draft-ietf-dhc-relay-server-security-03.txt   draft-ietf-dhc-relay-server-security-04.txt 
Network Working Group B. Volz Network Working Group B. Volz
Internet-Draft Cisco Systems Internet-Draft Cisco Systems
Intended status: Standards Track Y. Pal Intended status: Standards Track Y. Pal
Expires: August 11, 2017 Cisco Systems, Inc. Expires: September 30, 2017 Cisco Systems, Inc.
February 7, 2017 March 29, 2017
Security of Messages Exchanged Between Servers and Relay Agents Security of Messages Exchanged Between Servers and Relay Agents
draft-ietf-dhc-relay-server-security-03.txt draft-ietf-dhc-relay-server-security-04.txt
Abstract Abstract
The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) has no The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) has no
guidance for how to secure messages exchanged between servers and guidance for how to secure messages exchanged between servers and
relay agents. The Dynamic Host Configuration Protocol for IPv6 relay agents. The Dynamic Host Configuration Protocol for IPv6
(DHCPv6) states that IPsec should be used to secure messages (DHCPv6) states that IPsec should be used to secure messages
exchanged between servers and relay agents, but does not require exchanged between servers and relay agents, but does not require
encryption. And, with recent concerns about pervasive monitoring and encryption. And, with recent concerns about pervasive monitoring and
other attacks, it is appropriate to require securing relay to relay other attacks, it is appropriate to require securing relay to relay
skipping to change at page 1, line 39 skipping to change at page 1, line 39
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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."
This Internet-Draft will expire on August 11, 2017. This Internet-Draft will expire on September 30, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 31 skipping to change at page 2, line 31
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language and Terminology . . . . . . . . . . . . 3 2. Requirements Language and Terminology . . . . . . . . . . . . 3
3. Security of Messages Exchanged Between Servers and Relay 3. Security of Messages Exchanged Between Servers and Relay
Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction 1. Introduction
The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) [RFC2131] The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) [RFC2131]
and [RFC1542] has no guidance for how to secure messages exchanged and [RFC1542] has no guidance for how to secure messages exchanged
between servers and relay agents. The Dynamic Host Configuration between servers and relay agents. The Dynamic Host Configuration
Protocol for IPv6 (DHCPv6) [RFC3315] states that IPsec should be used Protocol for IPv6 (DHCPv6) [RFC3315] states that IPsec should be used
skipping to change at page 3, line 35 skipping to change at page 3, line 35
By using IPsec with encryption for this communication, the By using IPsec with encryption for this communication, the
potentially sensitive client message and relay included information, potentially sensitive client message and relay included information,
such as the DHCPv4 relay-agent information option (82) [RFC3046], such as the DHCPv4 relay-agent information option (82) [RFC3046],
vendor-specific information (for example, [CableLabs-DHCP]), and vendor-specific information (for example, [CableLabs-DHCP]), and
Access-Network-Identifier Option(s) [RFC7839], are protected from Access-Network-Identifier Option(s) [RFC7839], are protected from
pervasive monitoring and other attacks. pervasive monitoring and other attacks.
Relay agents and servers MUST exchange messages securely using the Relay agents and servers MUST exchange messages securely using the
IPsec mechanisms described in [RFC4301]. If a client message is IPsec mechanisms described in [RFC4301]. If a client message is
relayed through multiple relay agents, each of the relay agents MUST relayed through multiple relay agents (relay chain), each of the
have an established independent, pairwise trust relationships. That relay agents MUST have an established independent, pairwise trust
is, if messages from client C will be relayed by relay agent A to relationships. That is, if messages from client C will be relayed by
relay agent B and then to the server, relay agents A and B MUST be relay agent A to relay agent B and then to the server, relay agents A
configured to use IPsec for the messages they exchange, and relay and B MUST be configured to use IPsec for the messages they exchange,
agent B and the server MUST be configured to use IPsec for the and relay agent B and the server MUST be configured to use IPsec for
messages they exchange. the messages they exchange.
Selectors Relay agents are manually configured with the Selectors Relay agents are manually configured with the
addresses of the relay agent or server to addresses of the relay agent or server to
which DHCP messages are to be forwarded. which DHCP messages are to be forwarded.
Each relay agent and server that will be Each relay agent and server that will be
using IPsec for securing DHCP messages MUST using IPsec for securing DHCP messages MUST
also be configured with a list of the relay also be configured with a list of the relay
agents to which messages will be returned. agents to which messages will be returned.
The selectors for the relay agents and The selectors for the relay agents and
servers will be the pairs of addresses servers will be the pairs of addresses
skipping to change at page 4, line 29 skipping to change at page 4, line 29
as include additional sensitive information, as include additional sensitive information,
such as vendor-specific information (for such as vendor-specific information (for
example, [CableLabs-DHCP]) and [RFC7839]. example, [CableLabs-DHCP]) and [RFC7839].
Key management Because both relay agents and servers tend to Key management Because both relay agents and servers tend to
be managed by a single organizational entity, be managed by a single organizational entity,
public key schemes MAY be optional. Manually public key schemes MAY be optional. Manually
configured key management MAY suffice, but configured key management MAY suffice, but
does not provide defense against replayed does not provide defense against replayed
messages. Accordingly, IKEv2 [RFC7296] with messages. Accordingly, IKEv2 [RFC7296] with
preshared secrets SHOULD be supported. IKEv2 pre-shared secrets SHOULD be supported.
with public keys MAY be supported. IKEv2 with public keys MAY be supported.
Additional information on manual vs automated Additional information on manual vs automated
key management and when one should be used key management and when one should be used
over the other can be found in [RFC4107]. over the other can be found in [RFC4107].
