105 lines
3.6 KiB
JavaScript
105 lines
3.6 KiB
JavaScript
/*
|
|
Copyright 2019 0KIMS association.
|
|
|
|
This file is part of websnark (Web Assembly zkSnark Prover).
|
|
|
|
websnark is a free software: you can redistribute it and/or modify it
|
|
under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
websnark is distributed in the hope that it will be useful, but WITHOUT
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with websnark. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
const bigInt = require("big-integer");
|
|
const Circuit = require("snarkjs/src/circuit");
|
|
const bigInt2 = require("snarkjs/src/bigint");
|
|
const hexifyBigInts = require("../tools/stringifybigint").hexifyBigInts;
|
|
const unhexifyBigInts = require("../tools/stringifybigint").unhexifyBigInts;
|
|
const stringifyBigInts = require("../tools/stringifybigint").stringifyBigInts;
|
|
const unstringifyBigInts = require("../tools/stringifybigint").unstringifyBigInts;
|
|
const stringifyBigInts2 = require("snarkjs/src/stringifybigint").stringifyBigInts;
|
|
const unstringifyBigInts2 = require("snarkjs/src/stringifybigint").unstringifyBigInts;
|
|
|
|
function bigInt2BytesLE(_a, len) {
|
|
const b = Array(len);
|
|
let v = bigInt(_a);
|
|
for (let i=0; i<len; i++) {
|
|
b[i] = v.and(0xFF).toJSNumber();
|
|
v = v.shiftRight(8);
|
|
}
|
|
return b;
|
|
}
|
|
|
|
function bigInt2U32LE(_a, len) {
|
|
const b = Array(len);
|
|
let v = bigInt(_a);
|
|
for (let i=0; i<len; i++) {
|
|
b[i] = v.and(0xFFFFFFFF).toJSNumber();
|
|
v = v.shiftRight(32);
|
|
}
|
|
return b;
|
|
}
|
|
|
|
function convertWitness(witness) {
|
|
const buffLen = witness.length * 32;
|
|
const buff = new ArrayBuffer(buffLen);
|
|
const h = {
|
|
dataView: new DataView(buff),
|
|
offset: 0
|
|
};
|
|
const mask = bigInt2(0xFFFFFFFF);
|
|
for (let i = 0; i < witness.length; i++) {
|
|
for (let j = 0; j < 8; j++) {
|
|
const v = Number(witness[i].shr(j * 32).and(mask));
|
|
h.dataView.setUint32(h.offset, v, true);
|
|
h.offset += 4;
|
|
}
|
|
}
|
|
return buff;
|
|
}
|
|
|
|
function toHex32(number) {
|
|
let str = number.toString(16);
|
|
while (str.length < 64) str = "0" + str;
|
|
return str;
|
|
}
|
|
|
|
function toSolidityInput(proof) {
|
|
const flatProof = unstringifyBigInts([
|
|
proof.pi_a[0], proof.pi_a[1],
|
|
proof.pi_b[0][1], proof.pi_b[0][0],
|
|
proof.pi_b[1][1], proof.pi_b[1][0],
|
|
proof.pi_c[0], proof.pi_c[1],
|
|
]);
|
|
const result = {
|
|
proof: "0x" + flatProof.map(x => toHex32(x)).join("")
|
|
};
|
|
if (proof.publicSignals) {
|
|
result.publicSignals = hexifyBigInts(unstringifyBigInts(proof.publicSignals));
|
|
}
|
|
return result;
|
|
}
|
|
|
|
function genWitness(input, circuitJson) {
|
|
const circuit = new Circuit(unstringifyBigInts2(circuitJson));
|
|
const witness = circuit.calculateWitness(unstringifyBigInts2(input));
|
|
const publicSignals = witness.slice(1, circuit.nPubInputs + circuit.nOutputs + 1);
|
|
return {witness, publicSignals};
|
|
}
|
|
|
|
async function genWitnessAndProve(groth16, input, circuitJson, provingKey) {
|
|
const witnessData = genWitness(input, circuitJson);
|
|
const witnessBin = convertWitness(witnessData.witness);
|
|
const result = await groth16.proof(witnessBin, provingKey);
|
|
result.publicSignals = stringifyBigInts2(witnessData.publicSignals);
|
|
return result;
|
|
}
|
|
|
|
module.exports = {bigInt2BytesLE, bigInt2U32LE, toSolidityInput, genWitnessAndProve}; |