Dovecot and MariaDB/MySQL

[Michael A. Peters]

Howdy -

For most of my dovecot servers, they are small and I just use unix accounts.

However I am going to be running a new server for more general users, 
webmail (probably roundcube but I'm hacking roundcube quite a bit, 
enough that I'm calling it squarepeg instead so users familiar with 
roundcube will know it is quite different) and it will use MariaDB for 
account management.

I already have it working, following the instructions at 
https://www.linode.com/docs/email/postfix/email-with-postfix-dovecot-and-mysql-on-centos-5/ 
- those instructions also work in CentOS 7 with the latest Dovecot - but 
there is something that really bothers me.

It makes no provision for salting the password before the crypt function.

What I would like to do is when creating a new account, use /dev/urandom 
to generate a random salt for the account that is stuck in the database 
along with the account and used when validating the password.

That way in the event of a SQL injection attack that dumps the database 
- yes it is still bad, but 20 accounts that have the same password will 
have radically different hashes and thus won't be a clue that they are 
the same, the blackhat that gets the database dump would have to 
generate a rainbow table for each unique salt.

I've looked at at least a dozen different Dovecot / MariaDB howto guides 
and none of the ones I have looked at supported any kind of individual 
salting of the user passwords.

Can someone point me to a guide that does?

I don't mind keeping the salt in the database, I just want to be able to 
have a different salt for each account.

Thank you