BASE64 [was: various]

[Boris 'pi' Piwinger]

Matthias Andree <matthias.andree at gmx.de> wrote:

>I've spent some little thoughts on whether lex would be smart enough to
>parse the MIME structure while still emitting delimiters as tokens, and
>on-the-fly decoding of base64 and qp. I believe that
>Content-Transfer-Encoding should be taken into account because there are
>words (particularly with 4, 8, 12 characters) that make up valid base64
>words; 

Sounds good.

>OTOH, we should decide if we're actually interested in more than
>the headers of MIME parts that have Content-Type other than text/*.

I am not sure how you think about multipart/*. That might
well contain text parts, but you can find them anyways.

>I believe we should only parse text/*, convert things to UTF-8 (which will
>bring another dependency, iconv, jconv, whatever), and only read headers
>of other content types. As someone (I believe Boris) has pointed out,
>spammers won't use base64 to deceive spam traps because that will render
>the mail unreadable.

I once posted some statistics about the use of base64. To my
very surprise it was used by spammers significantly.

pi