CODEWITHSUNDEEP
node.js
samol
samol

Reputation: 20590

How to make crypto.randomBytes() to replace Math.random()

I need a cryptographically secure random number generator to replace Math.random()

I came across crypto.randomBytes() however, it returns a byte array. What is a way to make the byte array into 0-1 ( so that it is compatible with Math.random)

Upvotes: 4

Views: 2880

Answers (3)

Bhanu PS Kushwah
Bhanu PS Kushwah

Reputation: 99

For reactJS or node JS server side we can do as mention below

Below code will always return under the 100000

 const crypto = require('crypto'); 
 crypto.randomBytes(1)[0] * 200

It will also return always under the 100000

Math.floor(Math.random() * 100000)

For Ex: enter image description here

Upvotes: 0

Sigmatics
Sigmatics

Reputation: 793

This should do the trick:

crypto.randomBytes(4).readUInt32LE() / 0xffffffff;

randomBytes generates 4 random bytes, which are then read as a 32-bit unsigned integer in little endian. The max value of a 32bit unsigned int is 0xffffffff (or 4,294,967,295 in decimal). By dividing the randomly generated 32bit int by its max value you get a value between 0 and 1.

Upvotes: 4

mscdex
mscdex

Reputation: 106696

You could do something like:

var randomVal = (crypto.randomBytes(1)[0] / 255);

Upvotes: -1

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