Internet DRAFT - draft-xu-hip-hierarchical
draft-xu-hip-hierarchical
Network Working Group X. Xu
Internet-Draft S. Jiang
Intended status: Informational D. Zhang
Expires: September 13, 2012 Huawei Technologies Co.,Ltd
D. Korzun
HIIT
Z. Cao
March 12, 2012
Extensions of Host Identity Protocol (HIP) with Hierarchical Information
draft-xu-hip-hierarchical-03
Abstract
This document explores the benefits brought by extending the Host
Identity Protocol (HIP) with hierarchical information. In addition,
three types of candidate solutions are introduced.
Requirements Language
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].
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 September 13, 2012.
Copyright Notice
Copyright (c) 2012 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
Xu, et al. Expires September 13, 2012 [Page 1]
Internet-Draft Hierarchical HIP March 2012
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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Benefits introduced by Hierarchical Information . . . . . . . 3
3. Candidate Solutions . . . . . . . . . . . . . . . . . . . . . 4
4. Integrating Hierarchical Information into 128 Bits HITs . . . 5
4.1. Compatible flat-structured HITs . . . . . . . . . . . . . 7
4.2. HITs on nodes . . . . . . . . . . . . . . . . . . . . . . 7
4.3. Generating a hierarchical HIT . . . . . . . . . . . . . . 7
5. Transporting Hierarchical information outside HITs . . . . . . 8
5.1. Hierarchical_HIT Parameter . . . . . . . . . . . . . . . . 9
5.2. Hierarchical Information Registration . . . . . . . . . . 10
5.3. Domain Name System (DNS) Extension . . . . . . . . . . . . 10
6. Extending the length of HITs . . . . . . . . . . . . . . . . . 11
7. Analysis of the Three Solutions . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
Xu, et al. Expires September 13, 2012 [Page 2]
Internet-Draft Hierarchical HIP March 2012
1. Introduction
While having obtained a tremendous success, the current Internet
architecture shows its limits in many aspects. For example, the
current Internet cannot well support the incorporation of mobile and
multi-homed terminals, lacks essential security mechanisms, and
suffers from the issues caused by the explosively increased lengths
of routing tables. In order to address these challenges, a
comprehensive solution, the Host Identity Protocol (HIP), was
proposed. A simple principle behind HIP is to separate hosts'
identities from their topological locations in the Internet.
Currently, the basic architectures and protocols of HIP have been
developed, which are security-inherited and provides essential
supports for mobility and multi-homing features.
There is no hierarchcial information in the current HITs; hosts in
the current HIP architecture are organized as all "flat". This is
largely because a flat HIP namespace is simple and easy to implement.
This document first discusses the issues with the flat HIP
architecture and analyzes the benefits brought by integrating
hierarchical information with HIP in terms of security, management,
integration with hierarchical overlays and etc. Then, this document
introduces several potential solutions which can be used to
facilitate the integration of hierarchical information.
2. Benefits introduced by Hierarchical Information
Hierarchy is a practical methodology in the design and organization
of non-trivial distributed systems, and has been adopted in many
large-scale networks and distributed systems (e.g., Internet). It
brought benefits in terms of simplifying system architectures,
improving the capability of system management, facilitating audit and
security, and etc. To be consistent with the hierarchical features
of the Internet, two critical namespaces of the Internet, IP and
FQDN, are designed in hierarchical ways. However, based on certain
concerns (e.g., easy implementation), the current HIT namespace is
flat; HIP itself does not provide any support for hierarchy either.
This section attempts to demonstrate that current HIP, by using
hierarchical information, can be more efficient and flexible in many
typical scenarios.
Firstly, hierarchical information is essential for the combination of
HIP with hierarchical overlays (e.g., hierarchical resolution
mechanisms). Compared with flat overlays where resources are
maintained at essentially random nodes, hierarchical overlays are
able to support reasonable business and trust models where resources
Xu, et al. Expires September 13, 2012 [Page 3]
Internet-Draft Hierarchical HIP March 2012
are managed by Administrative Domains (ADs) with distinct boundaries.
For example, it is normally not desired for a country to have its
resolution infrastructure and the related data resources managed by
other countries. In order to correctly route across hierarchical
overlays, hierarchical information (e.g., AD identifiers) is required
to identify the destination AD where the desired resources are
maintained, while the resource identifiers are used to locate the
resources.
