Random hex strings

Random hex strings

How to generate random hex string in various languages

Posted
By Chris
2 min read

As a developer is sometimes happens that I need to generate some random bytes as a hexadecimal string. This could be the case if you need a short lived token of some kind.

This is not something you should use to generate a password for any environment.

So I have compiled a small sample in the languages I usually develop in.

C#

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using System;

Random random = new Random();
var bytes = new Byte[30];
random.NextBytes(bytes);

var hexArray = Array.ConvertAll(bytes, x => x.ToString("X2"));
var hexStr = String.Concat(hexArray);

Console.WriteLine(hexStr.ToLower());

Python

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import os, binascii

hex = binascii.b2a_hex(os.urandom(30))
print(hex)

Ruby

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require "securerandom"

hex = SecureRandom.hex(30)
puts(hex)

PHP

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$bytes = random_bytes(30);
echo bin2hex($bytes);

NodeJS

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const Crypto = require('crypto')

const buf = Crypto.randomBytes(30)
const token = buf.toString('hex')

console.log(token)
Software
general random
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