init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Bcpg/Sig/Features.cs

@@ -0,0 +1,52 @@
+using System;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Bcpg.Sig;
+
+public class Features : SignatureSubpacket
+{
+	public static readonly byte FEATURE_MODIFICATION_DETECTION = 1;
+
+	public bool SupportsModificationDetection => SupportsFeature(FEATURE_MODIFICATION_DETECTION);
+
+	private static byte[] FeatureToByteArray(byte feature)
+	{
+		return new byte[1] { feature };
+	}
+
+	public Features(bool critical, bool isLongLength, byte[] data)
+		: base(SignatureSubpacketTag.Features, critical, isLongLength, data)
+	{
+	}
+
+	public Features(bool critical, byte feature)
+		: base(SignatureSubpacketTag.Features, critical, isLongLength: false, FeatureToByteArray(feature))
+	{
+	}
+
+	public bool SupportsFeature(byte feature)
+	{
+		return Array.IndexOf((Array)data, (object?)feature) >= 0;
+	}
+
+	private void SetSupportsFeature(byte feature, bool support)
+	{
+		if (feature == 0)
+		{
+			throw new ArgumentException("cannot be 0", "feature");
+		}
+		int num = Array.IndexOf((Array)data, (object?)feature);
+		if (num >= 0 != support)
+		{
+			if (support)
+			{
+				data = Arrays.Append(data, feature);
+				return;
+			}
+			byte[] array = new byte[data.Length - 1];
+			Array.Copy(data, 0, array, 0, num);
+			Array.Copy(data, num + 1, array, num, array.Length - num);
+			data = array;
+		}
+	}
+}