pfSense

Jim Pingle wrote:

Though we could offer a higher number of rounds with SHA512, the number of rounds must be identical when hashing and checking the hash so it is not compatible with hashes made with the default number of rounds.

For what it's worth, both bcrypt and sha512crypt are designed to expect their variable work factors to be programmatically available to, and detected and used by, the authentication layer - for work factors to not be hard-coded on the authentication side (other than as default values at hash creation time only).

In other words, a given set of hashes should be able to contain an arbitrary mix of rounds, which are then automatically used as part of hash validation on a hash-by-hash basis. This allows for transparent forward and backward compatibility over time.

For example, if future hardware speeds make it attractive to change the bcrypt default from 10 to 12, then when all new hashes can be created with cost 12, all legacy cost 10 bcrypt hashes should also continue to Just Work.

Edit: interested readers may not be aware that sha512crypt has a "silent" default of 5000 rounds, and only when that value is overridden does the number of rounds explicitly appear in the hash:

$ mkpasswd -m SHA-512 -S $(tr -dc '[:alnum:]./' < /dev/urandom | fold -w ${1:-16} | head -n 1)
Password: 
$6$5XxpqcgR.YyEC9mk$9oeQAUShRn7ZhnmlOGihguD0QI5Mi2wvm5bs1RpfFteMCPoDSQ/vEBsES0hfoV9anwn3SAVEsT97Ha84L7g2v/

$ mkpasswd -m SHA-512 -S $(tr -dc '[:alnum:]./' < /dev/urandom | fold -w ${1:-16} | head -n 1) -R 5000
Password: 
$6$rounds=5000$6R37T0WdXN3MC3Hd$T9Ze7R6ZZHuw9WGNTM838.LmJOUpZ1kTCifMk0AGNqnDzQSEEqRWWt/8vr5mWgS2ZP7HyvRZ/D6JLFr1Ck6l4/

$ mkpasswd -m SHA-512 -S $(tr -dc '[:alnum:]./' < /dev/urandom | fold -w ${1:-16} | head -n 1) -R 800000
Password: 
$6$rounds=800000$GAuO13spo1MJYChS$jtB8CbJu2vKIwIljcDP/YLKKII5r6jhX/9kJrZbmPrsFDG0.D8IETRUIvaf9KEp7H91yj/vOG3tBKLtw2QO/z.

This has been merged and will be in snapshots soon.

For those who would like to try it out, even on 22.01/2.6.0, install the System Patches package and then create entries for 961f240c18f8421b0a28ee192ffa041e754e8f8e and then 8ddf2b5a999772754080825f07acf9b6326f1f04 to apply the fix.

Apply 961f240c18f8421b0a28ee192ffa041e754e8f8e first followed by 8ddf2b5a999772754080825f07acf9b6326f1f04