def lrw_b.twofish

bend-osdev-crypto@0.1.0.0 · PROOF.bend:1152

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/twofish.bend as Tf
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

1152def lrw_b.twofish(+k: Tf.LcTwofishKey, t: Maybe<&2, M.CmBlock>, +p: M.CmBlock) -> {p == Lw.cr.lrw.bdec(~Tf.LcTwofishKey, ~M.CmBlock, ~Tf.LcTwofish.decrypt, ~CM.CrBlk128.xor, k, t, Lw.cr.lrw.benc(~Tf.LcTwofishKey, ~M.CmBlock, ~Tf.LcTwofish.encrypt, ~CM.CrBlk128.xor, k, t, p)) : M.CmBlock}:
1153  match t:
1154    case None{}:
1155      Equal.sym(M.CmBlock, Tf.LcTwofish.decrypt(k, Tf.LcTwofish.encrypt(k, p)), p, LL.twofish_round_trip(k, p))
1156    case Some{+x}:
1157      %cmblock_xx(Tf.LcTwofish.encrypt(k, CM.CrBlk128.xor(p, x)), x) : {p == CM.CrBlk128.xor(Tf.LcTwofish.decrypt(k, _), x) : M.CmBlock}
1158      %Equal.sym(M.CmBlock, Tf.LcTwofish.decrypt(k, Tf.LcTwofish.encrypt(k, CM.CrBlk128.xor(p, x))), CM.CrBlk128.xor(p, x), LL.twofish_round_trip(k, CM.CrBlk128.xor(p, x))) : {p == CM.CrBlk128.xor(_, x) : M.CmBlock}
1159      cmblock_xx(p, x)