1  const chai = require("chai");
  2  const path = require("path");
  3  const wasm_tester = require("circom_tester").wasm;
  4  const Scalar = require("ffjavascript").Scalar;
  5  const buildBabyjub = require("circomlibjs").buildBabyjub;
  6  
  7  const assert = chai.assert;
  8  
  9  describe("Montgomery test", function () {
 10      let babyJub;
 11      let Fr;
 12      let circuitE2M;
 13      let circuitM2E;
 14      let circuitMAdd;
 15      let circuitMDouble;
 16  
 17      let g;
 18  
 19      let mg, mg2, g2, g3, mg3;
 20  
 21      this.timeout(100000);
 22  
 23  
 24      before( async() => {
 25          babyJub = await buildBabyjub();
 26          Fr = babyJub.F;
 27          g = [
 28              Fr.e("5299619240641551281634865583518297030282874472190772894086521144482721001553"),
 29              Fr.e("16950150798460657717958625567821834550301663161624707787222815936182638968203")
 30          ];
 31  
 32          circuitE2M = await wasm_tester(path.join(__dirname, "circuits", "edwards2montgomery.circom"));
 33          await circuitE2M.loadSymbols();
 34          circuitM2E = await wasm_tester(path.join(__dirname, "circuits", "montgomery2edwards.circom"));
 35          await circuitM2E.loadSymbols();
 36          circuitMAdd = await wasm_tester(path.join(__dirname, "circuits", "montgomeryadd.circom"));
 37          await circuitMAdd.loadSymbols();
 38          circuitMDouble = await wasm_tester(path.join(__dirname, "circuits", "montgomerydouble.circom"));
 39          await circuitMDouble.loadSymbols();
 40      });
 41  
 42      it("Convert Edwards to Montgomery and back again", async () => {
 43          let w, xout, yout;
 44  
 45          w = await circuitE2M.calculateWitness({ in: [Fr.toObject(g[0]), Fr.toObject(g[1])]}, true);
 46  
 47          xout = w[circuitE2M.symbols["main.out[0]"].varIdx];
 48          yout = w[circuitE2M.symbols["main.out[1]"].varIdx];
 49  
 50          mg = [xout, yout];
 51  
 52          w = await circuitM2E.calculateWitness({ in: [xout, yout]}, true);
 53  
 54          xout = w[circuitM2E.symbols["main.out[0]"].varIdx];
 55          yout = w[circuitM2E.symbols["main.out[1]"].varIdx];
 56  
 57          assert(Fr.eq(Fr.e(xout), g[0]));
 58          assert(Fr.eq(Fr.e(yout), g[1]));
 59      });
 60      it("Should double a point", async () => {
 61          let w, xout, yout;
 62  
 63          g2 = babyJub.addPoint(g,g);
 64  
 65          w = await circuitMDouble.calculateWitness({ in: mg}, true);
 66  
 67          xout = w[circuitE2M.symbols["main.out[0]"].varIdx];
 68          yout = w[circuitE2M.symbols["main.out[1]"].varIdx];
 69  
 70          mg2 = [xout, yout];
 71  
 72          w = await circuitM2E.calculateWitness({ in: mg2}, true);
 73  
 74          xout = w[circuitM2E.symbols["main.out[0]"].varIdx];
 75          yout = w[circuitM2E.symbols["main.out[1]"].varIdx];
 76  
 77  
 78          assert(Fr.eq(Fr.e(xout), g2[0]));
 79          assert(Fr.eq(Fr.e(yout), g2[1]));
 80      });
 81      it("Should add a point", async () => {
 82          let w, xout, yout;
 83  
 84          g3 = babyJub.addPoint(g,g2);
 85  
 86          w = await circuitMAdd.calculateWitness({ in1: mg, in2: mg2}, true);
 87  
 88          xout = w[circuitMAdd.symbols["main.out[0]"].varIdx];
 89          yout = w[circuitMAdd.symbols["main.out[1]"].varIdx];
 90  
 91          mg3 = [xout, yout];
 92  
 93          w = await circuitM2E.calculateWitness({ in: mg3}, true);
 94  
 95          xout = w[circuitM2E.symbols["main.out[0]"].varIdx];
 96          yout = w[circuitM2E.symbols["main.out[1]"].varIdx];
 97  
 98          assert(Fr.eq(Fr.e(xout), g3[0]));
 99          assert(Fr.eq(Fr.e(yout), g3[1]));
100      });
101  });