the password
a random number generator
how much work to do to slow down guessing attacks
specifies which PRF to use with PBKDF2 0 is HMAC(SHA-1) 1 is HMAC(SHA-256) 2 is CMAC(Blowfish) 3 is HMAC(SHA-384) 4 is HMAC(SHA-512) all other values are currently undefined
Create a password hash using PBKDF2