MAYBE this could work: If the algorithm that MySQL uses to encrypt the passwords is the same being used in the passwords file, then you only need to copy the password fields from the passwords file into the MySQL database. Unfortunately I'm a noob, so can't tell you if that's the case or not.
If the algorithms are different, I see only two ways to obtain the passwords:
- Again, The linux password file. There they are decrypted, so you will need to decrypt the passwords which I think (and hope) is VERY difficult to do.
- The instant when the users change their password. Maybe you could modify the script that asks users to modify the password to do the update in MySQL.