section>
    <section>
      <name>Security Considerations</name>
      <section>
        <name>No Support for CRMF</name>
        <t>This document uses PKCS #10 <xref target="RFC2986"/> for the
          "generate-certificate-signing-request"
          "generate-csr" action.  The use of Certificate
          Request Message Format (CRMF) <xref target="RFC4211"/> was considered,
          but it was unclear if there was market demand for it.  If it is desired
          to support CRMF in the future, a backwards compatible solution can be
          defined at that time.</t>
      </section>
      <section>
        <name>No Support for Key Generation</name>
        <t>Early revisions of this document included "rpc" statements for
            generating symmetric and asymmetric keys.  These statements were
            removed due to an inability to obtain consensus for how to
            generically identify the key-algorithm key algorithm to use.  Hence, the
            solution presented in this document only supports keys to be
        configured via an external client.</t>
        <t>Separate protocol-specific modules can present protocol-specific
            key-generating RPCs (e.g., the "generate-public-key" "generate-asymmetric-key-pair" RPC in
            <xref target="I-D.ietf-netconf-ssh-client-server"/> target="RFC9644"/>
            and <xref target="I-D.ietf-netconf-tls-client-server"/>).</t> target="RFC9645"/>).</t>
      </section>
      <section>
        <name>Unconstrained Public Key Usage</name>
        <t>This module defines the "public-key-grouping" grouping, which
            enables the configuration of public keys without constraints on
            their usage, e.g., what operations the key is allowed to be used
            for (encryption, (e.g., encryption, verification, or both).</t>
        <t>The "asymmetric-key-pair-grouping" grouping uses the aforementioned
            "public-key-grouping" grouping, grouping and carries the same traits.</t>
        <t>The "asymmetric-key-pair-with-cert-grouping" grouping uses the
            aforementioned "asymmetric-key-pair-grouping" grouping, whereby
            associated certificates MUST <bcp14>MUST</bcp14> constrain the usage of the public
            key according to local policy.</t>
      </section>
      <section>
        <name>Unconstrained Private Key Usage</name>
        <t>This module defines the "asymmetric-key-pair-grouping" grouping,
            which enables the configuration of private keys without
            constraints on their usage, e.g., what operations the key is
            allowed to be used for (e.g., signature, decryption, or both).</t>
        <t>The "asymmetric-key-pair-with-cert-grouping" grouping uses the aforementioned
            "asymmetric-key-pair-grouping" grouping, whereby configured certificates
            (e.g., identity certificates) may constrain the use of the public
            key according to local policy.</t>
      </section>
      <section>
        <name>Cleartext Passwords and Keys</name>
        <t>The module contained within this document enables, only when
          specific "feature" statements are enabled, for the cleartext
          value of passwords and keys to be stored in the configuration
          database.  Storing cleartext values for passwords and keys is
          NOT RECOMMENDED.</t>
          <bcp14>NOT RECOMMENDED</bcp14>.</t>
      </section>
      <section>
        <name>Encrypting Passwords and Keys</name>
        <t>The module contained within this document enables cleartext
            passwords and keys to be encrypted via another key, either
            symmetric or asymmetric.  Both formats use a CMS structure
            (EncryptedData and EnvelopedData EnvelopedData, respectively), which allows
            any encryption algorithm to be used.</t>
        <t>To securely encrypt a password or key with a symmetric key, a
        proper block cipher mode mode, such as an AEAD Authenticated Encryption with Associated Data (AEAD) or CBC MUST Cipher Block Chaining (CBC), <bcp14>MUST</bcp14> be used.

	This
            ensures that a random IV Initialization Vector (IV) is part of the input, which guarantees
            that the output for encrypting the same password or key still
            produces a different unpredictable ciphertext. This avoids leaking
            that some encrypted keys or passwords are the same and makes it
            much harder to pre-generate rainbow tables to brute force brute-force attack
            weak passwords.
	The ECB Electronic Codebook (ECB) block cipher mode MUST NOT <bcp14>MUST NOT</bcp14> be used.</t>
      </section>
      <section>
        <name>Deletion of Cleartext Key Values</name>
        <t>This module defines storage for cleartext key values that SHOULD <bcp14>SHOULD</bcp14>
            be zeroized when deleted, deleted so as to prevent the remnants of their
            persisted storage locations from being analyzed in any meaningful
            way.</t>
        <t>The cleartext key values are the "cleartext-symmetric-key" node defined in the
            "symmetric-key-grouping" grouping (<xref target="symmetric-key-grouping"/>)
              and the "cleartext-private-key" node defined in the "asymmetric-key-pair-grouping"
              grouping ("<xref (<xref target="asymmetric-key-pair-grouping"/>).</t>
      </section>
      <section>
        <name>Considerations for the "ietf-crypto-types" YANG Module</name>
        <t>This section follows is modeled after the template defined in <xref section="3.7.1" target="RFC8407"/>.</t>
        <t>The "ietf-crypto-types" YANG module in this document defines "grouping" statements
            that are designed to be accessed via YANG based YANG-based management
            protocols, such as NETCONF <xref target="RFC6241"/> and RESTCONF
            <xref target="RFC8040"/>.  Both of these protocols have
            mandatory-to-implement secure transport layers (e.g., SSH, TLS)
            with Secure Shell (SSH) <xref target="RFC4252"/>, TLS <xref target="RFC8446"/>, and QUIC <xref target="RFC9000"/>) and mandatory-to-implement mutual authentication.</t>
        <t>The Network Configuration Access Control Model (NACM) <xref target="RFC8341"/>
            provides the means to restrict access for particular users to a
            pre-configured
            preconfigured subset of all available protocol operations and
            content.</t>
        <t>Since the module in this document only defines groupings,
            these considerations are primarily for the designers of other
            modules that use these groupings.</t>
        <t>Some of the readable data nodes defined in this YANG module
            may be considered sensitive or vulnerable in some network
            environments. It is thus important to control read access
            (e.g., via get, get-config, or notification) to these
            data nodes. The following subtrees and data nodes have particular
            sensitivity/vulnerability:
        </t>
        <ul spacing="normal">
          <li>
            <t>The "cleartext-password" node:
            </t>
            <ul empty="true">
              <li>The "cleartext-password" node defined in the "password-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.</li>
            </ul>
          </li>
          <li>
            <t>The "cleartext-symmetric-key" node:
            </t>
            <ul empty="true">
              <li>The "cleartext-symmetric-key" node defined in the "symmetric-key-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.</li>
            </ul>
          </li>
          <li>
            <t>The "cleartext-private-key" node:
            </t>
            <ul empty="true">
              <li>The "cleartext-private-key" node defined in the "asymmetric-key-pair-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.</li> applied to it.</li>
            </ul>
          </li>
          <li>
            <t>The "cert-data" node:
            </t>
            <ul empty="true">
              <li>The "cert-data" node, node defined in both the "trust-anchor-cert-grouping"
                    and "end-entity-cert-grouping" groupings, groupings is additionally sensitive to
                    read operations, as certificates may provide insight into which other
                    resources/applications/servers this particular server communicates with,
                    as well as potentially  divulge personally identifying information (e.g.,
                    end-entity certificates).  For this reason, the NACM extension
                    "default-deny-all" has been applied.</li> applied to it.</li>
            </ul>
          </li>
        </ul>
        <t>All the writable data nodes defined by all the groupings defined
            in this module may be considered sensitive or vulnerable in
            some network environments.  For instance, even the modification
            of a public key or a certificate can dramatically alter the
            implemented security policy.  For this reason, the NACM extension
            "default-deny-write" has been applied to all the data nodes
            defined in the module.</t>
        <t>Some of the operations in this YANG module may be considered
            sensitive or vulnerable in some network environments. It is
            thus important to control access to these operations. These
            are the operations and their sensitivity/vulnerability:
        </t>
        <ul spacing="normal">
          <li>
            <t>generate-certificate-signing-request:
            <t>generate-csr:
            </t>
            <ul empty="true">
              <li>This "action" statement SHOULD <bcp14>SHOULD</bcp14> only be executed by authorized
                    users.  For this reason, the NACM extension "default-deny-all"
                    has been applied.  Note that NACM uses "default-deny-all"
                    to protect "RPC" "rpc" and "action" statements; it does not define,
                    e.g., an extension called "default-deny-execute".</li>
              <li>For this action, it is RECOMMENDED <bcp14>RECOMMENDED</bcp14> that implementations assert
                    channel binding <xref target="RFC5056"/>, target="RFC5056"/> so as to ensure
                    that the application layer that sent the request is the same
                    as the device authenticated when the secure transport layer
                    was established.</li>
            </ul>
          </li>
        </ul>
      </section>
    </section>
    <section>
      <name>IANA Considerations</name>
      <section>
        <name>The "IETF XML" IETF XML Registry</name>
        <t>This document registers one
        <t>IANA has registered the following URI in the "ns" subregistry registry
          of the "IETF XML" registry <xref target="RFC3688"/>.  Following
          the format in XML Registry" <xref target="RFC3688"/>, target="RFC3688"/>.</t>
<dl newline="false" spacing="compact">
   <dt>URI:</dt> <dd>urn:ietf:params:xml:ns:yang:ietf-crypto-types</dd>
   <dt>Registrant Contact:</dt> <dd>The IESG</dd>
   <dt>XML:</dt> <dd>N/A; the following
          registration requested URI is requested:</t>
        <artwork><![CDATA[
   URI: urn:ietf:params:xml:ns:yang:ietf-crypto-types
   Registrant Contact: The IESG
   XML: an XML namespace.</dd>
</dl>
<!--[rfced] note for IANA:
Please update comma to semicolon here.

