init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Parameters/DesParameters.cs

@@ -0,0 +1,101 @@
+using System;
+
+namespace Org.BouncyCastle.Crypto.Parameters;
+
+public class DesParameters : KeyParameter
+{
+	public const int DesKeyLength = 8;
+
+	private const int N_DES_WEAK_KEYS = 16;
+
+	private static readonly byte[] DES_weak_keys = new byte[128]
+	{
+		1, 1, 1, 1, 1, 1, 1, 1, 31, 31,
+		31, 31, 14, 14, 14, 14, 224, 224, 224, 224,
+		241, 241, 241, 241, 254, 254, 254, 254, 254, 254,
+		254, 254, 1, 254, 1, 254, 1, 254, 1, 254,
+		31, 224, 31, 224, 14, 241, 14, 241, 1, 224,
+		1, 224, 1, 241, 1, 241, 31, 254, 31, 254,
+		14, 254, 14, 254, 1, 31, 1, 31, 1, 14,
+		1, 14, 224, 254, 224, 254, 241, 254, 241, 254,
+		254, 1, 254, 1, 254, 1, 254, 1, 224, 31,
+		224, 31, 241, 14, 241, 14, 224, 1, 224, 1,
+		241, 1, 241, 1, 254, 31, 254, 31, 254, 14,
+		254, 14, 31, 1, 31, 1, 14, 1, 14, 1,
+		254, 224, 254, 224, 254, 241, 254, 241
+	};
+
+	public DesParameters(byte[] key)
+		: base(key)
+	{
+		if (IsWeakKey(key))
+		{
+			throw new ArgumentException("attempt to create weak DES key");
+		}
+	}
+
+	public DesParameters(byte[] key, int keyOff, int keyLen)
+		: base(key, keyOff, keyLen)
+	{
+		if (IsWeakKey(key, keyOff))
+		{
+			throw new ArgumentException("attempt to create weak DES key");
+		}
+	}
+
+	public static bool IsWeakKey(byte[] key, int offset)
+	{
+		if (key.Length - offset < 8)
+		{
+			throw new ArgumentException("key material too short.");
+		}
+		for (int i = 0; i < 16; i++)
+		{
+			bool flag = false;
+			for (int j = 0; j < 8; j++)
+			{
+				if (key[j + offset] != DES_weak_keys[i * 8 + j])
+				{
+					flag = true;
+					break;
+				}
+			}
+			if (!flag)
+			{
+				return true;
+			}
+		}
+		return false;
+	}
+
+	public static bool IsWeakKey(byte[] key)
+	{
+		return IsWeakKey(key, 0);
+	}
+
+	public static byte SetOddParity(byte b)
+	{
+		uint num = (uint)(b ^ 1);
+		num ^= num >> 4;
+		num ^= num >> 2;
+		num ^= num >> 1;
+		num &= 1;
+		return (byte)(b ^ num);
+	}
+
+	public static void SetOddParity(byte[] bytes)
+	{
+		for (int i = 0; i < bytes.Length; i++)
+		{
+			bytes[i] = SetOddParity(bytes[i]);
+		}
+	}
+
+	public static void SetOddParity(byte[] bytes, int off, int len)
+	{
+		for (int i = 0; i < len; i++)
+		{
+			bytes[off + i] = SetOddParity(bytes[off + i]);
+		}
+	}
+}