def by_okb

bend-collections-laws-crypto@1.0.0.0 · proofs/crypto/curve25519/canon.bend:32

import Base
import bend-collections-laws-crypto@1.0.0.0/src/crypto/curve25519/field.bend as F
import bend-collections-laws-crypto@1.0.0.0/proofs/lib/word.bend as WD
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/limbs.bend as LM
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/fold.bend as FD
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/consts.bend as K
import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/freeze.bend as FZ

32def by_okb(+one: Nat, +h1: {one == 1n : Nat}, +pp: Nat, +hP: {Nat.add(1n+pp, 19n) == WD.sc(255n, one) : Nat}, +x: List<&2, U32>, +cp: List<&2, U32>, +hx: {LM.okb(32n, x, 255n) == True{} : Bool}, +hk: {LM.okb(32n, cp, 128n) == True{} : Bool}, +hv: {K.valo(one, cp) == Nat.add(1n+pp, 38n) : Nat}, +b: Bool, +hb: {Nat.is_lt(v(LM.cc(F.carry(F.addl(x, cp), 0))), one) == b : Bool}) -> {LM.okb(32n, FZ.csg(x, cp), 255n) == True{} : Bool}:
33  match b:
34    case True{}:
35      %Equal.sym(List<&2, U32>, FZ.csg(x, cp), x, FZ.cs_zero(one, h1, x, cp, hx, hk, hb)) : {LM.okb(32n, _, 255n) == True{} : Bool}
36      hx
37    case False{}:
38      %Equal.sym(List<&2, U32>, FZ.csg(x, cp), LM.cl(F.carry(F.addl(x, cp), 0)), FZ.cs_one(one, h1, pp, hP, x, cp, hx, hk, hv, hb)) : {LM.okb(32n, _, 255n) == True{} : Bool}
39      FD.cr_okb(one, h1, F.addl(x, cp), FZ.ad_okb(one, h1, x, cp, hx, hk))