< draft-ietf-hip-dns-08.txt   draft-ietf-hip-dns-09.txt >
Network Working Group P. Nikander Network Working Group P. Nikander
Internet-Draft Ericsson Research Nomadic Lab Internet-Draft Ericsson Research Nomadic Lab
Expires: April 20, 2007 J. Laganier Intended status: Experimental J. Laganier
DoCoMo Euro-Labs Expires: October 15, 2007 DoCoMo Euro-Labs
October 17, 2006 April 13, 2007
Host Identity Protocol (HIP) Domain Name System (DNS) Extensions Host Identity Protocol (HIP) Domain Name System (DNS) Extensions
draft-ietf-hip-dns-08 draft-ietf-hip-dns-09
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 35 skipping to change at page 1, line 35
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 20, 2007. This Internet-Draft will expire on October 15, 2007.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
This document specifies a new resource record (RR) for the Domain This document specifies a new resource record (RR) for the Domain
Name System (DNS), and how to use it with the Host Identity Protocol 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 (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 Identity (HI, the public component of the node public-private key
pair), Host Identity Tag (HIT, a truncated hash of its public key), pair), Host Identity Tag (HIT, a truncated hash of its public key),
and the Domain Names of its rendezvous servers (RVS.) and the Domain Names of its rendezvous servers (RVS).
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . 4 2. Conventions used in this document . . . . . . . . . . . . . . 4
3. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 5 3. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Simple static singly homed end-host . . . . . . . . . . . 6 3.1. Simple static singly homed end-host . . . . . . . . . . . 6
3.2. Mobile end-host . . . . . . . . . . . . . . . . . . . . . 7 3.2. Mobile end-host . . . . . . . . . . . . . . . . . . . . . 7
4. Overview of using the DNS with HIP . . . . . . . . . . . . . . 9 4. Overview of using the DNS with HIP . . . . . . . . . . . . . . 9
4.1. Storing HI, HIT and RVS in DNS . . . . . . . . . . . . . . 9 4.1. Storing HI, HIT and RVS in the DNS . . . . . . . . . . . . 9
4.2. Initiating connections based on DNS names . . . . . . . . 9 4.2. Initiating connections based on DNS names . . . . . . . . 9
5. HIP RR Storage Format . . . . . . . . . . . . . . . . . . . . 10 5. HIP RR Storage Format . . . . . . . . . . . . . . . . . . . . 10
5.1. HIT length format . . . . . . . . . . . . . . . . . . . . 10 5.1. HIT length format . . . . . . . . . . . . . . . . . . . . 10
5.2. PK algorithm format . . . . . . . . . . . . . . . . . . . 10 5.2. PK algorithm format . . . . . . . . . . . . . . . . . . . 10
5.3. PK length format . . . . . . . . . . . . . . . . . . . . . 11 5.3. PK length format . . . . . . . . . . . . . . . . . . . . . 11
5.4. HIT format . . . . . . . . . . . . . . . . . . . . . . . . 11 5.4. HIT format . . . . . . . . . . . . . . . . . . . . . . . . 11
5.5. Public key format . . . . . . . . . . . . . . . . . . . . 11 5.5. Public key format . . . . . . . . . . . . . . . . . . . . 11
5.6. Rendezvous servers format . . . . . . . . . . . . . . . . 11 5.6. Rendezvous servers format . . . . . . . . . . . . . . . . 11
6. HIP RR Presentation Format . . . . . . . . . . . . . . . . . . 12 6. HIP RR Presentation Format . . . . . . . . . . . . . . . . . . 12
7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
Intellectual Property and Copyright Statements . . . . . . . . . . 21 Intellectual Property and Copyright Statements . . . . . . . . . . 21
1. Introduction 1. Introduction
This document specifies a new resource record (RR) for the Domain This document specifies a new resource record (RR) for the Domain
Name System (DNS) [RFC1034], and how to use it with the Host Identity Name System (DNS) [RFC1034], and how to use it with the Host Identity
Protocol (HIP) [I-D.ietf-hip-base]. This RR allows a HIP node to Protocol (HIP) [I-D.ietf-hip-base]. This RR allows a HIP node to
store in the DNS its Host Identity (HI, the public component of the store in the DNS its Host Identity (HI, the public component of the
node public-private key pair), Host Identity Tag (HIT, a truncated node public-private key pair), Host Identity Tag (HIT, a truncated
hash of its HI), and the Domain Names of its rendezvous servers hash of its HI), and the Domain Names of its rendezvous servers (RVS)
(RVS.) [I-D.ietf-hip-rvs] [I-D.ietf-hip-rvs].
