StrongRandom 2.1.0

StrongRandom

System.Random drop-in backed by a Cryptographically-Secure Pseudo-Random Number Generator (CSPRNG). Everywhere you use System.Random, StrongRandom can be used instead. Also ships extension methods that add NextBool, NextByte, NextChar, NextFloat, NextNormal and more to any Random instance.

Security note: NextBytes() is a direct call to the underlying CSPRNG and is safe. Integer-returning methods (Next, Next(max), Next(min, max)) and NextDouble() involve a transformation step that introduces a slight bias — do not rely on these for security-critical decisions such as key generation. Use NextBytes() for raw entropy.

Installation

dotnet add package StrongRandom

Quick start

using Extensions.Standard.Randomization;

// Drop-in: assign to a System.Random variable
Random rng = new StrongRandom();

int dice   = rng.Next(1, 7);          // 1–6
double d   = rng.NextDouble();        // [0, 1)
byte[] key = new byte[32];
rng.NextBytes(key);                   // CSPRNG-safe raw bytes

Extension methods (Utilities)

All extensions target System.Random, so they work with StrongRandom, plain new Random(), or a mock.

var rng = new StrongRandom();

bool coinFlip       = rng.NextBool();
byte b              = rng.NextByte();
char letter         = rng.NextLetter();
char alphanumeric   = rng.NextAlphanumeric();
float f             = rng.NextFloat(0f, 1f);
double normal       = rng.NextNormal(mean: 0, sd: 1);
char fromSet        = rng.NextChar("AEIOU");

Customising the provider

StrongRandom depends on IRandomProvider for its byte source. The default is BufferedRandomProvider(44), which pre-fetches 44 bytes per CSPRNG call to reduce overhead.

// Larger buffer — fewer round-trips to the CSPRNG
var rng = new StrongRandom(new BufferedRandomProvider(256));

// Custom provider (e.g. for testing)
public class MyProvider : IRandomProvider
{
    public void GetBytes(byte[] input) { /* ... */ }
}
var testRng = new StrongRandom(new MyProvider());

API

StrongRandom

Inherits from System.Random. All Random members work as expected; randomness comes from the CSPRNG provider.

BufferedRandomProvider

IRandomProvider

public interface IRandomProvider
{
    void GetBytes(byte[] input);
}

License

MIT — see LICENSE.