chpasswd: Check hash before write when using -e

[mmpx12]

Add is_valid_hash to prevent adding a bad hash in /etc/shadow (and so prevent user to be lock) when using chpasswd -e

# before
echo 'vinz:test123' | chpasswd -e
grep vinz /etc/shadow
vinz:test123:20280:0:99999:7:::

# now
echo 'vinz:test123' |sudo ./chpasswd -e
chpasswd: (line: 1) invalid password hash for user 'vinz'
chpasswd: error detected, changes ignored

[mmpx12]

@alejandro-colomar Everything should be resolved.

[alejandro-colomar]

Other than the minor style comments, I like this very much! Thanks!

Reviewed-by: Alejandro Colomar <alx@kernel.org>

[alejandro-colomar]

All's good. Please squash the commits into one, and I'll merge. Thanks!

[alejandro-colomar]

Please fix the commit message. It is currently:

 chpasswd: Check hash before write when using -e

chpasswd: Check hash before write when using -e (fixed)

chpasswd: Check hash before write when using -e (fixed 2)

chpasswd: Check hash before write when using -e (sorted hash from safest to weakest)

chpasswd: Check hash before write when using -e (typos and consitent regex order)

chpasswd: Check hash before write when using -e (use crypt(5) regex)

chpasswd: Check hash before write when using -e (fixed crypt(5) bad regex)

:)

[alejandro-colomar]

Add is_valid_hash to prevent adding a bad hash in /etc/shadow (and so prevent user to be lock) when using chpasswd -e

# before
echo 'vinz:test123' | chpasswd -e
grep vinz /etc/shadow
vinz:test123:20280:0:99999:7:::

# now
echo 'vinz:test123' |sudo ./chpasswd -e
chpasswd: (line: 1) invalid password hash for user 'vinz'
chpasswd: error detected, changes ignored

Please include this in the commit message, with the code examples indented with a tab.

[alejandro-colomar]

Add is_valid_hash to prevent adding a bad hash in /etc/shadow (and so prevent user to be lock) when using chpasswd -e

    # before
    echo 'vinz:test123' | chpasswd -e
    grep vinz /etc/shadow
    vinz:test123:20280:0:99999:7:::

    # now
    echo 'vinz:test123' | sudo ./chpasswd -e
    chpasswd: (line: 1) invalid password hash for user 'vinz'
    chpasswd: error detected, changes ignored

This (from the commit message) doesn't match the code from the patch. The parentheses around the line number are not there.

[alejandro-colomar]

LGTM. Thanks!

[mmpx12]

@alejandro-colomar i changed commit msg and error msg (used do_pam_passwd_non_interactive style) and changed "config.h" import