Currently, most of the Internet applications that need to communicate Currently, most of the Internet applications that need to communicate
with a remote host first translate a domain name (often obtained via with a remote host first translate a domain name (often obtained via
user input) into one or more IP address(es). This step occurs prior user input) into one or more IP address(es). This step occurs prior
to communication with the remote host, and relies on a DNS lookup. 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 With HIP, IP addresses are intended to be used mostly for on-the-wire
communication between end hosts, while most ULPs and applications use communication between end hosts, while most Upper Layer Protocols
HIs or HITs instead (ICMP might be an example of an ULP not using (ULP) and applications use HIs or HITs instead (ICMP might be an
them.) Consequently, we need a means to translate a domain name into example of an ULP not using them). Consequently, we need a means to
an HI. Using the DNS for this translation is pretty straightforward: translate a domain name into an HI. Using the DNS for this
We define a new HIP resource record. Upon query by an application or translation is pretty straightforward: We define a new HIP resource
ULP for a FQDN -> IP lookup, the resolver would then additionally record. Upon query by an application or ULP for a name to IP address
perform an FQDN -> HI lookup, and use it to construct the resulting lookup, the resolver would then additionally perform a name to HI
HI -> IP mapping (which is internal to the HIP layer.) The HIP layer lookup, and use it to construct the resulting HI to IP address
uses the HI -> IP mapping to translate HIs and HITs into IP addresses 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. and vice versa.
The HIP rendezvous extensions [I-D.ietf-hip-rvs] proposal allows a The HIP rendezvous extensions [I-D.ietf-hip-rvs] proposal allows a
HIP node to be reached via the IP address(es) of a third party, the 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 node's rendezvous server (RVS). An initiator willing to establish a
HIP association with a responder served by a RVS would typically HIP association with a responder served by a RVS would typically
initiate a HIP exchange by sending an I1 towards the RVS IP address initiate a HIP exchange by sending an I1 towards the RVS IP address
rather than towards the responder IP address. Consequently, we need rather than towards the responder IP address. Consequently, we need
a means to translate a domain name into the rendezvous server's a means to to find the name of a rendezvous server for a given host
domain name. name.
This draft introduces the new HIP DNS Resource Record to store This document introduces the new HIP DNS Resource Record to store
Rendezvous Server (RVS), Host Identity (HI) and Host Identity Tag Rendezvous Server (RVS), Host Identity (HI) and Host Identity Tag
(HIT) information. (HIT) information.
2. Conventions used in this document 2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC2119 [RFC2119]. document are to be interpreted as described in RFC2119 [RFC2119].
3. Usage Scenarios 3. Usage Scenarios
In this section, we briefly introduce a number of usage scenarios In this section, we briefly introduce a number of usage scenarios
where the DNS is useful with the Host Identity Protocol. where the DNS is useful with the Host Identity Protocol.
With HIP, most application and ULPs are unaware of the IP addresses With HIP, most application and ULPs are unaware of the IP addresses
used to carry packets on the wire. Consequently, a HIP node could used to carry packets on the wire. Consequently, a HIP node could
take advantage of having multiple IP addresses for fail-over, take advantage of having multiple IP addresses for fail-over,
redundancy, mobility, or renumbering, in a manner which is redundancy, mobility, or renumbering, in a manner which is
transparent to most ULPs and applications (because they are bound to transparent to most ULPs and applications (because they are bound to
HIs, hence they are agnostic to these IP address changes.) HIs, hence they are agnostic to these IP address changes).
In these situations, a node wishing to be reachable by reference to In these situations, for a node to be reachable by reference to its
its FQDN should store the following information in the DNS: Fully Qualified Domain Name (FQDN), the following information should
be stored in the DNS:
o A set of IP address(es) through A [RFC1035] and AAAA [RFC3596] o A set of IP address(es) through A [RFC1035] and AAAA [RFC3596] RR
RRs. sets (RRSets [RFC2181]).
o A Host Identity (HI), Host Identity Tag (HIT) and possibly a set o A Host Identity (HI), Host Identity Tag (HIT) and possibly a set
of rendezvous server(s) (RVS) through HIP RRs. of rendezvous servers (RVS) through HIP RRs.
When a HIP node wants to initiate a communication with another HIP When a HIP node wants to initiate a communication with another HIP
node, it first needs to perform a HIP base exchange to set-up a 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 association towards its peer. Although such an exchange can be
initiated opportunistically, i.e., without prior knowledge of the initiated opportunistically, i.e., without prior knowledge of the
responder's HI, by doing so both nodes knowingly risk man-in-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 middle attacks on the HIP exchange. To prevent these attacks, it is
recommended that the initiator first obtain the HI of the responder, recommended that the initiator first obtain the HI of the responder,
and then initiate the exchange. This can be done, for example, and then initiate the exchange. This can be done, for example,
through manual configuration or DNS lookups. Hence, a new HIP RR is through manual configuration or DNS lookups. Hence, a new HIP RR is
introduced. introduced.
