Add project files.

AscNet.Common/Util/Crypto.cs

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+namespace AscNet.Common.Util
+{
+    public static class Crypto
+    {
+        public static byte[] XORCrypt(byte[] data, byte[] key)
+        {
+            byte[] encryptedData = new byte[data.Length];
+
+            for (int i = 0; i < data.Length; i++)
+                encryptedData[i] = (byte)(data[i] ^ key[i % key.Length]);
+
+            return encryptedData;
+        }
+    }
+}