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

[Pete Resnick <[e-mail]>]

On 4/26/14 10:56 AM, Ned Freed wrote:
>>> I'd much rather pursue Pete's approach.
>>>        
>> I like it too, but I haven't fully grasped it.  On the 16th he wrote:
>>      
>>      If the originator's site is going to allow that, you could create a
>>      mechanism where the originator's site gets some sort of
>>      cryptographic data from the mailing list site and include that in
>>      its signed message, such that when the eventual recipient gets the
>>      message, it can verify that it came from a mailing list site that
>>      the originator explicitly sent the mail to.
>> https://mailarchive.ietf.org/arch/msg/ietf/T823fjs5PWq2BjvOZ-FzZ5YMjSA
>>      
>>   I assume the final message has a valid author's domain signature,
>>   otherwise we need to modify DMARC.
>>      
> Or override it.
>
>    
>> The only way I see is that the
>> MLM, after message modification, sends the message or its hash back to
>> the author's site to get it signed.  That sounds too complicated, so I
>> must be missing something.
>>      

As I said to someone earlier, I take it that the author's site is 
allowing the author to have the mailing list resend a modified version 
of their message, whatever the modifications might be. So all that the 
mailing list needs is a short-lived token (probably signing the Date: 
and From: fields, maybe encrypted with the *mailing list site's* key), 
resigned by the mailing list site along with whatever the mailing list 
sees fit to sign, such that the eventual recipient can see that the 
message (a) came via the mailing list from the mailing list's site and 
(b) the mailing list got the message (some short time ago) from the 
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.

> Perhaps it's time for a more concrete proposal to be written down.
>    

Ah, for a world with more time just to read these messages, let alone 
write down a proposal.

If there are others who have a handle on what I'm thinking about and 
want to work on this, I'm happy to spin up a WG to work this out. 
There's no way I'm going to be able to hold the pen on this, but I think 
I hear sufficient motivation to get this done.

pr

-- 
Pete Resnick<http://www.qualcomm.com/~presnick/>
Qualcomm Technologies, Inc. - [phone]