Internet DRAFT - draft-ietf-hip-rfc5205-bis
draft-ietf-hip-rfc5205-bis
Network Working Group J. Laganier
Internet-Draft Luminate Wireless, Inc.
Obsoletes: 5205 (if approved) January 31, 2016
Intended status: Standards Track
Expires: August 3, 2016
Host Identity Protocol (HIP) Domain Name System (DNS) Extension
draft-ietf-hip-rfc5205-bis-09
Abstract
This document specifies a new 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), Host Identity Tag (HIT, a truncated hash of its public key),
and the Domain Names of its rendezvous servers (RVSs). This document
obsoletes RFC5205.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 3, 2016.
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
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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.
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 . . . . . . . . . . . . . 8
4.1. Storing HI, HIT, and RVS in the DNS . . . . . . . . . . . 8
4.2. Initiating Connections Based on DNS Names . . . . . . . . 8
5. HIP RR Storage Format . . . . . . . . . . . . . . . . . . . . 9
5.1. HIT Length Format . . . . . . . . . . . . . . . . . . . . 10
5.2. PK Algorithm Format . . . . . . . . . . . . . . . . . . . 10
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. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
12.1. Normative references . . . . . . . . . . . . . . . . . . 14
12.2. Informative references . . . . . . . . . . . . . . . . . 16
Appendix A. Changes from RFC 5205 . . . . . . . . . . . . . . . 17
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
This document specifies a new 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), Host Identity Tag (HIT, a truncated hash of its
HI), and the Domain Names of its rendezvous servers (RVSs)
[I-D.ietf-hip-rfc5204-bis].
Currently, most of the Internet applications that need to communicate
with a remote host first translate a domain name (often obtained via
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user input) into one or more IP addresses. This step occurs prior to
communication with the remote host, and relies on a DNS lookup.
With HIP, IP addresses are intended to be used mostly for on-the-wire
communication between end hosts, while most Upper Layer Protocols
(ULP) and applications use HIs or HITs instead (ICMP might be an
example of an 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 new HIP resource
record. 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 [I-D.ietf-hip-rfc5204-bis] allows a HIP
node to be reached via the IP address(es) of a third party, the
node's rendezvous server (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 a
rendezvous server for a given host name.
This document introduces the new HIP DNS resource record to store the
Rendezvous Server (RVS), Host Identity (HI), and Host Identity Tag
(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 the Host Identity Protocol.
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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 fail-over,
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).
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 address(es) via A [RFC1035] and AAAA [RFC3596] RR sets
(RRSets [RFC2181]).
o A Host Identity (HI), Host Identity Tag (HIT), and possibly a set
of rendezvous servers (RVS) 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 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 new 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 rendezvous servers
(RVSs) [I-D.ietf-hip-rfc5204-bis]. A HIP host uses a rendezvous
server 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
resource records at the Responder FQDN, while those using an IP
address in APIs may typically first query for A and/or AAAA resource
records.
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In the following, we assume that the Initiator first queries for HIP
resource records 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.
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 fallback 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
Section 3.1 and Section 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(es) (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 resource record 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
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Which would return DNS packets with RCODE=0 and respectively one or
more A or AAAA RRs containing 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.
[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 Singly 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(es) (IP-R), its HI (HI-R), HIT (HIT-R), and the
domain name(s) of its rendezvous server(s) (e.g., rvs.example.com) in
HIP resource record(s). The mobile HIP node also needs to notify its
rendezvous servers of any change in its set of IP address(es).
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
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Which returns a DNS packet with RCODE=0 and one or more HIP RRs with
the HIT, HI, and RVS domain name(s) (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 IP address(es) of the Responder's RVS (e.g.,
IP-RVS) in their answer sections.
[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.
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4. Overview of Using the DNS with HIP
4.1. Storing HI, HIT, and RVS in the DNS
For any HIP node, its Host Identity (HI), the associated Host
Identity Tag (HIT), and the FQDN of its possible RVSs can be stored
in a DNS HIP RR. Any conforming implementation may store a Host
Identity (HI) and its associated Host Identity Tag (HIT) in a DNS HIP
RDATA format. HI and HIT are defined in Section 3 of the HIP
specification [RFC7401].
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 possibly
embedded along SHOULD only be used as an optimization (e.g., table
lookup).
