Internet DRAFT - draft-hujun-idr-bgp-ipsec-transport-mode
draft-hujun-idr-bgp-ipsec-transport-mode
idr J. Hu
Internet-Draft Nokia
Intended status: Standards Track October 10, 2019
Expires: April 12, 2020
BGP Provisioned IPsec Transport Mode Protected Tunnel Configuration
draft-hujun-idr-bgp-ipsec-transport-mode-00
Abstract
This document defines a method of using BGP to advertise IPsec
transport mode protected tunnel (like GRE tunnel with IPsec transport
mode protection) configuration along with NLRI, based on
[I-D.ietf-idr-tunnel-encaps] and [I-D.hujun-idr-bgp-ipsec].
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/.
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."
This Internet-Draft will expire on April 12, 2020.
Copyright Notice
Copyright (c) 2019 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Hu Expires April 12, 2020 [Page 1]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
1.2. IPsec Transport Protected sub-TLV . . . . . . . . . . . . 3
2. Semantics and Operation . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
[I-D.hujun-idr-bgp-ipsec] defines a method of using BGP to advertise
configuration for IPsec tunnel with ESP tunnel mode, however there
are other use cases require of using IPsec/ESP transport mode with
other types of IP tunnel, like GRE tunnel, as defined in [RFC4301]
and [RFC4303]. Figure 2 shows an example of IPv4 GRE tunnel packet
with ESP transport mode protection. This document defines a method
of using BGP to advertise configuration for these use cases.
----------------------------------------------------
|IPv4 header | ESP | GRE | Payload | ESP | ESP|
|(any options)| Hdr | Hdr | Packet | Trailer | ICV|
----------------------------------------------------
|<-- encryption --->|
|<-------- integrity ---->|
Figure 1: IPv4 GRE tunnel packet with ESP transport protection
The method follows same principle as [I-D.hujun-idr-bgp-ipsec], keep
changes to BGP minimal and not changing IKEv2/IPsec; however the
IPsec transport mode protected IP tunnel is not a tunnel stack or
nested tunnels, IPsec transport mode protection doesn't add extra IP
header.
The requirement of using IPsec transport mode is signaled by
including a sub-TLV: IPsec transport protected, in a BGP tunnel
encapsulation TLV.
1.1. 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
Hu Expires April 12, 2020 [Page 2]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.2. IPsec Transport Protected sub-TLV
This sub-TLV represents using IPsec transport mode protection for the
tunnel specified by parent tunnel encapsulation TLV, its value is a
IPsec configuration tag as defined in [I-D.hujun-idr-bgp-ipsec].
+--------------------------------------+
| IPsec Configuration tag (4 octets) |
+--------------------------------------+
Figure 2: IPsec Configuration Tag
For a given tunnel encapsulation TLV, IPsec configuration tag sub-TLV
MUST appear only one time.
2. Semantics and Operation
Except for what this document explicitly specifies, the semantics and
operation of tunnel encapsulation TLV with IPsec Transport Protected
sub-TLV are same as defined in [I-D.ietf-idr-tunnel-encaps] and
[I-D.hujun-idr-bgp-ipsec].
IPsec Transport Protected sub-TLV MAY be included in any type of IP
tunnel TLV specified in [I-D.ietf-idr-tunnel-encaps]; it MUST be
ignored when included in a IPsec tunnel TLV.
The inclusion of IPsec Transport Protected TLV and its value is
determined by local policy.
Following are the rules of operations:
1. All routers are pre-provisioned with Mapping between IPsec
configuration tag value and IPsec configurations include
authentication method/credentials
2. If a given NLRI needs a specific tunnel encapsulation with IPsec
transport mode protection, then advertising router need to
include an IPsec Transport Protected sub-TLV with required
configuration tag, in the corresponding tunnel encapsulation TLV/
attribute, along with the NLRI in BGP UPDATE U;
3. When a router need to forward a packet along a path is determined
by a BGP UPDATE which has a tunnel encapsulation attribute that
contains one or more tunnel TLV, router selects a tunnel TLV
based on Semantics defined in [I-D.ietf-idr-tunnel-encaps], if
Hu Expires April 12, 2020 [Page 3]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
the selected tunnel TLV contains IPsec Transport Protected sub-
TLV, then the router use first feasible CHILD_SA for IP tunnel
packet encryption, a CHILD SA is considered as feasible when it
meets all following conditions:
* it is ESP transport mode
* its private and public routing instance is same as routing
instance in which the packet to be forwarded
* its peer tunnel address is same as indicated by Remote
Endpoint sub-TLV
* the source and destination address of the packet to be
forwarded falls in the range of CHILD SA's traffic selector
* its transform and other configuration maps to the tag
indicated in the IPsec configuration tag sub-TLV
4. If router can't find such CHILD SA, then it will use IKEv2 to
create one with following IPsec configuration:
* ESP transport mode
* private and public routing instance is the routing instance in
which the packet to be forwarded
* peer tunnel address is specified by Remote Endpoint sub-TLV
* local traffic selector:
+ address range: local tunnel endpoint address
+ protocol: tag mapped configuration
+ port range: tag mapped configuration
* remote traffic selector:
+ address range: address in Remote Endpoint sub-TLV of
selected tunnel encapsulation TLV
+ protocol: tag mapped configuration
+ port range: tag mapped configuration
Hu Expires April 12, 2020 [Page 4]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
* other configurations come from mapping of the configuration
tag in IPsec Transport Protected sub-TLV of selected tunnel
encapsulation TLV
3. IANA Considerations
This document will request new values in IANA "BGP Tunnel
Encapsulation Attribute Sub-TLVs" registry for IPsec Transport
Protected sub-TLV.
