I need to synchronize a user account and password to an external source on a system with busybox and openssl installed. When the external source tells my system to update credentials, how do I change the user's password in a script? I will have the password in plain text.
This has to be automated, and from what I can tell busybox passwd is interactive and I don't particularly want to write an expect-type script for passwd if that's even possible. It looks like openssl can generate password hashes (openssl passwd -1 -salt "abcdefgh" {password}), but will I have to modify /etc/shadow directly?
Busybox has these commands available.