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Groups > linux.debian.user > #194962
| From | David Wright <deblis@lionunicorn.co.uk> |
|---|---|
| Newsgroups | linux.debian.user |
| Subject | Re: encryption |
| Date | 2018-04-22 04:00 +0200 |
| Message-ID | <vHcsh-5Je-5@gated-at.bofh.it> (permalink) |
| References | <vGK2Z-3Dx-1@gated-at.bofh.it> <vH3Il-8kQ-5@gated-at.bofh.it> <vH6ZA-2bM-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Sat 21 Apr 2018 at 13:04:20 (-0700), David Christensen wrote: > On 04/20/18 12:38, Brian wrote: > >DECRYPT=$(scrypt dec /usr/local/bin/myscript) && eval "$DECRYPT" > > On 04/21/18 09:36, David Wright wrote: > >If so, then won't the password be revealed by ps while eval is > >evaluating it? > > Apparently, not: > > 2018-04-21 13:02:16 dpchrist@vstretch ~/sandbox/sh > $ cat environment-var-ps > CMD="echo hello" && eval "$CMD" && sleep 3 && echo world! & > ps -f > > 2018-04-21 13:02:18 dpchrist@vstretch ~/sandbox/sh > $ dash environment-var-ps > hello > UID PID PPID C STIME TTY TIME CMD > dpchrist 1681 1268 0 11:42 pts/1 00:00:00 -bash > dpchrist 2541 1681 0 13:02 pts/1 00:00:00 dash environment-var-ps > dpchrist 2542 2541 0 13:02 pts/1 00:00:00 dash environment-var-ps > dpchrist 2543 2541 0 13:02 pts/1 00:00:00 ps -f > dpchrist 2544 2542 0 13:02 pts/1 00:00:00 sleep 3 > > 2018-04-21 13:02:21 dpchrist@vstretch ~/sandbox/sh > $ world! > > > 2018-04-21 13:03:03 dpchrist@vstretch ~/sandbox/sh > $ bash environment-var-ps > hello > UID PID PPID C STIME TTY TIME CMD > dpchrist 1681 1268 0 11:42 pts/1 00:00:00 -bash > dpchrist 2556 1681 0 13:03 pts/1 00:00:00 bash environment-var-ps > dpchrist 2557 2556 0 13:03 pts/1 00:00:00 bash environment-var-ps > dpchrist 2558 2556 0 13:03 pts/1 00:00:00 ps -f > dpchrist 2559 2557 0 13:03 pts/1 00:00:00 sleep 3 > > 2018-04-21 13:03:05 dpchrist@vstretch ~/sandbox/sh > $ world! That just demonstrates a race between "echo hello" and ps. Echo won, so all ps saw was the sleep command. What you need in $CMD is a command that's slow to execute and loses the race: wren!david 20:52:56 /tmp $ cat testing.sh CMD="echo hello && dd bs=1M if=/dev/urandom of=/dev/null count=100" && eval "$CMD" && echo world! & ps -f wren!david 20:53:01 /tmp $ bash testing.sh hello UID PID PPID C STIME TTY TIME CMD david 1591 1587 0 08:54 pts/4 00:00:00 bash david 11553 1591 0 20:53 pts/4 00:00:00 bash testing.sh david 11554 11553 0 20:53 pts/4 00:00:00 bash testing.sh david 11555 11553 0 20:53 pts/4 00:00:00 ps -f david 11556 11554 0 20:53 pts/4 00:00:00 dd bs=1M if=/dev/urandom of=/dev/null count=100 wren!david 20:53:04 /tmp $ 100+0 records in 100+0 records out 104857600 bytes (105 MB, 100 MiB) copied, 0.582277 s, 180 MB/s world! wren!david 20:53:07 /tmp $ dash testing.sh hello UID PID PPID C STIME TTY TIME CMD david 1591 1587 0 08:54 pts/4 00:00:00 bash david 11562 1591 0 20:53 pts/4 00:00:00 dash testing.sh david 11563 11562 0 20:53 pts/4 00:00:00 dash testing.sh david 11564 11562 0 20:53 pts/4 00:00:00 ps -f david 11565 11563 0 20:53 pts/4 00:00:00 dd bs=1M if=/dev/urandom of=/dev/null count=100 wren!david 20:53:11 /tmp $ 100+0 records in 100+0 records out 104857600 bytes (105 MB, 100 MiB) copied, 0.564181 s, 186 MB/s world! wren!david 20:53:12 /tmp $ Cheers, David.
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encryption Brian <ad44@cityscape.co.uk> - 2018-04-20 21:40 +0200
Re: encryption Greg Wooledge <wooledg@eeg.ccf.org> - 2018-04-20 22:00 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 02:10 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-21 17:30 +0200
Re: encryption john doe <johndoe65534@mail.com> - 2018-04-21 17:40 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 22:00 +0200
Re: encryption john doe <johndoe65534@mail.com> - 2018-04-22 08:30 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-22 20:30 +0200
Re: encryption Glenn English <ghe2001@gmail.com> - 2018-04-21 19:00 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 22:30 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 21:50 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-22 18:20 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-22 18:50 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-23 10:50 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-23 13:20 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-24 20:50 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-21 18:40 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-21 20:20 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-21 21:00 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-21 21:20 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 23:30 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-22 04:30 +0200
Re: encryption Curt <curty@free.fr> - 2018-04-22 11:20 +0200
Re: encryption Reco <recoverym4n@gmail.com> - 2018-04-22 11:50 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-22 19:10 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 22:50 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-21 22:10 +0200
Re: encryption David Wright <deblis@lionunicorn.co.uk> - 2018-04-22 04:00 +0200
Re: encryption Brian <ad44@cityscape.co.uk> - 2018-04-22 17:40 +0200
Re: encryption Richard Hector <richard@walnut.gen.nz> - 2018-04-23 08:00 +0200
Re: encryption Andrew McGlashan <andrew.mcglashan@affinityvision.com.au> - 2018-04-23 09:00 +0200
Re: encryption David Christensen <dpchrist@holgerdanske.com> - 2018-04-22 20:10 +0200
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