OLD: N/A, the requested URI is an XML namespace.
]]></artwork>
NEW: N/A; the requested URI is an XML namespace.
-->
      </section>
      <section>
        <name>The "YANG YANG Module Names" Names Registry</name>
        <t>This document registers one
        <t>IANA has registered the following YANG module in the
          "YANG Module Names" registry <xref target="RFC6020"/>.
          Following the format in <xref target="RFC6020"/>, the
          following registration is requested:</t>
        <artwork><![CDATA[
   name:         ietf-crypto-types
   namespace:    urn:ietf:params:xml:ns:yang:ietf-crypto-types
   prefix:       ct
   reference:    RFC AAAA
]]></artwork>
          </t>
<dl newline="false" spacing="compact">
  <dt>Name:</dt>         <dd>ietf-crypto-types</dd>
  <dt>Namespace:</dt>    <dd>urn:ietf:params:xml:ns:yang:ietf-crypto-types</dd>
  <dt>Prefix:</dt>       <dd>ct</dd>
  <dt>Reference:</dt>    <dd>RFC 9640</dd>
</dl>
      </section>
    </section>
  </middle>
  <back>

<displayreference target="I-D.ietf-netconf-http-client-server"
to="HTTP-CLIENT-SERVER"/>
<displayreference target="I-D.ietf-netconf-netconf-client-server"
to="NETCONF-CLIENT-SERVER"/>
<displayreference target="I-D.ietf-netconf-restconf-client-server"
to="RESTCONF-CLIENT-SERVER"/>

