Internet Engineering Task Force S. Kumar
Internet-Draft Samsung India Software Operations
Expires: April 9, 2006 L. Morand
France Telecom R&D
A. Yegin
Samsung Advanced Institute of
Technology
S. Madanapalli
Samsung India Software Operations
October 6, 2005
DHCPv4 option for PANA Authentication Agents
draft-ietf-dhc-paa-option-00.txt
Status of this Memo
By submitting this Internet-Draft, each author represents that any
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
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 9, 2006.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document defines a new Dynamic Host Configuration Protocol
version 4 (DHCPv4) option that contains a list of domain names or
Kumar, et al. Expires April 9, 2006 [Page 1]
Internet-Draft DHCPv4 PAA Option October 2005
IPv4 addresses that can be mapped to one or more of PANA
Authentication Agents (PAA). This is one of the many methods that a
PANA Client (PaC) can use to locate PANA Authentication Agents (PAA).
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. DHCPv4 specification dependency . . . . . . . . . . . . . . . 6
5. PANA Authentication Agent DHCPv4 Option . . . . . . . . . . . 7
5.1. PANA Authentication Agent Domain Name List . . . . . . . . 7
5.2. PANA Authentication Agent IPv4 Address List . . . . . . . 8
6. Client Operation . . . . . . . . . . . . . . . . . . . . . . . 10
7. DHCPv4 Server Operation . . . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
10. Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 14
11. Normative References . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
Intellectual Property and Copyright Statements . . . . . . . . . . 16
Kumar, et al. Expires April 9, 2006 [Page 2]
Internet-Draft DHCPv4 PAA Option October 2005
1. Introduction
The Protocol for carrying Authentication for Network Access (PANA)
[1] defines a new Extensible Authentication Protocol (EAP) lower
layer that uses IP between the protocol end points.
The PANA protocol is run between a PANA Client (PaC) and a PANA
Authentication Agent (PAA) in order to perform authentication and
authorization for the network access service.
This document specifies a new DHCPv4 option [2] that allows PANA
client (PaC) to discover PANA Authentication Agents (PAA). This is
one of the many methods for locating PAAs: manual configuration is an
example of another one.
Kumar, et al. Expires April 9, 2006 [Page 3]
Internet-Draft DHCPv4 PAA Option October 2005
2. Terminology
This document uses the PANA terminology defined in [1].
This document uses the DHCP terminology defined in [2] and [3].
Kumar, et al. Expires April 9, 2006 [Page 4]
Internet-Draft DHCPv4 PAA Option October 2005
3. Requirements
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, when they appear in this
document, are to be interpreted as described in [4].
Kumar, et al. Expires April 9, 2006 [Page 5]
Internet-Draft DHCPv4 PAA Option October 2005
4. DHCPv4 specification dependency
This document describes a new DHCPv4 option for obtaining a list of
domain names or IPv4 addresses to locate a PANA Authentication Agent.
This document should be read in conjunction with the DHCPv4
specifications [2] and [3].
Definitions for terms and acronyms not specifically defined in this
document are defined in [2] and [3].
Kumar, et al. Expires April 9, 2006 [Page 6]
Internet-Draft DHCPv4 PAA Option October 2005
5. PANA Authentication Agent DHCPv4 Option
This document defines a DHCPv4 option that carries either a 32-bit
(binary) IPv4 address list or, preferably, a domain name list to be
used by the PANA client to locate a PANA authentication Agent.
The option has two encodings, specified by the encoding byte ('enc')
that follows the code byte. If the encoding byte has the value 0, it
is followed by a list of domain names, as described below (Section
5.1). If the encoding byte has the value 1, it is followed by one or
more IPv4 addresses (Section 5.2). All implementations MUST support
both encodings. The 'option-length' field indicates the total number
of octets in the option following the 'option-length' field,
including the encoding byte.
5.1. PANA Authentication Agent Domain Name List
If the 'enc' byte has a value of 0, the encoding byte is followed by
a sequence of labels, encoded according to Section 3.1 of RFC 1035
[5], quoted below:
Domain names in messages are expressed in terms of a sequence of
labels. Each label is represented as a one octet length field
followed by that number of octets. Since every domain name ends
with the null label of the root, a domain name is terminated by a
length byte of zero. The high order two bits of every length
octet must be zero, and the remaining six bits of the length field
limit the label to 63 octets or less. To simplify
implementations, the total length of a domain name (i.e., label
octets and label length octets) is restricted to 255 octets or
less.
RFC 1035 encoding was chosen to accommodate future internationalized
domain name mechanisms.
The option MAY contain multiple domain names, but these SHOULD refer
to different NAPTR records, rather than different A records. Domain
names MUST be listed in order of preference.
Use of multiple domain names is not meant to replace NAPTR and SRV
records, but rather to allow a single DHCPv4 server to indicate
multiple PANA Authentication Agents available in the same access
network.
Clients MUST support compression according to the encoding in Section
4.1.4 of [5].
If the length of the domain list exceeds the maximum permissible
Kumar, et al. Expires April 9, 2006 [Page 7]
Internet-Draft DHCPv4 PAA Option October 2005
within a single option (254 octets), then the domain list MUST be
represented in the DHCP message as specified in [6].
