init commit

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

@@ -0,0 +1,217 @@
+using System;
+using System.Text;
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Asn1;
+
+public class DerBitString : DerStringBase
+{
+	private static readonly char[] table = new char[16]
+	{
+		'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+		'A', 'B', 'C', 'D', 'E', 'F'
+	};
+
+	protected readonly byte[] mData;
+
+	protected readonly int mPadBits;
+
+	public virtual int PadBits => mPadBits;
+
+	public virtual int IntValue
+	{
+		get
+		{
+			int num = 0;
+			int num2 = System.Math.Min(4, mData.Length);
+			for (int i = 0; i < num2; i++)
+			{
+				num |= mData[i] << 8 * i;
+			}
+			if (mPadBits > 0 && num2 == mData.Length)
+			{
+				int num3 = (1 << mPadBits) - 1;
+				num &= ~(num3 << 8 * (num2 - 1));
+			}
+			return num;
+		}
+	}
+
+	public static DerBitString GetInstance(object obj)
+	{
+		if (obj == null || obj is DerBitString)
+		{
+			return (DerBitString)obj;
+		}
+		if (obj is byte[])
+		{
+			try
+			{
+				return (DerBitString)Asn1Object.FromByteArray((byte[])obj);
+			}
+			catch (Exception ex)
+			{
+				throw new ArgumentException("encoding error in GetInstance: " + ex.ToString());
+			}
+		}
+		throw new ArgumentException("illegal object in GetInstance: " + Platform.GetTypeName(obj));
+	}
+
+	public static DerBitString GetInstance(Asn1TaggedObject obj, bool isExplicit)
+	{
+		Asn1Object asn1Object = obj.GetObject();
+		if (isExplicit || asn1Object is DerBitString)
+		{
+			return GetInstance(asn1Object);
+		}
+		return FromAsn1Octets(((Asn1OctetString)asn1Object).GetOctets());
+	}
+
+	public DerBitString(byte[] data, int padBits)
+	{
+		if (data == null)
+		{
+			throw new ArgumentNullException("data");
+		}
+		if (padBits < 0 || padBits > 7)
+		{
+			throw new ArgumentException("must be in the range 0 to 7", "padBits");
+		}
+		if (data.Length == 0 && padBits != 0)
+		{
+			throw new ArgumentException("if 'data' is empty, 'padBits' must be 0");
+		}
+		mData = Arrays.Clone(data);
+		mPadBits = padBits;
+	}
+
+	public DerBitString(byte[] data)
+		: this(data, 0)
+	{
+	}
+
+	public DerBitString(int namedBits)
+	{
+		if (namedBits == 0)
+		{
+			mData = new byte[0];
+			mPadBits = 0;
+			return;
+		}
+		int num = BigInteger.BitLen(namedBits);
+		int num2 = (num + 7) / 8;
+		byte[] array = new byte[num2];
+		num2--;
+		for (int i = 0; i < num2; i++)
+		{
+			array[i] = (byte)namedBits;
+			namedBits >>= 8;
+		}
+		array[num2] = (byte)namedBits;
+		int j;
+		for (j = 0; (namedBits & (1 << j)) == 0; j++)
+		{
+		}
+		mData = array;
+		mPadBits = j;
+	}
+
+	public DerBitString(Asn1Encodable obj)
+		: this(obj.GetDerEncoded())
+	{
+	}
+
+	public virtual byte[] GetOctets()
+	{
+		if (mPadBits != 0)
+		{
+			throw new InvalidOperationException("attempt to get non-octet aligned data from BIT STRING");
+		}
+		return Arrays.Clone(mData);
+	}
+
+	public virtual byte[] GetBytes()
+	{
+		byte[] array = Arrays.Clone(mData);
+		if (mPadBits > 0)
+		{
+			byte[] array3;
+			byte[] array2 = (array3 = array);
+			int num = array.Length - 1;
+			nint num2 = num;
+			array2[num] = (byte)(array3[num2] & (byte)(255 << mPadBits));
+		}
+		return array;
+	}
+
+	internal override void Encode(DerOutputStream derOut)
+	{
+		if (mPadBits > 0)
+		{
+			int num = mData[mData.Length - 1];
+			int num2 = (1 << mPadBits) - 1;
+			int num3 = num & num2;
+			if (num3 != 0)
+			{
+				byte[] array = Arrays.Prepend(mData, (byte)mPadBits);
+				array[^1] = (byte)(num ^ num3);
+				derOut.WriteEncoded(3, array);
+				return;
+			}
+		}
+		derOut.WriteEncoded(3, (byte)mPadBits, mData);
+	}
+
+	protected override int Asn1GetHashCode()
+	{
+		int num = mPadBits;
+		return num.GetHashCode() ^ Arrays.GetHashCode(mData);
+	}
+
+	protected override bool Asn1Equals(Asn1Object asn1Object)
+	{
+		if (!(asn1Object is DerBitString derBitString))
+		{
+			return false;
+		}
+		if (mPadBits == derBitString.mPadBits)
+		{
+			return Arrays.AreEqual(mData, derBitString.mData);
+		}
+		return false;
+	}
+
+	public override string GetString()
+	{
+		StringBuilder stringBuilder = new StringBuilder("#");
+		byte[] derEncoded = GetDerEncoded();
+		for (int i = 0; i != derEncoded.Length; i++)
+		{
+			uint num = derEncoded[i];
+			stringBuilder.Append(table[(num >> 4) & 0xF]);
+			stringBuilder.Append(table[derEncoded[i] & 0xF]);
+		}
+		return stringBuilder.ToString();
+	}
+
+	internal static DerBitString FromAsn1Octets(byte[] octets)
+	{
+		if (octets.Length < 1)
+		{
+			throw new ArgumentException("truncated BIT STRING detected", "octets");
+		}
+		int num = octets[0];
+		byte[] array = Arrays.CopyOfRange(octets, 1, octets.Length);
+		if (num > 0 && num < 8 && array.Length > 0)
+		{
+			int num2 = array[^1];
+			int num3 = (1 << num) - 1;
+			if ((num2 & num3) != 0)
+			{
+				return new BerBitString(array, num);
+			}
+		}
+		return new DerBitString(array, num);
+	}
+}