On Mon, 10 Nov 2003, Dustin Puryear wrote:
> We are battling the QP encoding issue. For those unfamiliar with this issue,
> when a binary that has been improperly encoded via QP encoding by an email
> client passes through Anomy it can become garbled if Anomy converts a CRLF
> to a LF (or vice-versa?).
>
> Every once in a while we get a PDF that is unreadable. I realize that the
> cause of the problem is the email client being silly, but unfortunately we
> can't fix the email client of users not under our umbrella. Therefore we
> need to consider a fix for Anomy.
>
> Here is my understanding of the problem:
>
> 1. A MUA uses QP encoding to MIME encode a binary file such as a PDF.
> 2. The message is routed to our mail server.
> 3. Our mail server hands the message to Anomy, which inspects the message.
> 4. During MIMEStream::RawRead() Anomy will replace \015\012 with \012, which
> breaks the PDF.
> 5. Anomy packs the message back up and returns to mail server.
> 6. Mail server delivers to our user.
> 7. User can't open PDF and so sends us a nice little email with colorful
> words. They also CC: the boss.
> 8. The boss then moves us from our nice cubicles to the basement where we
> are then surrounded by old printers flashing "PC LOAD LETTER".
>
> MIMEStream::Write() also seems to be doing something with newlines.
>
> Regardless of how ugly the solution is, what can we do here?
>
> 1. We can write code to determine if a PDF is attached. If so then bypass or
> abort Anomy entirely. Bad!
> 2. We can write code to determine that Anomy is dealing with a PDF as part
> of the larger message. If so then do not replace \015\012 with \012.
> Possible?
> 3. We can write code so that Anomy never does \015\012 for any QP encoding.
> This kills a good feature of QP encoding which allows users of various
> platforms to email one another. Possible?
4. You can add the \r\n back in afterwards if it's a PDF.
:)
>
> What can we do here?
>
> ---
> Dustin Puryear
> http://www.puryear-it.com
>
>
>
-- Tim Nelson Systems Administrator Sunet Internet Tel: +61 3 5241 1155 Fax: +61 3 5241 6187 Web: http://www.sunet.com.au/ Email: 100376@xyz.molar.is