The DHCPv4 option for this encoding has the format shown in Fig. 1.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length | enc | ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PAA Domain Name List |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: DHCPv4 option for PAA Domain Name List
option-code: OPTION_PANA_AGENT(TBD)
option-length: Number of octets following the 'option-length'
field, including the encoding byte, in octets; variable.
enc: Encoding byte set to 0
PAA Domain Name List: The domain names of the PANA Authentication
Agents for the client to use. The domain names are encoded
according to Section 3.1 of RFC 1035 [5].
5.2. PANA Authentication Agent IPv4 Address List
If the 'enc' byte has a value of 1, the encoding byte is followed by
a list of IPv4 addresses indicating one or more PANA Authentication
Agents available to the PANA client. PAAs MUST be listed in order of
preference.
The DHCPv4 option for this encoding has the format shown in Fig. 2.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length | enc | ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PAA IP Address | ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: DHCPv4 option for PAA IPv4 Address List
option-code: OPTION_PANA_AGENT(TBD)
option-length: Number of octets following the 'option-length'
field, including the encoding byte in octets; Must be a multiple
Kumar, et al. Expires April 9, 2006 [Page 8]
Internet-Draft DHCPv4 PAA Option October 2005
of 4 plus one.
enc: Encoding byte set to 1
PAA IP Address: IPv4 address of a PAA for the PaC to use. The
PAAs are listed in the order of preference for use by the PaC.
Kumar, et al. Expires April 9, 2006 [Page 9]
Internet-Draft DHCPv4 PAA Option October 2005
6. Client Operation
The client requests PAA DHCPv4 Option in a Parameter Request List as
described in [2] and [3].
If the PAA DHCPv4 option provided in response by the DHCPv4 server
contains multiple domain names, the client MUST try the records in
the order listed. The client only resolves the subsequent domain
names if attempts to contact the first one failed or denote a domain
administratively prohibited by client policy.
If the PAA DHCPv4 option provided in response by the DHCPv4 server
contains multiple IP addresses, the client MUST try the records in
the order listed.
Kumar, et al. Expires April 9, 2006 [Page 10]
Internet-Draft DHCPv4 PAA Option October 2005
7. DHCPv4 Server Operation
If a DHCPv4 server is configured with both PAA domain name list and
PAA IP address list, the DHCPv4 server should responds to the request
with the domain name list to be used by the PANA client.
A DHCP server MUST NOT mix the two list types (domain names and IPv4
address) in the same DHCPv4 message, even if it sends two different
instances of the same option.
Kumar, et al. Expires April 9, 2006 [Page 11]
Internet-Draft DHCPv4 PAA Option October 2005
8. Security Considerations
The security considerations in [1] and [2] apply. If an adversary
manages to modify the response from a DHCP server or insert its own
response, a PANA Client could be led to contact a rogue PANA Agent,
possibly one that then intercepts call requests or denies service.
Kumar, et al. Expires April 9, 2006 [Page 12]
Internet-Draft DHCPv4 PAA Option October 2005
9. IANA Considerations
IANA assignment for the following DHCPv4 option code is needed.
Option Name Value
----------------------------------
OPTION_PAA_AGENT TBD
Kumar, et al. Expires April 9, 2006 [Page 13]
Internet-Draft DHCPv4 PAA Option October 2005
10. Future Work
Defining similar options for DHCPv6 [7].
11. Normative References
[1] Forsberg, D., Ohba, Y., Patil, B., Tschofenig, H., and A. Yegin,
"Protocol for Carrying Authentication for Network Access (PANA),
draft-ietf-pana-pana-08 (work in progress)", Novemeber 2005.
[2] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131,
March 1997.
[3] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
[4] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[5] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[6] Lemon, T. and S. Cheshire, "Encoding Long Options in the Dynamic
Host Configuration Protocol (DHCPv4)", RFC 3396, November 2002.
[7] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M.
Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 3315, July 2003.
Kumar, et al. Expires April 9, 2006 [Page 14]
Internet-Draft DHCPv4 PAA Option October 2005
Authors' Addresses
Suraj Kumar
Samsung India Software Operations
No. 3/1 Millers Road
Bangalore
India
Phone: +91 80 51197777
Email: suraj.kumar@samsung.com
Lionel Morand
France Telecom R&D
38-40 rue du general Leclerc
Issy-les-Moulineaux, F-92130
France
Phone: +33 1 4529 6257
Email: lionel.morand@francetelecom.com
Alper E. Yegin
Samsung Advanced Institute of Technology
75 West Plumeria Drive
San Jose, CA 95134
USA
Phone: +1 408 544 5656
Email: alper.yegin@samsung.com
Syam Madanapalli
Samsung India Software Operations
No. 3/1 Millers Road
Bangalore
India
Phone: +91 80 51197777
Email: syam@samsung.com
Kumar, et al. Expires April 9, 2006 [Page 15]
Internet-Draft DHCPv4 PAA Option October 2005
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
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
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
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 (2005). 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
Funding for the RFC Editor function is currently provided by the
Internet Society.
Kumar, et al. Expires April 9, 2006 [Page 16]
