From 77c6cc4e0875b8eea8ea834798cd5a379d9b3919 Mon Sep 17 00:00:00 2001
From: celeron533 <zhuyilun8@hotmail.com>
Date: Sun, 16 Feb 2020 14:59:07 +0800
Subject: [PATCH] Add BouncyCastle AEAD

---
 .../AEAD/AEADBouncyCastleEncryptor.cs         | 74 +++++++++++++++++++
 shadowsocks-csharp/packages.config            |  1 +
 shadowsocks-csharp/shadowsocks-csharp.csproj  |  4 +
 test/CryptographyTest.cs                      | 44 +++++++++++
 4 files changed, 123 insertions(+)
 create mode 100644 shadowsocks-csharp/Encryption/AEAD/AEADBouncyCastleEncryptor.cs

diff --git a/shadowsocks-csharp/Encryption/AEAD/AEADBouncyCastleEncryptor.cs b/shadowsocks-csharp/Encryption/AEAD/AEADBouncyCastleEncryptor.cs
new file mode 100644
index 00000000..2147028c
--- /dev/null
+++ b/shadowsocks-csharp/Encryption/AEAD/AEADBouncyCastleEncryptor.cs
@@ -0,0 +1,74 @@
+using Org.BouncyCastle.Crypto.Engines;
+using Org.BouncyCastle.Crypto.Modes;
+using Org.BouncyCastle.Crypto.Parameters;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Shadowsocks.Encryption.AEAD
+{
+    public class AEADBouncyCastleEncryptor : AEADEncryptor//, IDisposable
+    {
+        public AEADBouncyCastleEncryptor(string method, string password)
+    : base(method, password)
+        {
+        }
+
+        static int CIPHER_AES=1;
+        private static readonly Dictionary<string, EncryptorInfo> _ciphers = new Dictionary<string, EncryptorInfo>
+        {
+            {"aes-128-gcm", new EncryptorInfo("AES-128-GCM", 16, 16, 12, 16, CIPHER_AES)},
+            {"aes-192-gcm", new EncryptorInfo("AES-192-GCM", 24, 24, 12, 16, CIPHER_AES)},
+            {"aes-256-gcm", new EncryptorInfo("AES-256-GCM", 32, 32, 12, 16, CIPHER_AES)},
+        };
+
+        protected override Dictionary<string, EncryptorInfo> getCiphers()
+        {
+            return _ciphers;
+        }
+
+        public override void cipherDecrypt(byte[] ciphertext, uint clen, byte[] plaintext, ref uint plen)
+        {
+            GcmBlockCipher cipher = new GcmBlockCipher(new AesEngine());
+            AeadParameters parameters = new AeadParameters(new KeyParameter(_sessionKey), tagLen * 8, _decNonce);
+
+            cipher.Init(false, parameters);
+            plaintext = new byte[cipher.GetOutputSize((int)clen)];
+            var len = cipher.ProcessBytes(ciphertext, 0, (int)clen, plaintext, 0);
+            cipher.DoFinal(plaintext, len);
+            plen = (uint)(plaintext.Length);
+        }
+
+        public override void cipherEncrypt(byte[] plaintext, uint plen, byte[] ciphertext, ref uint clen)
+        {
+            GcmBlockCipher cipher = new GcmBlockCipher(new AesEngine());
+            AeadParameters parameters = new AeadParameters(new KeyParameter(_sessionKey), tagLen * 8, _encNonce);
+
+            cipher.Init(true, parameters);
+            ciphertext = new byte[cipher.GetOutputSize((int)plen)];
+            var len = cipher.ProcessBytes(plaintext, 0, (int)plen, ciphertext, 0);
+            cipher.DoFinal(ciphertext, len);
+            clen = (uint)(ciphertext.Length);
+        }
+
+        public override void Dispose()
+        {
+            //throw new NotImplementedException();
+        }
+
+        public override void InitCipher(byte[] salt, bool isEncrypt, bool isUdp)
+        {
+            base.InitCipher(salt, isEncrypt, isUdp);
+
+            DeriveSessionKey(isEncrypt ? _encryptSalt : _decryptSalt,
+                 _Masterkey, _sessionKey);
+        }
+
+        public static List<string> SupportedCiphers()
+        {
+            return new List<string>(_ciphers.Keys);
+        }
+    }
+}
diff --git a/shadowsocks-csharp/packages.config b/shadowsocks-csharp/packages.config
index 911e1d9a..67621a9d 100644
--- a/shadowsocks-csharp/packages.config
+++ b/shadowsocks-csharp/packages.config
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="BouncyCastle" version="1.8.5" targetFramework="net472" />
   <package id="Caseless.Fody" version="1.8.3" targetFramework="net472" />
   <package id="Costura.Fody" version="3.3.3" targetFramework="net472" />
   <package id="Fody" version="4.2.1" targetFramework="net472" developmentDependency="true" />
diff --git a/shadowsocks-csharp/shadowsocks-csharp.csproj b/shadowsocks-csharp/shadowsocks-csharp.csproj
index bf562337..31095fd6 100644
--- a/shadowsocks-csharp/shadowsocks-csharp.csproj
+++ b/shadowsocks-csharp/shadowsocks-csharp.csproj
@@ -68,6 +68,9 @@
     <ApplicationManifest>app.manifest</ApplicationManifest>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="BouncyCastle.Crypto, Version=1.8.5.0, Culture=neutral, PublicKeyToken=0e99375e54769942">
+      <HintPath>..\packages\BouncyCastle.1.8.5\lib\BouncyCastle.Crypto.dll</HintPath>
+    </Reference>
     <Reference Include="Caseless, Version=1.8.3.0, Culture=neutral, PublicKeyToken=409b3227471b0f0d, processorArchitecture=MSIL">
       <HintPath>..\packages\Caseless.Fody.1.8.3\lib\net452\Caseless.dll</HintPath>
     </Reference>
@@ -114,6 +117,7 @@
     <Compile Include="Controller\LoggerExtension.cs" />
     <Compile Include="Controller\Service\PACDaemon.cs" />
     <Compile Include="Controller\System\Hotkeys\HotkeyCallbacks.cs" />
+    <Compile Include="Encryption\AEAD\AEADBouncyCastleEncryptor.cs" />
     <Compile Include="Encryption\AEAD\AEADEncryptor.cs" />
     <Compile Include="Encryption\AEAD\AEADMbedTLSEncryptor.cs" />
     <Compile Include="Encryption\AEAD\AEADOpenSSLEncryptor.cs" />
diff --git a/test/CryptographyTest.cs b/test/CryptographyTest.cs
index a5b78bbd..3fa82d34 100644
--- a/test/CryptographyTest.cs
+++ b/test/CryptographyTest.cs
@@ -230,6 +230,50 @@ namespace Shadowsocks.Test
             }
         }
 
