GNU bug report logs - #64807
30.0.50; Editing files using sudo with fprintd hangs

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 64807 in the body.
You can then email your comments to 64807 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Theodor Thornhill <theo <at> thornhill.no>
To: bug-gnu-emacs <at> gnu.org 
Subject: 30.0.50; Editing files using sudo with fprintd hangs
Date: Sun, 23 Jul 2023 18:28:34 +0200

Hi Emacs (and Michael, forgive me if this isn't relevant for you)

I'm using Ubuntu on a thinkpad with fingerprint scanner, and have
enabled it to be used when sudo is invoked, setting it in pam.d. Fprintd
is the program (I believe) that checks the fingerprint.

To make the issue a little clearer, I'll show an example that works like
intended in Emacs, and the one that does not.

Both

This works:
1. M-x eshell
2. type "sudo ls" then RET
3. observe that eshell prompts:
  "Place your finger on the fingerprint reader"
4. If fingerprint is wrong or you wait for some period (10 seconds I
believe) it falls back to normal.

See example prompt:

```
$ sudo ls
Place your finger on the fingerprint reader
Cargo.lock  Cargo.toml	src  target
$ sudo ls
Place your finger on the fingerprint reader
Verification timed out
[sudo] password for theodor: 
Cargo.lock  Cargo.toml	src  target
```

This doesn't work as intended:
1. C-x C-f /sudo:Theodor:/ RET
2. Observe that Emacs appears to be hanging
  - the cursor is now spinning, and "C-x o" and friends doesn't work
3. Scan fingerprint
  - all is ok
4. Wait for timeout
  - enter password
  - all is ok

So to sum up - in the eshell case we get some indication to scan the
fingerprint, in the sudo/tramp case we don't. Everything works as it
should, in that verification passes, but the UI is confusing, and it
appears to hang for other commands. C-g works.

Is there some way for Emacs to prompt for the fingerprint to be scanned,
and not to freeze up?

Let me know if I need to provide more information :)

Thanks,
Theo

Message #8 received at 64807 <at> debbugs.gnu.org (full text, mbox):

From: Michael Albinus <michael.albinus <at> gmx.de>
To: Theodor Thornhill <theo <at> thornhill.no>
Cc: 64807 <at> debbugs.gnu.org
Subject: Re: bug#64807: 30.0.50; Editing files using sudo with fprintd hangs
Date: Sun, 23 Jul 2023 19:21:50 +0200

Theodor Thornhill <theo <at> thornhill.no> writes:

> Hi Emacs (and Michael, forgive me if this isn't relevant for you)

Hi Theodor,

> I'm using Ubuntu on a thinkpad with fingerprint scanner, and have
> enabled it to be used when sudo is invoked, setting it in pam.d. Fprintd
> is the program (I believe) that checks the fingerprint.
>
> Is there some way for Emacs to prompt for the fingerprint to be scanned,
> and not to freeze up?

Tramp has support for 2FA security. Please add the fingerprint prompt to
the user option tramp-security-key-confirm-regexp. If there is a second
message, telling you that the security key (your finger :-) has been
confirmed, add this message to the user option
tramp-security-key-confirmed-regexp.

> Let me know if I need to provide more information :)

If it doesn't work, send me Tramp traces (tramp-verbose 6 shall be sufficient).

> Thanks,
> Theo

Best regards, Michael.

Message #11 received at 64807 <at> debbugs.gnu.org (full text, mbox):

From: Michael Albinus <michael.albinus <at> gmx.de>
To: Theodor Thornhill <theo <at> thornhill.no>
Cc: 64807 <at> debbugs.gnu.org
Subject: Re: bug#64807: 30.0.50; Editing files using sudo with fprintd hangs
Date: Mon, 28 Aug 2023 13:00:18 +0200

Michael Albinus <michael.albinus <at> gmx.de> writes:

Hi Theodor,

>> I'm using Ubuntu on a thinkpad with fingerprint scanner, and have
>> enabled it to be used when sudo is invoked, setting it in pam.d. Fprintd
>> is the program (I believe) that checks the fingerprint.
>>
>> Is there some way for Emacs to prompt for the fingerprint to be scanned,
>> and not to freeze up?
>
> Tramp has support for 2FA security. Please add the fingerprint prompt to
> the user option tramp-security-key-confirm-regexp. If there is a second
> message, telling you that the security key (your finger :-) has been
> confirmed, add this message to the user option
> tramp-security-key-confirmed-regexp.

I don't know whether this has worked for you. Could you pls tell?

And in case it works: Which message have you added to
tramp-security-key-confirm-regexp? Something I could add to Tramp proper?

>> Thanks,
>> Theo

Best regards, Michael.

Message #16 received at 64807-done <at> debbugs.gnu.org (full text, mbox):

From: Michael Albinus <michael.albinus <at> gmx.de>
To: Theodor Thornhill <theo <at> thornhill.no>
Cc: 64807-done <at> debbugs.gnu.org
Subject: Re: bug#64807: 30.0.50; Editing files using sudo with fprintd hangs
Date: Sun, 17 Sep 2023 09:11:34 +0200

Michael Albinus <michael.albinus <at> gmx.de> writes:

Hi Theodor,

>>> I'm using Ubuntu on a thinkpad with fingerprint scanner, and have
>>> enabled it to be used when sudo is invoked, setting it in pam.d. Fprintd
>>> is the program (I believe) that checks the fingerprint.
>>>
>>> Is there some way for Emacs to prompt for the fingerprint to be scanned,
>>> and not to freeze up?
>>
>> Tramp has support for 2FA security. Please add the fingerprint prompt to
>> the user option tramp-security-key-confirm-regexp. If there is a second
>> message, telling you that the security key (your finger :-) has been
>> confirmed, add this message to the user option
>> tramp-security-key-confirmed-regexp.
>
> I don't know whether this has worked for you. Could you pls tell?
>
> And in case it works: Which message have you added to
> tramp-security-key-confirm-regexp? Something I could add to Tramp proper?

No further comment, so I'm assuming it works. Closing the bug.

Best regards, Michael.

Message #19 received at 64807 <at> debbugs.gnu.org (full text, mbox):

From: Theodor Thornhill <theo <at> thornhill.no>
To: 64807 <at> debbugs.gnu.org
Subject: Re: bug#64807: closed (Re: bug#64807: 30.0.50; Editing files using
 sudo with fprintd hangs)
Date: Sun, 17 Sep 2023 10:19:43 +0200

[Message part 1 (text/html, inline)]

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.