def block_xx

bend-osdev-camellia@0.1.0.0 · PROOF.bend:10

import Base
import bend-osdev-mode-core@0.1.0.0/mode_core.bend as M
import bend-osdev-cipher-core@0.1.0.0/LAWS.bend as CoreL

10def block_xx(s: M.CmBlock, k: M.CmBlock) -> {s == M.CmBlock.xor(M.CmBlock.xor(s, k), k) : M.CmBlock}:
11  match s k:
12    case M.CmBlock{+a0, +a1, +a2, +a3} M.CmBlock{+b0, +b1, +b2, +b3}:
13      %CoreL.u32_xor_cancel(a0, b0) : {M.CmBlock{a0, a1, a2, a3} == M.CmBlock{_, U32.xor(U32.xor(a1, b1), b1), U32.xor(U32.xor(a2, b2), b2), U32.xor(U32.xor(a3, b3), b3)} : M.CmBlock}
14      %CoreL.u32_xor_cancel(a1, b1) : {M.CmBlock{a0, a1, a2, a3} == M.CmBlock{a0, _, U32.xor(U32.xor(a2, b2), b2), U32.xor(U32.xor(a3, b3), b3)} : M.CmBlock}
15      %CoreL.u32_xor_cancel(a2, b2) : {M.CmBlock{a0, a1, a2, a3} == M.CmBlock{a0, a1, _, U32.xor(U32.xor(a3, b3), b3)} : M.CmBlock}
16      %CoreL.u32_xor_cancel(a3, b3) : {M.CmBlock{a0, a1, a2, a3} == M.CmBlock{a0, a1, a2, _} : M.CmBlock}
17      {==}