+        [TestMethod]
+        public void TestBouncyCastleEncryption()
+        {
+            encryptionFailed = false;
+            // run it once before the multi-threading test to initialize global tables
+            RunSingleBouncyCastleEncryptionThread();
+            List<Thread> threads = new List<Thread>();
+            for (int i = 0; i < 10; i++)
+            {
+                Thread t = new Thread(new ThreadStart(RunSingleBouncyCastleEncryptionThread));
+                threads.Add(t);
+                t.Start();
+            }
+            foreach (Thread t in threads)
+            {
+                t.Join();
+            }
+            RNG.Close();
+            Assert.IsFalse(encryptionFailed);
+        }
+
+        private void RunSingleBouncyCastleEncryptionThread()
+        {
+            try
+            {
+                for (int i = 0; i < 10; i++)
+                {
+                    var random = new Random();
+                    IEncryptor encryptor;
+                    IEncryptor decryptor;
+                    encryptor = new Encryption.AEAD.AEADBouncyCastleEncryptor("aes-256-gcm", "barfoo!");
+                    encryptor.AddrBufLength = 1 + 4 + 2;// ADDR_ATYP_LEN + 4 + ADDR_PORT_LEN;
+                    decryptor = new Encryption.AEAD.AEADBouncyCastleEncryptor("aes-256-gcm", "barfoo!");
+                    decryptor.AddrBufLength = 1 + 4 + 2;// ADDR_ATYP_LEN + 4 + ADDR_PORT_LEN;
+                    RunEncryptionRound(encryptor, decryptor);
+                }
+            }
+            catch
+            {
+                encryptionFailed = true;
+                throw;
+            }
+        }
+
         [TestMethod]
         public void TestOpenSSLAEADEncryption()
         {