One document matched: draft-ietf-dnsext-dnssec-bis-updates-09.xml


<?xml version="1.0"?>
<!-- See http://xml.resource.org/ for tools on how to convert this text -->
<?rfc compact="yes" ?><?rfc editing="no" ?><?rfc sortrefs="yes" ?><?rfc symrefs="yes" ?><?rfc toc="yes" ?><rfc category="std" ipr="trust200902" docName="draft-ietf-dnsext-dnssec-bis-updates-09" updates="4033, 4034, 4035, 5155">

  <front>
    <title abbrev="DNSSECbis Implementation Notes">
      Clarifications and Implementation Notes for DNSSECbis
    </title>

    <author initials="S." surname="Weiler" fullname="Samuel Weiler">
      <organization>SPARTA, Inc.</organization>
      <address>
        <postal>
          <street>7110 Samuel Morse Drive</street>
          <city>Columbia, Maryland</city>
          <code>21046</code>
          <country>US</country>
        </postal>
        <email>weiler@tislabs.com</email>
      </address>
    </author>

    <author initials="D." surname="Blacka" fullname="David Blacka">
      <organization>VeriSign, Inc.</organization>
      <address>
	<postal>
	  <street>21345 Ridgetop Circle</street>
	  <city>Dulles</city>
	  <region>VA</region>
	  <code>20166</code>
	  <country>US</country>
	</postal>
	<email>davidb@verisign.com</email>
      </address>
    </author>

    <date year="2009"/>
    <keyword>DNSSEC</keyword>
    <!-- <area>Internet</area> -->

    <abstract>

      <t>This document is a collection of technical clarifications to
      the DNSSECbis document set.  It is meant to serve as a resource
      to implementors as well as a repository of DNSSECbis errata.</t>

    </abstract>

  </front>

  <middle>

    <section title="Introduction and Terminology">

      <t>This document lists some additions, clarifications and
      corrections to the core DNSSECbis specification, as originally
      described in <xref target="RFC4033"/>, <xref target="RFC4034"/>,
      and <xref target="RFC4035"/>.</t>

      <t>It is intended to serve as a resource for implementors and as
      a repository of items that need to be addressed when advancing
      the DNSSECbis documents from Proposed Standard to Draft
      Standard.</t>

      <section title="Structure of this Document">

        <t>The clarifications to DNSSECbis are sorted according to
        their importance, starting with ones which could, if ignored,
        lead to security problems and progressing down to
        clarifications that are expected to have little operational
        impact.</t>

      </section>

      <section title="Terminology">

        <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"/>.</t>

      </section>

    </section>

    <section title="Important Additions to DNSSSECbis">

      <t>This section updates the set of core DNSSEC protocol
      documents originally specified in Section 10 of <xref target="RFC4033"/>.</t>

      <section title="NSEC3 Support" anchor="nsec3">
        
	<t><xref target="RFC5155"/> describes the use and behavior of
	the NSEC3 and NSEC3PARAM records for hashed denial of
	existence.  Validator implementations are strongly encouraged
	to include support for NSEC3 because a number of highly
	visible zones are expected to use it.  Validators that do not
	support validation of responses using NSEC3 will likely be
	hampered in validating large portions of the DNS space.</t>

	<t><xref target="RFC5155"/> should be considered part of the
	DNS Security Document Family as described by <xref target="RFC4033"/>, Section 10.</t>

      </section>

      <section title="SHA-256 Support" anchor="sha256">

	<t><xref target="RFC4509"/> describes the use of SHA-256 as a
	digest algorithm for use with Delegation Signer (DS) RRs.
	<xref target="I-D.ietf-dnsext-dnssec-rsasha256"/> describes
	the use of the RSASHA256 algorithm for use in DNSKEY and RRSIG
	RRs.  Validator implementations are strongly encouraged to
	include support for this algorithm for DS, DNSKEY, and RRSIG
	records.</t>

	<t>Both <xref target="RFC4509"/> and <xref target="I-D.ietf-dnsext-dnssec-rsasha256"/> should also be
	considered part of the DNS Security Document Family as
	described by <xref target="RFC4033"/>, Section 10.</t>

      </section>

    </section>

    <section title="Security Concerns" anchor="major">

      <t>This section provides clarifications that, if overlooked,
      could lead to security issues.</t>

      <section title="Clarifications on Non-Existence Proofs" anchor="nsec-bug">

	<t><xref target="RFC4035"/> Section 5.4 under-specifies the
	algorithm for checking non-existence proofs.  In particular,
	the algorithm as presented would incorrectly allow an NSEC or
	NSEC3 RR from an ancestor zone to prove the non-existence of
	RRs in the child zone.</t>
	      
