bug#43302: password shows up in shell buffer (27.1)

bug#43302: password shows up in shell buffer (27.1)

[Nicholas Drozd]

The password input starring in shell mode seems to have changed in 27
from 26 to become more lax. Here is a small shell script:

#+begin_src shell
echo "Password:"
read -sr password
#+end_src

In 26, it looks like this when I run it:

#+begin_quote
$ bash password.sh
Password:
$
#+end_quote

The password is input starred into the minibuffer, not in the shell
buffer itself.

In 27, it looks like this:

#+begin_src
$ bash password.sh
Password:
asdf
$
#+end_src

The password (=asdf=) gets input directly into the shell buffer, unstarred.

I have tried on both Linux and Mac.

This may be related to
https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-09/msg00028.html

bug#43302: password shows up in shell buffer (27.1)

[Robert Pluim]

>>>>> On Wed, 9 Sep 2020 19:40:04 -0500, Nicholas Drozd <nicholasdrozd@gmail.com> said:

    Nicholas> This may be related to
    Nicholas> https://lists.gnu.org/archive/html/bug-gnu-emacs/2020-09/msg00028.html

The patch for that is in master, not in emacs-27, so something else is
going on.

Robert

bug#43302: password shows up in shell buffer (27.1)

[Lars Ingebrigtsen]

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Nicholas Drozd <nicholasdrozd@gmail.com> writes:

> In 27, it looks like this:
>
> #+begin_src
> $ bash password.sh
> Password:
> asdf
> $
> #+end_src
>
> The password (=asdf=) gets input directly into the shell buffer, unstarred.

I'm able to reproduce the behaviour in Emacs 27 and 28.  However, if you
say this:

echo -n "Password:"
read -sr password

Then Emacs will *** the password in the minibuffer, so comint only
triggers the password-reading behaviour if there's no newline there.

Now, Emacs 26 did handle this...  somewhat:


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That is, it would include the newline in the prompt.

So...  I think basically this works as intended currently: comint only
triggers the password-reading behaviour if the prompt is on the current
line (i.e., without a newline), so I'm closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#43302: password shows up in shell buffer (27.1)

[Nicholas Drozd]

Your workaround works, but the fact remains that the behavior changed
between 26 and 27, and it changed in a way that I as a user found
disturbing. I switched to 27, and on my first session I ran a script
that queried for a password. Previously Emacs had hid the password as
I expected, but in 27 my password was unexpectedly exposed on the
screen. It's a bug, and it should be fixed. (I would try to fix it
myself, but I have no idea where to start. With a little guidance I
could take a crack at it.)

Alternatively, it could have been an intentional change in behavior.
In that case it should be noted in NEWS. Something like: "shell-mode:
Passwords are protected in fewer circumstances." But that sounds more
like antinews than news.

On Wed, Jan 27, 2021 at 12:20 AM Lars Ingebrigtsen <larsi@gnus.org> wrote:
>
> Nicholas Drozd <nicholasdrozd@gmail.com> writes:
>
> > In 27, it looks like this:
> >
> > #+begin_src
> > $ bash password.sh
> > Password:
> > asdf
> > $
> > #+end_src
> >
> > The password (=asdf=) gets input directly into the shell buffer, unstarred.
>
> I'm able to reproduce the behaviour in Emacs 27 and 28.  However, if you
> say this:
>
> echo -n "Password:"
> read -sr password
>
> Then Emacs will *** the password in the minibuffer, so comint only
> triggers the password-reading behaviour if there's no newline there.
>
> Now, Emacs 26 did handle this...  somewhat:
>
>
> That is, it would include the newline in the prompt.
>
> So...  I think basically this works as intended currently: comint only
> triggers the password-reading behaviour if the prompt is on the current
> line (i.e., without a newline), so I'm closing this bug report.
>
> --
> (domestic pets only, the antidote for overdose, milk.)
>    bloggy blog: http://lars.ingebrigtsen.no

bug#43302: password shows up in shell buffer (27.1)

[Eli Zaretskii]

> From: Nicholas Drozd <nicholasdrozd@gmail.com>
> Date: Fri, 12 Feb 2021 14:50:01 -0600
> Cc: 43302@debbugs.gnu.org
> 
> Your workaround works, but the fact remains that the behavior changed
> between 26 and 27, and it changed in a way that I as a user found
> disturbing. I switched to 27, and on my first session I ran a script
> that queried for a password. Previously Emacs had hid the password as
> I expected, but in 27 my password was unexpectedly exposed on the
> screen. It's a bug, and it should be fixed. (I would try to fix it
> myself, but I have no idea where to start. With a little guidance I
> could take a crack at it.)

I'd start at comint-watch-for-password-prompt.