PKCS5.pbkdf2_hmac(pass, salt, iter, keylen, digest) => string
Class Public methods
Parameters
pass - string
salt - string - should be at least 8 bytes long.
iter - integer - should be greater than 1000. 20000 is
better.
keylen - integer
digest - a string or OpenSSL::Digest
object.
Available in OpenSSL 0.9.4.
Digests other than SHA1 may not be supported by other cryptography
libraries.