init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Prng/CryptoApiEntropySourceProvider.cs

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+using System;
+using System.Security.Cryptography;
+
+namespace Org.BouncyCastle.Crypto.Prng;
+
+public class CryptoApiEntropySourceProvider : IEntropySourceProvider
+{
+	private class CryptoApiEntropySource : IEntropySource
+	{
+		private readonly RandomNumberGenerator mRng;
+
+		private readonly bool mPredictionResistant;
+
+		private readonly int mEntropySize;
+
+		bool IEntropySource.IsPredictionResistant => mPredictionResistant;
+
+		int IEntropySource.EntropySize => mEntropySize;
+
+		internal CryptoApiEntropySource(RandomNumberGenerator rng, bool predictionResistant, int entropySize)
+		{
+			mRng = rng;
+			mPredictionResistant = predictionResistant;
+			mEntropySize = entropySize;
+		}
+
+		byte[] IEntropySource.GetEntropy()
+		{
+			byte[] array = new byte[(mEntropySize + 7) / 8];
+			mRng.GetBytes(array);
+			return array;
+		}
+	}
+
+	private readonly RandomNumberGenerator mRng;
+
+	private readonly bool mPredictionResistant;
+
+	public CryptoApiEntropySourceProvider()
+		: this(RandomNumberGenerator.Create(), isPredictionResistant: true)
+	{
+	}
+
+	public CryptoApiEntropySourceProvider(RandomNumberGenerator rng, bool isPredictionResistant)
+	{
+		if (rng == null)
+		{
+			throw new ArgumentNullException("rng");
+		}
+		mRng = rng;
+		mPredictionResistant = isPredictionResistant;
+	}
+
+	public IEntropySource Get(int bitsRequired)
+	{
+		return new CryptoApiEntropySource(mRng, mPredictionResistant, bitsRequired);
+	}
+}