circomlib/test/babyjub.js

const chai = require("chai");
const path = require("path");

const blake2b = require("blake2b");
const eddsa = require("../src/eddsa.js");
const F = require("../src/babyjub.js").F;

const assert = chai.assert;

const tester = require("circom").tester;
const utils = require("ffjavascript").utils;
const Scalar = require("ffjavascript").Scalar;

describe("Baby Jub test", function () {
    let circuitAdd;
    let circuitTest;
    let circuitPbk;

    this.timeout(100000);

    before( async() => {
        circuitAdd = await tester(path.join(__dirname, "circuits", "babyadd_tester.circom"));

        circuitTest = await tester(path.join(__dirname, "circuits", "babycheck_test.circom"));

        circuitPbk = await tester(path.join(__dirname, "circuits", "babypbk_test.circom"));
    });

    it("Should add point (0,1) and (0,1)", async () => {

        const input={
            x1: F.e(0),
            y1: F.e(1),
            x2: F.e(0),
            y2: F.e(1)
        };

        const w = await circuitAdd.calculateWitness(input, true);

        await circuitAdd.assertOut(w, {xout: F.e(0), yout: F.e(1)});
    });

    it("Should add 2 same numbers", async () => {

        const input={
            x1: F.e("17777552123799933955779906779655732241715742912184938656739573121738514868268"),
            y1: F.e("2626589144620713026669568689430873010625803728049924121243784502389097019475"),
            x2: F.e("17777552123799933955779906779655732241715742912184938656739573121738514868268"),
            y2: F.e("2626589144620713026669568689430873010625803728049924121243784502389097019475")
        };

        const w = await circuitAdd.calculateWitness(input, true);

        await circuitAdd.assertOut(w, {
            xout: F.e("6890855772600357754907169075114257697580319025794532037257385534741338397365"),
            yout: F.e("4338620300185947561074059802482547481416142213883829469920100239455078257889")
        });

    });

    it("Should add 2 different numbers", async () => {

        const input={
            x1: F.e("17777552123799933955779906779655732241715742912184938656739573121738514868268"),
            y1: F.e("2626589144620713026669568689430873010625803728049924121243784502389097019475"),
            x2: F.e("16540640123574156134436876038791482806971768689494387082833631921987005038935"),
            y2: F.e("20819045374670962167435360035096875258406992893633759881276124905556507972311")
        };

        const w = await circuitAdd.calculateWitness(input, true);

        await circuitAdd.assertOut(w, {
            xout: F.e("7916061937171219682591368294088513039687205273691143098332585753343424131937"),
            yout: F.e("14035240266687799601661095864649209771790948434046947201833777492504781204499")
        });

    });

    it("Should check (0,1) is a valid point", async() => {
        const w = await circuitTest.calculateWitness({x: 0, y:1}, true);

        await circuitTest.checkConstraints(w);
    });

    it("Should check (1,0) is an invalid point", async() => {
        try {
            await circuitTest.calculateWitness({x: 1, y: 0}, true);
            assert(false, "Should be a valid point");
        } catch(err) {
            assert(/Constraint\sdoesn't\smatch(.*)168700\s!=\s1/.test(err.message) );
        }
    });

    it("Should extract the public key from the private one", async () => {

        const rawpvk = Buffer.from("0001020304050607080900010203040506070809000102030405060708090021", "hex");
        const pvk    = eddsa.pruneBuffer(Buffer.from(blake2b(64).update(rawpvk).digest().slice(0,32)));
        const S      = Scalar.shr(utils.leBuff2int(pvk), 3);

        const A      = eddsa.prv2pub(rawpvk);

        const input = {
            in : S
        };

        const w = await circuitPbk.calculateWitness(input, true);

        await circuitPbk.assertOut(w, {Ax : A[0], Ay: A[1]});

        await circuitPbk.checkConstraints(w);
    });

});