Set the master password from terminal

Solution 1:

First, a few things to note:

On the Mac the files /etc/passwd and /etc/master.passwd are only consulted when the Mac is booted into single user mode.

I'm not sure what you mean by "set the master password" for the Mac. Do you mean set the password for the account 'root'?

Usually you use the passwd command to change passwords from the command line (there is no master.passwd command) but you can't use it from a script as it requires input.

To change a password in a script you need to use the dscl command.

Here is an example :

dscl . -passwd /Users/tonyw newpass

Note that the above would have to be run as root, which means your script would have to be run by root. Otherwise you have to add authentication to the dscl command thus:

dscl . -u Admin -P adminpassword -passwd /Users/tonyw newpass

The user Admin must have administrator privileges for the Mac.

(All of this is incredibly insecure as you have passwords in plain text in a script.)

Of course to set the password for 'root' just change the tonyw to root in the above.

Have a good look at dscl(1) to understand the options in the above.

Solution 2:

OK, for FileVault you need to use the fdesetup command. Set up a test Mac, have a long hard look at the man page and give it all a try. From the man page it looks like you can change the FileVault recovery password using the changerecovery option.

Sorry, but I'm not prepared to do the testing to give you the exact commands as getting it wrong could seriously screw my Mac. There are a bunch of examples in the man page.

BTW - I found it by going apropos FileVault at the command line. Always a good first step.