	<t>An "ancestor delegation" NSEC RR (or NSEC3 RR) is one
	with:</t>
	<t>
	  <list style="symbols">
	    <t>the NS bit set,</t>
	    <t>the SOA bit clear, and</t>
	    <t>a signer field that is shorter than the owner name of
	    the NSEC RR, or the original owner name for the NSEC3
	    RR.</t>
	  </list>
	</t>

	<t>Ancestor delegation NSEC or NSEC3 RRs MUST NOT be used to
	assume non-existence of any RRs below that zone cut, which
	include all RRs at that (original) owner name other than DS
	RRs, and all RRs below that owner name regardless of type.</t>

	<t>Similarly, the algorithm would also allow an NSEC RR at the
	same owner name as a DNAME RR, or an NSEC3 RR at the same
	original owner name as a DNAME, to prove the non-existence of
	names beneath that DNAME.  An NSEC or NSEC3 RR with the DNAME
	bit set MUST NOT be used to assume the non-existence of any
	subdomain of that NSEC/NSEC3 RR's (original) owner name.</t>

      </section>

      <section title="Validating Responses to an ANY Query" anchor="any-queries">

	<t><xref target="RFC4035"/> does not address how to validate
	responses when QTYPE=*.  As described in Section 6.2.2 of
	<xref target="RFC1034"/>, a proper response to QTYPE=* may
	include a subset of the RRsets at a given name. That is, it is
	not necessary to include all RRsets at the QNAME in the
	response.</t>

	<t>When validating a response to QTYPE=*, all received RRsets
	that match QNAME and QCLASS MUST be validated.  If any of
	those RRsets fail validation, the answer is considered Bogus.
	If there are no RRsets matching QNAME and QCLASS, that fact
	MUST be validated according to the rules in <xref target="RFC4035"/> Section 5.4 (as clarified in this
	document).  To be clear, a validator must not expect to
	receive all records at the QNAME in response to QTYPE=*.</t>

      </section>

      <section title="Check for CNAME" anchor="check-cname">

	<t>Section 5 of <xref target="RFC4035"/> says little about
	validating responses based on (or that should be based on)
	CNAMEs.  When validating a NOERROR/NODATA response, validators
	MUST check the CNAME bit in the matching NSEC or NSEC3 RR's
	type bitmap in addition to the bit for the query type.
	Without this check, an attacker could successfully transform a
	positive CNAME response into a NOERROR/NODATA response.</t>


      </section>

      <section title="Insecure Delegation Proofs">

	<t><xref target="RFC4035"/> Section 5.2 specifies that a
	validator, when proving a delegation is not secure, needs to
	check for the absence of the DS and SOA bits in the NSEC (or
	NSEC3) type bitmap.  The validator also needs to check for the
	presence of the NS bit in the matching NSEC (or NSEC3) RR
	(proving that there is, indeed, a delegation), or alternately
	make sure that the delegation is covered by an NSEC3 RR with
	the Opt-Out flag set.  If this is not checked, spoofed
	unsigned delegations might be used to claim that an existing
	signed record is not signed.</t>
      </section>

    </section>

    <section title="Interoperability Concerns" anchor="interop">

      <section title="Errors in Canonical Form Type Code List">

	<t>When canonicalizing DNS names, DNS names in the RDATA
	section of NSEC and RRSIG resource records are not
	downcased.</t>

	<t><xref target="RFC4034"/> Section 6.2 item 3 has a list of
	resource record types for which DNS names in the RDATA are
	downcased for purposes of DNSSEC canonical form (for both
	ordering and signing).  That list erroneously contains NSEC
	and RRSIG.  According to <xref target="RFC3755"/>, DNS names
	in the RDATA of NSEC and RRSIG should not be downcased.</t>

	<t>The same section also erroneously lists HINFO, and twice at
	that.  Since HINFO records contain no domain names, they are
	not subject to downcasing.</t>

      </section>

      <section title="Unknown DS Message Digest Algorithms" anchor="hash">

	<t>Section 5.2 of <xref target="RFC4035"/> includes rules for
	how to handle delegations to zones that are signed with
	entirely unsupported public key algorithms, as indicated by
	the key algorithms shown in those zone's DS RRsets.  It does
	not explicitly address how to handle DS records that use
	unsupported message digest algorithms.  In brief, DS records
	using unknown or unsupported message digest algorithms MUST be
	treated the same way as DS records referring to DNSKEY RRs of
	unknown or unsupported public key algorithms.</t>

