RandomNumberGeneratorImplementation.cs

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namespace System.Security.Cryptography;
 
internal sealed class RandomNumberGeneratorImplementation : RandomNumberGenerator
{
    internal static readonly RandomNumberGeneratorImplementation s_singleton = new RandomNumberGeneratorImplementation();
 
    private RandomNumberGeneratorImplementation()
    {
    }
 
    internal unsafe static void FillSpan(Span<byte> data)
    {
        if (data.Length > 0)
        {
            fixed (byte* pbBuffer = data)
            {
                GetBytes(pbBuffer, data.Length);
            }
        }
    }
 
    public override void GetBytes(byte[] data)
    {
        if (data == null)
        {
            throw new ArgumentNullException("data");
        }
        GetBytes(new Span<byte>(data));
    }
 
    public override void GetBytes(byte[] data, int offset, int count)
    {
        VerifyGetBytes(data, offset, count);
        GetBytes(new Span<byte>(data, offset, count));
    }
 
    public unsafe override void GetBytes(Span<byte> data)
    {
        if (data.Length > 0)
        {
            fixed (byte* pbBuffer = data)
            {
                GetBytes(pbBuffer, data.Length);
            }
        }
    }
 
    public override void GetNonZeroBytes(byte[] data)
    {
        if (data == null)
        {
            throw new ArgumentNullException("data");
        }
        GetNonZeroBytes(new Span<byte>(data));
    }
 
    public override void GetNonZeroBytes(Span<byte> data)
    {
        while (data.Length > 0)
        {
            GetBytes(data);
            int num = data.Length;
            for (int i = 0; i < data.Length; i++)
            {
                if (data[i] == 0)
                {
                    num = i;
                    break;
                }
            }
            for (int j = num + 1; j < data.Length; j++)
            {
                if (data[j] != 0)
                {
                    data[num++] = data[j];
                }
            }
            data = data.Slice(num);
        }
    }
 
    private unsafe static void GetBytes(byte* pbBuffer, int count)
    {
        global::Interop.BCrypt.NTSTATUS nTSTATUS = global::Interop.BCrypt.BCryptGenRandom(IntPtr.Zero, pbBuffer, count, 2);
        if (nTSTATUS != 0)
        {
            throw global::Interop.BCrypt.CreateCryptographicException(nTSTATUS);
        }
    }
}