refactoring encryptor

shadowsocks-csharp/Encrypt/EncryptorFactory.cs

@@ -0,0 +1,21 @@
+
+namespace shadowsocks_csharp.Encrypt
+{
+    public static class EncryptorFactory
+    {
+        public static IEncryptor GetEncryptor(string method, string password)
+        {
+            if (string.IsNullOrEmpty(method) || method.ToLowerInvariant() == "table")
+            {
+                return new TableEncryptor(method, password);
+            }
+
+            if (method.ToLowerInvariant() == "rc4")
+            {
+                return new Rc4Encryptor(method, password);
+            }
+
+            return new OpensslEncryptor(method, password);
+        }
+    }
+}