Secondly, the hierarchical information can be used to address the
uniqueness verification issues with HITs in current HIP solutions.
In current HIP solutions, the HIT of each host is required to be
unique all over the world, which is very difficult to guarantee.
However, if the Internet is divided into multiple administration
domains, this problem is relatively easier to address. As
hierarchical information (i.e., AD identifier) can be used to
identify the AD of a HIT, it only needs to be guaranteed that the HIT
is unique within the AD. The process of verifying the uniqueness of
HITs can be performed when the host registers its HIT with the AD.
Moreover, hierarchical information has been widely employed in
advanced authorization systems (e.g., attributes based or role-based
authorization systems) to make the access control aggregates. By
using AD identifiers, it is possible for security managers to design
the access control policies based on the AD of hosts so as to reduce
the length of access control lists. In contrast, there is nothing
common between flat HITs that were assigned by the same authority or
that their represented hosts have the same properties, and thus they
are difficult to be categorized.
Apart from the advantages mentioned above, hierarchical information
may associate HIP with better HIT administrating and auditing
capabilities. The hierarchical information makes HITs more
aggregative; they can be grouped according to its belonging authority
or domain. Each network operator just needs to manage and maintain
HITs and their mapping information in a relatively small range. Such
advantages can make HIP easier to be accepted by the countries or
organizations which have relatively strict management policies on
their networks.
3. Candidate Solutions
There are various ways to integrate hierarchical information into the
HIP architecture. In the current version of document, we select
three representative candidates, and more solution may be introduced
in future versions.
Xu, et al. Expires September 13, 2012 [Page 4]
Internet-Draft Hierarchical HIP March 2012
The first type of solution is to embed hierarchical information into
HITs directly. For instance, divide a HIT into two parts; the first
part indicates the hierarchical information of the host, and the
second pare is the identifier of the host. The principle behind this
type of solution is similar with IP addresses.
The second type of solution is to transport hierarchical information
somewhere outside HITs, e.g., in a certificate or in a parameter. In
the preceding case, the certificate can be transported within the
CERT parameter of the HIT header.
The third type of solution is a hybrid of the above two types of
solutions. This type of solution extends the length of the 128 bits
HITs. The extended place is used to contain hierarchical
information.
4. Integrating Hierarchical Information into 128 Bits HITs
In this section, we introduce an example hierarchically structured
HIT namespace. In this hierarchical HIT namespace, a 128-bit HIT
consists of two parts: an n-bit HIP AD ID and a (128-n)-bit local
host ID. (n is a subject to be decided in the future.) It can
represent maximum 2^n administrative domains and 2^(128-n) hosts
within each administrative domain. The Administrative Domain ID has
embedded organizational affiliation and global uniqueness. The local
host ID is a hash over the AD ID and the public key of the ID owner.
| n bits | 128-n bits |
+-------------------------------+---------------------------------+
| HIP Administrative Domain ID | local host ID |
+-------------------------------+---------------------------------+
HIT with Hierarchical Information
Since the local host ID is a hash result, the strength of the local
host ID in tolerating brute-force attacks is affected by its length.
If the hash algorithm cannot be inverted, the expected number of
iterations required for a brute force attack is O(2^(128-n)) in order
to find a local host ID that matches with a given local host ID.
Therefore, for the secure consideration, we recommend to only assign
necessary bits for HIP administrative domain ID and leave space for
the local host ID as much as possible. It should be noted that this
draft does not take into account the ORCHID prefix defined in
[RFC4843] for two reasons: firstly, ORCHID is only temporary assigned
for experimental usage till 2014 only. The proposal design in the
document is targeting to be used continuously after 2014. Secondly,
the fixed 28-bit orchid prefix reduces the security properties
massively and increase collusion possibility highly.
Xu, et al. Expires September 13, 2012 [Page 5]
Internet-Draft Hierarchical HIP March 2012
The HIP administrative domain, as its literal, is a logic region in
which the HIs of all nodes are assigned by the same authority.
Within a same HIP administrative domain, all the nodes should have
the same HIP AD ID or the same leftmost certain bits. Furthermore,
the authority may be organized internally hierarchically.
The HIP AD ID should be assigned by a global administrative
organization with the principle that every HIP AD ID must be globally
unique.
Consequentially, the HIP AD IDs may be organized hierarchically. For
example, a big organization may obtain a block of HIP AD IDs with an
assigned 16-bit prefix. It then can assign 24-bit HIP AD IDs to its
sub-organizations. All these sub-organizations have the same
leftmost 16-bit.
