ietf-822
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Re: [ietf-822] one can re-sign without a permission to re-sign header

2014-05-02 09:33:25
On 5/1/14 2:54 PM, John Levine wrote:
author's site. That shouldn't require the mailing list to communicate
with the author's site, but it might require the author's site to get
something from the mailing list's site.
That seems overcomplicated.  Just make the expiration time fairly
short, since it's a rare mailing list that takes more than a day to do
its thing.

Perhaps it's time for a more concrete proposal to be written down.
It occurred to me that there's a very simple way to do this:

http://datatracker.ietf.org/doc/draft-levine-may-forward/

On 5/1/14 2:54 PM, John Levine wrote:
author's site. That shouldn't require the mailing list to communicate
with the author's site, but it might require the author's site to get
something from the mailing list's site.
That seems overcomplicated.  Just make the expiration time fairly
short, since it's a rare mailing list that takes more than a day to do
its thing.

Perhaps it's time for a more concrete proposal to be written down.
It occurred to me that there's a very simple way to do this:

http://datatracker.ietf.org/doc/draft-levine-may-forward/

I don't see any replay protection in here at all. Nothing that says to keep the signature expiration relatively short, and nothing which a mailing list recipient could not subsequently use to send spam. The first issue just needs a mention. It's the second issue that needs to be addressed IMO:

As an originating site, I do not want to give permission to forward to just anyone. I want to indicate that I was sending to someone in particular, e.g., list@a.example, and *list@a.example* has permission to forward. (An originating site should be fine with their being a subsequent re-forwarding, say list@a.example sending to list(_at_)b(_dot_)com which forwards, but I think they'd expect list@a.example to have given permission to list(_at_)b(_dot_)com to re-forward, and the eventual recipient will be able to see that chain.)

That's why I suggest that the originating site is going to want to talk to the mailing list site: "This message was sent from user@mydomain to list@a.example. You had better see my signature *and* received it from a.example." Your proposal doesn't do that.

Maybe people who are now setting p=reject don't care. Maybe all they care about is a short-lived signature and permission to re-forward. But I don't think that's likely to be true. I think they care about the replay problem. Otherwise, it's inviting spammers to subscribe to (especially well-used) mailing lists so that they can get and endless supply of replayable signatures.

I wouldn't bother with what you've proposed.

pr

--
Pete Resnick<http://www.qualcomm.com/~presnick/>
Qualcomm Technologies, Inc. - +1 (858)651-4478

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