Network
Internet Engineering Task Force (IETF) P. Wouters
Internet-Draft
Request for Comments: 9478 Aiven
Intended status:
Category: Standards Track S. Prasad
Expires: 16 November 2023
ISSN: 2070-1721 Red Hat
15 May
September 2023
Labeled IPsec Traffic Selector support Support for IKEv2
draft-ietf-ipsecme-labeled-ipsec-12 the Internet Key Exchange
Protocol Version 2 (IKEv2)
Abstract
This document defines a new Traffic Selector (TS) Type (TS Type) for the
Internet Key Exchange Protocol version 2 (IKEv2) to add support for
negotiating Mandatory Access Control (MAC) security labels as a traffic selector
Traffic Selector of the Security Policy Database (SPD). Security
Labels for IPsec are also known as "Labeled IPsec". The new TS type is Type,
TS_SECLABEL, which consists of a variable length opaque field specifying that
specifies the security label.
Status of This Memo
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This Internet-Draft will expire on 16 November 2023.
https://www.rfc-editor.org/info/rfc9478.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Traffic Selector clarification . . . . . . . . . . . . . 3 Clarification
1.3. Security Label Traffic Selector negotiation . . . . . . . 4 Negotiation
2. TS_SECLABEL Traffic Selector Type . . . . . . . . . . . . . . 4
2.1. TS_SECLABEL payload format . . . . . . . . . . . . . . . 4 Payload Format
2.2. TS_SECLABEL properties . . . . . . . . . . . . . . . . . 5 Properties
3. Traffic Selector negotiation . . . . . . . . . . . . . . . . 5 Negotiation
3.1. Example TS negotiation . . . . . . . . . . . . . . . . . 6 Negotiation
3.2. Considerations for using multiple TS_TYPEs Using Multiple TS Types in a TS . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Implementation Status . . . . . . . . . . . . . . . . . . . . 7
6.1. Libreswan . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1.
6.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2.
6.2. Informative References . . . . . . . . . . . . . . . . . 9
Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
In computer security, Mandatory Access Control (MAC) usually refers
to systems in which all subjects and objects are assigned a security
label. A security label is composed of a set of security attributes.
The security labels along
Along with a system authorization policy policy, the security labels
determine access. Rules within the system authorization policy
determine whether the access will be granted based on the security
attributes of the subject and object.
Historically, security labels used by Multilevel Systems Multi-Level Secure (MLS)
systems are comprised of a sensitivity level (or classification)
field and a compartment (or category) field, as defined in [FIPS188] and [RFC5570].
As MAC systems evolved, other MAC models gained in popularity. For
example, SELinux, a Flux Advanced Security Kernel (FLASK)
implementation, has security labels represented as colon-
separated colon-separated
ASCII strings composed of values for identity, role, and type. The
security labels are often referred to as security contexts.
Traffic Selector (TS) payloads specify the selection criteria for
packets that will be forwarded over the newly set up IPsec Security
Association (SA) as enforced by the Security Policy Database (SPD,
see [RFC4301]). (SPD)
[RFC4301].
This document specifies a new Traffic Selector Type TS_SECLABEL TS Type, TS_SECLABEL, for IKEv2 that
can be used to negotiate security labels as additional selectors for
the Security Policy Database (SPD) SPD to further restrict the type of traffic that is allowed to be
sent and received over the IPsec SA.
1.1. Requirements Language
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.
1.2. Traffic Selector clarification Clarification
The negotiation of Traffic Selectors is specified in Section 2.9 of
[RFC7296]
[RFC7296], where it defines two TS Types (TS_IPV4_ADDR_RANGE and
TS_IPV6_ADDR_RANGE). The Traffic Selector TS payload format is specified in
Section 3.13 of [RFC7296]. However, the term Traffic
Selector "Traffic Selector" is
used to denote the traffic selector TS payloads and individual traffic selectors Traffic Selectors of
that payload. Sometimes Sometimes, the exact meaning can only be learned from
context or if the item is written in plural ("Traffic Selectors" or "TSs").
