[sylpheed:31304] Re: PGP/MIME-signing breaks sig delimiter
Hiroyuki Yamamoto
hiro-y at kcn.ne.jp
Mon May 14 18:55:57 JST 2007
Hello,
On Mon, 14 May 2007 11:31:32 +0200
"Michael Schwendt" <mschwendt at gmail.com> wrote:
> > Whitespace-stripping is done *before* signing, so it is not a
> > violation.
>
> Right. At the sender's side, but not at the recipient's side.
>
> Apparently, based on your later comment, some MUAs *do* alter the
> message contents prior to *verifying* the signature.
No, I just said some MUAs can't handle quoted-printable well.
> I didn't say that Sylpheed violates the guideline. Actually, it
> doesn't matter whether the user deletes whitespace or whether Sylpheed
> does it *before* the mail is passed on to GPGME. It is a normal edit
> operation that defines the mail to be sent. But the recipient needs to
> perform a matching series of modifications/conversions before it can
> verify the signature.
>
> RFC 3156 says:
>
> In most cases, trailing whitespace can either be removed, or
> protected by applying an appropriate content-transfer-encoding.
>
> Note the "either, or".
Sylpheed is using the former method to avoid the trailing-space problem.
> And:
>
> Implementor's note: It cannot be stressed enough that
> applications using this standard follow MIME's suggestion that you "be
> conservative in what you generate, and liberal in what you
> accept."
>
> With regard to "-- ", the way to go would be QP, so the space
> character is preserved. The recipient's MUA, however, must not strip
> this character either, but decode it and accept it.
>
> > In conclusion, I think it should be reverted to the previous
> > behavior, but with some exceptions (if charset=ISO-2022-JP, send
> > with 7bit with stripping trailing whitespaces).
>
> If just the whitespace in "-- " is preserved, does that also corrupt
> the mail then? Then that still is a case where Sylpheed, by default,
> should not try to work around bugs in the recipient's MUA.
Just preserving "-- " with 7bit CTE will not corrupt the mail on
recipient, but then it doesn't follow RFC 3156 (and it might be modified
along the way).
--
Hiroyuki Yamamoto <hiro-y at kcn.ne.jp>
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