        <t>The existing text says:</t>

	<t>
	  <list>
	    <t>If the validator does not support any of the algorithms
	    listed in an authenticated DS RRset, then the resolver has
	    no supported authentication path leading from the parent
	    to the child.  The resolver should treat this case as it
	    would the case of an authenticated NSEC RRset proving that
	    no DS RRset exists, as described above.</t>
	  </list>
	</t>

	<t>To paraphrase the above, when determining the security
	status of a zone, a validator disregards any DS records
	listing unknown or unsupported algorithms.  If none are left,
	the zone is treated as if it were unsigned.</t>

        <t>Modified to consider DS message digest algorithms, a
        validator also disregards any DS records using unknown or
        unsupported message digest algorithms.</t>

      </section>

      <section title="Private Algorithms" anchor="private">

	<t>As discussed above, section 5.2 of <xref target="RFC4035"/>
        requires that validators make decisions about the security
        status of zones based on the public key algorithms shown in
        the DS records for those zones.  In the case of private
        algorithms, as described in <xref target="RFC4034"/> Appendix
        A.1.1, the eight-bit algorithm field in the DS RR is not
        conclusive about what algorithm(s) is actually in use.</t>

        <t>If no private algorithms appear in the DS set or if any
        supported algorithm appears in the DS set, no special
        processing will be needed.  In the remaining cases, the
        security status of the zone depends on whether or not the
        resolver supports any of the private algorithms in use
        (provided that these DS records use supported hash functions,
        as discussed in <xref target="hash"/>).  In these cases, the
        resolver MUST retrieve the corresponding DNSKEY for each
        private algorithm DS record and examine the public key field
        to determine the algorithm in use.  The security-aware
        resolver MUST ensure that the hash of the DNSKEY RR's owner
        name and RDATA matches the digest in the DS RR.  If they do
        not match, and no other DS establishes that the zone is
        secure, the referral should be considered Bogus data, as
        discussed in <xref target="RFC4035"/>.</t>

        <t>This clarification facilitates the broader use of private
        algorithms, as suggested by <xref target="RFC4955"/>.</t>

      </section>

      <section title="Caution About Local Policy and Multiple RRSIGs" anchor="multi-rrsigs">

        <t>When multiple RRSIGs cover a given RRset, <xref target="RFC4035"/> Section 5.3.3 suggests that "the local
        resolver security policy determines whether the resolver also
	has to test these RRSIG RRs and how to resolve conflicts if
	these RRSIG RRs lead to differing results."  In most cases, a
	resolver would be well advised to accept any valid RRSIG as
	sufficient.  If the first RRSIG tested fails validation, a
	resolver would be well advised to try others, giving a
	successful validation result if any can be validated and
	giving a failure only if all RRSIGs fail validation.</t>

        <t>If a resolver adopts a more restrictive policy, there's a
        danger that properly-signed data might unnecessarily fail
        validation, perhaps because of cache timing issues.
        Furthermore, certain zone management techniques, like the
        Double Signature Zone-signing Key Rollover method described in
        section 4.2.1.2 of <xref target="RFC4641"/> might not work
        reliably.</t>

      </section>

      <section title="Key Tag Calculation" anchor="key-tags">

        <t><xref target="RFC4034"/> Appendix B.1 incorrectly defines
        the Key Tag field calculation for algorithm 1.  It correctly
        says that the Key Tag is the most significant 16 of the least
        significant 24 bits of the public key modulus.  However, <xref target="RFC4034"/> then goes on to incorrectly say that this
        is 4th to last and 3rd to last octets of the public key
        modulus.  It is, in fact, the 3rd to last and 2nd to last
        octets.</t>

      </section>

      <section title="Setting the DO Bit on Replies" anchor="clear-do-bit">

	<t><xref target="RFC4035"/> does not provide any instructions
	to servers as to how to set the DO bit.  Some authoritative
	server implementations have chosen to copy the DO bit settings
	from the incoming query to the outgoing response.  Others have
	chosen to never set the DO bit in responses.  Either behavior
	is permitted.  To be clear, in replies to queries with the
	DO-bit set servers may or may not set the DO bit.</t>

      </section>

      <section title="Setting the AD bit on Replies" anchor="ad-bit">
    
        <t>Section 3.2.3 of <xref target="RFC4035"/> describes under
        which conditions a validating resolver should set or clear the
        AD bit in a response.  In order to protect legacy stub
        resolvers and middleboxes, validating resolvers SHOULD only
        set the AD bit when a response both meets the conditions
        listed in RFC 4035, section 3.2.3, and the request contained
        either a set DO bit or a set AD bit.</t>