When a HIP node is frequently changing its IP address(es), the When a HIP node is frequently changing its IP address(es), the
dynamic DNS update latency may prevent it from publishing its new IP natural DNS latency for propagating changes may prevent it from
address(es) in the DNS. For solving this problem, the HIP publishing its new IP address(es) in the DNS. For solving this
architecture [RFC4423] introduces rendezvous servers (RVS.) A HIP problem, the HIP architecture [RFC4423] introduces rendezvous servers
host uses a rendezvous server as a rendezvous point, to maintain (RVS). A HIP host uses a rendezvous server as a rendezvous point, to
reachability with possible HIP initiators while moving maintain reachability with possible HIP initiators while moving
[I-D.ietf-hip-mm]. Such a HIP node would publish in the DNS its RVS [I-D.ietf-hip-mm]. 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 domain name(s) in a HIP RR, while keeping its RVS up-to-date with its
current set of IP addresses. current set of IP addresses.
When a HIP node wants to initiate a HIP exchange with a responder it 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 the will perform a number of DNS lookups. Depending on the type of the
implementation, the order in which those lookups will be issued may implementation, the order in which those lookups will be issued may
vary. For instance, implementations using HIT in APIS may typically vary. For instance, implementations using HIT in APIs may typically
first query for HIP resource records at the responder FQDN, while first query for HIP resource records at the responder FQDN, while
those using IP address in APIs may typically first query for A and/or those using IP address in APIs may typically first query for A and/or
AAAA resource records. AAAA resource records.
In the following we assume that the initiator first queries for HIP In the following we assume that the initiator first queries for HIP
resource records at the responder FQDN. resource records at the responder FQDN.
If the query for the HIP type was responded to with a DNS answer with 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 RCODE=3 (Name Error), then the responder's information is not present
in the DNS and further queries SHOULD NOT be made. 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 In case the query for the HIP records returned a DNS answer with
RCODE=0 (No Error), then the initiator sends out one more query for RCODE=0 (No Error) and an empty answer section, it means that no HIP
for A and AAAA types at the responder's FQDN. information is avalaible 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 sends out more queries for A and AAAA types at the
responder's FQDN.
Depending on the combinations of answer the situations described in Depending on the combinations of answers the situations described in
Section 3.1 and Section 3.2 can occur. Section 3.1 and Section 3.2 can occur.
Note that storing HIP RR information in the DNS at a FQDN which is Note that storing HIP RR information in the DNS at a FQDN which is
assigned to a non-HIP node might have ill effects on its reachability assigned to a non-HIP node might have ill effects on its reachability
by HIP nodes. by HIP nodes.
3.1. Simple static singly homed end-host 3.1. Simple static singly homed end-host
A HIP node (R) with a single static network attachment, wishing to be A HIP node (R) with a single static network attachment, wishing to be
reachable by reference to its FQDN (www.example.com), would store in reachable by reference to its FQDN (www.example.com), would store in
the DNS, in addition to its IP address(es) (IP-R), its Host Identity the DNS, in addition to its IP address(es) (IP-R), its Host Identity
(HI-R) and Host Identity Tag (HIT-R) in a HIP resource record. (HI-R) and Host Identity Tag (HIT-R) in a HIP resource record.
An initiator willing to associate with a node would typically issue An initiator willing to associate with a node would typically issue
the following queries: the following queries:
QNAME=www.example.com, QTYPE=HIP o QNAME=www.example.com, QTYPE=HIP
(QCLASS=IN is assumed and omitted from the examples) o (QCLASS=IN is assumed and omitted from the examples)
Which returns a DNS packet with RCODE=0 and one or more HIP RRs with 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 the HIT and HI (e.g. HIT-R and HI-R) of the responder in the answer
section, but no RVS. section, but no RVS.
QNAME=www.example.com, QTYPE=A o QNAME=www.example.com, QTYPE=A QNAME=www.example.com, QTYPE=AAAA
Which returns a DNS packet with RCODE=0 and one or more A or AAAA RRs Which returns DNS packets with RCODE=0 and one or more A or AAAA RRs
containing IP address(es) of the responder (e.g. IP-R) in the answer containing IP address(es) of the responder (e.g. IP-R) in the answer
section. section.
Caption: In the remainder of this document, for the sake of keeping Caption: In the remainder of this document, for the sake of keeping
diagrams simple and concise, several DNS queries and answers diagrams simple and concise, several DNS queries and answers
are represented as one single transaction, while in fact are represented as one single transaction, while in fact
there are several queries and answers flowing back and there are several queries and answers flowing back and
forth, as described in the textual examples. forth, as described in the textual examples.
[HIP? A? ] [HIP? A? ]
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| | [HIP HIT-R HI-R ] | | [HIP HIT-R HI-R ]
| | [A IP-R ] | | [A IP-R ]
| v | v
+-----+ +-----+ +-----+ +-----+
| |--------------I1------------->| | | |--------------I1------------->| |
| I |<-------------R1--------------| R | | I |<-------------R1--------------| R |
| |--------------I2------------->| | | |--------------I2------------->| |
| |<-------------R2--------------| | | |<-------------R2--------------| |
+-----+ +-----+ +-----+ +-----+
Static Singly Homed Host
The initiator would then send an I1 to the responder's IP addresses The initiator would then send an I1 to the responder's IP addresses
(IP-R.) (IP-R).