"TSes"). This section clarifies these terms as follows:
A Traffic Selector (no (capitalized, no acronym) is one selector for
traffic of a specific Traffic Selector Type (TS_TYPE). (TS Type). For example example,
a Traffic Selector of TS_TYPE TS Type TS_IPV4_ADDR_RANGE for UDP (protocol
17) traffic in the IP network 198.51.100.0/24 covering all ports, ports is
denoted as (17, 0, 198.51.100.0-198.51.100.255) 198.51.100.0-198.51.100.255).
A Traffic Selector TS payload (TS) is a set of one or more Traffic Selectors of the same or
different TS_TYPEs. TS Types. It typically contains one or more of the TS_TYPE TS Type
of TS_IPV4_ADDR_RANGE and/or TS_IPV6_ADDR_RANGE. For example, the
above Traffic Selector by itself in a TS payload is denoted as
TS((17, 0, 198.51.100.0-198.51.100.255))
1.3. Security Label Traffic Selector negotiation Negotiation
The negotiation of Traffic Selectors is specified in Section 2.9 of
[RFC7296] and states that the TSi/TSr payloads MUST contain at least
one Traffic Selector type. TS Type. This document adds a new TS_TYPE TS Type of TS_SECLABEL that is
valid only with at least one other type of
Traffic Selector. TS Type. That is, it cannot be
the only TS_TYPE TS Type present in a TSi or TSr payload. It MUST be used
along with an IP address selector type type, such as TS_IPV4_ADDR_RANGE
and/or TS_IPV6_ADDR_RANGE.
2. TS_SECLABEL Traffic Selector Type
This document defines a new TS Type, TS_SECLABEL TS_SECLABEL, that contains a
single new opaque Security Label.
2.1. TS_SECLABEL payload format Payload Format
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
+---------------+---------------+-------------------------------+
| TS Type | Reserved | Selector Length |
+---------------+---------------+-------------------------------+
| |
~ Security Label* ~
| |
+---------------------------------------------------------------+
Figure 1: Labeled IPsec Traffic Selector
*Note:
Note: All fields other than TS Type and Selector Length depend on the
TS Type. The fields shown is are for TS Type TS_SECLABEL, which is the
selector that this document defines.
*
TS Type (one octet) - octet): Set to 10 for TS_SECLABEL,
* TS_SECLABEL.
Selector Length (2 (two octets, unsigned integer) - integer): Specifies the length
of this Traffic Selector substructure including the header.
*
Security Label - Label: An opaque byte stream of at least one octet.
2.2. TS_SECLABEL properties Properties
The TS_SECLABEL Traffic Selector TS Type does not support narrowing or wildcards. It
MUST be used as an exact match value.
The TS_SECLABEL Traffic Selector TS Type MUST NOT be the only TS_TYPE TS Type present in the
TS payload payload, as TS_SECLABEL is complimentary to another type of
Traffic Selector. There MUST be an IP address Traffic Selector type Type
in addition to the TS_SECLABEL Traffic Selector type TS Type in the Traffic Selector Payload. TS payload. If a TS
payload is received with only TS_SECLABEL Traffic Selector types, TS Types, the exchange MUST
be aborted with an Error Notify message containing TS_UNACCEPTABLE.
The Security Label contents are opaque to the IKE implementation.
That is, the IKE implementation might not have any knowledge of
regarding the meaning of this selector, selector other than recognizing it as a
type and opaque value to pass to the SPD.
A zero length zero-length Security Label MUST NOT be used. If a received TS
payload contains a TS_TYPE TS Type of TS_SECLABEL with a zero length zero-length Security
Label, that specific Traffic Selector TS payload MUST be ignored. If no other
Traffic Selector of TS_TYPE TS
payload contains an acceptable TS_SECLABEL can be selected, TS Type, the exchange MUST
be aborted with a TS_UNACCEPTABLE Error Notify message. A zero zero-
length Security Label MUST NOT be interpreted as a wildcard security
label.