        <t>Note that the use of the AD bit in the query was previously
        undefined.  This document defines it as a signal indicating
        that the requester understands and is interested in the value
        of the AD bit in the response.  This allows a requestor to
        indicate that it understands the AD bit without also
        requesting DNSSEC data via the DO bit.</t>

      </section>

      <section title="Setting the CD bit on Requests" anchor="cd-bit">

        <t>When processing a request with the CD bit set, the resolver
        MUST set the CD bit on its upstream queries.</t>

	<!-- Should there be language to state the validators
	     should/must set the CD bit on upstream queries also when
	     it has a trust anchor at or above the QNAME (and thus
	     could reasonably be expected to be able to validate the
	     response.)  Or, alternately that validators should
	     *always* set the CD bit? -->

      </section>

      <section title="Nested Trust Anchors" anchor="nested-anchors">

	<t>A DNSSEC validator may be configured such that, for a given
	response, more than one trust anchor could be used to validate
	the chain of trust to the response zone.  For example, imagine
	a validator configured with trust anchors for "example." and
	"zone.example."  When the validator is asked to validate a
	response to "www.sub.zone.example.", either trust anchor could
	apply.</t>

	<t>When presented with this situation, DNSSEC validators
	SHOULD try all applicable trust anchors until one
	succeeds.</t>

        <t>There are some scenarios where different behaviors, such as
        choosing the trust anchor closest to the QNAME of the
        response, may be desired. A DNSSEC validator MAY enable such
        behaviors as configurable overrides.</t>
	
      </section>

    </section>

    <section title="Minor Corrections and Clarifications" anchor="minor">

      <section title="Finding Zone Cuts" anchor="grandparent">

	<t>Appendix C.8 of <xref target="RFC4035"/> discusses sending
	DS queries to the servers for a parent zone.  To do that, a
	resolver may first need to apply special rules to discover
	what those servers are.</t>

	<t>As explained in Section 3.1.4.1 of <xref target="RFC4035"/>, security-aware name servers need to apply
	special processing rules to handle the DS RR, and in some
	situations the resolver may also need to apply special rules
	to locate the name servers for the parent zone if the resolver
	does not already have the parent's NS RRset.  Section 4.2 of
	<xref target="RFC4035"/> specifies a mechanism for doing
	that.</t>

      </section>

      <section title="Clarifications on DNSKEY Usage" anchor="keys">

	<t>Questions of the form "can I use a different DNSKEY for
	signing this RRset" have occasionally arisen.</t>

	<t>The short answer is "yes, absolutely".  You can even use a
	different DNSKEY for each RRset in a zone, subject only to
	practical limits on the size of the DNSKEY RRset.  However, be
	aware that there is no way to tell resolvers what a
	particularly DNSKEY is supposed to be used for -- any DNSKEY
	in the zone's signed DNSKEY RRset may be used to authenticate
	any RRset in the zone.  For example, if a weaker or less
	trusted DNSKEY is being used to authenticate NSEC RRsets or
	all dynamically updated records, that same DNSKEY can also be
	used to sign any other RRsets from the zone.</t>

        <t>Furthermore, note that the SEP bit setting has no effect on
        how a DNSKEY may be used -- the validation process is
        specifically prohibited from using that bit by <xref target="RFC4034"/> section 2.1.2.  It is possible to use a
        DNSKEY without the SEP bit set as the sole secure entry point
        to the zone, yet use a DNSKEY with the SEP bit set to sign all
        RRsets in the zone (other than the DNSKEY RRset).  It's also
        possible to use a single DNSKEY, with or without the SEP bit
        set, to sign the entire zone, including the DNSKEY RRset
        itself.</t>

      </section>

      <section title="Errors in Examples" anchor="examples-nits">

        <t>The text in <xref target="RFC4035"/> Section C.1 refers to
        the examples in B.1 as "x.w.example.com" while B.1 uses
        "x.w.example".  This is painfully obvious in the second
        paragraph where it states that the RRSIG labels field value of
        3 indicates that the answer was not the result of wildcard
        expansion.  This is true for "x.w.example" but not for
        "x.w.example.com", which of course has a label count of 4
        (antithetically, a label count of 3 would imply the answer was
        the result of a wildcard expansion).</t>

        <t>The first paragraph of <xref target="RFC4035"/> Section C.6
        also has a minor error: the reference to "a.z.w.w.example"
        should instead be "a.z.w.example", as in the previous
        line.</t>

