sha512-crypt mysql and dovecot

Question

I have a question about understanding sha512-crypt hashing. I found this tutorial to set up dovecot and postfix with mysql. I followed the tutorial (with slight modifications) a

Answer 1

The salt is saved as part of the password. For example calling:

ENCRYPT('firstpassword', CONCAT('$6$', 'FooBarBaz')) 

Gives

$6$FooBarBaz$.T.G.7FRJqZ6N2FF7b3BEkr5j37CWhwgvPOOoccrr0bvkBbNMmLCxzqQqKJbNhnhC.583dTBLEuZcDuQe7NEe.

This stores both the algorithm used (6 being SHA512) and the salt ('FooBarBaz') both delinated by $.

Edit: To check a password you can use:

password = ENCRYPT('user_input', `password`)

ENCRYPT will grab the salt from the stored password and use this when checking user_input.

Full credit to hek2mgl for the password check he detailed in this answer.