If multiple Security Labels are allowed for a given Traffic Selector's IP
address range, protocol,
start and end address/port match, port range, the initiator includes all
of the these acceptable TS_SECLABEL's and the Security Labels. The responder MUST select
exactly one of them. the Security Labels.
A responder that selected a TS with TS_SECLABEL MUST use the Security
Label for all selector operations on the resulting TS. It MUST NOT
select a TS_SECLABEL without using the specified Security Label, even
if it deems the Security Label optional, as the initiator has
indicated (and expects) that the Security Label will be set for all
traffic matching the negotiated TS.
3. Traffic Selector negotiation Negotiation
If the TSi Payload payload contains a traffic selector for TS_TYPE of Traffic Selector with TS Type
TS_SECLABEL (along with another TS_TYPE), TS Type), the responder MUST create
each TS response for the other TS_TYPEs TS Types using its normal rules
specified for each of those TS_TYPE, TS Types, such as narrowing them
following the rules specified for that TS_TYPE, TS Type and then add adding
exactly one for the TS_TYPE TS Type of TS_SECLABEL to the TS Payload(s). payload(s). If
this is not possible, it MUST return a TS_UNACCEPTABLE Error Notify
payload.
If the Security Label traffic selector TS Type is optional from a configuration point
of view, an initiator will add the TS_SECLABEL to the TSi/TSr Payloads.
payloads. If the responder replies with TSi/TSr Payloads payloads that
include the TS_SECLABEL, then the Child SA MUST be created
including and
include the negotiated Security Label. If the responder did not
include a TS_SECLABEL in its response, then the initiator (which
deemed the Security Label optional) will install the Child SA without
including any Security Label. If the initiator required the
TS_SECLABEL, it MUST NOT install the Child SA and it MUST send a
Delete notification for the Child SA so the responder can uninstall
its Child SA.
3.1. Example TS negotiation Negotiation
An initiator could send: send the following:
TSi = ((17,24233,198.51.100.12-198.51.100.12),
(0,0,198.51.100.0-198.51.100.255),
(0,0,192.0.2.0-192.0.2.255),
TS_SECLABEL1, TS_SECLABEL2)
TSr = ((17,53,203.0.113.1-203.0.113.1),
(0,0,203.0.113.0-203.0.113.255),
TS_SECLABEL1, TS_SECLABEL2)
Figure 2: initiator Initiator TS payloads example Payloads Example
The responder could answer with the following example: following:
TSi = ((0,0,198.51.100.0-198.51.100.255),
TS_SECLABEL1)
TSr = ((0,0,203.0.113.0-203.0.113.255),
TS_SECLABEL1)
Figure 3: responder Responder TS payloads example Payloads Example
3.2. Considerations for using multiple TS_TYPEs Using Multiple TS Types in a TS
It would be unlikely that the traffic for TSi and TSr would have a
different Security Label, but this specification does allow allows this to be
specified. If the initiator does not support this, this and wants to
prevent the responder from picking different labels for the TSi / TSr TSi/TSr
payloads, it should attempt a Child SA negotiation and start with only the
first Security Label first, and upon failure only. Upon failure, the initiator should retry
a new Child SA negotiation with only the second Security Label.
If different IP ranges can only use different specific Security
Labels, then these should be negotiated in two different Child SA
negotiations. If in In the example above, if the initiator only allows
192.0.2.0/24 with TS_SECLABEL1, TS_SECLABEL1 and 198.51.100.0/24 with TS_SECLABEL2, than
then it MUST NOT combine these two ranges and security labels into
one Child SA negotiation.