      </section>

      <section title="Errors in RFC 5155" anchor="nsec3-nits">
        
        <t>A NSEC3 record that matches an Empty Non-Terminal
        effectively has no type associated with it. This NSEC3 record
        has an empty type bit map.  Section 3.2.1 of <xref target="RFC5155"/> contains the statement:</t>
        
        <t>
          <list>
            <t>Blocks with no types present MUST NOT be included.</t>
          </list>
        </t>

        <t>However, the same section contains a regular expression:</t>

        <t>
          <list>
            <t>Type Bit Maps Field = ( Window Block # | Bitmap Length |
            Bitmap )+</t>
          </list>
        </t>

        <t>The plus sign in the regular expression indicates that
        there is one or more of the preceding element. This means that
        there must be at least one window block. If this window block
        has no types, it contradicts with the first
        statement. Therefore, the correct text in RFC 5155 3.2.1
        should be:</t>

        <t>
          <list>
            <t>Type Bit Maps Field = ( Window Block # | Bitmap Length |
            Bitmap )*</t>
          </list>
        </t>

      </section>

    </section>

    <section title="IANA Considerations">

      <t>This document specifies no IANA Actions.</t>

    </section>

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

      <t>This document adds two cryptographic features to the core
      DNSSEC protocol.  Additionally, it addresses some ambiguities
      and omissions in the core DNSSEC documents that, if not
      recognized and addressed in implementations, could lead to
      security failures.  In particular, the validation algorithm
      clarifications in <xref target="major"/> are critical for
      preserving the security properties DNSSEC offers.  Furthermore,
      failure to address some of the interoperability concerns in
      <xref target="interop"/> could limit the ability to later change
      or expand DNSSEC, including adding new algorithms.</t>

