- There is a new password hash algorithm (SHA-256)
- There is obfuscation for passwords with the .mylogin.cnf file.
- The option to store slave passwords in a database table.
- It's now possible to supply a password to START SLAVE.
This blog post is a great new feature: Hiding passwords from your log files, automatically.
MySQL 5.6 will by default hide passwords from the general log. This is not just obfuscation as only the one-way hash will be put in the log files. By setting log-raw=OFF you can disable password hiding for the general log. The log-raw setting will only influence the general log, so the passwords in the slow query log and the binary logs will still be hidden.
With MySQL 5.5 this could be done manually by first storing the hash in a variable, but like many other work-arounds this is not needed anymore.
But it doesn't stop there. According to the manual the mysql client now won't log statements which match "*IDENTIFIED*:*PASSWORD*".
But don't forget that MySQL Server logfiles and MySQL Client logfiles should still be protected with the correct file permissions and the same is true for all other files like master.info. And if you store slave credentials inside the database these should be protected by using the MySQL privileges system, but that's even true if master.info is used as someone with too many database privileges might just load the contents with LOAD DATA INFILE.
Of course there there is still room for improvement:
It would be nice if we could easily enable connection security. MySQL and many other applications use TLS, but that has some performance overhead and isn't really easy to setup. And MySQL is still not secure-by-default, but easy-by-default...
So MySQL 5.6 improves security without needing any special configuration.