4. Security Considerations
It is assumed that the Security Label can be matched by the IKE
implementation to its own configured value, even if the IKE
implementation itself cannot interpret the Security Label value.
A packet that matches an SPD entry for all components components, except the
Security Label Label, would be treated as "not matching". If no other SPD
entries match, the (mis-labeled) (mislabeled) traffic might end up being
transmitted in the clear. It is presumed that other Mandatory Access
Control MAC methods are
in place to prevent mis-labeled mislabeled traffic from reaching the IPsec subsystem,
subsystem or that the IPsec subsystem itself would install a REJECT/DISCARD REJECT/
DISCARD rule in the SPD to prevent unlabeled traffic otherwise
matching a labeled security SPD rule from being transmitted without
IPsec protection.
5. IANA Considerations
This document defines one
IANA has added a new entry in the IKEv2 "IKEv2 Traffic Selector
Types registry:
[Note to RFC Editor (please remove before publication): This value
has already been added via Early Allocation.] Types"
registry [RFC7296] as follows.
+=======+=============+===========+
| Value | TS Type | Reference
----- --------------------------- ----------------- |
+=======+=============+===========+
| 10 | TS_SECLABEL [this document]
Figure 4
6. Implementation Status
[Note to RFC Editor: Please remove this section and the reference to
[RFC7942] before publication.]
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
Authors are requested to add a note to the | RFC Editor at the top of
this section, advising the Editor to remove the entire section before
publication, as well as the reference to [RFC7942].
6.1. Libreswan
Organization: The Libreswan Project
Name: https://lists.libreswan.org/mailman/listinfo/swan-dev/
Description: Implementation was introduced in 4.4, but 4.6 or newer
should be used
Level of maturity: beta
Coverage: Implements the entire draft using SElinux based labels
Licensing: GPLv2
Implementation experience: No interop testing has been done yet.
The code works including different labeled on-demand kernel
ACQUIRES.
Contact: Libreswan Development: swan-dev@libreswan.org
7. Acknowledgements
A large part of the introduction text was taken verbatim from
[draft-jml-ipsec-ikev2-security-label] whose authors are J Latten, D.
Quigley and J. Lu. Valery Smyslov provided valuable input regarding 9478 |
+-------+-------------+-----------+
Table 1: IKEv2 Traffic Selector semantics.
8.
Types Registry
6. References
8.1.
6.1. 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>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <https://www.rfc-editor.org/info/rfc7296>.
[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>.
8.2.
6.2. Informative References
[draft-jml-ipsec-ikev2-security-label]
[IPSEC-IKEV2-SECURITY-LABEL]
Latten, J., Quigley, D., and J. Lu, "Security Label
Extension to IKE", Work in Progress, Internet-Draft,
draft-jml-ipsec-ikev2-security-label-01, 28 January 2011.
[FIPS188] NIST, "National Institute of Standards and Technology,
"Standard Security Label for Information Transfer"",
Federal Information Processing Standard (FIPS) Publication
188, September 1994,
<https://csrc.nist.gov/publications/detail/fips/188/
archive/1994-09-06>. 2011,
<https://datatracker.ietf.org/doc/html/draft-jml-ipsec-
ikev2-security-label-01>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC5570] StJohns, M., Atkinson, R., and G. Thomas, "Common
Architecture Label IPv6 Security Option (CALIPSO)",
RFC 5570, DOI 10.17487/RFC5570, July 2009,
<https://www.rfc-editor.org/info/rfc5570>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness
Acknowledgements
A large part of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>. the introduction text was taken verbatim from
[IPSEC-IKEV2-SECURITY-LABEL], whose authors are Joy Latten, David
Quigley, and Jarrett Lu. Valery Smyslov provided valuable input
regarding IKEv2 Traffic Selector semantics.
Authors' Addresses
Paul Wouters
Aiven
Email: paul.wouters@aiven.io
Sahana Prasad
Red Hat
Email: sahana@redhat.com