    </section>


  </middle>

  <back>
    <references title="Normative References">
      <!-- Begin inclusion: reference.RFC.4033.xml --><reference anchor="RFC4033">
  <front>
    <title>DNS Security Introduction and Requirements</title>
    <author fullname="R. Arends" initials="R." surname="Arends">
      <organization/>
    </author>
    <author fullname="R. Austein" initials="R." surname="Austein">
      <organization/>
    </author>
    <author fullname="M. Larson" initials="M." surname="Larson">
      <organization/>
    </author>
    <author fullname="D. Massey" initials="D." surname="Massey">
      <organization/>
    </author>
    <author fullname="S. Rose" initials="S." surname="Rose">
      <organization/>
    </author>
    <date month="March" year="2005"/>
    <keyword>domain name system</keyword>
    <keyword>authentication</keyword>
    <keyword>origin integrity</keyword>
    <keyword>dnssec</keyword>
    <keyword>domain name system security extensions</keyword>
    <abstract>
      <t>The Domain Name System Security Extensions (DNSSEC) add data origin authentication and data integrity to the Domain Name System.  This document introduces these extensions and describes their capabilities and limitations.  This document also discusses the services that the DNS security extensions do and do not provide.  Last, this document describes the interrelationships between the documents that collectively describe DNSSEC. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4033"/>
  <format type="TXT" octets="52445" target="http://www.rfc-editor.org/rfc/rfc4033.txt"/>
  <!-- obsoletes RFC2535 RFC3008 RFC3090 RFC3445 RFC3655 RFC3658 RFC3755 RFC3757 RFC3845 -->
  <!-- updates RFC1034 RFC1035 RFC2136 RFC2181 RFC2308 RFC3225 RFC3007 RFC3597 RFC3226 -->
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.4033.xml -->
      <!-- Begin inclusion: reference.RFC.4034.xml --><reference anchor="RFC4034">
  <front>
    <title>Resource Records for the DNS Security Extensions</title>
    <author fullname="R. Arends" initials="R." surname="Arends">
      <organization/>
    </author>
    <author fullname="R. Austein" initials="R." surname="Austein">
      <organization/>
    </author>
    <author fullname="M. Larson" initials="M." surname="Larson">
      <organization/>
    </author>
    <author fullname="D. Massey" initials="D." surname="Massey">
      <organization/>
    </author>
    <author fullname="S. Rose" initials="S." surname="Rose">
      <organization/>
    </author>
    <date month="March" year="2005"/>
    <keyword>domain name system</keyword>
    <keyword>authentication</keyword>
    <keyword>origin integrity</keyword>
    <keyword>dnssec</keyword>
    <keyword>domain name system security extensions</keyword>
    <abstract>
      <t>This document is part of a family of documents that describe the DNS Security Extensions (DNSSEC). The DNS Security Extensions are a collection of resource records and protocol modifications that provide source authentication for the DNS. This document defines the public key (DNSKEY), delegation signer (DS), resource record digital signature (RRSIG), and authenticated denial of existence (NSEC) resource records. The purpose and format of each resource record is described in detail, and an example of each resource record is given. This document obsoletes RFC 2535 and incorporates changes from all updates to RFC 2535. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4034"/>
  <format type="TXT" octets="63879" target="http://www.rfc-editor.org/rfc/rfc4034.txt"/>
  <!-- obsoletes RFC2535 RFC3008 RFC3090 RFC3445 RFC3655 RFC3658 RFC3755 RFC3757 RFC3845 -->
  <!-- updates RFC1034 RFC1035 RFC2136 RFC2181 RFC2308 RFC3225 RFC3007 RFC3597 RFC3226 -->
  <!-- updated-by RFC4470 -->
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.4034.xml -->
      <!-- Begin inclusion: reference.RFC.4035.xml --><reference anchor="RFC4035">
  <front>
    <title>Protocol Modifications for the DNS Security Extensions</title>
    <author fullname="R. Arends" initials="R." surname="Arends">
      <organization/>
    </author>
    <author fullname="R. Austein" initials="R." surname="Austein">
      <organization/>
    </author>
    <author fullname="M. Larson" initials="M." surname="Larson">
      <organization/>
    </author>
    <author fullname="D. Massey" initials="D." surname="Massey">
      <organization/>
    </author>
    <author fullname="S. Rose" initials="S." surname="Rose">
      <organization/>
    </author>
    <date month="March" year="2005"/>
    <keyword>domain name system</keyword>
    <keyword>authentication</keyword>
    <keyword>origin integrity</keyword>
    <keyword>dnssec</keyword>
    <keyword>domain name system security extensions</keyword>
    <abstract>
      <t>This document is part of a family of documents that describe the DNS Security Extensions (DNSSEC). The DNS Security Extensions are a collection of new resource records and protocol modifications that add data origin authentication and data integrity to the DNS. This document describes the DNSSEC protocol modifications. This document defines the concept of a signed zone, along with the requirements for serving and resolving by using DNSSEC. These techniques allow a security-aware resolver to authenticate both DNS resource records and authoritative DNS error indications. This document obsoletes RFC 2535 and incorporates changes from all updates to RFC 2535. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4035"/>
  <format type="TXT" octets="130589" target="http://www.rfc-editor.org/rfc/rfc4035.txt"/>
  <!-- obsoletes RFC2535 RFC3008 RFC3090 RFC3445 RFC3655 RFC3658 RFC3755 RFC3757 RFC3845 -->
  <!-- updates RFC1034 RFC1035 RFC2136 RFC2181 RFC2308 RFC3225 RFC3007 RFC3597 RFC3226 -->
  <!-- updated-by RFC4470 -->
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.4035.xml -->
      <!-- Begin inclusion: reference.RFC.2119.xml --><reference anchor="RFC2119">
  <front>
    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
    <author fullname="S. Bradner" initials="S." surname="Bradner">
      <organization/>
    </author>
    <date month="March" year="1997"/>
    <keyword>Standards</keyword>
    <keyword>Track</keyword>
    <keyword>Documents</keyword>
    <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="RFC" value="2119"/>
  <seriesInfo name="BCP" value="14"/>
  <format type="TXT" octets="4723" target="http://www.rfc-editor.org/rfc/rfc2119.txt"/>
  <!-- current-status BEST CURRENT PRACTICE -->
  <!-- publication-status BEST CURRENT PRACTICE -->
</reference><!-- End inclusion: reference.RFC.2119.xml -->
      <!-- Begin inclusion: reference.RFC.1034.xml --><reference anchor="RFC1034">
  <front>
    <title>Domain names - concepts and facilities</title>
    <author fullname="P.V. Mockapetris" initials="P.V." surname="Mockapetris">
      <organization/>
    </author>
    <date month="November" year="1987"/>
    <keyword>DOMAIN</keyword>
    <abstract>
      <t>This RFC is the revised basic definition of The Domain Name System.  It obsoletes RFC-882.  This memo describes the domain style names and their used for host address look up and electronic mail forwarding.  It discusses the clients and servers in the domain name system and the protocol used between them.</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="1034"/>
  <seriesInfo name="STD" value="13"/>
