GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc8005

Internet Engineering Task Force (IETF) J. Laganier Request for Comments: 8005 Luminate Wireless, Inc. Obsoletes: 5205 October 2016 Category: Standards Track ISSN: 2070-1721

  Host Identity Protocol (HIP) Domain Name System (DNS) Extension

Abstract

 This document specifies a resource record (RR) for the Domain Name
 System (DNS) and how to use it with the Host Identity Protocol (HIP).
 This RR allows a HIP node to store in the DNS its Host Identity (HI),
 the public component of the node public-private key pair; its Host
 Identity Tag (HIT), a truncated hash of its public key (PK); and the
 domain names of its rendezvous servers (RVSs).  This document
 obsoletes RFC 5205.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc8005.

Copyright Notice

 Copyright (c) 2016 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Laganier Standards Track [Page 1] RFC 8005 HIP DNS Extension October 2016

Table of Contents

 1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
 2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
 3.  Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . .   3
   3.1.  Simple Static Single-Homed End Host . . . . . . . . . . .   5
   3.2.  Mobile End Host . . . . . . . . . . . . . . . . . . . . .   6
 4.  Overview of Using the DNS with HIP  . . . . . . . . . . . . .   7
   4.1.  Storing HI, HIT, and RVS in the DNS . . . . . . . . . . .   7
   4.2.  Initiating Connections Based on DNS Names . . . . . . . .   8
 5.  HIP RR Storage Format . . . . . . . . . . . . . . . . . . . .   9
   5.1.  HIT Length Format . . . . . . . . . . . . . . . . . . . .   9
   5.2.  PK Algorithm Format . . . . . . . . . . . . . . . . . . .   9
   5.3.  PK Length Format  . . . . . . . . . . . . . . . . . . . .  10
   5.4.  HIT Format  . . . . . . . . . . . . . . . . . . . . . . .  10
   5.5.  Public Key Format . . . . . . . . . . . . . . . . . . . .  10
   5.6.  Rendezvous Servers Format . . . . . . . . . . . . . . . .  10
 6.  HIP RR Presentation Format  . . . . . . . . . . . . . . . . .  11
 7.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .  12
 8.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   8.1.  Attacker Tampering with an Insecure HIP RR  . . . . . . .  13
   8.2.  Hash and HITs Collisions  . . . . . . . . . . . . . . . .  13
   8.3.  DNSSEC  . . . . . . . . . . . . . . . . . . . . . . . . .  14
 9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
 10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
   10.1.  Normative References . . . . . . . . . . . . . . . . . .  15
   10.2.  Informative References . . . . . . . . . . . . . . . . .  16
 Appendix A.  Changes from RFC 5205  . . . . . . . . . . . . . . .  17
 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  17
 Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  17
 Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  18

1. Introduction

 This document specifies a resource record (RR) for the Domain Name
 System (DNS) [RFC1034] and how to use it with the Host Identity
 Protocol (HIP) [RFC7401].  This RR allows a HIP node to store in the
 DNS its Host Identity (HI), the public component of the node public-
 private key pair; its Host Identity Tag (HIT), a truncated hash of
 its HI; and the domain names of its rendezvous servers (RVSs)
 [RFC8004].
 Currently, most of the Internet applications that need to communicate
 with a remote host first translate a domain name (often obtained via
 user input) into one or more IP addresses.  This step occurs prior to
 communication with the remote host and relies on a DNS lookup.

