SFC Working Group T. Reddy
Internet-Draft Cisco
Intended status: Informational D. Migault
Expires: July 24, 2016 Ericsson
C. Pignataro
P. Quinn
Cisco
C. Inacio
CERT/SEI/CMU
January 21, 2016
NSH Security and Privacy requirements
draft-reddy-sfc-nsh-security-req-00.txt
Abstract
This document defines Network Service Header (NSH) security and
privacy requirements.
Status of This Memo
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This Internet-Draft will expire on July 24, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements notation . . . . . . . . . . . . . . . . . . . . 2
3. NSH Security and Privacy Requirements . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Service function chaining (SFC) [RFC7665] involves steering traffic
flows through a set of service functions in a specific order, such an
ordered list of service functions is called a Service Function Chain
(SFC). The actual forwarding path used to realize an SFC is called
the Service Function Path (SFP). Network Service Headers (NSH)
[I-D.ietf-sfc-nsh] provides a mechanism to carry metadata between
service functions. The NSH structure is defined in
[I-D.ietf-sfc-nsh] and NSH data can be divided into two parts:
o Path information used to construct the SFP such as the SFP ID and
Service Index.
o Metadata carrying the information about the packets being chained.
Note that the payload encapsulated by NSH is not part of the NSH
data.
This document defines security requirments for NSH data and privacy
requirements for NSH metadata.
2. Requirements notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
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3. NSH Security and Privacy Requirements
This section provides requirements and recommendation for the SFC
Data Plane.
REQ1: In a SFC domain where attackers can modify NSH data or
generate spoofed NSH data, NSH data MUST be authenticated and
integrity protected.
REQ2: In a SFC domain where attackers can capture and replay NSH
data, NSH data MUST provide a mechanism for replay detection
and replay prevention mechanism MUST be enforced by the SF
component processing the NSH data.
REQ3: In a SFC domain where attackers can modify the NSH
encapsulated packet, NSH encapsulated packet MUST be
authenticated and integrity protected.
REQ4: In a SFC domain where pervasive monitoring [RFC7258] is
possible, NSH metadata MUST be encrypted and MUST NOT reveal
privacy sensitive metadata to attackers. Privacy specific
threats are discussed in Section 5.2 of [RFC6973].
REQ5: TBD: To avoid fragmentation and amplification attacks, NSH
data MUST be kept under Maximum Transmission Unit (MTU)
including the byte overhead of the encapsulated packet.
REQ6: Negotiation of authentication, message integrity protection
and encryption algorithms between SF components MUST be
capable of detecting downgrade attacks.
REQ7: No device other than the SF components in the SFP SHOULD be
able to update the integrity protected NSH data. SF
components not in the SFP SHOULD NOT hold the keying material
to act on the NSH data.
REQ8: No device other than the SF components in the SFP SHOULD be
able to decrypt and update the NSH metadata. SF components
not in the SFP SHOULD NOT hold the keying material to decrypt
the NSH metadata.
4. IANA Considerations
None.
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5. Security Considerations
NSH data is at risk from four primary attacks:
o A man-in-the middle attacker modifying NSH data.
o Attacker spoofing NSH data.
o Attacker capturing and replaying NSH data.
o NSH metadata revealing privacy sensitive information to attackers.
In a SFC domain where all the above attacks are possible, NSH data
MUST be authenticated, integrity protected, replay protection MUST be
supported and NSH metadata MUST be encrypted for confidentiality.
6. Acknowledgments
TODO
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,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>.
7.2. Informative References
[I-D.ietf-sfc-nsh]
Quinn, P. and U. Elzur, "Network Service Header", draft-
ietf-sfc-nsh-01 (work in progress), July 2015.
[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<http://www.rfc-editor.org/info/rfc7665>.
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[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973,
DOI 10.17487/RFC6973, July 2013,
<http://www.rfc-editor.org/info/rfc6973>.
Authors' Addresses
Tirumaleswar Reddy
Cisco Systems, Inc.
Cessna Business Park, Varthur Hobli
Bangalore, Karnataka 560103
India
Phone: +91 9886
Email: tireddy@cisco.com
Daniel Migault
Ericsson
8400 boulevard Decarie
Montreal, QC H4P 2N2
Canada
Phone: +1 514-452-2160
Email: daniel.migault@ericsson.com
Carlos Pignataro
Cisco Systems, Inc.
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
USA
Phone: +1 919-392-7428
Email: cpignata@cisco.com
Paul Quinn
Cisco Systems, Inc.
Email: paulq@cisco.com
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Christopher Inacio
CERT, Software Engineering Institute, Carnegie Mellon University
4500 5th Ave
Pittsburgh, PA 15213
USA
Phone: +1 412-268-3098
Email: inacio@cert.org
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