  <format type="TXT" octets="129180" target="http://www.rfc-editor.org/rfc/rfc1034.txt"/>
  <!-- obsoletes RFC0973 RFC0882 RFC0883 -->
  <!-- updated-by RFC1101 RFC1183 RFC1348 RFC1876 RFC1982 RFC2065 RFC2181 RFC2308 RFC2535 RFC4033 RFC4034 RFC4035 RFC4343 RFC4035 RFC4592 -->
  <!-- current-status STANDARD -->
  <!-- publication-status STANDARD -->
</reference><!-- End inclusion: reference.RFC.1034.xml -->
      <!-- Begin inclusion: reference.RFC.5155.xml --><reference anchor="RFC5155">
  <front>
    <title>DNS Security (DNSSEC) Hashed Authenticated Denial of Existence</title>
    <author fullname="B. Laurie" initials="B." surname="Laurie">
      <organization/>
    </author>
    <author fullname="G. Sisson" initials="G." surname="Sisson">
      <organization/>
    </author>
    <author fullname="R. Arends" initials="R." surname="Arends">
      <organization/>
    </author>
    <author fullname="D. Blacka" initials="D." surname="Blacka">
      <organization/>
    </author>
    <date month="March" year="2008"/>
    <keyword>domain name system</keyword>
    <keyword>nsec</keyword>
    <keyword>resource record</keyword>
    <keyword>nsec3</keyword>
    <abstract>
      <t>The Domain Name System Security (DNSSEC) Extensions introduced the NSEC resource record (RR) for authenticated denial of existence.  This document introduces an alternative resource record, NSEC3, which similarly provides authenticated denial of existence.  However, it also provides measures against zone enumeration and permits gradual expansion of delegation-centric zones. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="5155"/>
  <format type="TXT" octets="112338" target="http://www.rfc-editor.org/rfc/rfc5155.txt"/>
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.5155.xml -->
      <!-- Begin inclusion: reference.RFC.4509.xml --><reference anchor="RFC4509">
  <front>
    <title>Use of SHA-256 in DNSSEC Delegation Signer (DS) Resource Records (RRs)</title>
    <author fullname="W. Hardaker" initials="W." surname="Hardaker">
      <organization/>
    </author>
    <date month="May" year="2006"/>
    <keyword>domain name system</keyword>
    <keyword>dns</keyword>
    <keyword>dnskey</keyword>
    <abstract>
      <t>This document specifies how to use the SHA-256 digest type in DNS Delegation Signer (DS) Resource Records (RRs).  DS records, when stored in a parent zone, point to DNSKEYs in a child zone. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4509"/>
  <format type="TXT" octets="14155" target="http://www.rfc-editor.org/rfc/rfc4509.txt"/>
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.4509.xml -->
      <!-- Begin inclusion: reference.I-D.ietf-dnsext-dnssec-rsasha256.xml --><!-- Automatically generated, do not edit. --><reference anchor="I-D.ietf-dnsext-dnssec-rsasha256">
  <front>
    <title>Use of SHA-2 algorithms with RSA in DNSKEY and RRSIG Resource Records for DNSSEC</title>
    <author initials="J." surname="Jansen" fullname="Jelte Jansen"><organization/></author>
    <date day="4" month="June" year="2009"/>
  </front>
  <seriesInfo name="Internet-Draft" value="draft-ietf-dnsext-dnssec-rsasha256-14"/>
  <format type="TXT" target="http://www.ietf.org/internet-drafts/draft-ietf-dnsext-dnssec-rsasha256-14.txt"/>
</reference><!-- End inclusion: reference.I-D.ietf-dnsext-dnssec-rsasha256.xml -->
    </references>
    <references title="Informative References">
      <!-- Begin inclusion: reference.RFC.4955.xml --><reference anchor="RFC4955">
  <front>
    <title>DNS Security (DNSSEC) Experiments</title>
    <author fullname="D. Blacka" initials="D." surname="Blacka">
      <organization/>
    </author>
    <date month="July" year="2007"/>
    <keyword>domain namespace</keyword>
    <abstract>
      <t>This document describes a methodology for deploying alternate, non-backwards-compatible, DNS Security (DNSSEC) methodologies in an experimental fashion without disrupting the deployment of standard DNSSEC. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4955"/>
  <format type="TXT" octets="15417" target="http://www.rfc-editor.org/rfc/rfc4955.txt"/>
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.4955.xml -->
      <!-- Begin inclusion: reference.RFC.4641.xml --><reference anchor="RFC4641">
  <front>
    <title>DNSSEC Operational Practices</title>
    <author fullname="O. Kolkman" initials="O." surname="Kolkman">
      <organization/>
    </author>
    <author fullname="R. Gieben" initials="R." surname="Gieben">
      <organization/>
    </author>
    <date month="September" year="2006"/>
    <keyword>dns</keyword>
    <keyword>domain name space</keyword>
    <keyword>security extensions</keyword>
    <keyword>zone administrator</keyword>
    <keyword>DNS-SOC</keyword>
    <keyword>cryptology</keyword>
    <keyword>resource records</keyword>
    <keyword>rrs</keyword>
    <abstract>
      <t>This document describes a set of practices for operating the DNS with security extensions (DNSSEC). The target audience is zone administrators deploying DNSSEC. The document discusses operational aspects of using keys and signatures in the DNS. It discusses issues of key generation, key storage, signature generation, key rollover, and related policies. This document obsoletes RFC 2541, as it covers more operational ground and gives more up-to-date requirements with respect to key sizes and the new DNSSEC specification. This memo provides information for the Internet community.</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="4641"/>
  <format type="TXT" octets="79894" target="http://www.rfc-editor.org/rfc/rfc4641.txt"/>
  <!-- obsoletes RFC2541 -->
  <!-- current-status INFORMATIONAL -->
  <!-- publication-status INFORMATIONAL -->
</reference><!-- End inclusion: reference.RFC.4641.xml -->
      <!-- Begin inclusion: reference.RFC.3755.xml --><reference anchor="RFC3755">
  <front>
    <title>Legacy Resolver Compatibility for Delegation Signer (DS)</title>
    <author fullname="S. Weiler" initials="S." surname="Weiler">
      <organization/>
    </author>
    <date month="May" year="2004"/>
    <keyword>dnssec</keyword>
    <keyword>DNS Security</keyword>
    <keyword>rr</keyword>
    <keyword>resource record</keyword>
    <keyword>DNS-SECEXT</keyword>
    <keyword>dns</keyword>
    <keyword>authentication</keyword>
    <keyword>nsec</keyword>
    <keyword>nextsecure</keyword>
    <abstract>
      <t>As the DNS Security (DNSSEC) specifications have evolved, the syntax and semantics of the DNSSEC resource records (RRs) have changed.  Many deployed nameservers understand variants of these semantics.  Dangerous interactions can occur when a resolver that understands an earlier version of these semantics queries an authoritative server that understands the new delegation signer semantics, including at least one failure scenario that will cause an unsecured zone to be unresolvable.  This document changes the type codes and mnemonics of the DNSSEC RRs (SIG, KEY, and NXT) to avoid those interactions. [STANDARDS TRACK]</t>
    </abstract>
  </front>
  <seriesInfo name="RFC" value="3755"/>
  <format type="TXT" octets="19812" target="http://www.rfc-editor.org/rfc/rfc3755.txt"/>
  <!-- obsoleted-by RFC4033 RFC4034 RFC4035 -->
  <!-- updates RFC3658 RFC2535 -->
  <!-- updated-by RFC3757 RFC3845 -->
  <!-- current-status PROPOSED STANDARD -->
  <!-- publication-status PROPOSED STANDARD -->
</reference><!-- End inclusion: reference.RFC.3755.xml -->
    </references>