Laganier Standards Track [Page 2] RFC 8005 HIP DNS Extension October 2016

 With HIP, IP addresses are intended to be used mostly for on-the-wire
 communication between end hosts, while most Upper Layer Protocols
 (ULPs) and applications use HIs or HITs instead (ICMP might be an
 example of a ULP not using them).  Consequently, we need a means to
 translate a domain name into an HI.  Using the DNS for this
 translation is pretty straightforward: We define a HIP RR.  Upon
 query by an application or ULP for a name-to-IP-address lookup, the
 resolver would then additionally perform a name-to-HI lookup and use
 it to construct the resulting HI-to-IP-address mapping (which is
 internal to the HIP layer).  The HIP layer uses the HI-to-IP-address
 mapping to translate HIs and HITs into IP addresses, and vice versa.
 The HIP specification [RFC7401] specifies the HIP base exchange
 between a HIP Initiator and a HIP Responder based on a four-way
 handshake involving a total of four HIP packets (I1, R1, I2, and R2).
 Since the HIP packets contain both the Initiator and the Responder
 HIT, the Initiator needs to have knowledge of the Responder's HI and
 HIT prior to initiating the base exchange by sending an I1 packet.
 The HIP Rendezvous Extension [RFC8004] allows a HIP node to be
 reached via the IP address(es) of a third party, the node's RVS.  An
 Initiator willing to establish a HIP association with a Responder
 served by an RVS would typically initiate a HIP base exchange by
 sending the I1 packet initiating the exchange towards the RVS IP
 address rather than towards the Responder IP address.  Consequently,
 we need a means to find the name of an RVS for a given host name.
 This document introduces the HIP DNS RR to store the RVS, HI, and HIT
 information.

2. Conventions Used in This Document

 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 RFC 2119 [RFC2119].

3. Usage Scenarios

 In this section, we briefly introduce a number of usage scenarios
 where the DNS is useful with HIP.
 With HIP, most applications and ULPs are unaware of the IP addresses
 used to carry packets on the wire.  Consequently, a HIP node could
 take advantage of having multiple IP addresses for failover,
 redundancy, mobility, or renumbering, in a manner that is transparent
 to most ULPs and applications (because they are bound to HIs; hence,
 they are agnostic to these IP address changes).

Laganier Standards Track [Page 3] RFC 8005 HIP DNS Extension October 2016

 In these situations, for a node to be reachable by reference to its
 Fully Qualified Domain Name (FQDN), the following information should
 be stored in the DNS:
 o  A set of IP addresses via A [RFC1035] and AAAA [RFC3596] Resource
    Record Sets (RRSets) [RFC2181].
 o  An HI, a HIT, and possibly a set of RVSs through HIP RRs.
 The HIP RR is class independent.
 When a HIP node wants to initiate communication with another HIP
 node, it first needs to perform a HIP base exchange to set up a HIP
 association towards its peer.  Although such an exchange can be
 initiated opportunistically, i.e., without prior knowledge of the
 Responder's HI, by doing so both nodes knowingly risk
 man-in-the-middle (MitM) attacks on the HIP exchange.  To prevent
 these attacks, it is recommended that the Initiator first obtains the
 HI of the Responder and then initiates the exchange.  This can be
 done, for example, through manual configuration or DNS lookups.
 Hence, a HIP RR is introduced.
 When a HIP node is frequently changing its IP address(es), the
 natural DNS latency for propagating changes may prevent it from
 publishing its new IP address(es) in the DNS.  For solving this
 problem, the HIP Architecture [RFC4423] introduces RVSs [RFC8004].  A
 HIP host uses an RVS as a rendezvous point to maintain reachability
 with possible HIP Initiators while moving [RFC5206].  Such a HIP node
 would publish in the DNS its RVS domain name(s) in a HIP RR, while
 keeping its RVS up-to-date with its current set of IP addresses.
 When a HIP node wants to initiate a HIP exchange with a Responder, it
 will perform a number of DNS lookups.  Depending on the type of
 implementation, the order in which those lookups will be issued may
 vary.  For instance, implementations using HIT in Application
 Programming Interfaces (APIs) may typically first query for HIP RRs
 at the Responder FQDN, while those using an IP address in APIs may
 typically first query for A and/or AAAA RRs.
 In the following, we assume that the Initiator first queries for HIP
 RRs at the Responder FQDN.
 If the query for the HIP type was responded to with a DNS answer with
 RCODE=3 (Name Error), then the Responder's information is not present
 in the DNS, and further queries for the same owner name SHOULD NOT be
 made.

