websnark/src/utils.js

/*
    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");

exports.bigInt2BytesLE = 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;
};

exports.bigInt2U32LE = function bigInt2BytesLE(_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;
};