Re: [DNSOP] I-D Action: draft-ietf-dnsop-server-cookies-01.txt

[Willem Toorop <[e-mail]>]

Dear dnsop,

This version has an updated Client Cookie construction section in which
it is now REQUIRED to change a Client Cookie when the Client IP address
changes.

Previously (in versions before the previous version) the Client IP
address was used in Cookie construction, however that turned out to be
impractical to implement and therefore dropped from the previous version
recommending to disable DNS Cookies when privacy was a requirement.

Philip Homburg pointed out that, although impractical to determine the
Client IP before Client Cookie construction, it is feasible for a Client
to detect it when it learns a Server Cookie from a specific Server.  It
can subsequently be tried to be reused for the same Server which will
fail if the Client IP has changed.

This new (and practically implementable) requirement does not only
enhance privacy and make DNS Cookies work with the IPv6 Privacy
Extensions (by preventing tracking), it also makes them work in other
environments where Client source IP can change frequently, such as in
setups with multiple outgoing gateways.

Op 04-11-2019 om 21:58 schreef [e-mail]:
> 
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Domain Name System Operations WG of the IETF.
> 
>         Title           : Interoperable Domain Name System (DNS) Server Cookies
>         Authors         : Ondrej Sury
>                           Willem Toorop
>                           Donald E. Eastlake 3rd
>                           Mark Andrews
> 	Filename        : draft-ietf-dnsop-server-cookies-01.txt
> 	Pages           : 15
> 	Date            : 2019-11-04
> 
> Abstract:
>    DNS cookies, as specified in RFC 7873, are a lightweight DNS
>    transaction security mechanism that provides limited protection to
>    DNS servers and clients against a variety of denial-of-service and
>    amplification, forgery, or cache poisoning attacks by off-path
>    attackers.
> 
>    This document provides precise directions for creating Server Cookies
>    so that an anycast server set including diverse implementations will
>    interoperate with standard clients.
> 
>    This document updates [RFC7873]
> 
> 
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-dnsop-server-cookies/
> 
> There are also htmlized versions available at:
> https://tools.ietf.org/html/draft-ietf-dnsop-server-cookies-01
> https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-server-cookies-01
> 
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-ietf-dnsop-server-cookies-01
> 
> 
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
> 
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
> 
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