4. Security Considerations
IKEv2 is used to create IPsec tunnel, which ensures following:
o Traffic protection keys are generated dynamically during IKEv2
negotiation, only known by participating peer of the IPsec tunnel;
there is no central node to manage and distribute all keys.
o IKEv2 rekey mechanism refresh keys regularly; PFS(Perfect Forward
Secrecy) provides additional protection;
o Secure authentication mechanism that only allow authenticated peer
to create tunnel
o Traffic Selector guarantee that only agreed traffic is allowed to
be forwarded within the IPsec tunnel;
o Using a separate, dedicate protocol(IKEv2) for key management/
authentication ensure they are not tied to BGP, all existing and
future IKEv2 features could be used without changing BGP;
There is concern that malicious party might manipulate IPsec tunnel
encapsulation attribute to divert traffic, however this risk could be
mitigated by IKEv2 mutual authentication.
BGP route filter include outbound route filter [RFC5291], Origin
Validation [RFC6811] and BGPSec [RFC8205] could be used to further
secure BGP UPDATE message.
IKEv2 cookie [RFC7296] and varies mechanisms defined including client
puzzle defined in [RFC8019] could be used to protect IKEv2 from
Distributed Denial-of-Service Attacks.
Follow latest IETF ESP/IKEv2 implementation requirement and guidance
([RFC8221] and [RFC8247] at time of writing) to make sure always
using secure and up-to-date cryptographic algorithms;
Hu Expires April 12, 2020 [Page 5]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
5. Change Log
o v00 Sep 29, 2019: initial draft
6. References
6.1. Normative References
[I-D.hujun-idr-bgp-ipsec]
Hu, J., "BGP Provisioned IPsec Tunnel Configuration",
draft-hujun-idr-bgp-ipsec-01 (work in progress), September
2019.
[I-D.ietf-idr-tunnel-encaps]
Patel, K., Velde, G., and S. Ramachandra, "The BGP Tunnel
Encapsulation Attribute", draft-ietf-idr-tunnel-encaps-14
(work in progress), September 2019.
[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>.
[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>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
[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>.
6.2. Informative References
[RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering
Capability for BGP-4", RFC 5291, DOI 10.17487/RFC5291,
August 2008, <https://www.rfc-editor.org/info/rfc5291>.
[RFC6811] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
Austein, "BGP Prefix Origin Validation", RFC 6811,
DOI 10.17487/RFC6811, January 2013,
<https://www.rfc-editor.org/info/rfc6811>.
Hu Expires April 12, 2020 [Page 6]
Internet-Draft BGP Provisioned IPsec Transport mode October 2019
[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>.
[RFC8019] Nir, Y. and V. Smyslov, "Protecting Internet Key Exchange
Protocol Version 2 (IKEv2) Implementations from
Distributed Denial-of-Service Attacks", RFC 8019,
DOI 10.17487/RFC8019, November 2016,
<https://www.rfc-editor.org/info/rfc8019>.
[RFC8205] Lepinski, M., Ed. and K. Sriram, Ed., "BGPsec Protocol
Specification", RFC 8205, DOI 10.17487/RFC8205, September
2017, <https://www.rfc-editor.org/info/rfc8205>.
[RFC8221] Wouters, P., Migault, D., Mattsson, J., Nir, Y., and T.
Kivinen, "Cryptographic Algorithm Implementation
Requirements and Usage Guidance for Encapsulating Security
Payload (ESP) and Authentication Header (AH)", RFC 8221,
DOI 10.17487/RFC8221, October 2017,
<https://www.rfc-editor.org/info/rfc8221>.
[RFC8247] Nir, Y., Kivinen, T., Wouters, P., and D. Migault,
"Algorithm Implementation Requirements and Usage Guidance
for the Internet Key Exchange Protocol Version 2 (IKEv2)",
RFC 8247, DOI 10.17487/RFC8247, September 2017,
<https://www.rfc-editor.org/info/rfc8247>.
Author's Address
Hu Jun
Nokia
777 East Middlefield Road
Mountain View CA 95148
United States
Email: jun.hu@nokia.com
Hu Expires April 12, 2020 [Page 7]