    <references>
      <name>References</name>
      <references>
        <name>Normative References</name>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <author fullname="S. Bradner" initials="S." surname="Bradner"/>
            <date month="March" year="1997"/>
            <abstract>
              <t>In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="2119"/>
          <seriesInfo name="DOI" value="10.17487/RFC2119"/>
        </reference>
        <!--<?rfc include="reference.RFC.2404.xml"?>-->
        <!--<?rfc include="reference.RFC.3565.xml"?>
        <?rfc include="reference.RFC.3686.xml"?>
        <?rfc include="reference.RFC.4106.xml"?>-->
        <reference anchor="RFC4253" target="https://www.rfc-editor.org/info/rfc4253" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4253.xml">
          <front>
            <title>The Secure Shell (SSH) Transport Layer Protocol</title>
            <author fullname="T. Ylonen" initials="T." surname="Ylonen"/>
            <author fullname="C. Lonvick" initials="C." role="editor" surname="Lonvick"/>
            <date month="January" year="2006"/>
            <abstract>
              <t>The Secure Shell (SSH) is a protocol for secure remote login and other secure network services over an insecure network.</t>
              <t>This document describes the SSH transport layer protocol, which typically runs on top of TCP/IP. The protocol can be used as a basis for a number of secure network services. It provides strong encryption, server authentication, and integrity protection. It may also provide compression.</t>
              <t>Key exchange method, public key algorithm, symmetric encryption algorithm, message authentication algorithm, and hash algorithm are all negotiated.</t>
              <t>This document also describes the Diffie-Hellman key exchange method and the minimal set of algorithms that are needed to implement the SSH transport layer protocol. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="4253"/>
          <seriesInfo name="DOI" value="10.17487/RFC4253"/>
        </reference>
        <!--<?rfc include="reference.RFC.4279.xml"?>
        <?rfc include="reference.RFC.4309.xml"?>
        <?rfc include="reference.RFC.4494.xml"?>
        <?rfc include="reference.RFC.4543.xml"?>
        <?rfc include="reference.RFC.4868.xml"?>-->
        <reference anchor="RFC5280" target="https://www.rfc-editor.org/info/rfc5280" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5280.xml">
          <front>
            <title>Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile</title>
            <author fullname="D. Cooper" initials="D." surname="Cooper"/>
            <author fullname="S. Santesson" initials="S." surname="Santesson"/>
            <author fullname="S. Farrell" initials="S." surname="Farrell"/>
            <author fullname="S. Boeyen" initials="S." surname="Boeyen"/>
            <author fullname="R. Housley" initials="R." surname="Housley"/>
            <author fullname="W. Polk" initials="W." surname="Polk"/>
            <date month="May" year="2008"/>
            <abstract>
              <t>This memo profiles the X.509 v3 certificate and X.509 v2 certificate revocation list (CRL) for use in the Internet. An overview of this approach and model is provided as an introduction. The X.509 v3 certificate format is described in detail, with additional information regarding the format and semantics of Internet name forms. Standard certificate extensions are described and two Internet-specific extensions are defined. A set of required certificate extensions is specified. The X.509 v2 CRL format is described in detail along with standard and Internet-specific extensions. An algorithm for X.509 certification path validation is described. An ASN.1 module and examples are provided in the appendices. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5280"/>
          <seriesInfo name="DOI" value="10.17487/RFC5280"/>
        </reference>
        <reference anchor="RFC5652" target="https://www.rfc-editor.org/info/rfc5652" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5652.xml">
          <front>
            <title>Cryptographic Message Syntax (CMS)</title>
            <author fullname="R. Housley" initials="R." surname="Housley"/>
            <date month="September" year="2009"/>
            <abstract>
              <t>This document describes the Cryptographic Message Syntax (CMS). This syntax is used to digitally sign, digest, authenticate, or encrypt arbitrary message content. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="70"/>
          <seriesInfo name="RFC" value="5652"/>
          <seriesInfo name="DOI" value="10.17487/RFC5652"/>
        </reference>
        <!--<?rfc include="reference.RFC.5656.xml"?>-->
        <reference anchor="RFC5958" target="https://www.rfc-editor.org/info/rfc5958" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5958.xml">
          <front>
            <title>Asymmetric Key Packages</title>
            <author fullname="S. Turner" initials="S." surname="Turner"/>
            <date month="August" year="2010"/>
            <abstract>
              <t>This document defines the syntax for private-key information and a content type for it. Private-key information includes a private key for a specified public-key algorithm and a set of attributes. The Cryptographic Message Syntax (CMS), as defined in RFC 5652, can be used to digitally sign, digest, authenticate, or encrypt the asymmetric key format content type. This document obsoletes RFC 5208. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5958"/>
          <seriesInfo name="DOI" value="10.17487/RFC5958"/>
        </reference>
        <reference anchor="RFC6031" target="https://www.rfc-editor.org/info/rfc6031" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6031.xml">
          <front>
            <title>Cryptographic Message Syntax (CMS) Symmetric Key Package Content Type</title>
            <author fullname="S. Turner" initials="S." surname="Turner"/>
            <author fullname="R. Housley" initials="R." surname="Housley"/>
            <date month="December" year="2010"/>
            <abstract>
              <t>This document defines the symmetric key format content type. It is transport independent. The Cryptographic Message Syntax (CMS) can be used to digitally sign, digest, authenticate, or encrypt this content type. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6031"/>
          <seriesInfo name="DOI" value="10.17487/RFC6031"/>
        </reference>
        <!--<?rfc include="reference.RFC.6187.xml"?>-->
        <reference anchor="RFC6960" target="https://www.rfc-editor.org/info/rfc6960" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6960.xml">
          <front>
            <title>X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP</title>
            <author fullname="S. Santesson" initials="S." surname="Santesson"/>
            <author fullname="M. Myers" initials="M." surname="Myers"/>
            <author fullname="R. Ankney" initials="R." surname="Ankney"/>
            <author fullname="A. Malpani" initials="A." surname="Malpani"/>
            <author fullname="S. Galperin" initials="S." surname="Galperin"/>
            <author fullname="C. Adams" initials="C." surname="Adams"/>
            <date month="June" year="2013"/>
            <abstract>
              <t>This document specifies a protocol useful in determining the current status of a digital certificate without requiring Certificate Revocation Lists (CRLs). Additional mechanisms addressing PKIX operational requirements are specified in separate documents. This document obsoletes RFCs 2560 and 6277. It also updates RFC 5912.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6960"/>
          <seriesInfo name="DOI" value="10.17487/RFC6960"/>
        </reference>
        <reference anchor="RFC6991" target="https://www.rfc-editor.org/info/rfc6991" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6991.xml">
          <front>
            <title>Common YANG Data Types</title>
            <author fullname="J. Schoenwaelder" initials="J." role="editor" surname="Schoenwaelder"/>
            <date month="July" year="2013"/>
            <abstract>
              <t>This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6991"/>
          <seriesInfo name="DOI" value="10.17487/RFC6991"/>
        </reference>
        <reference anchor="RFC7093" target="https://www.rfc-editor.org/info/rfc7093" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7093.xml">
          <front>
            <title>Additional Methods for Generating Key Identifiers Values</title>
            <author fullname="S. Turner" initials="S." surname="Turner"/>
            <author fullname="S. Kent" initials="S." surname="Kent"/>
            <author fullname="J. Manger" initials="J." surname="Manger"/>
            <date month="December" year="2013"/>
            <abstract>
              <t>This document specifies additional example methods for generating Key Identifier values for use in the AKI (Authority Key Identifier) and SKI (Subject Key Identifier) certificate extensions.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7093"/>
          <seriesInfo name="DOI" value="10.17487/RFC7093"/>
        </reference>
        <!--<?rfc include="reference.RFC.7919.xml"?>-->
        <reference anchor="RFC7950" target="https://www.rfc-editor.org/info/rfc7950" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7950.xml">
          <front>
            <title>The YANG 1.1 Data Modeling Language</title>
            <author fullname="M. Bjorklund" initials="M." role="editor" surname="Bjorklund"/>
            <date month="August" year="2016"/>
            <abstract>
              <t>YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7950"/>
          <seriesInfo name="DOI" value="10.17487/RFC7950"/>
        </reference>
        <reference anchor="RFC8017" target="https://www.rfc-editor.org/info/rfc8017" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8017.xml">
          <front>
            <title>PKCS #1: RSA Cryptography Specifications Version 2.2</title>
            <author fullname="K. Moriarty" initials="K." role="editor" surname="Moriarty"/>
            <author fullname="B. Kaliski" initials="B." surname="Kaliski"/>
            <author fullname="J. Jonsson" initials="J." surname="Jonsson"/>
            <author fullname="A. Rusch" initials="A." surname="Rusch"/>
            <date month="November" year="2016"/>
            <abstract>
              <t>This document provides recommendations for the implementation of public-key cryptography based on the RSA algorithm, covering cryptographic primitives, encryption schemes, signature schemes with appendix, and ASN.1 syntax for representing keys and for identifying the schemes.</t>
              <t>This document represents a republication of PKCS #1 v2.2 from RSA Laboratories' Public-Key Cryptography Standards (PKCS) series. By publishing this RFC, change control is transferred to the IETF.</t>
              <t>This document also obsoletes RFC 3447.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8017"/>
          <seriesInfo name="DOI" value="10.17487/RFC8017"/>
        </reference>
        <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml">
          <front>
            <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
            <author fullname="B. Leiba" initials="B." surname="Leiba"/>
            <date month="May" year="2017"/>
            <abstract>
              <t>RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="8174"/>
          <seriesInfo name="DOI" value="10.17487/RFC8174"/>
        </reference>
        <!--<?rfc include="reference.RFC.8268.xml"?>
        <?rfc include="reference.RFC.8332.xml"?>-->
        <reference anchor="RFC8341" target="https://www.rfc-editor.org/info/rfc8341" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8341.xml">
          <front>
            <title>Network Configuration Access Control Model</title>
            <author fullname="A. Bierman" initials="A." surname="Bierman"/>
            <author fullname="M. Bjorklund" initials="M." surname="Bjorklund"/>
            <date month="March" year="2018"/>
            <abstract>
              <t>The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.</t>
              <t>This document obsoletes RFC 6536.</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="91"/>
          <seriesInfo name="RFC" value="8341"/>
          <seriesInfo name="DOI" value="10.17487/RFC8341"/>
        </reference>
        <!--<?rfc include="reference.RFC.8422.xml"?>
        <?rfc include="reference.RFC.8446.xml"?>-->

