| Internet-Draft | RADIUS Attributes DHCP Suboption | October 2022 |
| Boucadair | Expires 20 April 2023 | [Page] |
- Workgroup:
- Network Working Group
- Internet-Draft:
- draft-boucadair-dhcwg-rfc4014-update-01
- Updates:
- 4014 (if approved)
- Published:
- Intended Status:
- Standards Track
- Expires:
RADIUS Attributes Permitted in RADIUS Attributes DHCP Suboption
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.¶
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 https://datatracker.ietf.org/drafts/current/.¶
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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 document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
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.¶
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.¶
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 |
- 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].¶
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, , <https://www.rfc-editor.org/info/rfc2119>.
- [RFC2131]
- Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, DOI 10.17487/RFC2131, , <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, , <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, , <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, , <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, , <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>.
- [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, , <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, , <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, , <https://www.rfc-editor.org/info/rfc7037>.