Unix & Linux: Change Password of a user in /etc/shadow (3 Solutions!!)

Описание

Unix & Linux: Change Password of a user in /etc/shadow


The Question: I would like to change the password of a user in the /etc/shadow. I can't use
password changing programs like passwd. It must be done by editing the /etc/
shadow. The /etc/shadow is on a mounted hard drive and chroot is not working.
For example:
root:$asdf.1AH.MJ3sivd4$YFoFnasdf4cZW9H6G6cbT4.1VBmasdfmv.a0wCU/
i3zEFasdfasdf4W.:15843:0:99999:7:::
otheruser:$asdf.1AH.MJ3sivd4$YFoFnasdf4cZW9H6G6cbT4.1VBmasdfmv.a0wCU/
i3zEFasdfasdf4W.:15843:0:99999:7:::
Can anybody provide me a shell script to change the password of root with sed
or awk or something like that?

Solutions: Please watch the whole video to see all solutions, in order of how many people found them helpful

== This solution helped 12 people ==
You can use the mkpasswd tool to do this. There's a good primer on how to use
it over on cyberciti.biz, titled: http://www.cyberciti.biz/faq/generating-
random-password/.
**** Example ****
mkpasswd --char=10 --crypt-md5
The package is usually called makepasswd, but the tool is typically called
mkpasswd.
See the http://linux.die.net/man/1/mkpasswd for more details.
**** Generating contents of /etc/shadow directly ****
The following python command will generate the portion that goes into the /etc/
shadow file:
Python
$ python -c "import crypt, getpass, pwd; print crypt.crypt('password',
'$6$SALTsalt$')"
Perl
$ perl -e 'print crypt("password","$6$saltsalt$") . "n"'
Which generates the following output:
$6$SALTsalt$UiZikbV3VeeBPsg8./
Q5DAfq9aj7CVZMDU6ffBiBLgUEpxv7LMXKbcZ9JSZnYDrZQftdG319XkbLVMvWcF/Vr/
**** Changing the /etc/shadow ****
Here's a command that will change the existing entry with the newly generated
password field from the command above.
perl -pe 's|(root):($.*?:)|1:$6$SALTsalt$UiZikbV3VeeBPsg8./
Q5DAfq9aj7CVZMDU6ffBiBLgUEpxv7LMXKbcZ9JSZnYDrZQftdG319XkbLVMvWcF/Vr/:|' /etc/
shadow ＞ /etc/shadow.new
NOTE: This is a rough example but works. You'll need to take the results from
the command that generated the hashed password, and escape the dollar signs ($)
with slashes ($).
The results are stored in a new file /etc/shadow.new. Once you've confirmed the
results you can replace /etc/shadow with the new file, /etc/shadow.new.

Remove the password all together for the user in /etc/shadow, boot the system,
login with no password, then use the passwd command. If possible, do not bring
the system on the network until this is completed.

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