If it's crypto padding surely it has to be a normatively specified value to allow checksums to work? So this would be documented.
I think it's more likely to be an off by one picking up C string terminal byte or initialised alloc() space. Uninitialised would be random. G On Fri, 7 Nov 2025, 7:40 am Ken Hornstein, <[email protected]> wrote: > >Remember that time in early 2024 when I had NUL characters in my emails. > >I guess it occuring again, and at least one MTA dislikes it. > >Maybe it never went away. I got some suggestions then, but I think the > >problem disappeared again before I could act on them... > > > >I have checked, it occurs on laptop (Ubuntu) and desktop (Devuan). > >I am running self-built nmh from source code on each. > > > > (reason: 554 5.6.0 Message contains NUL characters) > > I am kind of surprised that there is at least one MTA that complains! > > >And now today, many complaints... > > > >I thought it was related to doing either PGP/MIME signatures, or even PGP > >clearsignatures. BUT, looking at my +outgoing box, it affects 41 of 130 > >messages. Some of which are not PGP signed at all. OTH, I think that it > >affects all messages which are PGP signed. > >I've not found a way to reproduce this via just MH commands. > > > >I've replaced my "send" program on path with one that logs more stuff, > but I > >am not sure what else to debug now. I did this via overriding > "mh-send-prog" > > > >dyas-[~](3.3.8) mcr 10229 %hexdump -C Mail/outgoing/104 > >000002f0 65 79 38 63 6c 31 54 4b 63 34 69 4e 66 50 35 57 > |ey8cl1TKc4iNfP5W| > >00000300 47 68 41 3d 3d 0a 3d 52 57 50 30 0a 2d 2d 2d 2d > |GhA==.=RWP0.----| > >00000310 2d 45 4e 44 20 50 47 50 20 53 49 47 4e 41 54 55 |-END PGP > SIGNATU| > >00000320 52 45 2d 2d 2d 2d 2d 0a 00 00 00 00 00 00 00 00 > |RE-----.........| > > I have to say that this sure looks like some kind of crypto padding, > because > it ends right on 16 byte boundary. But in your next message it doesn't, so > maybe that isn't it. > > I guess what I would instrument would be: > > - What does the draft look like before send(1) gets it? send(1) will > generally > just take whatever you give it and shove it out on the wire, so I would > be surprised if that was the failure point (but I've been surprised > before!) > > - What the message looks like before and after GPG signs it. > > --Ken > >
