Re: problem with mailing list and multipart/mime?

[Laurent Bercot <ska-supervision@skarnet.org>]

> I've received two copies of this email: one sent to me and second sent to
> maillist. Copy sent to me works ok - correct signed message. Copy sent to
> maillist is broken. So, looks like maillist bug.

 The mailing-list software *modifies* the message - namely, it adds a few
headers (such as List-Unsubscribe) and removes other headers (such as
Return-Path - for obvious reasons). So, it's normal that you cannot
verify the signature of a message after it goes through the list.

 The adding and removal of headers should be perfectly safe and I don't
think there's a bug in there. On the other hand, there *might* be a
problem with the handling of MIME types, because it's something
complex. The set of MIME types that are forbidden (i.e. if such a MIME
type is encountered in a multipart message, the corresponding part of
the message will be deleted) is the default set for the version of
ezmlm-idx I am using. It includes text/html; it does not include
text/plain, of course; and it does not include application/pgp-signature.

 Since messages are modified when going through the list, it makes no
sense to sign them, so I might as well add application/pgp-signature
to the list of removed MIME parts, and end this bit of confusion.

 If you think you have exhibited a real bug, such as a text/plain part
of a MIME message being removed, please send proof to me: a message
sent 1. to the list and 2. directly to me (using the address in the
"From:" header of this message, and replying to the confirmation
request), so I can compare the two and use it to investigate. But
ezmlm-idx has worked flawlessly for years, and the MIME filter has
being treating us pretty well, so I don't think there's a bug involved -
at most, a misconfiguration on my part is possible.

 Anyway I'll be away for the week-end, so we'll see this next Monday.

-- 
 Laurent