def xor_front

bend-collections-laws-crypto@1.0.0.0 · src/crypto/chacha/chacha20.bend:66

import Base

66# XOR the keystream onto the front of xs, as far as both go.
67def xor_front(ks: List<&2, U32>, xs: List<&2, U32>) -> List<&2, U32>:
68  match ks xs:
69    case k <> kt x <> xt: U32.xor(x, k) <> xor_front(kt, xt)
70    case _ _: Nil{}