TRAM M. Petit-Huguenin
Internet-Draft Jive Communications
Intended status: Standards Track O. Johansson
Expires: November 20, 2014 Edvina AB
G. Salgueiro
Cisco Systems
May 19, 2014
Using DNS-based Authentication of Named Entities (DANE) to validate TLS
certificates for the Session Traversal Utilities for NAT (STUN) protocol
draft-petithuguenin-tram-stun-dane-00
Abstract
This document defines how DNS-based Authentication of Named Entities
(DANE) can be used to validate TLS certificates with the Session
Traversal Utilities for NAT (STUN) protocol.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 3
6.1. Normative References . . . . . . . . . . . . . . . . . . 3
6.2. Informative References . . . . . . . . . . . . . . . . . 4
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
This document defines how DNS-based Authentication of Named Entities
[RFC6698] (DANE) can be used to validate TLS certificates with the
Session Traversal Utilities for NAT [RFC5389] (STUN) protocol.
STUN [RFC5389] uses Transport Layer Security [RFC5246] (TLS) as a
secure transport and [I-D.ietf-tram-stun-dtls] subsequently added
Datagram Transport Layer Security [RFC6347] as a secure transport
more suited for the originally intended purpose of STUN, which is to
support multimedia sessions. Both transports require to have the
certificate presented by the server validated following the rules
established by [RFC2818]. Additionaly [RFC5389] provides rules on
how to use DNS SRV Resource Records [RFC2782] to resolve a domain
name to a list of host name for the purpose of load balancing and
increased reliability. These rules were subsequently enhanced to
support S-NAPTR Resource Records [RFC5928] to add the possibility of
selecting the preferred transport and redirect between domains.
DANE [RFC6698] improves the mechanism established by [RFC2818] by
enabling the administrators of domain names to specify the keys used
the secure servers in their domains. The benefits of this approach
emcompass increasing flexibility, getting less reliance on trust
anchors, enabling Perfect Forward Secrecy (PFS) and much more.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "MAY", and "OPTIONAL"
in this document are to be interpreted as described in [RFC2119] when
they appear in ALL CAPS. When these words are not in ALL CAPS (such
as "must" or "Must"), they have their usual English meanings, and are
not to be interpreted as RFC 2119 key words.
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"Source Domain" and "Host Name" are defined in [I-D.ietf-dane-srv].
3. Operations
STUN clients that are conform with this specification, and that are
using one or more DNS lookups to find the server, and that have
established that all DNS Resource Records from the Source Domain to
the Host Name are secure according to DNSsec [RFC4033] (i.e. that the
AD bit is set in all the DNS answers), and that have selected a
secure protocol (e.g. TLS or DTLS) MUST lookup for a TLSA Resource
Record for the protocol, port and Host Name selected. If the TLSA
Resource Record is secure then the STUN client MUST use it to
validate the certificate presented by the STUN server. If there is
no TLSA Resource Record or if the Resource Record is not secure, then
the client MUST fallback to the validation process defined in
[RFC5389] and [I-D.ietf-tram-stun-dtls].
Note that only STUN Usages where the connection is the result of a
DNS lookup are to be used with DANE which, for the list of STUN
Usages listed in [I-D.ietf-tram-stun-dtls], means these:
NAT Discovery Usage
NAT Behavior Discovery Usage
TURN Usage
4. Security Considerations
Using DANE as (D)TLS certificate validation mechanism does not
introduce any specific security considerations beyond those for STUN
over TLS detailed in [RFC5389] and those for STUN over DTLS detailed
in [I-D.ietf-tram-stun-dtls].
5. IANA Considerations
This document has no IANA actions.
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
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[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements", RFC
4033, March 2005.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing,
"Session Traversal Utilities for NAT (STUN)", RFC 5389,
October 2008.
[RFC5928] Petit-Huguenin, M., "Traversal Using Relays around NAT
(TURN) Resolution Mechanism", RFC 5928, August 2010.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, January 2012.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, August 2012.
[I-D.ietf-tram-stun-dtls]
Petit-Huguenin, M. and G. Salgueiro, "Datagram Transport
Layer Security (DTLS) as Transport for Session Traversal
Utilities for NAT (STUN)", draft-ietf-tram-stun-dtls-02
(work in progress), May 2014.
[I-D.ietf-dane-srv]
Finch, T., Miller, M., and P. Saint-Andre, "Using DNS-
Based Authentication of Named Entities (DANE) TLSA records
with SRV and MX records.", draft-ietf-dane-srv-05 (work in
progress), February 2014.
6.2. Informative References
[RFC7065] Petit-Huguenin, M., Nandakumar, S., Salgueiro, G., and P.
Jones, "Traversal Using Relays around NAT (TURN) Uniform
Resource Identifiers", RFC 7065, November 2013.
Appendix A. Examples
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With the DNS RRs in Figure 1 and an ordered TURN transport list of
{DTLS, TLS, TCP, UDP}, a TURN client conform to this specification
and using the TURN URI [RFC7065] "turns:example.com" will try first
to connect to the TURN server at address 192.0.2.1:5389 using DTLS
and using DANE to verify the certificate subsequently presented by
the server.
If this connection does not succeed, the client will then try to
connect to the TURN server at 192.0.2.1:5000 but will not use DANE
for the certificate verification even as a TLSA RR is available,
because the DNSsec validation chain is broken in this case.
Using a TURN URI of "turns:example.com;transport=udp" bypasses the
NAPTR lookup, but at the expense of preventing the TLS fallback.
example.com.
IN NAPTR 100 10 "" RELAY:turn.tls:turn.dtls "" example.net.
IN RRSIG NAPTR ...
_turns._tcp.example.com.
IN SRV 0 0 5000 a.example.net.
_turns._udp.example.com.
IN SRV 0 0 5349 a.example.net.
IN RRSIG SRV ...
example.net.
IN NAPTR 200 10 "" RELAY:turn.tcp:turn.tls "" stream.example.net.
IN NAPTR 100 10 "" RELAY:turn.udp:turn.dtls "" datagram.example.net.
IN RRSIG NAPTR ...
datagram.example.net.
IN NAPTR 100 10 S RELAY:turn.udp "" _turn._udp.example.net.
IN NAPTR 100 10 S RELAY:turn.dtls "" _turns._udp.example.net.
IN RRSIG NAPTR ...
stream.example.net.
IN NAPTR 200 10 S RELAY:turn.tcp "" _turn._tcp.example.net.
IN NAPTR 200 10 S RELAY:turn.tls "" _turns._tcp.example.net.
IN RRSIG NAPTR ...
_turn._udp.example.net.
IN SRV 0 0 3478 a.example.net.
_turn._tcp.example.net.
IN SRV 0 0 5000 a.example.net.
_turns._udp.example.net.
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IN SRV 0 0 5349 a.example.net.
IN RRSIG SRV ...
_turns._tcp.example.net.
IN SRV 0 0 5000 a.example.net.
a.example.net.
IN A 192.0.2.1
IN RRSIG A ...
_5389._udp.a.example.net.
IN TLSA ...
IN RRSIG TLSA ...
_5000._tcp.a.example.net.
IN TLSA ...
IN RRSIG TLSA ...
Figure 1
Authors' Addresses
Marc Petit-Huguenin
Jive Communications
1275 West 1600 North, Suite 100
Orem, UT 84057
USA
Email: marcph@getjive.com
Olle E. Johansson
Edvina AB
Runbovaegen 10
Sollentuna SE-192 48
SE
Email: oej@edvina.net
Gonzalo Salgueiro
Cisco Systems
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
US
Email: gsalguei@cisco.com
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