Re: Entering passphrase twice when sending PGP signed message

[Simon Josefsson <jas@extundo.com>]

Matthias Andree <ma@dt.e-technik.uni-dortmund.de> writes:

> Simon Josefsson <jas@extundo.com> writes:
>
>> This happens if you use Gcc, and it is because the message is encoded
>> once for sendmail/SMTP/NNTP and once for the Gcc copy, as you assume.
>> But this can't be fixed easily, because the copy that is Gcc'ed is not
>> the same as the one that is mailed or posted.
>
> That's a bug then. The local copy must be identical to what's sent out,
> save for the standardized differences (Newsgroups: potentially).

What purpose would this serve?  If you want a copy of what is sent in
mail, there is Bcc.  I'm not sure if there is a similar feature for
getting a copy of what is posted in news, though.

The advantage of generate Gcc separately from mail and news is, of
course, that your local copy isn't restricted to the arbitrary, and
sometimes incompatible, limitations in mail and news, and to support
Gcc rewriting functionality, e.g. gnus-gcc-externalize-attachments.

>> An extreme example is the `gnus-gcc-externalize-attachments', which
>> make Gcc differ distinctly from the SMTP/NTTP version of the mail.
>> The more subtle examples are charset handling, news differ from mail,
>> so making gcc equal one of them still wouldn't solve the problem in
>> general.
>
> As long as the whole "object" conforms to the intersection of RFC-2822
> and RFC-1036, there's not much difference that matters for local storing
> of what has been sent a second before.

Yup, and I wouldn't argue against optimizing the Gcc process, so that
it simply copies the outgoing "object" verbatim, when that is
possible.  But deciding if that situation applies or not seems
non-trivial.

(The logic would have to, besides checking for the intersection
between (2)822 and 1036(bis), also check if any of the enabled Gcc
rewriting features would modify the "object".  Even so, it must have
knowledge about certain MML tags, such as security tags, which
generate different output each time, but can (probably, and not in all
situations) be considered equal, for Gcc:ing purposes.  Also remember
that MIME encoding can be different in news than from mail too.)

>> Another approach would be to attack the source of the problem,
>> passphrases.  The gpg-agent seems like a good solution to that.
>
> The problem appears to be that the saved article differs from the sent
> article, which is a no-no.

There are already features that require the saved article to differ
from what was sent, so it is not always a bad thing, assuming people
do use those features.