3.2. Mobile end-host 3.2. Mobile end-host
A mobile HIP node (R) wishing to be reachable by reference to its 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 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 to its IP address(es) (IP-R), its HI (HI-R), HIT (HIT-R) and the
domain name(s) of its rendezvous server(s) (rvs.example.com) in HIP domain name(s) of its rendezvous server(s) (e.g. rvs.example.com) in
resource record(s). The mobile HIP node also needs to notify its 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). rendezvous servers of any change in its set of IP address(es).
An initiator willing to associate with such mobile node would An initiator willing to associate with such mobile node would
typically issue the following queries: typically issue the following queries:
QNAME=www.example.com, QTYPE=HIP o QNAME=www.example.com, QTYPE=HIP
Which returns a DNS packet with RCODE=0 and one or more HIP RRs with 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 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. rvs.example.com) of the responder in the answer section.
QNAME=rvs.example.com, QTYPE=A o QNAME=rvs.example.com, QTYPE=A QNAME=www.example.com, QTYPE=AAAA
Which returns a DNS packet with RCODE=0 and one or more A or AAAA RRs Which returns DNS packets with RCODE=0 and one or more A or AAAA RRs
containing IP address(es) of the responder's RVS (e.g. IP-RVS) in containing IP address(es) of the responder's RVS (e.g. IP-RVS) in
the answer section. the answer section.
[HIP? ] [HIP? ]
[www.example.com] [www.example.com]
[A? ] [A? ]
[rvs.example.com] +-----+ [rvs.example.com] +-----+
+----------------------------------------->| | +----------------------------------------->| |
| | DNS | | | DNS |
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| | | +-----+ | | | | +-----+ |
| | | | | | | |
| | | | | | | |
| v | v | v | v
+-----+ +-----+ +-----+ +-----+
| |<---------------R1------------| | | |<---------------R1------------| |
| I |----------------I2----------->| R | | I |----------------I2----------->| R |
| |<---------------R2------------| | | |<---------------R2------------| |
+-----+ +-----+ +-----+ +-----+
The initiator would then send an I1 to the RVS IP address (IP-RVS.) 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 Following, the RVS will relay the I1 up to the mobile node's IP
address (IP-R), which will complete the HIP exchange. address (IP-R), which will complete the HIP exchange.
4. Overview of using the DNS with HIP 4. Overview of using the DNS with HIP
4.1. Storing HI, HIT and RVS in DNS 4.1. Storing HI, HIT and RVS in the DNS
Any conforming implementation may store a Host Identity (HI) and its For any HIP node its Host Identity (HI), the associated Host Identity
associated Host Identity Tag (HIT) in a DNS HIP RDATA format. If a Tag (HIT), and the FQDN of its possible RVSs can be stored in a DNS
particular form of an HI does not already have a specified RDATA HIP RR. Any conforming implementation may store a Host Identity (HI)
format, a new RDATA-like format SHOULD be defined for the HI. HI and and its associated Host Identity Tag (HIT) in a DNS HIP RDATA format.
HIT are defined in Section 3 of [I-D.ietf-hip-base]. HI and HIT are defined in Section 3 of [I-D.ietf-hip-base].
Upon return of a HIP RR, a host MUST always calculate the HI- 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 derivative HIT to be used in the HIP exchange, as specified in
Section 3 of the HIP base specification [I-D.ietf-hip-base], while Section 3 of the HIP base specification [I-D.ietf-hip-base], while
the HIT possibly embedded along SHOULD only be used as an the HIT possibly embedded along SHOULD only be used as an
optimization (e.g. table lookup.) optimization (e.g. table lookup).
The HIP resource record may also contain one or more domain name(s) 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 of rendezvous server(s) towards which HIP I1 packets might be sent to
trigger the establishment of an association with the entity named by trigger the establishment of an association with the entity named by
this resource record [I-D.ietf-hip-rvs]. this resource record [I-D.ietf-hip-rvs].
The rendezvous server field of the HIP resource record stored at a The rendezvous server field of the HIP resource record stored at a
given domain name MAY include the domain name itself. A semantically given owner name MAY include the owner name itself. A semantically
equivalent situation occurs if no rendezvous server is stored in the equivalent situation occurs if no rendezvous server is present in the
HIP resource record of that domain. Such situations occurs in two HIP resource record stored at that owner name. Such situations
cases: occurs in two cases:
o The host is mobile, and the A and/or AAAA resource record(s) o The host is mobile, and the A and/or AAAA resource record(s)
stored at its domain name contains the IP address(es) of its stored at its host name contains the IP address(es) of its
rendezvous server rather than its own one. rendezvous server rather than its own one.
o The host is stationary, and can be reached directly at IP o The host is stationary, and can be reached directly at IP
address(es) contained in A and/or AAAA resource record(s) stored address(es) contained in A and/or AAAA resource record(s) stored
at its domain name. This a degenerated case of rendezvous service at its host name. This a degenerated case of rendezvous service
where the host somewhat acts as a rendezvous server for itself. where the host somewhat acts as a rendezvous server for itself.
