Internet DRAFT - draft-uberti-ip-handling-ex-mdns
draft-uberti-ip-handling-ex-mdns
RTCWEB J. Uberti
Internet-Draft J. de Borst
Intended status: Informational Q. Wang
Expires: May 6, 2019 Google
Y. Fablet
Apple Inc.
November 02, 2018
WebRTC IP Address Handling Extensions for Multicast DNS
draft-uberti-ip-handling-ex-mdns-00
Abstract
This document extends the previous WebRTC IP Address Handling
Requirements with new modes that make use of Multicast DNS ICE
candidates, and updates the recommendations accordingly.
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
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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 May 6, 2019.
Copyright Notice
Copyright (c) 2018 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
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include Simplified BSD License text as described in Section 4.e of
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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. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. New Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.1. Mode 2.1 . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Mode 2.2 . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Additional Applications . . . . . . . . . . . . . . . . . . . 3
6. Security Considerations . . . . . . . . . . . . . . . . . . . 3
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
8.1. Normative References . . . . . . . . . . . . . . . . . . 4
8.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
[IPHandling] describes the privacy problems associated with exposing
IP addresses to web applications, but admits that there is no
solution to the issue of exposing private IP addresses that does not
carry a corresponding impact on connectivity.
[mDNSCandidates] introduces a new technique based on Multicast DNS
(mDNS) that obscures private IP addresses with mDNS names. This
solves the privacy issues associated with exposing local IP
addresses, and mitigates most of the aforementioned connectivity
impact.
This document extends the set of modes defined in [IPHandling] with
new options based on the mDNS technique. Different choices are
provided, each with their own benefits and drawbacks.
2. Terminology
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].
3. New Modes
Using the mDNS technique, we define two new modes, namely Mode 2.1
and 2.2. These modes are identical to Mode 2 from [IPHandling], but
the technique from [mDNSCandidates] is used to protect the selected
private IP addresses. Accordingly, the privacy guidelines outlined
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in [mDNSCandidates], Section 5 MUST be followed in each new mode in
order to prevent accidental disclosure of a private IP address.
3.1. Mode 2.1
The local IPv4 address associated with the preferred interface MUST
be replaced with a mDNS name, as described in [mDNSCandidates],
Section 3.1. Any local IPv6 addresses associated with the preferred
interface MUST also be replaced with mDNS names, unless they are
[RFC4941] privacy-preserving addresses.
3.2. Mode 2.2
All local IPv4 and IPv6 addresses MUST be replaced with mDNS names,
as described in [mDNSCandidates], Section 3.1.
4. Analysis
The only difference between Mode 2.1 and Mode 2.2 is how [RFC4941]
addresses are handled. In either case, a direct connection is
possible if the mDNS addresses created for the local IP addresses can
be resolved. However, when mDNS fails, either because it is disabled
on the network, or the endpoints are not on the same segment, Mode
2.1 may allow a direct connection where Mode 2.2 does not.
The exact impact on applications needs to be determined
experimentally. This document will be updated with a specific
recommendation once this information is known.
5. Additional Applications
The mDNS technique may also have value even when all network
interfaces are used by the ICE agent, i.e., in Mode 1 from
[IPHandling], by minimizing the amount of information regarding the
local network that is disclosed to the remote peer. Accordingly, a
future update of this document may define additional modes that apply
the mDNS technique to Mode 1. This is an area for further study.
6. Security Considerations
The modes defined here, on their own, present no new security
considerations. Considerations for the mDNS technique are detailed
in [mDNSCandidates], Section 6.
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7. IANA Considerations
This document requires no actions from IANA.
8. References
8.1. 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>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<https://www.rfc-editor.org/info/rfc4941>.
8.2. Informative References
[IPHandling]
Shieh, G., "WebRTC IP Address Handling Requirements",
April 2018, <https://tools.ietf.org/html/
draft-ietf-rtcweb-ip-handling>.
[mDNSCandidates]
Wang, Q., "Using Multicast DNS to protect privacy when
exposing ICE candidates", October 2018,
<https://tools.ietf.org/html/
draft-ietf-rtcweb-mdns-ice-candidates>.
Authors' Addresses
Justin Uberti
Google
Email: juberti@google.com
Jeroen de Borst
Google
Email: jeroendb@google.com
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Qingsi Wang
Google
Email: qingsi@google.com
Youenn Fablet
Apple Inc.
Email: youenn@apple.com
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