The HIP resource record may also contain one or more domain name(s)
of rendezvous server(s) towards which HIP I1 packets might be sent to
trigger the establishment of an association with the entity named by
this resource record [I-D.ietf-hip-rfc5204-bis].
The rendezvous server field of the HIP resource record stored at a
given owner name MAY include the owner name itself. A semantically
equivalent situation occurs if no rendezvous server is present in the
HIP resource record stored at that owner name. Such situations occur
in two cases:
o The host is mobile, and the A and/or AAAA resource record(s)
stored at its host name contain the IP address(es) of its
rendezvous server 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 resource record(s)
stored at its host name. This is a degenerate case of rendezvous
service where the host somewhat acts as a rendezvous server 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 Host Identity Protocol exchange SHOULD be initiated
whenever a ULP attempts to communicate with an entity and the DNS
lookup returns HIP resource records.
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The HIP resource records 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 to
be 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 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 from
between multiple RRs when more than one is returned. The RVS
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 public key algorithm type, the
HIT length, a HIT, a public key (i.e., a HI), and optionally one or
more rendezvous server(s).
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 Servers field is OPTIONAL.
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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 public key 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].
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 public key types defined in this document (RSA and DSA)
reuse the public key 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 public key format of
type 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 Servers field indicates one or more variable length
wire-encoded domain names of rendezvous server(s), as described in
Section 3.3 of RFC 1035 [RFC1035]. The wire-encoded format is self-
describing, so the length is implicit. The domain names MUST NOT be
compressed. The rendezvous server(s) are listed in order of
preference (i.e., first rendezvous server(s) are preferred), defining
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an implicit order amongst rendezvous servers of a single RR. When
multiple HIP RRs are present at the same owner name, this implicit
order of rendezvous servers within an RR MUST NOT be used to infer a
preference order between rendezvous servers 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 [RFC4648]
of the public key. The encoding MUST NOT contain whitespace(s) to
distinguish it from the Rendezvous Servers 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 Servers field is represented by one or more domain
name(s) separated by whitespace(s).
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 )
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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 HI and HIT but no RVS:
www.example.com. IN HIP ( 2 200100107B1A74DF365639CC39F1D578
AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cI
vM4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ry
ra+bSRGQb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXd
XF5D )
Example of a node with a HI, 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 a HI, 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.
A HIP node SHOULD obtain HIP RRs from a trusted party trough a secure
channel ensuring data integrity and authenticity of the RRs. DNSSEC
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[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
signature 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 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 public key (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 Man-in-the-Middle attacks on the
cryptographic core of the eventual HIP exchange (Responder's HIP RR
rewritten by the attacker).
The HIP RR may contain a rendezvous server domain name resolved into
a destination IP address where the named peer is reachable by an I1,
as per the HIP Rendezvous Extension [I-D.ietf-hip-rfc5204-bis].
Thus, an attacker 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, 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
HIP end-node implementation SHOULD NOT authenticate its HIP peers
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based solely on a HIT retrieved from the DNS, but SHOULD rather 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
IANA is requested to replace references to [RFC5205] by references to
this document in the the DNS RR type code registry.
IANA is requested to allocate the following algorithm type in the
IPSECKEY RR [RFC4025] registry:
[IANA-TBD] is ECDSA
10. Contributors
Pekka Nikander co-authored an earlier, experimental version of this
specification [RFC5205].
11. 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, Erik Nordmark, and Gabriel Montenegro.
Some parts of this document stem from the HIP specification
[RFC7401]. Finally, thanks Sheng Jiang for performing the Internet
Area Directorate review of this document in the course of the
publication process.
12. References
12.1. Normative references
[I-D.ietf-hip-rfc5204-bis]
Laganier, J. and L. Eggert, "Host Identity Protocol (HIP)
Rendezvous Extension", draft-ietf-hip-rfc5204-bis-07 (work
in progress), December 2015.
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[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>.
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[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>.
12.2. 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] Henderson, T., Ed., "End-Host Mobility and Multihoming
with the Host Identity Protocol", RFC 5206, April 2008.
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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
Elliptic Curve Digital Signature Algorithm (ECDSA).
o Clarified that new query must be made when the time that passed
since a RR was retrieved exceeds the TTL of the RR.
o Added considerations related to multiple HIP RRs being associated
with a single name.
Author's Address
Julien Laganier
Luminate Wireless, Inc.
Cupertino, CA
USA
EMail: julien.ietf@gmail.com
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