Laganier Standards Track [Page 4] RFC 8005 HIP DNS Extension October 2016

 In case the query for the HIP records returned a DNS answer with
 RCODE=0 (No Error) and an empty answer section, it means that no HIP
 information is available at the Responder name.  In such a case, if
 the Initiator has been configured with a policy to fall back to
 opportunistic HIP (initiating without knowing the Responder's HI) or
 plain IP, it would send out more queries for A and AAAA types at the
 Responder's FQDN.
 Depending on the combinations of answers, the situations described in
 Sections 3.1 and 3.2 can occur.
 Note that storing HIP RR information in the DNS at an FQDN that is
 assigned to a non-HIP node might have ill effects on its reachability
 by HIP nodes.

3.1. Simple Static Single-Homed End Host

 In addition to its IP address or addresses (IP-R), a HIP node (R)
 with a single static network attachment that wishes to be reachable
 by reference to its FQDN (www.example.com) to act as a Responder
 would store in the DNS a HIP RR containing its Host Identity (HI-R)
 and Host Identity Tag (HIT-R).
 An Initiator willing to associate with a node would typically issue
 the following queries:
 o  Query #1: QNAME=www.example.com, QTYPE=HIP
 (QCLASS=IN is assumed and omitted from the examples)
 Which returns a DNS packet with RCODE=0 and one or more HIP RRs with
 the HIT and HI (e.g., HIT-R and HI-R) of the Responder in the answer
 section, but no RVS.
 o  Query #2: QNAME=www.example.com, QTYPE=A
 o  Query #3: QNAME=www.example.com, QTYPE=AAAA
 Which would return DNS packets with RCODE=0 and, respectively, one or
 more A or AAAA RRs containing the IP address(es) of the Responder
 (e.g., IP-R) in their answer sections.
 Caption: In the remainder of this document, for the sake of keeping
          diagrams simple and concise, several DNS queries and answers
          are represented as one single transaction, while in fact
          there are several queries and answers flowing back and
          forth, as described in the textual examples.

Laganier Standards Track [Page 5] RFC 8005 HIP DNS Extension October 2016

             [HIP? A?        ]
             [www.example.com]            +-----+
        +-------------------------------->|     |
        |                                 | DNS |
        | +-------------------------------|     |
        | |  [HIP? A?        ]            +-----+
        | |  [www.example.com]
        | |  [HIP HIT-R HI-R ]
        | |  [A IP-R         ]
        | v
      +-----+                              +-----+
      |     |--------------I1------------->|     |
      |  I  |<-------------R1--------------|  R  |
      |     |--------------I2------------->|     |
      |     |<-------------R2--------------|     |
      +-----+                              +-----+
                       Static Single-Homed Host
 The Initiator would then send an I1 to the Responder's IP addresses
 (IP-R).

3.2. Mobile End Host

 A mobile HIP node (R) wishing to be reachable by reference to its
 FQDN (www.example.com) would store in the DNS, possibly in addition
 to its IP address or addresses (IP-R), its HI (HI-R), its HIT
 (HIT-R), and the domain name or names of its RVS or servers (e.g.,
 rvs.example.com) in a HIP RR or records.  The mobile HIP node also
 needs to notify its RVSs of any change in its set of IP addresses.
 An Initiator willing to associate with such a mobile node would
 typically issue the following queries:
 o  Query #1: QNAME=www.example.com, QTYPE=HIP
 Which returns a DNS packet with RCODE=0 and one or more HIP RRs with
 the HIT, HI, and RVS domain name or names (e.g., HIT-R, HI-R, and
 rvs.example.com) of the Responder in the answer section.
 o  Query #2: QNAME=rvs.example.com, QTYPE=A
 o  Query #3: QNAME=rvs.example.com, QTYPE=AAAA
 Which return DNS packets with RCODE=0 and, respectively, one or more
 A or AAAA RRs containing an IP address(es) of the Responder's RVS
 (e.g., IP-RVS) in their answer sections.