	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2986.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4252.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4253.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5280.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5652.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5915.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5958.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6031.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6960.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6991.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7093.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7950.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8017.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8040.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/>
	<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8341.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8446.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9000.xml"/>

        <reference anchor="ITU.X680.2021" target="https://www.itu.int/rec/T-REC-X.680-202102-I">
          <front>
            <title>Information technology - Abstract Syntax Notation One (ASN.1):
              Specification of basic notation
            </title>
            <author>
              <organization>International Telecommunication Union</organization>
              <organization>ITU-T</organization>
            </author>
            <date month="February" year="2021"/>
          </front>
          <seriesInfo name="ITU-T Recommendation X.680," value="ISO/IEC 8824-1:2021"/> Recommendation" value="X.680"/>
	  <seriesInfo name="ISO/IEC" value="8824-1:2021"/>
        </reference>

        <reference anchor="ITU.X690.2021" target="https://www.itu.int/rec/T-REC-X.690-202102-I">
          <front>
            <title>Information Technology - ASN.1 encoding rules: Specification of Basic
            Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished
            Encoding Rules (DER)</title>
            <author>
              <organization>International Telecommunication Union</organization>
              <organization>ITU-T</organization>
            </author>
            <date month="February" year="2021"/>
          </front>
          <seriesInfo name="ITU-T Recommendation X.690," value="ISO/IEC 8825-1:2021"/> Recommendation" value="X.690"/>
	  <seriesInfo name="ISO/IEC" value="8825-1:2021"/>
        </reference>

      </references>
      <references>
        <name>Informative References</name>
        <reference anchor="RFC2986" target="https://www.rfc-editor.org/info/rfc2986" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2986.xml">
          <front>
            <title>PKCS #10: Certification Request Syntax Specification Version 1.7</title>
            <author fullname="M. Nystrom" initials="M." surname="Nystrom"/>
            <author fullname="B. Kaliski" initials="B." surname="Kaliski"/>
            <date month="November" year="2000"/>
            <abstract>
              <t>This memo represents a republication of PKCS #10 v1.7 from RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, and change control is retained within the PKCS process. The body

        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4211.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5056.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7317.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8259.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8407.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"/>
        <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8792.xml"/>

<!-- [I-D.ietf-netconf-trust-anchors] IESG state: RFC Ed Queue as of this document, except for the security considerations section, is taken directly from the PKCS #9 v2.0 or the PKCS #10 v1.7 document. This memo provides information for the Internet community.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="2986"/>
          <seriesInfo name="DOI" value="10.17487/RFC2986"/>
        </reference>
        <!--<?rfc include="reference.RFC.3174.xml"?>--> 03/21/24-->
       <reference anchor="RFC3688" target="https://www.rfc-editor.org/info/rfc3688" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3688.xml"> anchor="RFC9641" target="https://www.rfc-editor.org/info/rfc9641">
	 <front>
            <title>The IETF XML Registry</title>
            <author fullname="M. Mealling" initials="M." surname="Mealling"/>
            <date month="January" year="2004"/>
            <abstract>
              <t>This document describes an IANA maintained registry
	   <title>A YANG Data Model for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="81"/>
          <seriesInfo name="RFC" value="3688"/>
          <seriesInfo name="DOI" value="10.17487/RFC3688"/>
        </reference>
        <reference anchor="RFC4211" target="https://www.rfc-editor.org/info/rfc4211" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4211.xml">
          <front>
            <title>Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF)</title> a Truststore</title>
	   <author fullname="J. Schaad" initials="J." surname="Schaad"/> initials="K." surname="Watsen" fullname="Kent Watsen">
	     <organization>Watsen Networks</organization>
	   </author>
	   <date month="September" year="2005"/>
            <abstract>
              <t>This document describes the Certificate Request Message Format (CRMF) syntax and semantics. This syntax is used to convey a request for a certificate to a Certification Authority (CA), possibly via a Registration Authority (RA), for the purposes of X.509 certificate production. The request will typically include a public key and the associated registration information. This document does not define a certificate request protocol. [STANDARDS-TRACK]</t>
            </abstract> year="2024"/>
	 </front>
	 <seriesInfo name="RFC" value="4211"/> value="9641"/>
	 <seriesInfo name="DOI" value="10.17487/RFC4211"/> value="10.17487/RFC9641"/>
       </reference>
        <!--<?rfc include="reference.RFC.4493.xml"?>-->
        <reference anchor="RFC5056" target="https://www.rfc-editor.org/info/rfc5056" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5056.xml">
          <front>
            <title>On the Use of Channel Bindings to Secure Channels</title>
            <author fullname="N. Williams" initials="N." surname="Williams"/>
            <date month="November" year="2007"/>
            <abstract>
              <t>The concept of channel binding allows applications to establish that the two end-points of a secure channel at one network layer are the same

<!-- [I-D.ietf-netconf-keystore] IESG state: RFC Ed Queue as at a higher layer by binding authentication at the higher layer to the channel at the lower layer. This allows applications to delegate session protection to lower layers, which has various performance benefits.</t>
              <t>This document discusses and formalizes the concept of channel binding to secure channels. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5056"/>
          <seriesInfo name="DOI" value="10.17487/RFC5056"/>
        </reference> 03/21/24-->
        <reference anchor="RFC5915" target="https://www.rfc-editor.org/info/rfc5915" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5915.xml"> anchor="RFC9642" target="https://www.rfc-editor.org/info/rfc9642">
	  <front>
            <title>Elliptic Curve Private Key Structure</title>
            <author fullname="S. Turner" initials="S." surname="Turner"/>
	    <title>A YANG Data Model for a Keystore</title>
	    <author fullname="D. Brown" initials="D." surname="Brown"/> initials="K." surname="Watsen" fullname="Kent Watsen">
	      <organization>Watsen Networks</organization>
	    </author>
	    <date month="June" year="2010"/>
            <abstract>
              <t>This document specifies the syntax and semantics for conveying Elliptic Curve (EC) private key information. The syntax and semantics defined herein are based on similar syntax and semantics defined by the Standards for Efficient Cryptography Group (SECG). This document is not an Internet Standards Track specification; it is published for informational purposes.</t>
            </abstract> month="September" year="2024"/>
	  </front>
	  <seriesInfo name="RFC" value="5915"/> value="9642"/>
	  <seriesInfo name="DOI" value="10.17487/RFC5915"/> value="10.17487/RFC9642"/>
	</reference>

