def open_len

bend-collections@1.0.0.0 · src/crypto/aead/chacha20poly1305.bend:58

import Base
import bend-collections@1.0.0.0/src/crypto/chacha/chacha20.bend as CH

58def open_len(short: Bool, +key: List<&2, U32>, +nonce: List<&2, U32>, +aad: List<&2, U32>, +data: List<&2, U32>) -> Maybe<&2, List<&2, U32>>:
59  match short:
60    case True{}: None{}
61    case False{}:
62      +n = Nat.sub(List.length(&2, U32, data), 16n)
63      open_split(key, nonce, aad, CH.take(n, data), CH.skip(n, data))