# Method __builtin.Nettle.Hash()->openssl_pbkdf()

Method openssl_pbkdf

  ``string(8bit)` openssl_pbkdf(`string(8bit)` `password`, `string(8bit)` `salt`, `int` `rounds`, `int` `bytes`)`

Description

  Password Based Key Derivation Function from OpenSSL.

  This when used with Crypto.MD5 and a single round is the function used to derive the key to encrypt Standards.PEM body data.

FIXME

  Derived from OpenSSL. Is there any proper specification?

  It seems to be related to PBKDF1 from RFC2898.

See also

  pbkdf1(), pbkdf2(), `crypt_password()`