keyblock_crypt
ret = keyblock_crypt(enc, enc_keyblock, ivec, data, num_data);
ret = keyblock_crypt(enc, enc_keyblock, ivec, data, num_data);
ret = keyblock_crypt(enc, enc_keyblock, NULL, data, num_data);
ret = keyblock_crypt(enc, enc_keyblock, 0, data, num_data);