DNS wire-format over HTTP
draft-ietf-dnsop-dns-wireformat-http-01
Internet Engineering Task Force L. Song
Internet-Draft Beijing Internet Institute
Intended status: Experimental P. Vixie
Expires: September 28, 2017 TISF
S. Kerr
R. Wan
Beijing Internet Institute
March 27, 2017
DNS wire-format over HTTP
draft-ietf-dnsop-dns-wireformat-http-01
Abstract
This memo introduces a way to tunnel DNS data over HTTP. This may be
useful in any situation where DNS is not working properly, such as
when there is middlebox misbehavior.
Status of This Memo
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This Internet-Draft will expire on September 28, 2017.
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Internet-Draft DNS wire-format over HTTP March 2017
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Methodology and Configuration . . . . . . . . . . . . . . . . 3
3. DNS-over-HTTP Message Format . . . . . . . . . . . . . . . . 4
3.1. Request Method . . . . . . . . . . . . . . . . . . . . . 5
3.2. Response Status Code . . . . . . . . . . . . . . . . . . 5
3.3. Header Fields . . . . . . . . . . . . . . . . . . . . . . 6
3.4. Message Body . . . . . . . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 7
6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
RFC 1035 [RFC1035] specifies the wire format for DNS messages. It
also specifies DNS transport on UDP and TCP on port 53, which is
still used today. However, there are other ways to access DNS
database, for example in a different data format or via alternative
DNS transport. These approaches are summarized in [draft-shane-
review-DNS-over-http].
One of alternative way of using DNS described in that document is to
transport DNS binary data inside HTTP, with the goal of improving DNS
service availability. The DNS traffic is simply sent as web traffic
using port 80/443 over HTTP. It can bypass badly behaving middle
boxes like firewalls, proxies or traffic shaping devices on path
which might interfere with normal DNS traffic [RFC5625] [DOTSE]
[SAC035].
This approach has the advantage that HTTP usually makes it through
even the worst coffee shop or hotel room firewalls, as Internet users
expect web browsing to always work. It also benefits from HTTP's
support for persistent TCP connections (see section 6.3 in
[RFC7230]). Note that 5966bis [I-D.ietf-dnsop-5966bis] specifies the
persistent feature for DNS on TCP port 53, but current DNS software
does not generally support this mode of operation. Finally, HTTPS
provides data integrity and privacy.
One alternative idea is to simply use a VPN, rather than a custom
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