pbkdf
kdfinfo->pbkdf.generic.len = sizeof(kdfinfo->pbkdf);
kdfinfo->pbkdf.generic.type = SR_CRYPTOKDFT_BCRYPT_PBKDF;
kdfinfo->pbkdf.rounds = rflag;
arc4random_buf(kdfinfo->pbkdf.salt, sizeof(kdfinfo->pbkdf.salt));
derive_key(kdfinfo->pbkdf.generic.type, kdfinfo->pbkdf.rounds,
kdfinfo->pbkdf.salt, sizeof(kdfinfo->pbkdf.salt),
struct sr_crypto_pbkdf pbkdf;
#define pbkdf _kdfhint.pbkdf