[Openswan dev] Opportunistic encryption questions

Paul Wouters paul at xelerance.com
Sat Apr 1 02:09:49 CEST 2006

On Tue, 28 Mar 2006, s baker wrote:

>    It seems to me that the power of opportunistic encryption
> grows as the user base grows.  In order to take advantage of this,
> the more people using it the better.  To have more people
> who don't have control of DNS to participate, I think that
> some other key distribution capability needs to be present, most
> reasonably as a fallback in case a DNS record cannot be found.
>    This could be accomplished with a keyserver running on the
> receiving node.  When the initiator connects, it would see if
> there was a static key, then try reverse DNS, then try a
> well known port at the destination to ask for a key.  I recall
> seeing that there are key servers already available that could
> fulfill this requirement.
>    I realize that this is more vulnerable to a man-in-the-middle
> attack than a reverse DNS key distribution is.

BTNS will address these issues. In the future, it will be possible
to just try an IKE connection and exchange the keys inline. Of
course there is a risk with a man-in-the-middle attack, but once
you have a BTNS connection, it can be "upgraded" using a trusted
third party check (such as key in DNS, some CA, or some new method)

>    So I am interested in where this idea would stand.  Is someone
> working on it already?  Is it likely to be added to openswan
> if it were developed?

A seperate key exchange protocol would not be accepted for openswan.
But the BTNS extensions would be integrated into openswan.

See further: http://www.ietf.org/html.charters/btns-charter.html


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