init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Asn1/DerInteger.cs

@@ -0,0 +1,96 @@
+using System;
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Asn1;
+
+public class DerInteger : Asn1Object
+{
+	public const string AllowUnsafeProperty = "Org.BouncyCastle.Asn1.AllowUnsafeInteger";
+
+	private readonly byte[] bytes;
+
+	public BigInteger Value => new BigInteger(bytes);
+
+	public BigInteger PositiveValue => new BigInteger(1, bytes);
+
+	internal static bool AllowUnsafe()
+	{
+		string environmentVariable = Platform.GetEnvironmentVariable("Org.BouncyCastle.Asn1.AllowUnsafeInteger");
+		if (environmentVariable != null)
+		{
+			return Platform.EqualsIgnoreCase("true", environmentVariable);
+		}
+		return false;
+	}
+
+	public static DerInteger GetInstance(object obj)
+	{
+		if (obj == null || obj is DerInteger)
+		{
+			return (DerInteger)obj;
+		}
+		throw new ArgumentException("illegal object in GetInstance: " + Platform.GetTypeName(obj));
+	}
+
+	public static DerInteger GetInstance(Asn1TaggedObject obj, bool isExplicit)
+	{
+		if (obj == null)
+		{
+			throw new ArgumentNullException("obj");
+		}
+		Asn1Object asn1Object = obj.GetObject();
+		if (isExplicit || asn1Object is DerInteger)
+		{
+			return GetInstance(asn1Object);
+		}
+		return new DerInteger(Asn1OctetString.GetInstance(asn1Object).GetOctets());
+	}
+
+	public DerInteger(int value)
+	{
+		bytes = BigInteger.ValueOf(value).ToByteArray();
+	}
+
+	public DerInteger(BigInteger value)
+	{
+		if (value == null)
+		{
+			throw new ArgumentNullException("value");
+		}
+		bytes = value.ToByteArray();
+	}
+
+	public DerInteger(byte[] bytes)
+	{
+		if (bytes.Length > 1 && ((bytes[0] == 0 && (bytes[1] & 0x80) == 0) || (bytes[0] == byte.MaxValue && (bytes[1] & 0x80) != 0)) && !AllowUnsafe())
+		{
+			throw new ArgumentException("malformed integer");
+		}
+		this.bytes = Arrays.Clone(bytes);
+	}
+
+	internal override void Encode(DerOutputStream derOut)
+	{
+		derOut.WriteEncoded(2, bytes);
+	}
+
+	protected override int Asn1GetHashCode()
+	{
+		return Arrays.GetHashCode(bytes);
+	}
+
+	protected override bool Asn1Equals(Asn1Object asn1Object)
+	{
+		if (!(asn1Object is DerInteger derInteger))
+		{
+			return false;
+		}
+		return Arrays.AreEqual(bytes, derInteger.bytes);
+	}
+
+	public override string ToString()
+	{
+		return Value.ToString();
+	}
+}