One promising allocation solution of HIP AD ID is following current
routable IP address allocation system [RFC2050]. At first IANA
allocates some HIP AD ID prefixes to RIR (Region Internet Registry)
or NIR (National Internet Registry),then RIR or NIR sub-allocates the
HIP AD ID prefix to LIR or backbone ISP that subdivides the tag
prefix to middle or small ISP. Historical experience of routable IP
address allocation indicates that the allocation system can ensure
global uniqueness of HIP AD IDs.
An advantage of this solution is that the HHIT architecture can build
a distributed catalogue based on current IP address Internet
Registry. Each level Internet Registry only needs to maintain its
HHIT information. This catalogue is like current IP Whois Server
operated by each IP address Internet Registry. But it should include
many more attributes about a HHIT, such as organizational
affiliation, geographical information, privacy protection rule etc.
The catalogue should be independent of current IP Whois system and IP
address Internet Registry should provide some mechanism to translate
HHIT to its useful attributes on demand of various applications.
The local host IDs remains the original meaning of HIT - "a hashed
encoding of the Host Identity". For each HIP administrative domain,
it is mandatory to maintain the uniqueness of all local host IDs. It
is guaranteed by the process of generating a HIT, see Section 5.
For resolution purposes, HITs are aggregatable with AD IDs of
arbitrary bit-length, similar to IPv4 addresses under Classless
Inter-Domain Routing [RFC4632].
Xu, et al. Expires September 13, 2012 [Page 6]
Internet-Draft Hierarchical HIP March 2012
4.1. Compatible flat-structured HITs
Obviously, not all hosts are willing to use hierarchical HITs in all
scenarios for various reasons, such as privacy. Therefore, it is
useful that the hierarchical HIT architecture keep compatible with
the flat HIT architecture.
The flat HITs can be defined as a specific sub-set of the
hierarchical HITs architecture. With the same reserved Flat HIT Tag
(3 or 4 bits) at the beginning, for example, the left-most 3 bits is
000, the flat HITs can be used as defined in [RFC4423].
| 128 bits |
+-----------------------------------------------------------------+
|FHIT Tag| Flat host identity tag |
+-----------------------------------------------------------------+
4.2. HITs on nodes
HIP-enabled nodes may have considerable or little knowledge of the
internal structure of hierarchical HITs, depending on the role the
node plays (for instance, host versus mapping server). At a minimum,
a node may consider pre-generated HITs have no internal structure:
| 128 bits |
+-----------------------------------------------------------------+
| host identity tag |
+-----------------------------------------------------------------+
Only sophisticated hosts may additionally be aware of the type of
their HITS and use the hierarchical structure of HITs to simplify the
resolution procedure.
4.3. Generating a hierarchical HIT
The process of generating a new hierarchical HIT takes three input
values: an n-bit HIP AD ID, a 2-bit collusion count, (an example, it
is a subject to be changed in the future.) the host identity (the
public key of an asymmetric key pair). A hierarchical HIT should be
generated as follows:
1. Set the 2-bit collision count to zero.
2. Concatenate from left to right the HIP AD ID, the collusion
count, and the host identity. Execute the SHA-1 algorithm on the
concatenation. Take the (128-2-n) leftmost bits of the SHA-1
hash value.
3. Concatenate from left to right the n-bit HIP AD ID, the 2-bit
collusion count and (128-2-n)-bit hash output to form a 128-bit
Xu, et al. Expires September 13, 2012 [Page 7]
Internet-Draft Hierarchical HIP March 2012
HIT.
4. Perform duplicate detection within the HIP administrative domain
scope. If a HIT collision is detected, increment the collision
count by one and go back to step 2. However, after four
collisions, stop and report the error. (Note: the duplicate
detection mechanism is not discussed in this document. It may be
broadcast or central registration.)
The design that includes the HIP AD ID in the hash input is mainly
against the re-computation attack: create a database of HITs and
matching public keys. With the design, an attacker must create a
separate database for each HIP administrative domain.
The design reduces the number of bit of hash output 2 bits lower. It
does reduce the safety. However, O(2^(128-2-n)) iterations is large
enough to prevent brute-force attacks.
For security reason, the abovementioned SHA-1 hash algorithm may be
replaced by any safer algorithm.