An RVS receiving such an I1 would then relay it to the appropriate An RVS receiving such an I1 would then relay it to the appropriate
responder (the owner of the I1 receiver HIT.) The responder will responder (the owner of the I1 receiver HIT). The responder will
then complete the exchange with the initiator, typically without then complete the exchange with the initiator, typically without
ongoing help from the RVS. ongoing help from the RVS.
4.2. Initiating connections based on DNS names 4.2. Initiating connections based on DNS names
On a HIP node, a Host Identity Protocol exchange SHOULD be initiated On a HIP node, a Host Identity Protocol exchange SHOULD be initiated
whenever an Upper Layer Protocol attempts to communicate with an whenever an ULP attempts to communicate with an entity and the DNS
entity and the DNS lookup returns HIP resource records. lookup returns HIP resource records.
5. HIP RR Storage Format 5. HIP RR Storage Format
The RDATA for a HIP RR consists of a public key algorithm type, the The RDATA for a HIP RR consists of a public key algorithm type, the
HIT length, a HIT, a public key, and optionally one or more HIT length, a HIT, a public key, and optionally one or more
rendezvous server(s). rendezvous server(s).
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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5.1. HIT length format 5.1. HIT length format
The HIT length indicates the length in bytes of the HIT field. This The HIT length indicates the length in bytes of the HIT field. This
is an 8 bits unsigned integer. is an 8 bits unsigned integer.
5.2. PK algorithm format 5.2. PK algorithm format
The PK algorithm field indicates the public key cryptographic The PK algorithm field indicates the public key cryptographic
algorithm and the implied public key field format. This is an 8 bits algorithm and the implied public key field format. This is an 8 bits
unsigned integer. This document reuses the values defined for the unsigned integer. This document reuses the values defined for the
'algorithm type' of the IPSECKEY RR [RFC4025] 'gateway type' field. 'algorithm type' of the IPSECKEY RR [RFC4025].
The presently defined values are shown here for reference:
1 A DSA key is present, in the format defined in RFC2536
[RFC2536].
2 A RSA key is present, in the format defined in RFC3110 Presently defined values are listed in Section 9 for reference.
[RFC3110].
5.3. PK length format 5.3. PK length format
The PK length indicates the length in bytes of the Public key field. The PK length indicates the length in bytes of the Public key field.
This is a 16 bits unsigned integer in network byte order. This is a 16 bits unsigned integer in network byte order.
5.4. HIT format 5.4. HIT format
The HIT is stored, as a binary value, in network byte order. The HIT is stored, as a binary value, in network byte order.
5.5. Public key format 5.5. Public key format
Both of the public key types defined in this document (RSA and DSA) Both of the public key types defined in this document (RSA and DSA)
reuse the public key formats defined for the IPSECKEY RR [RFC4025] reuse the public key formats defined for the IPSECKEY RR [RFC4025].
(which in turns contains the algorithm-specific portion of the KEY RR
RDATA, all of the KEY RR DATA after the first four octets,
corresponding to the same portion of the KEY RR that must be
specified by documents that define a DNSSEC algorithm.)
In the future, if a new algorithm is to be used both by IPSECKEY RR
and HIP RR, it should use the same public key encoding for both RRs.
Unless specified otherwise, the HIP RR public key field SHOULD use
the same public key format as the IPSECKEY RR RDATA for the
corresponding algorithm.
The DSA key format is defined in RFC2536 [RFC2536]. The DSA key format is defined in RFC2536 [RFC2536].
The RSA key format is defined in RFC3110 [RFC3110] and the RSA key The RSA key format is defined in RFC3110 [RFC3110] and the RSA key
size limit (4096 bits) is relaxed in the IPSECKEY RR [RFC4025] size limit (4096 bits) is relaxed in the IPSECKEY RR [RFC4025]
specification. specification.
5.6. Rendezvous servers format 5.6. Rendezvous servers format
The Rendezvous servers field indicates one or more variable length The Rendezvous servers field indicates one or more variable length
wire-encoded domain names rendezvous server(s), as described in wire-encoded domain names of rendezvous server(s), as described in
Section 3.3 of RFC1035 [RFC1035]. The wire-encoded format is self- Section 3.3 of RFC1035 [RFC1035]. The wire-encoded format is self-
describing, so the length is implicit. The domain names MUST NOT be describing, so the length is implicit. The domain names MUST NOT be
compressed. The rendezvous server(s) are listed in order of compressed. The rendezvous server(s) are listed in order of
preference (i.e. first rendezvous server(s) are preferred). preference (i.e. first rendezvous server(s) are preferred), defining
an implicit order amongst rendezvous server 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 6. HIP RR Presentation Format
This section specifies the representation of the HIP RR in a zone This section specifies the representation of the HIP RR in a zone
data master file. master file.
The HIT length field is not represented as it is implicitly known The HIT length field is not represented as it is implicitly known
thanks to the HIT field representation. thanks to the HIT field representation.
The PK algorithm field is represented as unsigned integers. The PK algorithm field is represented as unsigned integers.
The PK length field is not represented as it is implicitly known
thanks to the Public key field representation.
