def cam_fl_inv

bend-osdev-camellia@0.1.0.0 · PROOF.bend:22

import Base
import bend-osdev-cipher-core@0.1.0.0/cipher_core.bend as L
import bend-osdev-cipher-core@0.1.0.0/LAWS.bend as CoreL
import bend-osdev-camellia@0.1.0.0/camellia.bend as C

22def cam_fl_inv(x: L.LcBlock64, k: L.LcBlock64) -> {x == C.cam.flinv(C.cam.fl(x, k), k) : L.LcBlock64}:
23  match x k:
24    case L.LcBlock64{+x1, +x2} L.LcBlock64{+k1, +k2}:
25      %CoreL.u32_xor_cancel(x1, U32.or(U32.xor(x2, L.lc.rotl(U32.and(x1, k1), 1n)), k2)) : {L.LcBlock64{x1, x2} == L.LcBlock64{_, U32.xor(U32.xor(x2, L.lc.rotl(U32.and(x1, k1), 1n)), L.lc.rotl(U32.and(_, k1), 1n))} : L.LcBlock64}
26      %CoreL.u32_xor_cancel(x2, L.lc.rotl(U32.and(x1, k1), 1n)) : {L.LcBlock64{x1, x2} == L.LcBlock64{x1, _} : L.LcBlock64}
27      {==}