How to use getRandomValues() in nodejs? - node.js

Question

I am using a Javascript to generate wireguard keypairs but it's browser faced so i removed the window objects and have one more issue that prevents creation of private key.
the issue is this line of code that i cannot run in nodejs:
function generatePresharedKey() {
var privateKey = new Uint8Array(32);
var crypto = require('crypto');
crypto.getRandomValues(privateKey);
return privateKey;
}
this is the error i get
crypto.getRandomValues(privateKey);
^
TypeError: crypto.getRandomValues is not a function
if i try to call getRandomValues using require it says that it cannot find module. var getRandomValues = require('get-random-values');
How to do i import it ? npm install get-random-values doesn't help.
any advice ?
fiddle here :
/*! SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2015-2020 Jason A. Donenfeld <Jason#zx2c4.com>. All Rights Reserved.
*/
function gf(init) {
var r = new Float64Array(16);
if (init) {
for (var i = 0; i < init.length; ++i)
r[i] = init[i];
}
return r;
}
function pack(o, n) {
var b, m = gf(), t = gf();
for (var i = 0; i < 16; ++i)
t[i] = n[i];
carry(t);
carry(t);
carry(t);
for (var j = 0; j < 2; ++j) {
m[0] = t[0] - 0xffed;
for (var i = 1; i < 15; ++i) {
m[i] = t[i] - 0xffff - ((m[i - 1] >> 16) & 1);
m[i - 1] &= 0xffff;
}
m[15] = t[15] - 0x7fff - ((m[14] >> 16) & 1);
b = (m[15] >> 16) & 1;
m[14] &= 0xffff;
cswap(t, m, 1 - b);
}
for (var i = 0; i < 16; ++i) {
o[2 * i] = t[i] & 0xff;
o[2 * i + 1] = t[i] >> 8;
}
}
function carry(o) {
var c;
for (var i = 0; i < 16; ++i) {
o[(i + 1) % 16] += (i < 15 ? 1 : 38) * Math.floor(o[i] / 65536);
o[i] &= 0xffff;
}
}
function cswap(p, q, b) {
var t, c = ~(b - 1);
for (var i = 0; i < 16; ++i) {
t = c & (p[i] ^ q[i]);
p[i] ^= t;
q[i] ^= t;
}
}
function add(o, a, b) {
for (var i = 0; i < 16; ++i)
o[i] = (a[i] + b[i]) | 0;
}
function subtract(o, a, b) {
for (var i = 0; i < 16; ++i)
o[i] = (a[i] - b[i]) | 0;
}
function multmod(o, a, b) {
var t = new Float64Array(31);
for (var i = 0; i < 16; ++i) {
for (var j = 0; j < 16; ++j)
t[i + j] += a[i] * b[j];
}
for (var i = 0; i < 15; ++i)
t[i] += 38 * t[i + 16];
for (var i = 0; i < 16; ++i)
o[i] = t[i];
carry(o);
carry(o);
}
function invert(o, i) {
var c = gf();
for (var a = 0; a < 16; ++a)
c[a] = i[a];
for (var a = 253; a >= 0; --a) {
multmod(c, c, c);
if (a !== 2 && a !== 4)
multmod(c, c, i);
}
for (var a = 0; a < 16; ++a)
o[a] = c[a];
}
function clamp(z) {
z[31] = (z[31] & 127) | 64;
z[0] &= 248;
}
function generatePublicKey(privateKey) {
var r, z = new Uint8Array(32);
var a = gf([1]),
b = gf([9]),
c = gf(),
d = gf([1]),
e = gf(),
f = gf(),
_121665 = gf([0xdb41, 1]),
_9 = gf([9]);
for (var i = 0; i < 32; ++i)
z[i] = privateKey[i];
clamp(z);
for (var i = 254; i >= 0; --i) {
r = (z[i >>> 3] >>> (i & 7)) & 1;
cswap(a, b, r);
cswap(c, d, r);
add(e, a, c);
subtract(a, a, c);
add(c, b, d);
subtract(b, b, d);
multmod(d, e, e);
multmod(f, a, a);
multmod(a, c, a);
multmod(c, b, e);
add(e, a, c);
subtract(a, a, c);
multmod(b, a, a);
subtract(c, d, f);
multmod(a, c, _121665);
add(a, a, d);
multmod(c, c, a);
multmod(a, d, f);
multmod(d, b, _9);
multmod(b, e, e);
cswap(a, b, r);
cswap(c, d, r);
}
invert(c, c);
multmod(a, a, c);
pack(z, a);
return z;
}
function generatePresharedKey() {
var privateKey = new Uint8Array(32);
//var crypto = require('crypto').randomBytes;
//var getRandomValues = require('get-random-values');
//crypto.getRandomValues(privateKey);
const webcrypto = require('crypto').webcrypto;
webcrypto.getRandomValues(privateKey);
return privateKey;
}
function generatePrivateKey() {
var privateKey = generatePresharedKey();
clamp(privateKey);
return privateKey;
}
function encodeBase64(dest, src) {
var input = Uint8Array.from([(src[0] >> 2) & 63, ((src[0] << 4) | (src[1] >> 4)) & 63, ((src[1] << 2) | (src[2] >> 6)) & 63, src[2] & 63]);
for (var i = 0; i < 4; ++i)
dest[i] = input[i] + 65 +
(((25 - input[i]) >> 8) & 6) -
(((51 - input[i]) >> 8) & 75) -
(((61 - input[i]) >> 8) & 15) +
(((62 - input[i]) >> 8) & 3);
}
function keyToBase64(key) {
var i, base64 = new Uint8Array(44);
for (i = 0; i < 32 / 3; ++i)
encodeBase64(base64.subarray(i * 4), key.subarray(i * 3));
encodeBase64(base64.subarray(i * 4), Uint8Array.from([key[i * 3 + 0], key[i * 3 + 1], 0]));
base64[43] = 61;
return String.fromCharCode.apply(null, base64);
}
function generateKeypair() {
var privateKey = generatePrivateKey();
var publicKey = generatePublicKey(privateKey);
return {
publicKey: keyToBase64(publicKey),
privateKey: keyToBase64(privateKey)
};
}
function doSomething() {
const keypair = generateKeypair()
var m = JSON.stringify(keypair)
var op = JSON.parse(m)
console.log(keypair)
//console.log(op.publicKey)
document.getElementById("demo").innerHTML = op.publicKey + "</br>" + op.privateKey;
}
doSomething();

Answer 1

Class: Crypto
Added in: v15.0.0
Calling require('crypto').webcrypto returns an instance of the Crypto
class. Crypto is a singleton that provides access to the remainder of
the crypto API.
Example:
const privateKey = new Uint8Array(32);
const webcrypto = require('crypto').webcrypto;
webcrypto.getRandomValues(privateKey);
Result:
÷ÆVY{ñÕÓ»ÃVíA0²†xò¥x´ü^18

Answer 2

You need to understand getRandomValues is on window.crypto that means it works on browser. To make it work on Node.js you need to install get-random-values
npm i get-random-values
In your module add this:
const getRandomValues = require('get-random-values'),
array = new Uint8Array(10);
getRandomValues(array);
console.log(getRandomValues(array));