The HIT field is represented as the Base16 encoding [RFC4648] (a.k.a. The HIT field is represented as the Base16 encoding [RFC4648] (a.k.a.
hex or hexadecimal) of the HIT. The encoding MUST NOT contain hex or hexadecimal) of the HIT. The encoding MUST NOT contain
whitespace(s). whitespaces to be able to distinguish it from the public key field.
The Public Key field is represented as the Base64 encoding [RFC4648] The Public Key field is represented as the Base64 encoding [RFC4648]
of the public key. The encoding MAY contain whitespace(s), and such of the public key. The encoding MUST NOT contain whitespace(s) to be
whitespace(s) MUST be ignored. able to distinguish from the Rendezvous Servers field.
The Rendezvous servers field is represented by one or more The PK length field is not represented as it is implicitly known
uncompressed domain name(s) 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 HPIHI record is: The complete representation of the HPIHI record is:
IN HIP ( pk-algorithm IN HIP ( pk-algorithm
base16-encoded-hit base16-encoded-hit
base64-encoded-public-key base64-encoded-public-key
rendezvous-server[1] rendezvous-server[1]
... ...
rendezvous-server[n] ) rendezvous-server[n] )
When no RVS are present, the representation of the HPIHI record is:
IN HIP ( pk-algorithm
base16-encoded-hit
base64-encoded-public-key )
7. Examples 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: Example of a node with HI and HIT but no RVS:
www.example.com. IN HIP ( 2 4009D9BA7B1A74DF365639CC39F1D578 www.example.com. IN HIP ( 2 200100107B1A74DF365639CC39F1D578
AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIv AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIvM4p
M4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy 9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRGQ
87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRG b1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXdXF5D )
Qb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48A
WkskmdHaVDP4BcelrTI3rMXdXF5D )
Example of a node with a HI, HIT and one RVS: Example of a node with a HI, HIT and one RVS:
www.example.com. IN HIP ( 2 4009D9BA7B1A74DF365639CC39F1D578 www.example.com. IN HIP ( 2 200100107B1A74DF365639CC39F1D578
AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIv AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIvM4p
M4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy 9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRGQ
87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRG b1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXdXF5D
Qb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48A rvs.example.com. )
WkskmdHaVDP4BcelrTI3rMXdXF5D
rvs.example.com )
Example of a node with a HI, HIT and two RVS: Example of a node with a HI, HIT and two RVS:
www.example.com. IN HIP ( 2 4009D9BA7B1A74DF365639CC39F1D578 www.example.com. IN HIP ( 2 200100107B1A74DF365639CC39F1D578
AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIv AwEAAbdxyhNuSutc5EMzxTs9LBPCIkOFH8cIvM4p
M4p9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy 9+LrV4e19WzK00+CI6zBCQTdtWsuxKbWIy87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRGQ
87UOoJTwkUs7lBu+Upr1gsNrut79ryra+bSRG b1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48AWkskmdHaVDP4BcelrTI3rMXdXF5D
Qb1slImA8YVJyuIDsj7kwzG7jnERNqnWxZ48A rvs1.example.com.
WkskmdHaVDP4BcelrTI3rMXdXF5D rvs2.example.com. )
rvs1.example.com
rvs2.example.com )
8. Security Considerations 8. Security Considerations
Though the security considerations of the HIP DNS extensions still This section contains a description of the known threats involved
need to be more investigated and documented, this section contains a with the usage of the HIP DNS extensions.
description of the known threats involved with the usage of the HIP
DNS extensions.
In a manner similar to the IPSECKEY RR [RFC4025], the HIP DNS In a manner similar to the IPSECKEY RR [RFC4025], the HIP DNS
Extensions allows to provision two HIP nodes with the public keying Extensions allows to provision two HIP nodes with the public keying
material (HI) of their peer. These HIs will be subsequently used in material (HI) of their peer. These HIs will be subsequently used in
a key exchange between the peers. Hence, the HIP DNS Extensions a key exchange between the peers. Hence, the HIP DNS Extensions
introduce the same kind of threats that IPSECKEY does, plus threats introduce the same kind of threats that IPSECKEY does, plus threats
caused by the possibility given to a HIP node to initiate or accept a caused by the possibility given to a HIP node to initiate or accept a
HIP exchange using "opportunistic" or "unpublished initiator HI" HIP exchange using "opportunistic" or "unpublished initiator HI"
modes. modes.
A HIP node SHOULD obtain HIP RRs from a trusted party trough a secure A HIP node SHOULD obtain HIP RRs from a trusted party trough a secure
channel insuring proper data integrity of the RRs. DNSSEC [RFC4033] channel insuring data integrity and authenticity of the RRs. DNSSEC
[RFC4034] [RFC4035] provides such a secure channel. [RFC4033] [RFC4034] [RFC4035] provides such a secure channel.
However, it should be emphasized that DNSSEC does only offer data
integrity and authenticty 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 In the absence of a proper secure channel, both parties are
vulnerable to MitM and DoS attacks, and unrelated parties might be vulnerable to MitM and DoS attacks, and unrelated parties might be
subject to DoS attacks as well. These threats are described in the subject to DoS attacks as well. These threats are described in the
following sections. following sections.