Laganier Standards Track [Page 6] RFC 8005 HIP DNS Extension October 2016

            [HIP?           ]
            [www.example.com]
            [A?             ]
            [rvs.example.com]                     +-----+
       +----------------------------------------->|     |
       |                                          | DNS |
       | +----------------------------------------|     |
       | |  [HIP?                          ]      +-----+
       | |  [www.example.com               ]
       | |  [HIP HIT-R HI-R rvs.example.com]
       | |
       | |  [A?             ]
       | |  [rvs.example.com]
       | |  [A IP-RVS       ]
       | |
       | |                +-----+
       | | +------I1----->| RVS |-----I1------+
       | | |              +-----+             |
       | | |                                  |
       | | |                                  |
       | v |                                  v
      +-----+                              +-----+
      |     |<---------------R1------------|     |
      |  I  |----------------I2----------->|  R  |
      |     |<---------------R2------------|     |
      +-----+                              +-----+
                            Mobile End Host
 The Initiator would then send an I1 to the RVS IP address (IP-RVS).
 Following, the RVS will relay the I1 up to the mobile node's IP
 address (IP-R), which will complete the HIP exchange.

4. Overview of Using the DNS with HIP

4.1. Storing HI, HIT, and RVS in the DNS

 For any HIP node, its HI, the associated HIT, and the FQDN of its
 possible RVSs can be stored in a DNS HIP RR.  Any conforming
 implementation may store an HI and its associated HIT in a DNS HIP
 RDATA format.  HI and HIT are defined in Section 3 of the HIP
 specification [RFC7401].

Laganier Standards Track [Page 7] RFC 8005 HIP DNS Extension October 2016

 Upon return of a HIP RR, a host MUST always calculate the
 HI-derivative HIT to be used in the HIP exchange, as specified in
 Section 3 of the HIP specification [RFC7401], while the HIT included
 in the HIP RR SHOULD only be used as an optimization (e.g., table
 lookup).
 The HIP RR may also contain one or more domain names of one or more
 RVSs towards which HIP I1 packets might be sent to trigger the
 establishment of an association with the entity named by this RR
 [RFC8004].
 The Rendezvous Server field of the HIP RR stored at a given owner
 name MAY include the owner name itself.  A semantically equivalent
 situation occurs if no RVS is present in the HIP RR stored at that
 owner name.  Such situations occur in two cases:
 o  The host is mobile, and the A and/or AAAA RR(s) stored at its host
    name contain the IP address(es) of its RVS rather than its own
    one.
 o  The host is stationary and can be reached directly at the IP
    address(es) contained in the A and/or AAAA RR(s) stored at its
    host name.  This is a degenerate case of rendezvous service where
    the host somewhat acts as an RVS for itself.
 An RVS receiving such an I1 would then relay it to the appropriate
 Responder (the owner of the I1 receiver HIT).  The Responder will
 then complete the exchange with the Initiator, typically without
 ongoing help from the RVS.

4.2. Initiating Connections Based on DNS Names

 On a HIP node, a HIP exchange SHOULD be initiated whenever a ULP
 attempts to communicate with an entity, and the DNS lookup returns
 HIP RRs.
 HIP RRs have a Time To Live (TTL) associated with them.  When the
 number of seconds that passed since the record was retrieved exceeds
 the record's TTL, the record MUST be considered no longer valid and
 deleted by the entity that retrieved it.  If access to the record is
 necessary to initiate communication with the entity to which the
 record corresponds, a new query MUST be made to retrieve a fresh copy
 of the record.
 There may be multiple HIP RRs associated with a single name.  It is
 outside the scope of this specification as to how a host chooses
 between multiple RRs when more than one is returned.  The RVS

Laganier Standards Track [Page 8] RFC 8005 HIP DNS Extension October 2016

 information may be copied and aligned across multiple RRs, or may be
 different for each one; a host MUST check that the RVS used is
 associated with the HI being used, when multiple choices are present.

5. HIP RR Storage Format

 The RDATA for a HIP RR consists of a PK Algorithm Type, the HIT
 length, a HIT, a PK (i.e., an HI), and optionally one or more RVSs.
  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |  HIT length   | PK algorithm  |          PK length            |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                                                               |
 ~                           HIT                                 ~
 |                                                               |
 +                     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     |                                         |
 +-+-+-+-+-+-+-+-+-+-+-+                                         +
 |                           Public Key                          |
 ~                                                               ~
 |                                                               |
 +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                               |                               |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
 |                                                               |
 ~                       Rendezvous Servers                      ~
 |                                                               |
 +             +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |             |
 +-+-+-+-+-+-+-+
 The HIT length, PK algorithm, PK length, HIT, and Public Key fields
 are REQUIRED.  The Rendezvous Server field is OPTIONAL.

