def bx.block

bend-osdev-cipher-modes@0.1.0.0 · PROOF.bend:60

import Base
import bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend as M

60# xor(a, xor(a, b)) == b on blocks
61def bx.block(+a: M.CmBlock, +b: M.CmBlock) -> {M.CmBlock.xor(a, M.CmBlock.xor(a, b)) == b : M.CmBlock}:
62  match a b:
63    case M.CmBlock{a0, a1, a2, a3} M.CmBlock{b0, b1, b2, b3}:
64      %bx.u32(a0, b0) : {M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock{b0, b1, b2, b3})) == M.CmBlock{_, b1, b2, b3} : M.CmBlock}
65      %bx.u32(a1, b1) : {M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock{b0, b1, b2, b3})) == M.CmBlock{U32.xor(a0, U32.xor(a0, b0)), _, b2, b3} : M.CmBlock}
66      %bx.u32(a2, b2) : {M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock{b0, b1, b2, b3})) == M.CmBlock{U32.xor(a0, U32.xor(a0, b0)), U32.xor(a1, U32.xor(a1, b1)), _, b3} : M.CmBlock}
67      %bx.u32(a3, b3) : {M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock.xor(M.CmBlock{a0, a1, a2, a3}, M.CmBlock{b0, b1, b2, b3})) == M.CmBlock{U32.xor(a0, U32.xor(a0, b0)), U32.xor(a1, U32.xor(a1, b1)), U32.xor(a2, U32.xor(a2, b2)), _} : M.CmBlock}
68      {==}