8.1. Attacker tampering with an insecure HIP RR 8.1. Attacker tampering with an insecure HIP RR
The HIP RR contains public keying material in the form of the named 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 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 these are not sensitive to attacks where an adversary gains knowledge
of them. However, an attacker that is able to mount an active attack 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) 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 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 of the eventual HIP exchange (responder's HIP RR rewritten by the
attacker.) attacker).
The HIP RR may contain a rendezvous server domain name resolved into 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 a destination IP address where the named peer is reachable by an I1
(HIP Rendezvous Extensions IPSECKEY RR [I-D.ietf-hip-rvs].) Thus, an (HIP Rendezvous Extensions IPSECKEY RR [I-D.ietf-hip-rvs]). Thus, an
attacker able to tamper with this RR is able to redirect I1 packets 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 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 attacks. Note that this kind of attack is not specific to HIP and
exists independently to whether or not HIP and the HIP RR are used. 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. Such an attacker might tamper with A and AAAA RRs as well.
An attacker might obviously use these two attacks in conjunction: It An attacker might obviously use these two attacks in conjunction: It
will replace the responder's HI and RVS IP address by its owns in a 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 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 exchanged packets to him and mount a MitM on HIP. In this case HIP
won't provide confidentiality nor initiator HI protection from won't provide confidentiality nor initiator HI protection from
eavesdroppers. eavesdroppers.
8.2. Hash and HITs Collisions 8.2. Hash and HITs Collisions
As many cryptographic algorithm, some secure hashes (e.g. SHA1, used As many cryptographic algorithms, some secure hashes (e.g. SHA1,
by HIP to generate a HIT from an HI) eventually become insecure, used by HIP to generate a HIT from an HI) eventually become insecure,
because an exploit has been found in which an attacker with a because an exploit has been found in which an attacker with a
reasonable computation power breaks one of the security features of reasonable computation power breaks one of the security features of
the hash (e.g. its supposed collision resistance.) This is why a HIP the hash (e.g. its supposed collision resistance). This is why a HIP
end-node implementation SHOULD NOT authenticate its HIP peers based end-node implementation SHOULD NOT authenticate its HIP peers based
solely on a HIT retrieved from DNS, but SHOULD rather use HI-based solely on a HIT retrieved from the DNS, but SHOULD rather use HI-
authentication. based authentication.
8.3. DNSSEC 8.3. DNSSEC
In the absence of DNSSEC, the HIP RR is subject to the threats In the absence of DNSSEC, the HIP RR is subject to the threats
described in RFC 3833 [RFC3833]. described in RFC 3833 [RFC3833].
9. IANA Considerations 9. IANA Considerations
IANA should allocate one new RR type code (TBD, 55?) for the HIP RR IANA should allocate one new RR type code (TBD, 55?) for the HIP RR
from the standard RR type space. from the standard RR type space.
IANA does not need to open a new registry for public key algorithms IANA does not need to open a new registry for public key algorithms
of the HIP RR because the HIP RR reuses "algorithms types" defined of the HIP RR because the HIP RR reuses "algorithms types" defined
for the IPSECKEY RR [RFC4025]. The presently defined values are for the IPSECKEY RR [RFC4025]. Presently defined values are shown
shown here for reference: here for reference only:
0 is reserved 0 is reserved
1 is RSA 1 is RSA
2 is DSA 2 is DSA
In the future, if a new algorithm is to be used for the HIP RR, a new
algorithm type and corresponding public key encoding should be
defined for the IPSECKEY RR. The HIP RR should reuse both the same
algorithm type and the same corresponding public key format as the
IPSECKEY RR.
10. Acknowledgments 10. Acknowledgments
As usual in the IETF, this document is the result of a collaboration As usual in the IETF, this document is the result of a collaboration
between many people. The authors would like to thanks the author between many people. The authors would like to thanks the author
(Michael Richardson), contributors and reviewers of the IPSECKEY RR (Michael Richardson), contributors and reviewers of the IPSECKEY RR
[RFC4025] specification, which this document was framed after. The [RFC4025] specification, which this document was framed after. The
authors would also like to thanks the following people, who have authors would also like to thanks the following people, who have
provided thoughtful and helpful discussions and/or suggestions, that provided thoughtful and helpful discussions and/or suggestions, that
have helped improving this document: Jeff Ahrenholz, Rob Austein, have helped improving this document: Jeff Ahrenholz, Rob Austein,
Hannu Flinck, Tom Henderson, Olaf Kolkman, Miika Komu, Andrew Hannu Flinck, Olafur Gu[eth]mundsson, Tom Henderson, Peter Koch, Olaf
McGregor, Erik Nordmark, and Gabriel Montenegro. Some parts of this Kolkman, Miika Komu, Andrew McGregor, Erik Nordmark, and Gabriel
draft stem from [I-D.ietf-hip-base]. Montenegro. Some parts of this document stem from
[I-D.ietf-hip-base].