5.1. HIT Length Format

 The HIT length indicates the length in bytes of the HIT field.  This
 is an 8-bit unsigned integer.

5.2. PK Algorithm Format

 The PK algorithm field indicates the PK cryptographic algorithm and
 the implied Public Key field format.  This is an 8-bit unsigned
 integer.  This document reuses the values defined for the 'Algorithm
 Type' of the IPSECKEY RR [RFC4025].

Laganier Standards Track [Page 9] RFC 8005 HIP DNS Extension October 2016

 Presently defined values are listed in Section 9 for reference.

5.3. PK Length Format

 The PK length indicates the length in bytes of the Public Key field.
 This is a 16-bit unsigned integer in network byte order.

5.4. HIT Format

 The HIT is stored as a binary value in network byte order.

5.5. Public Key Format

 Two of the PK types defined in this document (RSA and Digital
 Signature Algorithm (DSA)) reuse the PK formats defined for the
 IPSECKEY RR [RFC4025].
 The DSA key format is defined in RFC 2536 [RFC2536].
 The RSA key format is defined in RFC 3110 [RFC3110], and the RSA key
 size limit (4096 bits) is relaxed in the IPSECKEY RR [RFC4025]
 specification.
 In addition, this document similarly defines the PK format of type
 Elliptic Curve Digital Signature Algorithm (ECDSA) as the algorithm-
 specific portion of the DNSKEY RR RDATA for ECDSA [RFC6605], i.e, all
 of the DNSKEY RR DATA after the first four octets, corresponding to
 the same portion of the DNSKEY RR that must be specified by documents
 that define a DNSSEC algorithm.

5.6. Rendezvous Servers Format

 The Rendezvous Server field indicates one or more variable length
 wire-encoded domain names of one or more RVSs, concatenated and
 encoded as described in Section 3.3 of RFC 1035 [RFC1035]:
 "<domain-name> is a domain name represented as a series of labels,
 and terminated by a label with zero length".  Since the wire-encoded
 format is self-describing, the length of each domain name is
 implicit: The zero length label termination serves as a separator
 between multiple RVS domain names concatenated in the Rendezvous
 Server field of a same HIP RR.  Since the length of the other portion
 of the RR's RRDATA is known, and the overall length of the RR's RDATA
 is also known (RDLENGTH), all the length information necessary to
 parse the HIP RR is available.
 The domain names MUST NOT be compressed.  The RVS or servers are
 listed in order of preference (i.e., the first RVS or servers are
 preferred), defining an implicit order amongst RVSs of a single RR.

Laganier Standards Track [Page 10] RFC 8005 HIP DNS Extension October 2016

 When multiple HIP RRs are present at the same owner name, this
 implicit order of RVSs within an RR MUST NOT be used to infer a
 preference order between RVSs stored in different RRs.

6. HIP RR Presentation Format

 This section specifies the representation of the HIP RR in a zone
 master file.
 The HIT length field is not represented, as it is implicitly known
 thanks to the HIT field representation.
 The PK algorithm field is represented as unsigned integers.
 The HIT field is represented as the Base16 encoding [RFC4648] (a.k.a.
 hex or hexadecimal) of the HIT.  The encoding MUST NOT contain
 whitespaces to distinguish it from the Public Key field.
 The Public Key field is represented as the Base64 encoding of the PK,
 as defined in Section 4 of [RFC4648].  The encoding MUST NOT contain
 whitespace(s) to distinguish it from the Rendezvous Server field.
 The PK length field is not represented, as it is implicitly known
 thanks to the Public Key field representation containing no
 whitespaces.
 The Rendezvous Server field is represented by one or more domain
 names separated by whitespace(s).  Such whitespace is only used in
 the HIP RR representation format and is not part of the HIP RR wire
 format.
 The complete representation of the HIP record is:
 IN  HIP   ( pk-algorithm
             base16-encoded-hit
             base64-encoded-public-key
             rendezvous-server[1]
                     ...
             rendezvous-server[n] )
 When no RVSs are present, the representation of the HIP record is:
 IN  HIP   ( pk-algorithm
             base16-encoded-hit
             base64-encoded-public-key )