5. Transporting Hierarchical information outside HITs
As mentioned previously, there are at least two methods of
transporting hierarchical information in HIP headers, i.e., using
certificates and using parameters. Compared with the certificate
oriented method, it is relatively more efficient to use parameters to
transport hierarchical information. For instance, some parameters of
a certificate (e.g., the name and the public key of the subject) are
already contained in HIT headers. When using a certificate to
transport hierarchical information, these parameters may have to be
transported again, causing redundancy. In addition, certificates
have to be signed by issuers. The signature of a certificate can be
used to verify the authenticity of the transported hierarchical
information, which is very useful when the certificate is used to
transport hierarchical information for the source HIT of a HIP
packet. However, when the certificate is used to transport
hierarchical information for the destination HIT of a HIP packet, the
signature is redundant because the receiver of the packet needs not
to verify the authenticity of its hierarchical information. Another
concern is performance. A HIT can be attached with multiple
certificates which are issued by diverse third parties for the
various purposes. The system thus may have to go through all the
certificates in order to find the proper certificate issued by the AD
and use it to assess the validity of the HIT.
In the remainder of this section, we mainly introduce an example
Xu, et al. Expires September 13, 2012 [Page 8]
Internet-Draft Hierarchical HIP March 2012
Hierarchical_HIT Parameter which is used to transport hierarchical
information. In addition, several associated extensions are
proposed.
5.1. Hierarchical_HIT Parameter
This parameter contains the information about the AD and should be
transported in R1 and I2 packets of basic.
Type 61698
Length length in octets, excluding Type, Length, and Padding
ADI Type type of the Administration Domain Identifier field
ADI Length length of the FQDN or NAI in octets
NB Length length of the Not Before Time field in octets
NA Length length of the Not After Time field in octets
AD the identifier of the AD of the sender
Identifier
Not Before the beginning of the valid period of the HIT of the sender
Time
Not After the end of the valid period of the HIT of the sender
Time
SIG alg signature algorithm
Signature the signature is generated by the AD previously,
calculated over the concatenation of Host Identity field
of HOST_ID, and AD Identifier, Not Before Time, Not After
Time fields of the Hierarchical_HIT parameter.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|ADIType| ADI Length | NB Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NA Length | Sig Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SIG alg | AD Identifier /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Not Before Time /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Not After Time /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Signature /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The following ADI Types have been defined:
Xu, et al. Expires September 13, 2012 [Page 9]
Internet-Draft Hierarchical HIP March 2012
+------------------------------------------------------+-------+
| Type | Value |
+------------------------------------------------------+-------+
| none included | 0 |
| FQDN (Fully Qualified Domain Name, in binary format) | 1 |
| NAI (Network Access Identifier) | 2 |
+------------------------------------------------------+-------+
The format for the FQDN is defined in[RFC1035] Section 3.1. The
format for NAI is defined in [RFC4282]. Not Before Time and Not
After Time fields can either UTCTime or GeneralizedTime defined in
[RFC2459]. SIG alg is set to 0 when there is no signature included.
In this case, Sig Length is set 0 as well.
Note that the parameter introduced in this section only consists of
very essential information. The parameter may need to be extended or
modified before being applied in future.
5.2. Hierarchical Information Registration
If the authenticity of the hierarchical information of a HIT needs to
be proved in practice, the HIT need to register with an AD and obtain
the signature. The registration process can be whether in-band or
out-of-band. In the following diagram, a protocol for hierarchical
information registration is illustrated.
+-----+ +------+
| | I1 | |
| |--------------------------->| |
| |<---------------------------| |
| I | R1(REG_INFO) | AD |
| | I2(REG_REQ) |Server|
| |--------------------------->| |
| |<---------------------------| |
| | R2(REG_RES) | |
+-----+ +------+
This protocol is an extension of basic by using the HIP Registration
Extension [RFC5203]. In R1, AD Server sends the service it provides
to Initiator in the REG_INFO element. Initiator then attaches the
REG-REQ element and the HHIT parameter with the I2 message. The
Signature field in the parameter is left unfilled. The AD server
signs the HHIT and its parameters, and sends the signature back in
R2.
5.3. Domain Name System (DNS) Extension
This section introduces a DNS extension which further extends the HIP
RR Storage Format proposed in [RFC5205].