    <section title="Acknowledgments">

      <t>The editors would like the thank Rob Austein for his previous
      work as an editor of this document.</t>

      <t>The editors are extremely grateful to those who, in addition
      to finding errors and omissions in the DNSSECbis document set,
      have provided text suitable for inclusion in this document.</t>

      <t>The lack of specificity about handling private algorithms, as
      described in <xref target="private"/>, and the lack of
      specificity in handling ANY queries, as described in <xref target="any-queries"/>, were discovered by David Blacka.</t>

      <t>The error in algorithm 1 key tag calculation, as described in
      <xref target="key-tags"/>, was found by Abhijit Hayatnagarkar.
      Donald Eastlake contributed text for <xref target="key-tags"/>.</t>

      <t>The bug relating to delegation NSEC RR's in <xref target="nsec-bug"/> was found by Roy Badami.  Roy Arends found
      the related problem with DNAME.</t>

      <t>The errors in the <xref target="RFC4035"/> examples were
      found by Roy Arends, who also contributed text for <xref target="examples-nits"/> of this document.</t>

      <t>The editors would like to thank Ed Lewis, Danny Mayer, Olafur
      Gudmundsson, Suzanne Woolf, and Scott Rose for their substantive
      comments on the text of this document.</t>

    </section>

  </back>

</rfc>

PAFTECH AB 2003-20262026-04-24 02:56:46