Laganier Standards Track [Page 11] RFC 8005 HIP DNS Extension October 2016

7. Examples

 In the examples below, the Public Key field containing no whitespace
 is wrapped, since it does not fit in a single line of this document.
 Example of a node with an HI and a HIT but no RVS:
 www.example.com.      IN  HIP ( 2 200100107B1A74DF365639CC39F1D578
                                 AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cI
 vM4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ry
 ra+bSRGQb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXd
 XF5D )
 Example of a node with an HI, a HIT, and one RVS:
 www.example.com.      IN  HIP ( 2 200100107B1A74DF365639CC39F1D578
                                 AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cI
 vM4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ry
 ra+bSRGQb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXd
 XF5D
                                 rvs.example.com. )
 Example of a node with an HI, a HIT, and two RVSs:
 www.example.com.      IN  HIP ( 2 200100107B1A74DF365639CC39F1D578
                                 AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cI
 vM4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ry
 ra+bSRGQb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXd
 XF5D
                                 rvs1.example.com.
                                 rvs2.example.com. )

8. Security Considerations

 This section contains a description of the known threats involved
 with the usage of the HIP DNS Extension.
 In a manner similar to the IPSECKEY RR [RFC4025], the HIP DNS
 Extension allows for the provision of two HIP nodes with the public
 keying material (HI) of their peer.  These HIs will be subsequently
 used in a key exchange between the peers.  Hence, the HIP DNS
 Extension is subject, as the IPSECKEY RR, to threats stemming from
 attacks against unsecured HIP RRs, as described in the remainder of
 this section.

Laganier Standards Track [Page 12] RFC 8005 HIP DNS Extension October 2016

 A HIP node SHOULD obtain HIP RRs from a trusted party through a
 secure channel ensuring data integrity and authenticity of the RRs.
 DNSSEC [RFC4033] [RFC4034] [RFC4035] provides such a secure channel.
 However, it should be emphasized that DNSSEC only offers data
 integrity and authenticity guarantees to the channel between the DNS
 server publishing a zone and the HIP node.  DNSSEC does not ensure
 that the entity publishing the zone is trusted.  Therefore, the RRSIG
 of the HIP RRSet MUST NOT be misinterpreted as a certificate binding
 the HI and/or the HIT to the owner name.
 In the absence of a proper secure channel, both parties are
 vulnerable to MitM and Denial-of-Service (DoS) attacks, and unrelated
 parties might be subject to DoS attacks as well.  These threats are
 described in the following sections.

8.1. Attacker Tampering with an Insecure HIP RR

 The HIP RR contains public keying material in the form of the named
 peer's PK (the HI) and its secure hash (the HIT).  Both of these are
 not sensitive to attacks where an adversary gains knowledge of them.
 However, an attacker that is able to mount an active attack on the
 DNS, i.e., tampers with this HIP RR (e.g., using DNS spoofing), is
 able to mount MitM attacks on the cryptographic core of the eventual
 HIP exchange (Responder's HIP RR rewritten by the attacker).
 The HIP RR may contain an RVS domain name resolved into a destination
 IP address where the named peer is reachable by an I1, as per the HIP
 Rendezvous Extension [RFC8004].  Thus, an attacker that is able to
 tamper with this RR is able to redirect I1 packets sent to the named
 peer to a chosen IP address for DoS or MitM attacks.  Note that this
 kind of attack is not specific to HIP and exists independently of
 whether or not HIP and the HIP RR are used.  Such an attacker might
 tamper with A and AAAA RRs as well.
 An attacker might obviously use these two attacks in conjunction: It
 will replace the Responder's HI and RVS IP address by its own in a
 spoofed DNS packet sent to the Initiator HI, and then redirect all
 exchanged packets to him and mount a MitM on HIP.  In this case, HIP
 won't provide confidentiality nor Initiator HI protection from
 eavesdroppers.

