poseidon-encryption/test/pedersen2.js

Standalone package for Poseidon encryption. All credits to https://github.com/weijiekoh/circomlib/tree/feat/poseidon-encryption

const path = require("path");

const F1Field = require("ffjavascript").F1Field;
const Scalar = require("ffjavascript").Scalar;
exports.p = Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617");
const Fr = new F1Field(exports.p);

const wasm_tester = require("circom_tester").wasm;

const babyJub = require("circomlibjs").babyjub;
const pedersen = require("circomlibjs").pedersenHash;


describe("Pedersen test", function() {
    let circuit;
    this.timeout(100000);
    before( async() => {

        circuit = await wasm_tester(path.join(__dirname, "circuits", "pedersen2_test.circom"));
    });
    it("Should pedersen at zero", async () => {

        let w;

        w = await circuit.calculateWitness({ in: 0}, true);

        const b = Buffer.alloc(32);

        const h = pedersen.hash(b);
        const hP = babyJub.unpackPoint(h);

        await circuit.assertOut(w, {out: hP});

    });
    it("Should pedersen with 253 ones", async () => {

        let w;

        const n = Fr.sub(Fr.shl(Fr.one, Fr.e(253)), Fr.one);

        w = await circuit.calculateWitness({ in: n}, true);

        const b = Buffer.alloc(32);
        for (let i=0; i<31; i++) b[i] = 0xFF;
        b[31] = 0x1F;

        const h = pedersen.hash(b);
        const hP = babyJub.unpackPoint(h);

        await circuit.assertOut(w, {out: hP});

    });
});