Add OpenSSL 1.1.0g support due to hardware acceleration

Note: If you want to compile it by yourself, please make sure
do NOT use `no-asm` configure option, since the main point of
this commit is to utilize assembly in openssl

Add OpenSSL test

shadowsocks-csharp/Encryption/EncryptorFactory.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Reflection;
+using System.Text;
 using Shadowsocks.Encryption.AEAD;
 using Shadowsocks.Encryption.Stream;
 
@@ -26,21 +27,42 @@ namespace Shadowsocks.Encryption
                 AEADSodiumEncryptorSupportedCiphers.Remove("aes-256-gcm");
             }
 
-            foreach (string method in StreamMbedTLSEncryptor.SupportedCiphers())
+            // XXX: sequence matters, OpenSSL > Sodium > MbedTLS
+            foreach (string method in StreamOpenSSLEncryptor.SupportedCiphers())
             {
-                _registeredEncryptors.Add(method, typeof(StreamMbedTLSEncryptor));
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(StreamOpenSSLEncryptor));
             }
+
             foreach (string method in StreamSodiumEncryptor.SupportedCiphers())
             {
-                _registeredEncryptors.Add(method, typeof(StreamSodiumEncryptor));
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(StreamSodiumEncryptor));
             }
-            foreach (string method in AEADMbedTLSEncryptorSupportedCiphers)
+
+            foreach (string method in StreamMbedTLSEncryptor.SupportedCiphers())
             {
-                _registeredEncryptors.Add(method, typeof(AEADMbedTLSEncryptor));
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(StreamMbedTLSEncryptor));
             }
+
+
+            foreach (string method in AEADOpenSSLEncryptor.SupportedCiphers())
+            {
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(AEADOpenSSLEncryptor));
+            }
+
             foreach (string method in AEADSodiumEncryptorSupportedCiphers)
             {
-                _registeredEncryptors.Add(method, typeof(AEADSodiumEncryptor));
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(AEADSodiumEncryptor));
+            }
+
+            foreach (string method in AEADMbedTLSEncryptorSupportedCiphers)
+            {
+                if (!_registeredEncryptors.ContainsKey(method))
+                    _registeredEncryptors.Add(method, typeof(AEADMbedTLSEncryptor));
             }
         }
 
@@ -50,12 +72,29 @@ namespace Shadowsocks.Encryption
             {
                 method = "aes-256-cfb";
             }
+
             method = method.ToLowerInvariant();
             Type t = _registeredEncryptors[method];
+
             ConstructorInfo c = t.GetConstructor(ConstructorTypes);
             if (c == null) throw new System.Exception("Invalid ctor");
             IEncryptor result = (IEncryptor) c.Invoke(new object[] {method, password});
             return result;
         }
+
+        public static string DumpRegisteredEncryptor()
+        {
+            var sb = new StringBuilder();
+            sb.Append(Environment.NewLine);
+            sb.AppendLine("=========================");
+            sb.AppendLine("Registered Encryptor Info");
+            foreach (var encryptor in _registeredEncryptors)
+            {
+                sb.AppendLine(String.Format("{0}=>{1}", encryptor.Key, encryptor.Value.Name));
+            }
+
+            sb.AppendLine("=========================");
+            return sb.ToString();
+        }
     }
 }