8.2. Hash and HITs Collisions

 As with many cryptographic algorithms, some secure hashes (e.g.,
 SHA1, used by HIP to generate a HIT from an HI) eventually become
 insecure, because an exploit has been found in which an attacker with
 reasonable computation power breaks one of the security features of
 the hash (e.g., its supposed collision resistance).  This is why a

Laganier Standards Track [Page 13] RFC 8005 HIP DNS Extension October 2016

 HIP end-node implementation SHOULD NOT authenticate its HIP peers
 based solely on a HIT retrieved from the DNS, but rather SHOULD use
 HI-based authentication.

8.3. DNSSEC

 In the absence of DNSSEC, the HIP RR is subject to the threats
 described in RFC 3833 [RFC3833].

9. IANA Considerations

 [RFC5205], obsoleted by this document, made the following definition
 and reservation in the "Resource Record (RR) TYPEs" subregistry under
 "Domain Name System (DNS) Parameters":
 Value   Type
 -----   ----
 55      HIP
 In the "Resource Record (RR) TYPEs" subregistry under "Domain Name
 System (DNS) Parameters", references to [RFC5205] have been replaced
 by references to this document.
 As [RFC5205], this document reuses the Algorithm Types defined by
 [RFC4025] for the IPSEC KEY RR.  Presently defined values are shown
 here for reference only:
 Value   Description
 -----   --------------------------------------------------------
   1     A DSA key is present, in the format defined in [RFC2536]
   2     A RSA key is present, in the format defined in [RFC3110]
 IANA has made the following assignment in the "Algorithm Type Field"
 subregistry under "IPSECKEY Resource Record Parameters" [RFC4025]:
 Value   Description
 -----   -----------
   3     An ECDSA key is present, in the format defined in [RFC6605]

Laganier Standards Track [Page 14] RFC 8005 HIP DNS Extension October 2016

10. References

10.1. Normative References

 [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
            STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
            <http://www.rfc-editor.org/info/rfc1034>.
 [RFC1035]  Mockapetris, P., "Domain names - implementation and
            specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
            November 1987, <http://www.rfc-editor.org/info/rfc1035>.
 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119,
            DOI 10.17487/RFC2119, March 1997,
            <http://www.rfc-editor.org/info/rfc2119>.
 [RFC2181]  Elz, R. and R. Bush, "Clarifications to the DNS
            Specification", RFC 2181, DOI 10.17487/RFC2181, July 1997,
            <http://www.rfc-editor.org/info/rfc2181>.
 [RFC3596]  Thomson, S., Huitema, C., Ksinant, V., and M. Souissi,
            "DNS Extensions to Support IP Version 6", RFC 3596,
            DOI 10.17487/RFC3596, October 2003,
            <http://www.rfc-editor.org/info/rfc3596>.
 [RFC4025]  Richardson, M., "A Method for Storing IPsec Keying
            Material in DNS", RFC 4025, DOI 10.17487/RFC4025, March
            2005, <http://www.rfc-editor.org/info/rfc4025>.
 [RFC4033]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
            Rose, "DNS Security Introduction and Requirements",
            RFC 4033, DOI 10.17487/RFC4033, March 2005,
            <http://www.rfc-editor.org/info/rfc4033>.
 [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
            Rose, "Resource Records for the DNS Security Extensions",
            RFC 4034, DOI 10.17487/RFC4034, March 2005,
            <http://www.rfc-editor.org/info/rfc4034>.
 [RFC4035]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
            Rose, "Protocol Modifications for the DNS Security
            Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
            <http://www.rfc-editor.org/info/rfc4035>.
 [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
            Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
            <http://www.rfc-editor.org/info/rfc4648>.

Laganier Standards Track [Page 15] RFC 8005 HIP DNS Extension October 2016

 [RFC6605]  Hoffman, P. and W. Wijngaards, "Elliptic Curve Digital
            Signature Algorithm (DSA) for DNSSEC", RFC 6605,
            DOI 10.17487/RFC6605, April 2012,
            <http://www.rfc-editor.org/info/rfc6605>.
 [RFC7401]  Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
            Henderson, "Host Identity Protocol Version 2 (HIPv2)",
            RFC 7401, DOI 10.17487/RFC7401, April 2015,
            <http://www.rfc-editor.org/info/rfc7401>.
 [RFC8004]  Laganier, J. and L. Eggert, "Host Identity Protocol (HIP)
            Rendezvous Extension", RFC 8004, DOI 10.17487/RFC8004,
            October 2016, <http://www.rfc-editor.org/info/rfc8004>.

