def hchacha20

bend-collections-laws-crypto@1.0.0.0 · src/crypto/chacha/chacha20.bend:155

import Base

155# HChaCha20(key, nonce): the 32-byte subkey, or None unless 32 and 16 bytes.
156def hchacha20(+key_bytes: List<&2, U32>, +nonce_bytes: List<&2, U32>) -> Maybe<&2, List<&2, U32>>:
157  when(valid(key_bytes, nonce_bytes, 16n), hchacha20_unchecked(key_bytes, nonce_bytes))