Julien Laganier is partly funded by Ambient Networks, a research Julien Laganier is partly funded by Ambient Networks, a research
project supported by the European Commission under its Sixth project supported by the European Commission under its Sixth
Framework Program. The views and conclusions contained herein are Framework Program. The views and conclusions contained herein are
those of the authors and should not be interpreted as necessarily those of the authors and should not be interpreted as necessarily
representing the official policies or endorsements, either expressed representing the official policies or endorsements, either expressed
or implied, of the Ambient Networks project or the European or implied, of the Ambient Networks project or the European
Commission. Commission.
11. References 11. References
skipping to change at page 18, line 18 skipping to change at page 18, line 18
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", [RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, November 1987. STD 13, RFC 1034, November 1987.
[RFC1035] Mockapetris, P., "Domain names - implementation and [RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2536] Eastlake, D., "DSA KEYs and SIGs in the Domain Name System [RFC2181] Elz, R. and R. Bush, "Clarifications to the DNS
(DNS)", RFC 2536, March 1999. Specification", RFC 2181, July 1997.
[RFC3110] Eastlake, D., "RSA/SHA-1 SIGs and RSA KEYs in the Domain
Name System (DNS)", RFC 3110, May 2001.
[RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi, [RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi,
"DNS Extensions to Support IP Version 6", RFC 3596, "DNS Extensions to Support IP Version 6", RFC 3596,
October 2003. October 2003.
[RFC4025] Richardson, M., "A Method for Storing IPsec Keying [RFC4025] Richardson, M., "A Method for Storing IPsec Keying
Material in DNS", RFC 4025, March 2005. Material in DNS", RFC 4025, March 2005.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements", Rose, "DNS Security Introduction and Requirements",
skipping to change at page 18, line 48 skipping to change at page 18, line 45
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005. Extensions", RFC 4035, March 2005.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006. Encodings", RFC 4648, October 2006.
[I-D.ietf-hip-base] [I-D.ietf-hip-base]
Moskowitz, R., "Host Identity Protocol", Moskowitz, R., "Host Identity Protocol",
draft-ietf-hip-base-06 (work in progress), June 2006. draft-ietf-hip-base-07 (work in progress), February 2007.
[I-D.ietf-hip-rvs] [I-D.ietf-hip-rvs]
Laganier, J. and L. Eggert, "Host Identity Protocol (HIP) Laganier, J. and L. Eggert, "Host Identity Protocol (HIP)
Rendezvous Extension", draft-ietf-hip-rvs-05 (work in Rendezvous Extension", draft-ietf-hip-rvs-05 (work in
progress), June 2006. progress), June 2006.
11.2. Informative references 11.2. Informative references
[RFC2536] Eastlake, D., "DSA KEYs and SIGs in the Domain Name System
(DNS)", RFC 2536, March 1999.
[RFC3110] Eastlake, D., "RSA/SHA-1 SIGs and RSA KEYs in the Domain
Name System (DNS)", RFC 3110, May 2001.
[RFC4423] Moskowitz, R. and P. Nikander, "Host Identity Protocol [RFC4423] Moskowitz, R. and P. Nikander, "Host Identity Protocol
(HIP) Architecture", RFC 4423, May 2006. (HIP) Architecture", RFC 4423, May 2006.
[I-D.ietf-hip-mm] [I-D.ietf-hip-mm]
Nikander, P., "End-Host Mobility and Multihoming with the Henderson, T., "End-Host Mobility and Multihoming with the
Host Identity Protocol", draft-ietf-hip-mm-04 (work in Host Identity Protocol", draft-ietf-hip-mm-05 (work in
progress), June 2006. progress), March 2007.
[RFC3833] Atkins, D. and R. Austein, "Threat Analysis of the Domain [RFC3833] Atkins, D. and R. Austein, "Threat Analysis of the Domain
Name System (DNS)", RFC 3833, August 2004. Name System (DNS)", RFC 3833, August 2004.
Authors' Addresses Authors' Addresses
Pekka Nikander Pekka Nikander
Ericsson Research Nomadic Lab Ericsson Research Nomadic Lab
JORVAS FIN-02420 JORVAS FIN-02420
FINLAND FINLAND
skipping to change at page 21, line 5 skipping to change at page 21, line 5
Julien Laganier Julien Laganier
DoCoMo Communications Laboratories Europe GmbH DoCoMo Communications Laboratories Europe GmbH
Landsberger Strasse 312 Landsberger Strasse 312
Munich 80687 Munich 80687
Germany Germany
Phone: +49 89 56824 231 Phone: +49 89 56824 231
Email: julien.ietf@laposte.net Email: julien.ietf@laposte.net
URI: http://www.docomolab-euro.com/ URI: http://www.docomolab-euro.com/
Intellectual Property Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
skipping to change at page 21, line 29 skipping to change at page 21, line 45
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
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ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2006). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is provided by the IETF
Internet Society. Administrative Support Activity (IASA).
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