mi è toccato risolverlo.. ed ecco la guida:
Sometimes, you need to put a non-interactive passwords using scripts,
as you can see, you can’t use passwd tool, because it only works using
interactive way.

chpasswd reads a list of user name
and password pairs from standard input and uses this information to
update a group of existing users. Each line is of the format:


By default the supplied password must be in clear-text. Default
encryption algorithm is DES. Also the password age will be updated, if

This command is intended to be used in a large system environment where many accounts are created at a single time.

Available Options

The options which apply to the chpasswd command are:

-e, --encrypted – Supplied passwords are in encrypted form.

-h, --help – Display help message and exit.

-m, --md5 – Use MD5 encryption instead of DES when the supplied passwords are not encrypted

Check passwords using the following command

echo “user:pass” | chpasswd