<!-- [I-D.ietf-netconf-tcp-client-server] IESG state: RFC Ed Queue as of 03/21/24-->
        <reference anchor="RFC6020" target="https://www.rfc-editor.org/info/rfc6020" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6020.xml"> anchor="RFC9643" target="https://www.rfc-editor.org/info/rfc9643">
	  <front>
	    <title>YANG - A Data Modeling Language Groupings for the Network Configuration Protocol (NETCONF)</title>
            <author fullname="M. Bjorklund" initials="M." role="editor" surname="Bjorklund"/>
            <date month="October" year="2010"/>
            <abstract>
              <t>YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, TCP Clients and NETCONF notifications. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="6020"/>
          <seriesInfo name="DOI" value="10.17487/RFC6020"/>
        </reference>
        <!--<?rfc include="reference.RFC.6234.xml"?>-->
        <reference anchor="RFC6241" target="https://www.rfc-editor.org/info/rfc6241" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6241.xml">
          <front>
            <title>Network Configuration Protocol (NETCONF)</title> TCP Servers</title>
	    <author fullname="R. Enns" initials="R." role="editor" surname="Enns"/> initials="K." surname="Watsen" fullname="Kent Watsen">
	      <organization>Watsen Networks</organization>
	    </author>
	    <author fullname="M. Bjorklund" initials="M." role="editor" surname="Bjorklund"/>
            <author fullname="J. Schoenwaelder" initials="J." role="editor" surname="Schoenwaelder"/>
            <author fullname="A. Bierman" initials="A." role="editor" surname="Bierman"/>
            <date month="June" year="2011"/>
            <abstract>
              <t>The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration surname="Scharf" fullname="Michael Scharf">
	      <organization>Hochschule Esslingen - University of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK]</t>
            </abstract> Applied Sciences</organization>
	    </author>
	    <date month="September" year="2024"/>
	  </front>
	  <seriesInfo name="RFC" value="6241"/> value="9643"/>
	  <seriesInfo name="DOI" value="10.17487/RFC6241"/> value="10.17487/RFC9643"/>
	</reference>
        <!--<?rfc include="reference.RFC.6239.xml"?>
        <?rfc include="reference.RFC.6507.xml"?>
        <?rfc include="reference.RFC.8032.xml"?>-->

<!-- [I-D.ietf-netconf-ssh-client-server] IESG state: RFC Ed Queue as of 03/21/24-->
       <reference anchor="RFC7317" target="https://www.rfc-editor.org/info/rfc7317" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7317.xml"> anchor="RFC9644" target="https://www.rfc-editor.org/info/rfc9644">
	 <front>
            <title>A YANG Data Model for System Management</title>
            <author fullname="A. Bierman" initials="A." surname="Bierman"/>
            <author fullname="M. Bjorklund" initials="M." surname="Bjorklund"/>
            <date month="August" year="2014"/>
            <abstract>
              <t>This document defines a YANG data model for the configuration and identification of some common system properties within a device containing a Network Configuration Protocol (NETCONF) server. This document also includes data node definitions
	   <title>YANG Groupings for system identification, time-of-day management, user management, DNS resolver configuration, SSH Clients and some protocol operations for system management.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7317"/>
          <seriesInfo name="DOI" value="10.17487/RFC7317"/>
        </reference>
        <reference anchor="RFC8040" target="https://www.rfc-editor.org/info/rfc8040" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8040.xml">
          <front>
            <title>RESTCONF Protocol</title>
            <author fullname="A. Bierman" initials="A." surname="Bierman"/>
            <author fullname="M. Bjorklund" initials="M." surname="Bjorklund"/> SSH Servers</title>
	   <author fullname="K. Watsen" initials="K." surname="Watsen"/> surname="Watsen" fullname="Kent Watsen">
	     <organization>Watsen Networks</organization>
	   </author>
	   <date month="January" year="2017"/>
            <abstract>
              <t>This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).</t>
            </abstract> month="September" year="2024"/>
	 </front>
	 <seriesInfo name="RFC" value="8040"/> value="9644"/>
	 <seriesInfo name="DOI" value="10.17487/RFC8040"/> value="10.17487/RFC9644"/>
       </reference>

<!-- [I-D.ietf-netconf-tls-client-server] IESG state: RFC Ed Queue as of 03/21/24-->
        <reference anchor="RFC8340" target="https://www.rfc-editor.org/info/rfc8340" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8340.xml"> anchor="RFC9645" target="https://www.rfc-editor.org/info/rfc9645">
	  <front>
	    <title>YANG Tree Diagrams</title>
            <author fullname="M. Bjorklund" initials="M." surname="Bjorklund"/> Groupings for TLS Clients and TLS Servers</title>
	    <author fullname="L. Berger" initials="L." role="editor" surname="Berger"/> initials="K." surname="Watsen" fullname="Kent Watsen">
	      <organization>Watsen Networks</organization>
	    </author>
	    <date month="March" year="2018"/>
            <abstract>
              <t>This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language.</t>
            </abstract> month="September" year="2024"/>
	  </front>
	  <seriesInfo name="BCP" value="215"/>
          <seriesInfo name="RFC" value="8340"/> value="9645"/>
	  <seriesInfo name="DOI" value="10.17487/RFC8340"/> value="10.17487/RFC9645"/>
	</reference>
        <reference anchor="RFC8407" target="https://www.rfc-editor.org/info/rfc8407" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8407.xml">
          <front>
            <title>Guidelines for Authors and Reviewers

<!-- [I-D.ietf-netconf-http-client-server] IESG state: IESG Evaluation::AD Followup as of Documents Containing YANG Data Models</title>
            <author fullname="A. Bierman" initials="A." surname="Bierman"/>
            <date month="October" year="2018"/>
            <abstract>
              <t>This memo provides guidelines for authors and reviewers 8/15/24-->
<xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-netconf-http-client-server"/>

<!-- [I-D.ietf-netconf-netconf-client-server] IESG state: AD Evaluation as of specifications containing YANG modules. Recommendations and procedures are defined, which are intended to increase interoperability and usability 8/15/24-->
<xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-netconf-netconf-client-server"/>

<!-- [I-D.ietf-netconf-restconf-client-server] IESG state: AD Evaluation as of Network Configuration Protocol (NETCONF) and RESTCONF protocol implementations that utilize YANG modules. This document obsoletes RFC 6087.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="216"/>
          <seriesInfo name="RFC" value="8407"/>
          <seriesInfo name="DOI" value="10.17487/RFC8407"/>
        </reference>
        <!--<?rfc include="reference.RFC.8439.xml"?>--> 8/15/24-->
<xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-netconf-restconf-client-server"/>

<reference anchor="RFC8342" target="https://www.rfc-editor.org/info/rfc8342" xml:base="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8342.xml"> anchor="W3C.REC-xml-20081126"
target="https://www.w3.org/TR/2008/REC-xml-20081126/">
  <front>
            <title>Network Management Datastore Architecture (NMDA)</title>
    <title>Extensible Markup Language (XML) 1.0
    (Fifth Edition)</title>
    <author fullname="M. Bjorklund" initials="M." surname="Bjorklund"/> initials="T." surname="Bray" fullname="Tim Bray"/>
    <author fullname="J. Schoenwaelder" initials="J." surname="Schoenwaelder"/>
            <author fullname="P. Shafer" initials="P." surname="Shafer"/> surname="Paoli" fullname="Jean Paoli"/>
    <author fullname="K. Watsen" initials="K." surname="Watsen"/> initials="C.M." surname="Sperberg-McQueen" fullname="C. M.
Sperberg-McQueen"/>
    <author fullname="R. Wilton" initials="R." surname="Wilton"/> initials="E." surname="Maler" fullname="Eve Maler"/>
    <author initials="F." surname="Yergeau" fullname="François Yergeau"/>
    <date month="March" year="2018"/>
            <abstract>
              <t>Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.</t>
            </abstract> month="November" year="2008"/>
  </front>
  <seriesInfo name="RFC" value="8342"/>
          <seriesInfo name="DOI" value="10.17487/RFC8342"/> name="World Wide Web Consortium
                    Recommendation" value="REC-xml-20081126"/>
</reference>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-crypto-types.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-trust-anchors.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-keystore.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-tcp-client-server.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-ssh-client-server.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-tls-client-server.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-http-client-server.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-netconf-client-server.xml"/>
        <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-netconf-restconf-client-server.xml"/>

      </references>
    </references>
    <section anchor="change-log">
      <name>Change Log</name>
      <section>
        <name>I-D to 00</name>
        <ul spacing="normal">
          <li>Removed groupings and notifications.</li>
          <li>Added typedefs for identityrefs.</li>
          <li>Added typedefs for other RFC 5280 structures.</li>
          <li>Added typedefs for other RFC 5652 structures.</li>
          <li>Added convenience typedefs for RFC 4253, RFC 5280, and RFC 5652.</li>
        </ul>
      </section>
      <section>
        <name>00 to 01</name>
        <ul spacing="normal">
          <li>Moved groupings from the draft-ietf-netconf-keystore here.</li>
        </ul>
      </section>
      <section>
        <name>01 to 02</name>
        <ul spacing="normal">
          <li>Removed unwanted "mandatory" and "must" statements.</li>
          <li>Added many new crypto algorithms (thanks Haiguang!)</li>
          <li>Clarified in asymmetric-key-pair-with-certs-grouping,
                 in certificates/certificate/name/description, that
                 if the name MUST NOT match the name of a certificate
                 that exists independently in &lt;operational&gt;, enabling
                 certs installed by the manufacturer (e.g., an IDevID).</li>
        </ul>
      </section>
      <section>
        <name>02 to 03</name>
        <ul spacing="normal">
          <li>renamed base identity 'asymmetric-key-encryption-algorithm' to 'asymmetric-key-algorithm'.</li>
          <li>added new 'asymmetric-key-algorithm' identities for secp192r1, secp224r1, secp256r1,
                 secp384r1, and secp521r1.</li>
          <li>removed 'mac-algorithm' identities for mac-aes-128-ccm, mac-aes-192-ccm, mac-aes-256-ccm,
                 mac-aes-128-gcm, mac-aes-192-gcm, mac-aes-256-gcm, and mac-chacha20-poly1305.</li>
          <li>for all -cbc and -ctr identities, renamed base identity 'symmetric-key-encryption-algorithm'
                 to 'encryption-algorithm'.</li>
          <li>for all -ccm and -gcm identities, renamed base identity 'symmetric-key-encryption-algorithm'
                 to 'encryption-and-mac-algorithm' and renamed the identity to remove the "enc-" prefix.</li>
          <li>for all the 'signature-algorithm' based identities, renamed from 'rsa-*' to 'rsassa-*'.</li>
          <li>removed all of the "x509v3-" prefixed 'signature-algorithm' based identities.</li>
          <li>added 'key-exchange-algorithm' based identities for 'rsaes-oaep' and 'rsaes-pkcs1-v1_5'.</li>
          <li>renamed typedef 'symmetric-key-encryption-algorithm-ref' to 'symmetric-key-algorithm-ref'.</li>
          <li>renamed typedef 'asymmetric-key-encryption-algorithm-ref' to 'asymmetric-key-algorithm-ref'.</li>
          <li>added typedef 'encryption-and-mac-algorithm-ref'.</li>
          <li>Updated copyright date, boilerplate template, affiliation, and folding algorithm.</li>
        </ul>
      </section>
      <section>
        <name>03 to 04</name>
        <ul spacing="normal">
          <li>ran YANG module through formatter.</li>
        </ul>
      </section>
      <section>
        <name>04 to 05</name>
        <ul spacing="normal">
          <li>fixed broken symlink causing reformatted YANG module to not show.</li>
        </ul>
      </section>
      <section>
        <name>05 to 06</name>
        <ul spacing="normal">
          <li>Added NACM annotations.</li>
          <li>Updated Security Considerations section.</li>
          <li>Added 'asymmetric-key-pair-with-cert-grouping' grouping.</li>
          <li>Removed text from 'permanently-hidden' enum regarding
                such keys not being backed up or restored.</li>
          <li>Updated the boilerplate text in module-level "description"
                statement to match copyeditor convention.</li>
          <li>Added an explanation to the 'public-key-grouping' and
                'asymmetric-key-pair-grouping' statements as for why the
                nodes are not mandatory (e.g., because they may exist only
                in &lt;operational&gt;.</li>
          <li>Added 'must' expressions to the 'public-key-grouping' and
                'asymmetric-key-pair-grouping' statements ensuring sibling
                nodes are either all exist or do not all exist.</li>
          <li>Added an explanation to the 'permanently-hidden' that the
                value cannot be configured directly by clients and servers
                MUST fail any attempt to do so.</li>
          <li>Added 'trust-anchor-certs-grouping' and 'end-entity-certs-grouping'
                (the plural form of existing groupings).</li>
          <li>Now states that keys created in &lt;operational&gt; by the
                *-hidden-key actions are bound to the lifetime of the parent
                'config true' node, and that subsequent invocations of either
                action results in a failure.</li>
        </ul>
      </section>
      <section>
        <name>06 to 07</name>
        <ul spacing="normal">
          <li>Added clarifications that implementations SHOULD assert that
                configured certificates contain the matching public key.</li>
          <li>Replaced the 'generate-hidden-key' and 'install-hidden-key' actions
                with special 'crypt-hash' -like input/output values.</li>
        </ul>
      </section>
      <section>
        <name>07 to 08</name>
        <ul spacing="normal">
          <li>Removed the 'generate-key and 'hidden-key' features.</li>
          <li>Added grouping symmetric-key-grouping</li>
          <li>Modified 'asymmetric-key-pair-grouping' to have a 'choice'
                 statement for the keystone module to augment into, as well
                 as replacing the 'union' with leafs (having different NACM
                 settings.</li>
        </ul>
      </section>
      <section>
        <name>08 to 09</name>
        <ul spacing="normal">
          <li>Converting algorithm from identities to enumerations.</li>
        </ul>
      </section>
      <section>
        <name>09 to 10</name>
        <ul spacing="normal">
          <li>All the below changes are to the algorithm enumerations defined in ietf-crypto-types.</li>
          <li>Add in support for key exchange over x.25519 and x.448 based on RFC 8418.</li>
          <li>Add in SHAKE-128, SHAKE-224, SHAKE-256, SHAKE-384 and SHAKE 512</li>
          <li>Revise/add in enum of signature algorithm for x25519 and x448</li>
          <li>Add in des3-cbc-sha1 for IPSec</li>
          <li>Add in sha1-des3-kd for IPSec</li>
          <li>Add in  definit for rc4-hmac and rc4-hmac-exp. These two algorithms have been deprecated in RFC 8429. But some existing draft in i2nsf may still want to use them.</li>
          <li>Add x25519 and x448 curve for asymmetric algorithms</li>
          <li>Add signature algorithms ed25519, ed25519-cts, ed25519ph</li>
          <li>add signature algorithms ed448, ed448ph</li>
          <li>Add in rsa-sha2-256 and rsa-sha2-512 for SSH protocols (rfc8332)</li>
        </ul>
      </section>
      <section>
        <name>10 to 11</name>
        <ul spacing="normal">
          <li>Added a "key-format" identity.</li>
          <li>Added symmetric keys to the example in <xref target="crypto-types-examples"/>.</li>
        </ul>
      </section>
      <section>
        <name>11 to 12</name>
        <ul spacing="normal">
          <li>Removed all non-essential (to NC/RC) algorithm types.</li>
          <li>Moved remaining algorithm types each into its own module.</li>
          <li>Added a 'config false' "algorithms-supported" list to each of the algorithm-type modules.</li>
        </ul>
      </section>
      <section>
        <name>12 to 13</name>
        <ul spacing="normal">
          <li>Added the four features: "[encrypted-]one-[a]symmetric-key-format", each protecting a 'key-format' identity of the same name.</li>
          <li>Added 'must' expressions asserting that the 'key-format' leaf exists whenever a non-hidden key is specified.</li>
          <li>Improved the 'description' statements and added 'reference' statements for the 'key-format' identities.</li>
          <li>Added a questionable forward reference to "encrypted-*" leafs in a couple 'when' expressions.</li>
          <li>Did NOT move "config false" alg-supported lists to SSH/TLS drafts.</li>
        </ul>
      </section>
      <section>
        <name>13 to 14</name>
        <ul spacing="normal">
          <li>Resolved the "FIXME: forward ref" issue by modulating 'must', 'when', and 'mandatory' expressions.</li>
          <li>Moved the 'generatesymmetric-key' and 'generate-asymmetric-key' actions from ietf-keystore to
                ietf-crypto-types, now as RPCs.</li>
          <li>Cleaned up various description statements and removed lingering FIXMEs.</li>
          <li>Converted the "iana-&lt;alg-type&gt;-algs" YANG modules to IANA registries with
                instructions for how to generate modules from the registries, whenever they may
                be updated.</li>
        </ul>
      </section>
      <section>
        <name>14 to 15</name>
        <ul spacing="normal">
          <li>Removed the IANA-maintained registries for symmetric, asymmetric, and hash algorithms.</li>
          <li>Removed the "generate-symmetric-key" and "generate-asymmetric-key" RPCs.</li>
          <li>Removed the "algorithm" node in the various symmetric and asymmetric key groupings.</li>
          <li>Added 'typedef csr' and 'feature certificate-signing-request-generation'.</li>
          <li>Refined a usage of "end-entity-cert-grouping" to make the "cert" node mandatory true.</li>
          <li>Added a "Note to Reviewers" note to first page.</li>
        </ul>
      </section>
      <section>
        <name>15 to 16</name>
        <ul spacing="normal">
          <li>Updated draft title (refer to "Groupings" too).</li>
          <li>Removed 'end-entity-certs-grouping' as it wasn't being used anywhere.</li>
          <li>Removed 'trust-anchor-certs-grouping' as it was no longer being used
                after modifying 'inline-or-truststore-certs-grouping' to use lists (not
                leaf-lists).</li>
          <li>Renamed "cert" to "cert-data" in trust-anchor-cert-grouping.</li>
          <li>Added "csr-info" typedef, to complement the existing "csr" typedef.</li>
          <li>Added "ocsp-request" and "ocsp-response" typedefs, to complement
                the existing "crl" typedef.</li>
          <li>Added "encrypted" cases to both symmetric-key-grouping and
                asymmetric-key-pair-grouping (Moved from Keystore draft).</li>
          <li>Expanded "Data Model Overview section(s) [remove "wall" of tree diagrams].</li>
          <li>Updated the Security Considerations section.</li>
        </ul>
      </section>
      <section>
        <name>16 to 17</name>
        <ul spacing="normal">
          <li>[Re]-added a "Strength of Keys Configured" Security Consideration</li>
          <li>Prefixed "cleartext-" in the "key" and "private-key" node names.</li>
        </ul>
      </section>
      <section>
        <name>17 to 18</name>
        <ul spacing="normal">
          <li>Fixed issues found by the SecDir review of the "keystore" draft.</li>
          <li>Added "password-grouping", discussed during the IETF 108 session.</li>
        </ul>
      </section>
      <section>
        <name>18 to 19</name>
        <ul spacing="normal">
          <li>Added a "Unconstrained Public Key Usage" Security Consideration to address
                 concern raised by SecDir of the 'truststore' draft.</li>
          <li>Added a "Unconstrained Private Key Usage" Security Consideration to address
                concern raised by SecDir of the 'truststore' draft.</li>
          <li>Changed the encryption strategy, after conferring with Russ Housley.</li>
          <li>Added a "password-grouping" example to the "crypto-types-usage" example.</li>
          <li>Added an "Encrypting Passwords" section to Security Consideration.</li>
          <li>Addressed other comments raised by YANG Doctor.</li>
        </ul>
      </section>
      <section>
        <name>19 to 20</name>
        <ul spacing="normal">
          <li>Nits found via YANG Doctors reviews.</li>
          <li>Aligned modules with `pyang -f` formatting.</li>
        </ul>
      </section>
      <section>
        <name>20 to 21</name>
        <ul spacing="normal">
          <li>Replaced "base64encodedvalue==" with "BASE64VALUE=".</li>
          <li>Accommodated SecDir review by Valery Smyslov.</li>
        </ul>
      </section>
      <section>
        <name>21 to 22</name>
        <ul spacing="normal">
          <li>fixup the 'WG Web' and 'WG List' lines in YANG module(s)</li>
          <li>fixup copyright (i.e., s/Simplified/Revised/) in YANG module(s)</li>
          <li>added 'hidden-keys' feature.</li>
        </ul>
      </section>
      <section>
        <name>22 to 23</name>
        <ul spacing="normal">
          <li>Fixed an example to reference correct key.</li>
          <li>Fixed an example to not have line-returns around the encoding for a binary value.</li>
        </ul>
      </section>
      <section>
        <name>23 to 24</name>
        <ul spacing="normal">
          <li>Added mandatory leaf "csr-format" to action "generate-csr".</li>
          <li>s/certificate-signing-request/csr/g in the YANG module.</li>
        </ul>
      </section>
      <section>
        <name>24 to 25</name>
        <ul spacing="normal">
          <li>Updated per Shepherd reviews impacting the suite of drafts.</li>
        </ul>
      </section>
      <section>
        <name>25 to 26</name>
        <ul spacing="normal">
          <li>Updated per Shepherd reviews impacting the suite of drafts.</li>
        </ul>
      </section>
      <section>
        <name>26 to 27</name>
        <ul spacing="normal">
          <li>Updated per Tom Petch and AD reviews.</li>
          <li>Renamed numerous "feature" statements and some "grouping" statements (in YANG)</li>
          <li>Added "csr-format" and "p10-csr-format" identities to doc (they were already in YANG)</li>
          <li>Clarified that the 'rsa-private-key-format' and 'ec-private-key-format' formats must be encoded using DER</li>
          <li>Added 'if-feature cleartext-passwords' statement to 'case cleartext-password' in grouping 'password-grouping'.</li>
          <li>Added 'if-feature cleartext-keys' statement to 'case cleartext-key' in grouping 'symmetric-key-grouping'.</li>
          <li>Added 'if-feature cleartext-cleartext-private-keys' statement to 'case cleartext-private-key' in grouping 'asymmetric-key-grouping'.</li>
          <li>Updated Section titles.</li>
          <li>Clarified Security Considerations about the "generate-public-key" RPCs.</li>
        </ul>
      </section>
      <section>
        <name>27 to 28</name>
        <ul spacing="normal">
          <li>Mostly addresses AD review comments.</li>
          <li>Also addresses on-list comment regarding public-keys being "mandatory true."</li>
          <li>Added note to Editor to fix line foldings.</li>
          <li>Factored 'private-key-grouping' from 'asymmetric-key-pair-grouping'.</li>
          <li>Made public-key in 'asymmetric-key-pair-grouping' be "mandatory false".</li>
          <li>Renamed 'encrypted-by-choice-grouping' to 'encrypted-by-grouping'.</li>
        </ul>
      </section>
      <section>
        <name>28 to 29</name>
        <ul spacing="normal">
          <li>Addresses Gen-ART review by Dale Worley.</li>
          <li>Addresses review by Tom Petch.</li>
        </ul>
      </section>
      <section>
        <name>29 to 30</name>
        <ul spacing="normal">
          <li>Addresses 1st-round of IESG reviews.</li>
        </ul>
      </section>
      <section>
        <name>30 to 32</name>
        <ul spacing="normal">
          <li>Addresses issues found in OpsDir of the ssh-client-server draft.</li>
          <li>Removed "Strength of Keys Conveyed" section.</li>
          <li>Renamed Security Considerations section s/Template for/Considerations for/</li>
          <li>Improved Security Consideration for 'cert-data' node.</li>
        </ul>
      </section>
      <section>
        <name>32 to 34</name>
        <ul spacing="normal">
          <li>Nothing changed.  Only bumped for automation...</li>
        </ul>
      </section>
    </section>
    <section numbered="false">
      <name>Acknowledgements</name>
      <t>The authors would like to thank the following for
        lively discussions on list and in the halls (ordered
          by first name):
          Balázs Kovács,
          Carsten Bormann,
          Dale Worley,
          Eric Voit,
          Éric Vyncke,
          Francesca Palombini,
          Jürgen Schönwälder,
          Lars Eggert,
          Liang Xia,
          Martin Björklund,
          Mahesh Jethanandani,
          Murray Kucherawy,
          Nick Hancock,
          Orie Steele,
          Paul Wouters,
          Rich Salz,
          Rifaat Shekh-Yusef,
          Rob Wilton,
          Roman Danyliw,
          Russ Housley,
          Sandra Murphy,
          Tom Petch,
          Valery Smyslov,
          Wang Haiguang,
          Warren Kumari,
          and Zaheduzzaman Sarker.
          <contact fullname="Balázs Kovács"/>,
          <contact fullname="Carsten Bormann"/>,
          <contact fullname="Dale Worley"/>,
          <contact fullname="Eric Voit"/>,
          <contact fullname="Éric Vyncke"/>,
          <contact fullname="Francesca Palombini"/>,
          <contact fullname="Jürgen Schönwälder"/>,
          <contact fullname="Lars Eggert"/>,
          <contact fullname="Liang Xia"/>,
          <contact fullname="Mahesh Jethanandani"/>,
          <contact fullname="Martin Björklund"/>,
          <contact fullname="Murray Kucherawy"/>,
          <contact fullname="Nick Hancock"/>,
          <contact fullname="Orie Steele"/>,
          <contact fullname="Paul Wouters"/>,
          <contact fullname="Rich Salz"/>,
          <contact fullname="Rifaat Shekh-Yusef"/>,
          <contact fullname="Rob Wilton"/>,
          <contact fullname="Roman Danyliw"/>,
          <contact fullname="Russ Housley"/>,
          <contact fullname="Sandra Murphy"/>,
          <contact fullname="Tom Petch"/>,
          <contact fullname="Valery Smyslov"/>,
          <contact fullname="Wang Haiguang"/>,
          <contact fullname="Warren Kumari"/>,
          and <contact fullname="Zaheduzzaman Sarker"/>.
      </t>
    </section>
  </back>
</rfc>