def lrw_b.cast6

bend-osdev-crypto@0.1.0.0 · PROOF.bend:1304

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/cast6.bend as C6
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

1304def lrw_b.cast6(+k: C6.LcCast6Key, t: Maybe<&2, M.CmBlock>, +p: M.CmBlock) -> {p == Lw.cr.lrw.bdec(~C6.LcCast6Key, ~M.CmBlock, ~C6.LcCast6.decrypt, ~CM.CrBlk128.xor, k, t, Lw.cr.lrw.benc(~C6.LcCast6Key, ~M.CmBlock, ~C6.LcCast6.encrypt, ~CM.CrBlk128.xor, k, t, p)) : M.CmBlock}:
1305  match t:
1306    case None{}:
1307      Equal.sym(M.CmBlock, C6.LcCast6.decrypt(k, C6.LcCast6.encrypt(k, p)), p, LL.cast6_round_trip(k, p))
1308    case Some{+x}:
1309      %cmblock_xx(C6.LcCast6.encrypt(k, CM.CrBlk128.xor(p, x)), x) : {p == CM.CrBlk128.xor(C6.LcCast6.decrypt(k, _), x) : M.CmBlock}
1310      %Equal.sym(M.CmBlock, C6.LcCast6.decrypt(k, C6.LcCast6.encrypt(k, CM.CrBlk128.xor(p, x))), CM.CrBlk128.xor(p, x), LL.cast6_round_trip(k, CM.CrBlk128.xor(p, x))) : {p == CM.CrBlk128.xor(_, x) : M.CmBlock}
1311      cmblock_xx(p, x)