Re: [dmarc-ietf] Apropos of the de-munging draft

[Alessandro Vesely <[e-mail]>]

On 2020-08-02 7:51 p.m., John Levine wrote:
> In article <[e-mail]> you write:
>>> Unwrapping a MIME attachment is a lot easier than the proposed DKIM
>>> unmunging but I doubt either is going to show up in MUAs any time
>>> soon. Perhaps you could do it in a mail gateway.
>>
>>
>> Looking at the steps required to carry out the proposed unmunging, "a lot easier" doesn't seem to be an accurate measurement.
> 
> In python it's about two lines since there are well debugged libraries to handle MIME.  Same in most other languages.


If you use a library, most common operations can be done better than unusual ones, the actual complexity notwithstanding.

The steps I outlined for tf=footer[*] can be done adding a few lines to Murray's library, in C.


> I still would be amazed if any MUAs did this, also keeping in mind that the changes that MLMs make ARE USEFUL.


Agreed.  IMHO, Murray's lib should do just a virtual unmunge, while canonicalizing.

To actually replace From: with the original Author: can be done by the MDA, based on trusted A-Rs, after any dot-forward.

Best
Ale
-- 

[*] https://mailarchive.ietf.org/arch/msg/dmarc/2ZN7DS5NktoyEPItZ5vzr-xd0Mc