Xu, et al. Expires September 13, 2012 [Page 10]
Internet-Draft Hierarchical HIP March 2012
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|ADIType| ADI Length | NB Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NA Length | HIT /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Public Key /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Rendezvous Server /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | AD Identifier /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Not Before Time /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Not After Time /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ |
+-+-+-+-+
Apart from the fields illustrated in [RFC5205], the extension
includes following fields: ADI type, ADI Length, NB Length, NA
Length, AD Identifier, Not Before Time, Not After Time. Because the
meanings of these fields is identical to their counterparts in the
Hierarchical_HIT Parameter, they are not introduced here in detail.
6. Extending the length of HITs
In this section, we introduce a hybrid of the above two types of
solutions. In this solution, hierarchical information is integrated
within HITs. Unlike the solution proposed in section 3, the space of
the flat hash part of a HIT does not have to be occupied. Instead,
the whole length of the HIT is extended, and the extended space is
used to contain the hierarchical information. An example of such
hierarchical HITs is presented in the following figure.
| 128 bits |
+-----------------------------------------------------------------+
| hierarchical information part |
+-----------------------------------------------------------------+
| flat hash part |
+-----------------------------------------------------------------+
The enlarged HIT presented in the figure can be broken into two
parts: the hierarchical information part and the flat hash part. In
this example, the flat hash part is generated by hashing the
Xu, et al. Expires September 13, 2012 [Page 11]
Internet-Draft Hierarchical HIP March 2012
concatenation of hierarchical information part and the associated
public key. In order to keep enough capability in tolerating brute
force attacks and be compatible with TCP, it is recommended the flat
hash part is set 128 bits long. When receiving such a HIT, a user
only transfers the flat hash part to the TCP layer, and thus TCP will
treat it as an ordinary IPv6 address.
7. Analysis of the Three Solutions
A criticism on the first type of solution is that the capability of
an identifier in tolerating brute-force attacks is affected as a part
of the space of the identifier that is occupied by the topological
information. This issue can be largely addressed by puzzles which
have been employed in Cryptographically Generated Addresses (CGA)
[RFC3972]. Also, it is possible to extend the length of HITs to
enhance their tolerant capability on brute force attacks.
Another concern with hierarchical HITs is that they are not suitable
for the scenario where hosts do not intend to disclose their
hierarchical information. In section 4, these problems and
associated solutions are introduced.
The second type of solution allows a user to flexibly present or hide
the hierarchical information in various circumstances. A
disadvantage imposed by this type of solution is that more traffic
needs to be transported as both certificates and parameters may
contain redundant information.
Compared with the first type of solution, the capability of the third
type of solution in tolerating brute force attacks is not influenced.
Additionally, compared with the second type of solution, the third
type of solution avoids transporting the redundant information.
However, a disadvantage of the third type of solution is that it
modifies the architecture of HIP headers.
8. IANA Considerations
The namespace, HIP AD ID, defined in section 4 is an n-bit long
value, which represents a globally unique HIP administrative domain.
IANA may found an authority institute to manage the global assignment
of HIP AD ID.
Additionally, IANA is expected to allocate a type code for the
Hierarchical_HIT Parameter illustrated in section 5.
Note to RFC Editor: this section may be removed on publication as an
Xu, et al. Expires September 13, 2012 [Page 12]
Internet-Draft Hierarchical HIP March 2012
RFC.
9. Security Considerations
The hierarchical HIT routing infrastructure provides some mechanisms
for defending attacks (e.g., proving HIT ownership, certificate
binding hierarchical HITs to a trusted third party, or random AD
IDs). Below we list some possible attacks on hierarchical HITs.
Forging hierarchical HITs. An attacker generates a HIT with certain
attack-suitable properties for using it for further attacks.
Classes of such properties are listed below. For checking the
existence of a HIT, the name resolution system (DNS/DHT) can be
used.
Intrusion. Generation of HITs belonging to some organization. As
a result the attacker can participate in communications between
organization's hosts. Organization's AD ID is known to the
attacker, and 64-bit hash value is generated. The attacker has
to prove the ownership of that HIT since it does not have the
private key.
Substitution. An attacker tries to use the HIT already existed in
the organization. As a result, the attacker substitutes good
host. Generation of HITs (64 bits of hash value) randomly or
by enumeration. For every HIT the attacker tries to join the
system.
Cutting. AD ID can code a hierarchy with in a large organization.