10.2. Informative References

 [RFC2536]  Eastlake 3rd, D., "DSA KEYs and SIGs in the Domain Name
            System (DNS)", RFC 2536, DOI 10.17487/RFC2536, March 1999,
            <http://www.rfc-editor.org/info/rfc2536>.
 [RFC3110]  Eastlake 3rd, D., "RSA/SHA-1 SIGs and RSA KEYs in the
            Domain Name System (DNS)", RFC 3110, DOI 10.17487/RFC3110,
            May 2001, <http://www.rfc-editor.org/info/rfc3110>.
 [RFC3833]  Atkins, D. and R. Austein, "Threat Analysis of the Domain
            Name System (DNS)", RFC 3833, DOI 10.17487/RFC3833, August
            2004, <http://www.rfc-editor.org/info/rfc3833>.
 [RFC4423]  Moskowitz, R. and P. Nikander, "Host Identity Protocol
            (HIP) Architecture", RFC 4423, DOI 10.17487/RFC4423, May
            2006, <http://www.rfc-editor.org/info/rfc4423>.
 [RFC5205]  Nikander, P. and J. Laganier, "Host Identity Protocol
            (HIP) Domain Name System (DNS) Extensions", RFC 5205,
            DOI 10.17487/RFC5205, April 2008,
            <http://www.rfc-editor.org/info/rfc5205>.
 [RFC5206]  Nikander, P., Henderson, T., Ed., Vogt, C., and J. Arkko,
            "End-Host Mobility and Multihoming with the Host Identity
            Protocol", RFC 5206, DOI 10.17487/RFC5206, April 2008,
            <http://www.rfc-editor.org/info/rfc5206>.

Laganier Standards Track [Page 16] RFC 8005 HIP DNS Extension October 2016

Appendix A. Changes from RFC 5205

 o  Updated HIP references to revised HIP specifications.
 o  Extended DNS HIP RR to support for Host Identities based on ECDSA.
 o  Clarified that new query must be made when the time that passed
    since an RR was retrieved exceeds the TTL of the RR.
 o  Added considerations related to multiple HIP RRs being associated
    with a single name.
 o  Clarified that the Base64 encoding in use is as per Section 4 of
    [RFC4648].
 o  Clarified the wire format when more than one RVS is defined in one
    RR.
 o  Clarified that "whitespace" is used as the delimiter in the human-
    readable representation of the RR but is not part of the wire
    format.

Acknowledgments

 As usual in the IETF, this document is the result of a collaboration
 between many people.  The authors would like to thank the author
 (Michael Richardson), contributors, and reviewers of the IPSECKEY RR
 [RFC4025] specification, after which this document was framed.  The
 authors would also like to thank the following people, who have
 provided thoughtful and helpful discussions and/or suggestions, that
 have helped improve this document: Jeff Ahrenholz, Rob Austein, Hannu
 Flinck, Olafur Gudmundsson, Tom Henderson, Peter Koch, Olaf Kolkman,
 Miika Komu, Andrew McGregor, Gabriel Montenegro, and Erik Nordmark.
 Some parts of this document stem from the HIP specification
 [RFC7401].  Finally, thanks to Sheng Jiang for performing the
 Internet Area Directorate review of this document in the course of
 the publication process.

Contributors

 Pekka Nikander coauthored an earlier, experimental version of this
 specification [RFC5205].

Laganier Standards Track [Page 17] RFC 8005 HIP DNS Extension October 2016

Author's Address

 Julien Laganier
 Luminate Wireless, Inc.
 Cupertino, CA
 United States of America
 Email: julien.ietf@gmail.com

Laganier Standards Track [Page 18]

/data/webs/external/dokuwiki/data/pages/rfc/rfc8005.txt · Last modified: 2016/10/14 23:30 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki