draft-brown-eppsig.xml

<?xml version="1.0" encoding="US-ASCII"?>

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]>

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<rfc category="exp" docName="draft-brown-eppsig" ipr="trust200902">

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ipr values: full3667, noModification3667, noDerivatives3667
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<!-- ***** FRONT MATTER ***** -->

<front>

<title abbrev="Launch Phase Mapping for EPP">XML Digital Signatures Extension for the Extensible Provisioning Protocol</title>

<author fullname="Gavin Brown" initials="G.B." surname="Brown">

<organization>CentralNic Ltd</organization>

<address>

<postal>

<street>35-39 Mooregate</street>

<city>London</city>

<region>England</region>

<code>EC2R 6AR</code>

<country>GB</country>

</postal>

<phone>+44 8700 170 900</phone>

<email>gavin.brown@centralnic.com</email>

<uri>http://www.centralnic.com</uri>

</address>

</author>

<date month="September" year="2011" />

<!-- Meta-data Declarations -->

<area>Applications</area>

<workgroup>Internet Engineering Task Force</workgroup>

<keyword>EPP, XML, Signatures, Cryptography</keyword>

<abstract>

<t>This document describes an Extensible Provisioning Protocol (EPP)
extension mapping for the use of XML Digital Signatures.
</t>

</abstract>

</front>

<middle>

<section title="Introduction">

<t>This document describes an extension mapping for version 1.0 of the
<xref target="RFC5730">Extensible Provisioning Protocol (EPP)</xref>.
This EPP mapping provides a mechanism by which <xref target="RFC3275">digital
signatures</xref> may be incorporated into EPP frames.</t>

<t>While EPP provides a number of security features, such as strong client-server
authentication, it provides no mechanism for non-repudiation or authentication
of origin. This extension provides a means by which the contents of an EPP frame
may be digitally signed, preventing future repudiation by the client or server
which produced them.</t>

<section title="Conventions Used in This Document">

<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in
<xref target="RFC2119">RFC 2119</xref>.</t>

<t>
XML is case sensitive.  Unless stated otherwise, XML specifications
and examples provided in this document MUST be interpreted in the
character case presented in order to develop a conforming
implementation.
</t>

<t>
"eppSig-1.0" is used as an abbreviation for "urn:centralnic:params:xml:ns:eppSig-1.0".
The XML namespace prefix "eppSig" is used, but implementations MUST NOT depend on it and
instead employ a proper namespace-aware XML parser and serializer to interpret and output
the XML documents.
</t>

</section>

</section>

<section title="Use Cases">

<t>Digital signatures may be useful in a number of scenarios, such as:</t>

<t><list style="format %d.">
  <t>a registry which charges a very high fee for object provisioning, where the
  cost of refunds and chargebacks is sufficiently high that it is necessary to deter
  frivolous registration requests.</t>

  <t>a registry operating at a high level of security, where defence-in-depth
  and the need to provide a full audit trail require strong authenticity of provisioning
  requests.</t>

  <t>future extensions to EPP may permit use of transport protocols such as
  <xref target="RFC5321">SMTP</xref> or <xref target="RFC6120">XMPP</xref>, which
  cannot provide end-to-end authenticity of frames.</t>
</list></t>

</section>

<section title="Extension Elements">

<t>This extension defines a single element, &lt;eppSig:signature&gt;, which may
appear in the &lt;extension&gt; element of &lt;command&gt; and &lt;result&gt;
frames.</t>

<t>The &lt;eppSig:signature&gt; element may contain any element permitted in
<xref target="RFC3275"/>.</t>

<section title="Example Frames">

<t>Example &lt;command&gt; frame containing an XML digital signature:</t>

<figure>
<artwork><![CDATA[
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<epp
 xmlns="urn:ietf:params:xml:ns:epp-1.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 <command>
  <create>
   <domain:create
    xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
    <domain:name>example.com</domain:name>
    <domain:period unit="y">2</domain:period>
    <domain:ns>
     <domain:hostObj>ns1.example.com</domain:hostObj>
     <domain:hostObj>ns2.example.com</domain:hostObj>
    </domain:ns>
    <domain:registrant>jd1234</domain:registrant>
    <domain:contact type="admin">sh8013</domain:contact>
    <domain:contact type="tech">sh8013</domain:contact>
    <domain:authInfo>
     <domain:pw>2fooBAR</domain:pw>
    </domain:authInfo>
   </domain:create>
  </create>
  <extension>
   <eppSig:signature
    xmlns:eppSig="urn:centralnic:params:xml:ns:eppSig-1.0">
    <ds:Signature
     xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
     <ds:SignedInfo>
      <ds:CanonicalizationMethod
       Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
      <ds:SignatureMethod
       Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
      <ds:Reference>
       <ds:Transforms>
        <ds:Transform
 Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
       </ds:Transforms>
       <ds:DigestMethod
        Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
       <ds:DigestValue>
        UJEib8S59LmAwI9z1imSEKVn/D4=
       </ds:DigestValue>
      </ds:Reference>
     </ds:SignedInfo>
     <ds:SignatureValue>
      iqnL15xs5AoaNxjqtmekYevtCblgZhLAio...
     </ds:SignatureValue>
    </ds:Signature>
   </eppSig:signature>
  </extension>
  <clTRID>ABC-12345</clTRID>
 </command>
</epp>
]]></artwork>
</figure>

<t>Example &lt;result&gt; frame containing an XML digital signature:</t>

<figure><artwork><![CDATA[
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
 <response>
  <result code="1000">
   <msg>Command completed successfully</msg>
  </result>
  <resData>
   <domain:creData xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
    <domain:name>example.com</domain:name>
    <domain:crDate>1999-04-03T22:00:00.0Z</domain:crDate>
    <domain:exDate>2001-04-03T22:00:00.0Z</domain:exDate>
   </domain:creData>
  </resData>
  <extension>
   <eppSig:signature
    xmlns:eppSig="urn:centralnic:params:xml:ns:eppSig-1.0">
    <ds:Signature
     xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
     <ds:SignedInfo>
      <ds:CanonicalizationMethod
       Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
      <ds:SignatureMethod
       Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
      <ds:Reference>
       <ds:Transforms>
        <ds:Transform
 Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
       </ds:Transforms>
       <ds:DigestMethod
        Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
       <ds:DigestValue>
        EEijkGTFZEbgbOnZ/XIR/VSKPAM=
       </ds:DigestValue>
      </ds:Reference>
     </ds:SignedInfo>
     <ds:SignatureValue>
      iqnL15xs5AoaNxjqtmekYevtCblgZhLAio...
     </ds:SignatureValue>
    </ds:Signature>
   </eppSig:signature>
  </extension>
  <trID>
   <clTRID>ABC-12345</clTRID>
   <svTRID>54321-XYZ</svTRID>
  </trID>
 </response>
</epp>
]]></artwork></figure>
</section>

</section>

<section title="Use of Signatures">
<t>
Servers which support this extension MUST include the extension namespace in an
&lt;extURI&gt; element in the the &lt;svcExtension&gt; element of the
&lt;greeting&gt; frame sent to the client at the beginning of a session (and in
response to a &lt;hello&gt; command). The server MUST include an
&lt;eppSig:signature&gt; element, containing a valid XML digital signature, in
the &lt;extension&gt; element of all &lt;result&gt; frames.</t>

<t>
Clients which support this extension MUST include the extension namespace in an
&lt;objURI&gt; element in the the &lt;svcs&gt; element of the
&lt;login&gt; frame sent to the server at the beginning of each session, if that
server also supports the extension. The client MUST include an
&lt;eppSig:signature&gt; element, containing a valid XML digital
signature, in the &lt;extension&gt; element of all &lt;command&gt; frames.</t>

</section>

<section title="Verification of Signatures">

<t>
If a server which supports this extension receives a signed &lt;command&gt;
frame from a client, it MUST verify the signature of the frame. If the signature
is successfully verified, the server MUST proceed with the processing of the
&lt;command&gt; frame as normal. If the signature cannot be successfully
verified, the server MUST not proceed with the processing of the &lt;command&gt;
frame, and MUST return a 2200 authentication error to the client.
</t>

<t>
If a client which supports this extension receives a signed &lt;result&gt;
frame from a server, it MUST verify the signature of the frame. If the signature
cannot be successfully verified, the client MAY notify the end user of an error,
but SHOULD notify an operator or system administrator for subsequent investigation.
</t>

</section>

<section title="Formal Syntax">

<figure>

<artwork><![CDATA[
<?xml version="1.0" encoding="UTF-8"?>

<schema
  targetNamespace="urn:centralnic:params:xml:ns:eppSig-1.0"
  xmlns:eppSig="urn:centralnic:params:xml:ns:eppSig-1.0"
  xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
  xmlns="http://www.w3.org/2001/XMLSchema"
  elementFormDefault="qualified">

  <import namespace="http://www.w3.org/2000/09/xmldsig#" />

  <annotation>
    <documentation>
      Extensible Provisioning Protocol v1.0
      XML digital signature extension schema
    </documentation>
  </annotation>

  <!--
  Child elements found in EPP commands.
  -->
  <element name="signature" type="eppSig:signatureType"/>

  <complexType name="signatureType">
    <sequence>
      <any namespace="http://www.w3.org/2000/09/xmldsig#" />
    </sequence>
  </complexType>
</schema>
]]></artwork>

</figure>

</section>

<section anchor="Security" title="Security Considerations">

<t>XML Digital Signatures use a Public Key Infrastructure. To verify a digital
signature, one must use the signer's public key: to ensure the authenticity of
the signature, this key must be obtained via a secure, out-of-band channel.</t>

<t>Clients and servers which support this extension MUST exchange public key
information using a facility that provides privacy and integrity services to
protect against unintended disclosure and modification while in transit. For
example, a server might publish its public key as a self-signed certificate in a
<xref target="DANE">TLSA</xref> resource record in the DNS. Alternatively, both
clients and servers may exchange keys via a <xref target="RFC2818">HTTPS</xref>
service which securely authenticates both parties.</t>

</section>

<section anchor="IANA" title="IANA Considerations">

<t>This document uses URNs to describe XML namespaces and XML schemas
conforming to a registry mechanism described in <xref target="RFC3688"/>.  Two
URI assignments were requested and have been registered by the IANA.</t>

<t>Registration request for the digital signature namespace:</t>

<t>URI: urn:centralnic:params:xml:ns:eppSig-1.0</t>

<t>Registrant Contact: See the "Author's Address" section of this
document.</t>

<t>XML: None.  Namespace URIs do not represent an XML specification.</t>

<t>Registration request for the registry grace period XML schema:</t>

<t>URI: urn:centralnic:params:xml:ns:eppSig-1.0</t>

<t>Registrant Contact: See the "Author's Address" section of this
document.</t>

<t>XML: See the "Formal Syntax" section of this document.</t>

</section>

</middle>

<back>

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<references title="Normative References">

&RFC2119;

&RFC2818;

&RFC3275;

&RFC3688;

&RFC5321;

&RFC5730;

&RFC6120;

<reference anchor="DANE">
  <front>
    <title>Using Secure DNS to Associate Certificates with Domain Names For TLS</title>
    <author fullname="Paul Hoffman" initials="P.H." surname="Hoffman" />
    <author fullname="Jakob Schlyter" initials="J.S." surname="Schlyter" />
    <date month="September" year="2011" day="7" />
  </front>
</reference>

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