[Rt-devel] Bug: Forward + GnuPG sign = illegal MIME encoding base64

Ruslan Zakirov ruslan.zakirov at gmail.com
Tue Oct 20 15:13:27 EDT 2009

Hello Otmar,

I believe you that something is wrong, not sure what exactly.

If we are talking about RFCs 3156 and 1847 then it's important to look
at section 2.1 in http://www.faqs.org/rfcs/rfc1847.html, paragraph
that says the following:

In addition, if the multipart/signed object is EVER to be transferred
over the standard Internet SMTP infrastructure, the resulting MIME
body is constrained to 7 bits -- that is, the use of material
requiring either 8bit or binary content-transfer-encoding is NOT
allowed. Such 8bit or binary material MUST be encoded using either the
quoted-printable or base64 encodings.

On Tue, Oct 20, 2009 at 6:07 PM, Otmar Lendl <ol at bofh.priv.at> wrote:
> This was a bit tricky to debug:
> We kept getting complaints about empty forwards from our RT 3.8.2 / RTIR
> installations. Testing Forwards manually (/RTIR/Forward.html) showed the
> desired attachment, though. At least in mutt. Not in Thunderbird.
> Finally Amavis tipped us off: "illegal MIME encoding [base64] for message/rfc822".
> It turns out that an attachement of type message/rfc822 must
> not be encoded by itself. Plain RT is fine, it uses "binary" as
> encoding. Nothing wrong about that.
> Now, we do have GnuPG signing enabled for this queue, and thus the message gets
> passed through the signing engine, and here (quite understandable), the code
> wants to play it safe and recodes to base64. And not the individual leafs of the
> MIME tree (which would be fine), but the message/rfc822 part itself.
> Bad karma.
> The kolab people also ran into a similar issue some time ago, see:
> https://www.intevation.de/roundup/aegypten/issue661
> Anyway, I do not have a good solution for that, for the moment I decided
> to simply disable signing for forwards.
> Does someone else have a good idea where to tweak the gnuPG code to get
> this right?
> cheers,
> /ol
> --
> -=-  Otmar Lendl  --  ol at bofh.priv.at  --  http://lendl.priv.at/  -=-
> _______________________________________________
> List info: http://lists.bestpractical.com/cgi-bin/mailman/listinfo/rt-devel

Best regards, Ruslan.

More information about the Rt-devel mailing list