Internet DRAFT - draft-boucadair-dhcwg-rfc4014-update
draft-boucadair-dhcwg-rfc4014-update
Network Working Group M. Boucadair
Internet-Draft Orange
Updates: 4014 (if approved) 17 October 2022
Intended status: Standards Track
Expires: 20 April 2023
RADIUS Attributes Permitted in RADIUS Attributes DHCP Suboption
draft-boucadair-dhcwg-rfc4014-update-01
Abstract
The RADIUS Attributes suboption, specified in RFC 4014, enables a
DHCP relay agent to pass identification and authorization information
received during RADIUS authentication to a DHCP server. However, RFC
4014 defines a frozen list of RADIUS attributes that can be included
in such a suboption.
This document updates RFC 4014 by relaxing that constraint and
allowing to tag additional RADIUS Attributes as permitted in the
RADIUS Attributes DHCP suboption.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 20 April 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
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Please review these documents carefully, as they describe your rights
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and restrictions with respect to this document. Code Components
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Updates to RFC4014 . . . . . . . . . . . . . . . . . . . . . 3
3.1. Section 3 of RFC4014 . . . . . . . . . . . . . . . . . . 3
3.2. Section 4 of RFC4014 . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
The RADIUS Attributes suboption ([RFC4014]) enables a network element
to pass identification and authorization attributes received during
RADIUS authentication [RFC2865] to a DHCP server [RFC2131]. However,
[RFC4014] defines a frozen set of RADIUS attributes that can be
included in such a suboption. This limitation is suboptimal in
contexts where new services are deployed (e.g., support of encrypted
DNS [I-D.ietf-add-dnr]).
Section 3 updates RFC 4014 by relaxing that constraint and allowing
to tag additional RADIUS Attributes as permitted in the RADIUS
Attributes DHCP suboption. To that aim, a new IANA registry is
created to maintain the set of permitted attributes in the RADIUS
Attributes DHCP suboption. The maintenance of such a registry is
similar to the one in [RFC7037].
[I-D.ietf-opsawg-add-encrypted-dns] defines the DHCPv4-Options RADIUS
attribute that can be used by a DHCP relay agent, collocated with a
RADIUS client, to pass attributes obtained from a RADIUS server to a
DHCP server. The DHCPv4-Options RADIUS attribute can, for example,
include a list of encrypted DNS resolvers.
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2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Updates to RFC4014
3.1. Section 3 of RFC4014
This document updates Section 3 of [RFC4014] as follows:
OLD:
To avoid dependencies between the address allocation and other
state information between the RADIUS server and the DHCP server,
the DHCP relay agent SHOULD include only the attributes in the
table below in an instance of the RADIUS Attributes suboption.
The table, based on the analysis in RFC 3580 [8], lists attributes
that MAY be included:
# Attribute
--- ---------
1 User-Name (RFC 2865 [3])
6 Service-Type (RFC 2865)
26 Vendor-Specific (RFC 2865)
27 Session-Timeout (RFC 2865)
88 Framed-Pool (RFC 2869)
100 Framed-IPv6-Pool (RFC 3162 [7])
NEW:
To avoid dependencies between the address allocation and other
state information between the RADIUS server and the DHCP server,
the DHCP relay agent SHOULD include only the attributes in the
IANA-maintained registry (Section 4) in an instance of the RADIUS
Attributes suboption.
3.2. Section 4 of RFC4014
This document updates Section 4 of [RFC4014] as follows:
OLD:
If the relay agent relays RADIUS attributes not included in the
table in Section 4, the DHCP server SHOULD ignore them.
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NEW:
If the relay agent relays RADIUS attributes not included in the
IANA-maintained registry (Section 4), the DHCP server SHOULD
ignore them.
4. IANA Considerations
IANA is requested to create a new sub-registry entitled "RADIUS
Attributes Permitted in RADIUS Attributes Sub-option" in the "Dynamic
Host Configuration Protocol (DHCP) and Bootstrap Protocol (BOOTP)
Parameters" registry [BOOTP].
The allocation policy of this new sub-registry is Expert Review per
[RFC8126]. Designated experts should carefully consider the security
implications of allowing the relay agent to include new RADIUS
attributes to this registry.
The initial content of this sub-registry is listed in Table 1. The
reference may include the document that registers or specifies the
Attribute.
+===========+==================+===================================+
| Type Code | Attribute | Reference |
+===========+==================+===================================+
| 1 | User-Name | RFC 2865 |
+-----------+------------------+-----------------------------------+
| 6 | Service-Type | RFC 2865 |
+-----------+------------------+-----------------------------------+
| 26 | Vendor-Specific | RFC 2865 |
+-----------+------------------+-----------------------------------+
| 27 | Session-Timeout | RFC 2865 |
+-----------+------------------+-----------------------------------+
| 88 | Framed-Pool | RFC 2869 |
+-----------+------------------+-----------------------------------+
| 100 | Framed-IPv6-Pool | RFC 3162 |
+-----------+------------------+-----------------------------------+
| TBA | DHCPv4-Options | I-D.ietf-opsawg-add-encrypted-dns |
+-----------+------------------+-----------------------------------+
Table 1: RADIUS Attributes Permitted in RADIUS Attributes Suboption
Note to the RFC Editor: Please replace "TBA" with the code assigned
for the DHCPv4-Options Attribute in
[I-D.ietf-opsawg-add-encrypted-dns].
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5. Security Considerations
This document does not add new security considerations to those
already discussed in Section 7 of [RFC4014].
6. Acknowledgements
Thanks to Bernie Volz for the comments.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol",
RFC 2131, DOI 10.17487/RFC2131, March 1997,
<https://www.rfc-editor.org/info/rfc2131>.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, DOI 10.17487/RFC2865, June 2000,
<https://www.rfc-editor.org/info/rfc2865>.
[RFC4014] Droms, R. and J. Schnizlein, "Remote Authentication Dial-
In User Service (RADIUS) Attributes Suboption for the
Dynamic Host Configuration Protocol (DHCP) Relay Agent
Information Option", RFC 4014, DOI 10.17487/RFC4014,
February 2005, <https://www.rfc-editor.org/info/rfc4014>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References
[BOOTP] IANA, "Dynamic Host Configuration Protocol (DHCP) and
Bootstrap Protocol (BOOTP) Parameters",
<https://www.iana.org/assignments/bootp-dhcp-parameters/
bootp-dhcp-parameters.xhtml>.
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[I-D.ietf-add-dnr]
Boucadair, M., Reddy, T., Wing, D., Cook, N., and T.
Jensen, "DHCP and Router Advertisement Options for the
Discovery of Network-designated Resolvers (DNR)", Work in
Progress, Internet-Draft, draft-ietf-add-dnr-13, 13 August
2022, <https://www.ietf.org/archive/id/draft-ietf-add-dnr-
13.txt>.
[I-D.ietf-opsawg-add-encrypted-dns]
Boucadair, M. and T. Reddy.K, "RADIUS Extensions for
Encrypted DNS", Work in Progress, Internet-Draft, draft-
ietf-opsawg-add-encrypted-dns-03, 6 October 2022,
<https://www.ietf.org/archive/id/draft-ietf-opsawg-add-
encrypted-dns-03.txt>.
[RFC7037] Yeh, L. and M. Boucadair, "RADIUS Option for the DHCPv6
Relay Agent", RFC 7037, DOI 10.17487/RFC7037, October
2013, <https://www.rfc-editor.org/info/rfc7037>.
Author's Address
Mohamed Boucadair
Orange
35000 Rennes
France
Email: mohamed.boucadair@orange.com
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