def lrw_b.sm4

bend-osdev-crypto@0.1.0.0 · PROOF.bend:924

import Base
import bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend as M
import bend-osdev-legacy-ciphers@0.1.0.0/sm4.bend as S
import bend-osdev-legacy-ciphers@0.1.0.0/LAWS.bend as LL
import bend-osdev-crypto@0.1.0.0/lrw.bend as Lw
import bend-osdev-crypto@0.1.0.0/inst_cm.bend as CM

924def lrw_b.sm4(+k: S.LcSm4Key, t: Maybe<&2, M.CmBlock>, +p: M.CmBlock) -> {p == Lw.cr.lrw.bdec(~S.LcSm4Key, ~M.CmBlock, ~S.LcSm4.decrypt, ~CM.CrBlk128.xor, k, t, Lw.cr.lrw.benc(~S.LcSm4Key, ~M.CmBlock, ~S.LcSm4.encrypt, ~CM.CrBlk128.xor, k, t, p)) : M.CmBlock}:
925  match t:
926    case None{}:
927      Equal.sym(M.CmBlock, S.LcSm4.decrypt(k, S.LcSm4.encrypt(k, p)), p, LL.sm4_round_trip(k, p))
928    case Some{+x}:
929      %cmblock_xx(S.LcSm4.encrypt(k, CM.CrBlk128.xor(p, x)), x) : {p == CM.CrBlk128.xor(S.LcSm4.decrypt(k, _), x) : M.CmBlock}
930      %Equal.sym(M.CmBlock, S.LcSm4.decrypt(k, S.LcSm4.encrypt(k, CM.CrBlk128.xor(p, x))), CM.CrBlk128.xor(p, x), LL.sm4_round_trip(k, CM.CrBlk128.xor(p, x))) : {p == CM.CrBlk128.xor(_, x) : M.CmBlock}
931      cmblock_xx(p, x)