enum PseudoRandomFunction

Available pseudo random functions.

`1`	`PRF_HMAC_MD5` PRF_HMAC_MD5 --> RFC_2104.
`2`	`PRF_HMAC_SHA1` PRF_HMAC_SHA1 --> RFC2104.
`4`	`PRF_AES128_XCBC` PRF_AES128_XCBC --> RFC_4434.
`8`	`PRF_AES128_CMAC` PRF_AES128_CMAC --> RFC_4615.

enum PseudoRandomFunction