Sieve and encoded Headers

Bron Gondwana brong at
Mon Feb 8 02:28:12 EST 2010

On Mon, Feb 08, 2010 at 07:53:21AM +0100, Garry wrote:
> Hi,
> after wondering for a while why occasionally my sieve script rules
> wouldn't work, I just found the reason (I guess) - Sieve doesn't
> (correctly?) decode utf encoded header lines which e.g. are in a format
> like this:
> Subject: =?utf-8?B?W0xPR10gV2F0Y2hsaXN0OiBzbWVhZ29sIGZvdW5kIEdydcOfIGF1cyBkZXIgVW50ZXJ3ZWx0IChVbmtub3duIENhY2hlKQ==?=
> I'm using version: "Cyrus timsieved v2.2.13-Debian-2.2.13-19" ... is it
> something that is fixed in a newer version? I tried finding something on
> the net, but at least the first couple of results pages didn't yield any
> insight ...

No - it's not fixed in any released version.  It is fixed in the FastMail
Cyrus patches - but it's a very invasive change to the charset encoding,
so it's been kept out of the stable line for now.

I've CC'd Ken on this - I wonder if it's worth going back and doing a
"minimal still compatible" set of patches that fixes charset encoding in
sieve without actually changing the on disk format of the cyrus.cache
(which is what requires reconstructs to make things work again)

But - I can tell you that we're not going to be backporting this sort of
thing to the 2.2 series, so you'll certainly need to upgrade!

Bron ( also - it will break any sieve rules that try to detect charset
       encodings by string matching on the Subject header - which we
       have seen in the wild as a SPAM detection technique )

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