def sp.nib

bend-osdev-legacy-ciphers@0.1.0.0 · serpent.bend:115

import Base

115def sp.nib(b: LcSpBox, inv: Bool, n: LcSpNib) -> LcSpNib:
116  match n:
117    case LcSpNib{x0, x1, x2, x3}:
118      +v = U32.or(U32.or(Bool.to_u32(x0), U32.shl(Bool.to_u32(x1))), U32.or(U32.shln(Bool.to_u32(x2), 2n), U32.shln(Bool.to_u32(x3), 3n)))
119      +w = sp.sbox(b, inv, v)
120      LcSpNib{sp.bit(w, 0n), sp.bit(w, 1n), sp.bit(w, 2n), sp.bit(w, 3n)}