Re: [TUHS] off-topic list

On 23 Jun 2018 18:18 -0600, from tuhs(a)minnie.tuhs.org (Grant Taylor via TUHS): The problem, of course (and I hope this is keeping this Unixy enough), with that approach is that it won't handle headers split across multiple lines (I'm looking at you, Received:, but you aren't alone), and that it'll match lines in the body of the message as well (such as the "Subject: " line in the body of your message), unless the body happens to be e.g. Base64 encoded which instead complicates searching for non-header material. For sure neither is insurmountable even with standard tools, but it does require a bit more complexity than a simple egrep to properly parse even a single message, let alone a combination of multiple ones (as seen in mbox mailboxes, for example). At that point having specific tools, such as formail, that understand the specific file format does start to make sense... There isn't really much conceptual difference between writing, say, formail -X Subject: < message.txt and egrep "^Subject: " message.txt but the way the former handles certain edge cases is definitely better than that of the latter. Make everything as simple as possible, but not simpler. (That goes for web pages, too, by the way.) I believe the correct way would indeed be to validate, strip and possibly re-sign. That way, everyone would (should) be making correct claims about a message's origin. FWIW, SPF presents a similar problem with message forwarding without address rewriting... so it's definitely not just DKIM. -- Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se “The most dangerous thought that you can have as a creative person is to think you know what you’re doing.” (Bret Victor)