RandomBytes.cs

using System;
using System.Numerics;
using System.Security.Cryptography;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Cryptography.Functions
{
    public class RandomBytes : FunctionOneScalarVariable
    {
        public RandomBytes(ScriptNode Argument, int Start, int Length, Expression Expression)
            : base(Argument, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(RandomBytes);
 
        public override IElement EvaluateScalar(double Argument, Variables Variables)
        {
            int N = (int)Argument;
            if (N != Argument || N < 0)
                throw new ScriptRuntimeException("Number of bytes must be non-negative.", this);
 
            byte[] Bin = new byte[N];
 
            lock (rnd)
            {
                rnd.GetBytes(Bin);
            }
 
            return new ObjectValue(Bin);
        }
 
        private static readonly RandomNumberGenerator rnd = RandomNumberGenerator.Create();
 
    }
}