Session Traversal Utilities for NAT (STUN) Usage for Consent Freshness
RFC 7675
Internet Engineering Task Force (IETF) M. Perumal
Request for Comments: 7675 Ericsson
Category: Standards Track D. Wing
ISSN: 2070-1721 Cisco Systems, Inc.
R. Ravindranath
T. Reddy
Cisco Systems
M. Thomson
Mozilla
October 2015
Session Traversal Utilities for NAT (STUN) Usage for Consent Freshness
Abstract
To prevent WebRTC applications, such as browsers, from launching
attacks by sending traffic to unwilling victims, periodic consent to
send needs to be obtained from remote endpoints.
This document describes a consent mechanism using a new Session
Traversal Utilities for NAT (STUN) usage.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7675.
Perumal, et al. Standards Track [Page 1]
RFC 7675 STUN Usage for Consent Freshness October 2015
Copyright Notice
Copyright (c) 2015 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Design Considerations . . . . . . . . . . . . . . . . . . . . 4
5. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Expiration of Consent . . . . . . . . . . . . . . . . . . 5
5.2. Immediate Revocation of Consent . . . . . . . . . . . . . 6
6. DiffServ Treatment for Consent . . . . . . . . . . . . . . . 7
7. DTLS Applicability . . . . . . . . . . . . . . . . . . . . . 7
8. Security Considerations . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
To prevent attacks on peers, endpoints have to ensure the remote peer
is willing to receive traffic. Verification of peer consent before
sending traffic is necessary in deployments like WebRTC to ensure
that a malicious JavaScript cannot use the browser as a platform for
launching attacks. This is performed both when the session is first
established to the remote peer using Interactive Connectivity
Establishment (ICE) [RFC5245] connectivity checks, and periodically
for the duration of the session using the procedures defined in this
document.
When a session is first established, ICE implementations obtain an
initial consent to send by performing STUN connectivity checks. This
document describes a new STUN usage with exchange of request and
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RFC 7675 STUN Usage for Consent Freshness October 2015
response messages that verifies the remote peer's ongoing consent to
receive traffic. This consent expires after a period of time and
needs to be continually renewed, which ensures that consent can be
terminated.
This document defines what it takes to obtain, maintain, and lose
consent to send. Consent to send applies to a single 5-tuple. How
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