On Wed, 2010-03-24 at 01:14 +0100, Jonas Eckerman wrote:
> Not exactly that, but I have written a non-image-specific SA plugin that
> can check for mismatches. It's a bit overkill if you only want to check
> for mismatches for images though.
>
> It uses the freedesktop file magic database to recognize file content,
> and provides eval rules to check for file types and mismatches between
> content, mime type and file extension. If the freedesktop database
> contains info for SVG and BMP (it should) it can check for those mismatches.
>
> It's named MimeMagic and is available at
> <http://whatever.frukt.org/spamassassin.text.shtml>
>
Thanks, Jonas. That looks very useful. I've replaced my old
IMAGE_MISMATCH rule with an equivalent based on MimeMagic that uses:
header IMAGE_MISMATCH eval:mimemagic_mismatch_contenttype('jpg', 'gif',
'png', 'bmp', 'svg')
instead of the previous set of subrules and a meta.
I don't think MimeMagic is overkill. It is probably only a matter of
time before non-image files turn up with equivalent lying content types
and/or extensions and adding rules to catch them will be trivial.
Martin
