wasm_field2.js

import { getThreadRng } from "./random.js";
import * as Scalar from "./scalar.js";


export default class WasmField2 {

    constructor(tm, prefix, F) {
        this.tm = tm;
        this.prefix = prefix;

        this.F = F;
        this.type = "F2";
        this.m = F.m * 2;
        this.n8 = this.F.n8*2;
        this.n32 = this.F.n32*2;
        this.n64 = this.F.n64*2;

        this.pOp1 = tm.alloc(F.n8*2);
        this.pOp2 = tm.alloc(F.n8*2);
        this.pOp3 = tm.alloc(F.n8*2);
        this.tm.instance.exports[prefix + "_zero"](this.pOp1);
        this.zero = tm.getBuff(this.pOp1, this.n8);
        this.tm.instance.exports[prefix + "_one"](this.pOp1);
        this.one = tm.getBuff(this.pOp1, this.n8);

        this.negone = this.neg(this.one);
        this.two = this.add(this.one, this.one);

    }

    op2(opName, a, b) {
        this.tm.setBuff(this.pOp1, a);
        this.tm.setBuff(this.pOp2, b);
        this.tm.instance.exports[this.prefix + opName](this.pOp1, this.pOp2, this.pOp3);
        return this.tm.getBuff(this.pOp3, this.n8);
    }

    op2Bool(opName, a, b) {
        this.tm.setBuff(this.pOp1, a);
        this.tm.setBuff(this.pOp2, b);
        return !!this.tm.instance.exports[this.prefix + opName](this.pOp1, this.pOp2);
    }

    op1(opName, a) {
        this.tm.setBuff(this.pOp1, a);
        this.tm.instance.exports[this.prefix + opName](this.pOp1, this.pOp3);
        return this.tm.getBuff(this.pOp3, this.n8);
    }

    op1Bool(opName, a) {
        this.tm.setBuff(this.pOp1, a);
        return !!this.tm.instance.exports[this.prefix + opName](this.pOp1, this.pOp3);
    }

    add(a,b) {
        return this.op2("_add", a, b);
    }

    eq(a,b) {
        return this.op2Bool("_eq", a, b);
    }

    isZero(a) {
        return this.op1Bool("_isZero", a);
    }

    sub(a,b) {
        return this.op2("_sub", a, b);
    }

    neg(a) {
        return this.op1("_neg", a);
    }

    inv(a) {
        return this.op1("_inverse", a);
    }

    isNegative(a) {
        return this.op1Bool("_isNegative", a);
    }

    toMontgomery(a) {
        return this.op1("_toMontgomery", a);
    }

    fromMontgomery(a) {
        return this.op1("_fromMontgomery", a);
    }

    mul(a,b) {
        return this.op2("_mul", a, b);
    }

    mul1(a,b) {
        return this.op2("_mul1", a, b);
    }

    div(a, b) {
        this.tm.setBuff(this.pOp1, a);
        this.tm.setBuff(this.pOp2, b);
        this.tm.instance.exports[this.prefix + "_inverse"](this.pOp2, this.pOp2);
        this.tm.instance.exports[this.prefix + "_mul"](this.pOp1, this.pOp2, this.pOp3);
        return this.tm.getBuff(this.pOp3, this.n8);
    }

    square(a) {
        return this.op1("_square", a);
    }

    isSquare(a) {
        return this.op1Bool("_isSquare", a);
    }

    sqrt(a) {
        return this.op1("_sqrt", a);
    }

    exp(a, b) {
        if (!(b instanceof Uint8Array)) {
            b = Scalar.toLEBuff(Scalar.e(b));
        }
        this.tm.setBuff(this.pOp1, a);
        this.tm.setBuff(this.pOp2, b);
        this.tm.instance.exports[this.prefix + "_exp"](this.pOp1, this.pOp2, b.byteLength, this.pOp3);
        return this.tm.getBuff(this.pOp3, this.n8);
    }

    e(a, b) {
        if (a instanceof Uint8Array) return a;
        if ((Array.isArray(a)) && (a.length == 2)) {
            const c1 = this.F.e(a[0], b);
            const c2 = this.F.e(a[1], b);
            const res = new Uint8Array(this.F.n8*2);
            res.set(c1);
            res.set(c2, this.F.n8*2);
            return res;
        } else {
            throw new Error("invalid F2");
        }
    }

    toString(a, radix) {
        const s1 = this.F.toString(a.slice(0, this.F.n8), radix);
        const s2 = this.F.toString(a.slice(this.F.n8), radix);
        return `[${s1}, ${s2}]`;
    }

    fromRng(rng) {
        const c1 = this.F.fromRng(rng);
        const c2 = this.F.fromRng(rng);
        const res = new Uint8Array(this.F.n8*2);
        res.set(c1);
        res.set(c2, this.F.n8);
        return res;
    }

    random() {
        return this.fromRng(getThreadRng());
    }

    toObject(a) {
        const c1 = this.F.toObject(a.slice(0, this.F.n8));
        const c2 = this.F.toObject(a.slice(this.F.n8, this.F.n8*2));
        return [c1, c2];
    }

    fromObject(a) {
        const buff = new Uint8Array(this.F.n8*2);
        const b1 = this.F.fromObject(a[0]);
        const b2 = this.F.fromObject(a[1]);
        buff.set(b1);
        buff.set(b2, this.F.n8);
        return buff;
    }

    c1(a) {
        return a.slice(0, this.F.n8);
    }

    c2(a) {
        return a.slice(this.F.n8);
    }

}