FX_CHACHA20_KEYSIZE
ASSERT_DEBUG(keysz == FX_CHACHA20_KEYSIZE, "keysz: %zu", keysz);
uint8_t newkey[FX_CHACHA20_KEYSIZE];
uint8_t newkey[FX_CHACHA20_KEYSIZE];
uint8_t newkey[FX_CHACHA20_KEYSIZE];
uint8_t root_state[FX_CHACHA20_KEYSIZE];
_Static_assert(FX_CHACHA20_KEYSIZE <= FXRNG_HASH_SZ, "");
chacha_keysetup(&rng->rng_prf, u.hash_out, FX_CHACHA20_KEYSIZE * 8);
_Static_assert(FX_CHACHA20_KEYSIZE == RANDOM_KEYSIZE, "");
ASSERT_DEBUG(len == FX_CHACHA20_KEYSIZE, "chacha20 uses 256 bit keys");