Security policy DHCP messages between relay agents and Security policy DHCP messages between relay agents and
servers MUST only be accepted from DHCP peers servers MUST only be accepted from DHCP peers
as identified in the local configuration. as identified in the local configuration.
Authentication Shared keys, indexed to the source IP address Authentication Shared keys, indexed to the source IP address
of the received DHCP message, are adequate in of the received DHCP message, are adequate in
this application. this application.
Note: As using IPsec with multicast has additional complexities (see
[RFC5374]), relay agents SHOULD be configured to forward DHCP
messages to unicast addresses.
4. Security Considerations 4. Security Considerations
The security model specified in this document is hop-by-hop. For The security model specified in this document is hop-by-hop. For
DHCPv6, there could be multiple relay agents between a client and DHCPv6, there could be multiple relay agents between a client and
server and each of these hops needs to be secured. For DHCPv4, there server and each of these hops needs to be secured. For DHCPv4, there
is no support for multiple relays. is no support for multiple relays.
As this document only mandates securing messages exchanged between As this document only mandates securing messages exchanged between
relay agents and servers, the message exchanges between clients and relay agents and servers, the message exchanges between clients and
the first hop relay agent or server are not secured. Clients may the first hop relay agent or server are not secured. Clients may
skipping to change at page 5, line 43 skipping to change at page 5, line 48
5. IANA Considerations 5. IANA Considerations
This document has no requests of the fantastic IANA team. This document has no requests of the fantastic IANA team.
6. Acknowledgments 6. Acknowledgments
The motivation for this document was several IESG discusses on recent The motivation for this document was several IESG discusses on recent
DHCP relay agent options. DHCP relay agent options.
Thanks to Kim Kinnear, Jinmei Tatuya, and Tomek Mrugalski for Thanks to Kim Kinnear, Jinmei Tatuya, Francis Dupont, and Tomek
reviewing drafts and helping to improve the document. And, thanks to Mrugalski for reviewing drafts and helping to improve the document.
the authors of [RFC3315] for the original Section 21.1 text. And, thanks to the authors of [RFC3315] for the original Section 21.1
text.
7. References 7. References
7.1. Normative References 7.1. Normative References
[RFC1542] Wimer, W., "Clarifications and Extensions for the [RFC1542] Wimer, W., "Clarifications and Extensions for the
Bootstrap Protocol", RFC 1542, DOI 10.17487/RFC1542, Bootstrap Protocol", RFC 1542, DOI 10.17487/RFC1542,
October 1993, <http://www.rfc-editor.org/info/rfc1542>. October 1993, <http://www.rfc-editor.org/info/rfc1542>.
[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, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 6, line 42 skipping to change at page 6, line 45
<http://www.rfc-editor.org/info/rfc7321>. <http://www.rfc-editor.org/info/rfc7321>.
7.2. Informative References 7.2. Informative References
[CableLabs-DHCP] [CableLabs-DHCP]
"CableLabs' DHCP Options Registry", "CableLabs' DHCP Options Registry",
<http://www.cablelabs.com/specification/ <http://www.cablelabs.com/specification/
cablelabs-dhcp-options-registry-2/>. cablelabs-dhcp-options-registry-2/>.
[I-D.ietf-dhc-sedhcpv6] [I-D.ietf-dhc-sedhcpv6]
Jiang, S., Li, L., Cui, Y., Jinmei, T., Lemon, T., and D. Li, L., Jiang, S., Cui, Y., Jinmei, T., Lemon, T., and D.
Zhang, "Secure DHCPv6", draft-ietf-dhc-sedhcpv6-20 (work Zhang, "Secure DHCPv6", draft-ietf-dhc-sedhcpv6-21 (work
in progress), January 2017. in progress), February 2017.
[RFC3046] Patrick, M., "DHCP Relay Agent Information Option", [RFC3046] Patrick, M., "DHCP Relay Agent Information Option",
RFC 3046, DOI 10.17487/RFC3046, January 2001, RFC 3046, DOI 10.17487/RFC3046, January 2001,
<http://www.rfc-editor.org/info/rfc3046>. <http://www.rfc-editor.org/info/rfc3046>.
[RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic [RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic
Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107, Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107,
June 2005, <http://www.rfc-editor.org/info/rfc4107>. June 2005, <http://www.rfc-editor.org/info/rfc4107>.
[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality [RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality
for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006, for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
<http://www.rfc-editor.org/info/rfc4552>. <http://www.rfc-editor.org/info/rfc4552>.
[RFC5374] Weis, B., Gross, G., and D. Ignjatic, "Multicast
Extensions to the Security Architecture for the Internet
Protocol", RFC 5374, DOI 10.17487/RFC5374, November 2008,
<http://www.rfc-editor.org/info/rfc5374>.
[RFC6221] Miles, D., Ed., Ooghe, S., Dec, W., Krishnan, S., and A. [RFC6221] Miles, D., Ed., Ooghe, S., Dec, W., Krishnan, S., and A.
Kavanagh, "Lightweight DHCPv6 Relay Agent", RFC 6221, Kavanagh, "Lightweight DHCPv6 Relay Agent", RFC 6221,
DOI 10.17487/RFC6221, May 2011, DOI 10.17487/RFC6221, May 2011,
<http://www.rfc-editor.org/info/rfc6221>. <http://www.rfc-editor.org/info/rfc6221>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>. 2014, <http://www.rfc-editor.org/info/rfc7258>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T. [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
 End of changes. 11 change blocks. 
20 lines changed or deleted 31 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/