initial commit

Intelix.Helper.Encrypted/RC4Crypt.cs

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+namespace Intelix.Helper.Encrypted;
+
+public class RC4Crypt
+{
+	public static byte[] Decrypt(byte[] key, byte[] data)
+	{
+		if (key == null)
+		{
+			return null;
+		}
+		if (key.Length == 0)
+		{
+			return null;
+		}
+		if (data == null)
+		{
+			return null;
+		}
+		byte[] array = new byte[256];
+		for (int i = 0; i < 256; i++)
+		{
+			array[i] = (byte)i;
+		}
+		int num = 0;
+		for (int j = 0; j < 256; j++)
+		{
+			num = (num + array[j] + key[j % key.Length]) & 0xFF;
+			Swap(array, j, num);
+		}
+		byte[] array2 = new byte[data.Length];
+		int num2 = 0;
+		num = 0;
+		for (int k = 0; k < data.Length; k++)
+		{
+			num2 = (num2 + 1) & 0xFF;
+			num = (num + array[num2]) & 0xFF;
+			Swap(array, num2, num);
+			byte b = array[(array[num2] + array[num]) & 0xFF];
+			array2[k] = (byte)(data[k] ^ b);
+		}
+		return array2;
+	}
+
+	private static void Swap(byte[] arr, int a, int b)
+	{
+		byte b2 = arr[a];
+		arr[a] = arr[b];
+		arr[b] = b2;
+	}
+}