The hierarchy of AD ID is based on prefixes. As a result, an
attacker can generate a HIT that shares a prefix with the AD ID
of the organization. Hence the attacker cuts a part of HIT
space. Similarly to intrusion and substitution except that the
generated HITs share some prefix with the given AD ID.
Accumulation. Valid HITs can be prepared in advance, i.e.,
collected in a database. Similarly to substitution attack, the
attacker generates HITs and tries to join. Is it possible to
identify that the HIT is in use and what is the ratio of
successful identifications (does HIT exist or not) .
Sybils. Introduction of many forged HITs. They incrementally
appear in the system. The attacker has a host with a valid HIT
joined to the system. Can this host introduce new participants
(with new HITs) easier than a newcomer without a protege.
Xu, et al. Expires September 13, 2012 [Page 13]
Internet-Draft Hierarchical HIP March 2012
Denial of Service. The hierarchical HIT infrastructure consists of
DNS and DHT servers. In addition, there can be third-party
servers, e.g., for license binding. All such servers are a target
to DoS attacks, including DDoS.
1. Generation of a high-rate request flow to a DNS server.
2. Generation of a high-rate request flow to a DHT server (or a
set of severs of a given organization).
3. Generation of a high-rate request flow to a third-party
server. It controls its service rate limiting incoming
requests.
Pollution. Similarly to DoS attacks, DNS and DHT servers are target
to incorrect data.1. The attacker tries to store bogus AAAA
records for hierarchical HIT in DNS. 2. Similarly to the
intrusion and substitution attacks, the attacker tries to insert
bogus HITs into DHT system of a given organization.
10. Acknowledgements
Thanks Thomas. R. Henderson for his kindly prove-reading and
precious comments.
11. References
11.1. Normative References
[RFC2050] Hubbard, K., Kosters, M., Conrad, D., Karrenberg, D., and
J. Postel, "INTERNET REGISTRY IP ALLOCATION GUIDELINES",
BCP 12, RFC 2050, November 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2459] Housley, R., Ford, W., Polk, T., and D. Solo, "Internet
X.509 Public Key Infrastructure Certificate and CRL
Profile", RFC 2459, January 1999.
[RFC4282] Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
Network Access Identifier", RFC 4282, December 2005.
[RFC4423] Moskowitz, R. and P. Nikander, "Host Identity Protocol
(HIP) Architecture", RFC 4423, May 2006.
Xu, et al. Expires September 13, 2012 [Page 14]
Internet-Draft Hierarchical HIP March 2012
[RFC5201] Moskowitz, R., Nikander, P., Jokela, P., and T. Henderson,
"Host Identity Protocol", RFC 5201, April 2008.
[RFC5203] Laganier, J., Koponen, T., and L. Eggert, "Host Identity
Protocol (HIP) Registration Extension", RFC 5203,
April 2008.
[RFC5205] Nikander, P. and J. Laganier, "Host Identity Protocol
(HIP) Domain Name System (DNS) Extensions", RFC 5205,
April 2008.
11.2. Informative References
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, March 2005.
[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
(CIDR): The Internet Address Assignment and Aggregation
Plan", BCP 122, RFC 4632, August 2006.
[RFC4843] Nikander, P., Laganier, J., and F. Dupont, "An IPv6 Prefix
for Overlay Routable Cryptographic Hash Identifiers
(ORCHID)", RFC 4843, April 2007.
Authors' Addresses
Xiaohu Xu
Huawei Technologies Co.,Ltd
HuaWei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District
Beijing, 100085
P. R. China
Phone:
Fax:
Email: xuxh@huawei.com
URI:
Xu, et al. Expires September 13, 2012 [Page 15]
Internet-Draft Hierarchical HIP March 2012
Sheng Jiang
Huawei Technologies Co.,Ltd
HuaWei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District
Beijing, 100085
P. R. China
Phone:
Fax:
Email: shengjiang@huawei.com
URI:
Dacheng Zhang
Huawei Technologies Co.,Ltd
HuaWei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District
Beijing, 100085
P. R. China
Phone:
Fax:
Email: zhangdacheng@huawei.com
URI:
Dmitry Korzun
HIIT
Phone:
Fax:
Email: Dmitry.Korzun@hiit.fi
URI:
Zhen Cao
Xuanwumenxi Ave. No.32
Beijing, 100053
China
Phone: 86-10-52686688
Fax:
Email: zehn.cao@gmail.com, caozhen@chinamobile.com
URI:
Xu, et al. Expires September 13, 2012 [Page 16]
