数据加密在通讯环应用是必不可少的，TLS加密通讯则是现有通讯的加密标准，可以使用.NETCore带的SslStream来集成这一功能；但SslStream的读写操作功能有限，在组件设计中不仅让SslStream使用PipeStream,同时也可以让SslStream直接转换成PipeStream进行更简便的数据流操作。

扩展

为了更好地让SslStream和PipeStream相结合操作，所以对SslStream扩展出一个新的类SslStreamX,通过它可以更好的在流数据处理隐藏SslStream和PipeStream之间的操作处理。

  1.     class SslStreamX : SslStream
  2.     {
  3.         //构建SslStreamX,并指写来源的缓冲池，编码，存储字序和基础的数据流
  4.         public SslStreamX(IBufferPool pool, Encoding encoding, bool littleEndian, Stream innerStream, bool leaveInnerStreamOpen) 
  5.         : base(innerStream, leaveInnerStreamOpen)
  6.         {
  7.             BufferPool = pool;
  8.             Encoding = encoding;
  9.             LittleEndian = littleEndian;
  10.             mPipeStream = new PipeStream(BufferPool, LittleEndian, Encoding);
  11.             mPipeStream.FlashCompleted = OnWriterFlash;
  12.             mPipeStream.InnerStream = this;
  13.         }
  14.         //构建SslStreamX,并指写来源的缓冲池，编码，存储字序，基础的数据流和验证回调方法
  15.         public SslStreamX(
  16.             IBufferPool pool, Encoding encoding, bool littleEndian, Stream innerStream, RemoteCertificateValidationCallback callback)
  17.             : base(innerStream, false, callback, null)
  18.         {
  19.             BufferPool = pool;
  20.             Encoding = encoding;
  21.             LittleEndian = littleEndian;
  22.             mPipeStream = new PipeStream(BufferPool, LittleEndian, Encoding);
  23.             mPipeStream.FlashCompleted = OnWriterFlash;
  24.             mPipeStream.InnerStream = this;
  25.         }
  28.         public IBufferPool BufferPool { get; set; }
  30.         public Encoding Encoding { get; set; }
  32.         public bool LittleEndian { get; set; }
  34.         private PipeStream mPipeStream;
  35.         //提交数据到SslStream
  36.         private void OnWriterFlash(Buffers.IBuffer data)
  37.         {
  38.             StreamHelper.WriteBuffer(this, data);
  39.         }
  40.         //提交数据
  41.         public override void Flush()
  42.         {
  43.             if (mPipeStream != null)
  44.                 mPipeStream.Flush();
  45.             base.Flush();
  46.         }
  47.         //获取当前SslStream对应的PipeStream
  48.         public PipeStream GetPipeStream()
  49.         {
  50.             return mPipeStream;
  51.         }
  53.         public Exception SyncDataError { get; set; }
  55.         public bool AsyncDataStatus { get; set; }
  56.         //同步接收的数据到PipeStream中
  57.         public async void SyncData(Action receive)
  58.         {
  59.             while (true)
  60.             {
  61.                 var dest = GetPipeStream();
  62.                 IBuffer buffer = null;
  63.                 try
  64.                 {
  65.                     buffer = BufferPoolGroup.DefaultGroup.Next().Pop();
  66.                     int rlen = await ReadAsync(buffer.Data, 0, buffer.Size);
  67.                     if (rlen > 0)
  68.                     {
  69.                         buffer.SetLength(rlen);
  70.                         dest.Import(buffer);
  71.                     }
  72.                     else
  73.                     {
  74.                         buffer.Free();
  75.                         SyncDataError = new BXException("ssl receive null data!");
  76.                         break;
  77.                     }
  79.                 }
  80.                 catch (Exception e_)
  81.                 {
  82.                     SyncDataError = e_;
  83.                     buffer?.Free();
  84.                     break;
  85.                 }
  86.                 finally
  87.                 {
  88.                    receive?.Invoke();
  89.                 }
  90.             }
  91.         }
  92.         //释放流
  93.         protected override void Dispose(bool disposing)
  94.         {
  95.             base.Dispose(disposing);
  96.             if (mPipeStream != null)
  97.             {
  98.                 mPipeStream.Dispose();
  99.                 mPipeStream = null;
  100.             }
  101.         }
  102.     }

(https://github.com/IKende/BeetleX/blob/master/src/BeetleX/Buffers/SslStramX.cs)
由于实现机制上的差异，SslStreamX的读写数据流是不建议直接调用SslStream的Read/Write方法进行;而是通过GetPipeStream获取内部的PipeStream进行一个写入操作;实际上PipeStream的写入并没有直接提交给SslStreamX,而是当SslStreamX提交的时候再把写入的数据流一次过提交给SslStream。

数据同步

SslStreamX提供了一个同步数据的方法SyncData，主要是通过异步读取基础数据流，如果有数据则读取的数据导入到内部的PipeStream对象并回调; 接下来看一下如何在Socket中使用SslStreamX.

  1.         public void CreateSSL(AsyncCallback asyncCallback, ListenHandler listen, IServer server)
  2.         {
  3.             try
  4.             {
  5.                 if (server.EnableLog(EventArgs.LogType.Info))
  6.                     server.Log(EventArgs.LogType.Info, null, $"{RemoteEndPoint} create ssl stream");
  7.                 mBaseNetStream.SSL = true;
  8.                 mSslStream = new SslStreamX(this.SendBufferPool, server.Options.Encoding,
  9.                     server.Options.LittleEndian, mBaseNetStream, false);
  10.                 mSslStream.BeginAuthenticateAsServer(listen.Certificate, false, listen.SslProtocols,true, new AsyncCallback(asyncCallback),
  11.                      new Tuple<TcpSession, SslStream>(this, this.mSslStream));
  12.             }
  13.             catch (Exception e_)
  14.             {
  15.                 if (server.EnableLog(EventArgs.LogType.Warring))
  16.                     server.Log(EventArgs.LogType.Warring, this, $"{this.RemoteEndPoint} create session ssl error {e_.Message}@{e_.StackTrace}");
  17.                 this.Dispose();
  18.             }
  19.         }

（https://github.com/IKende/BeetleX/blob/master/src/BeetleX/Buffers/SslStramX.cs）
以上是组件针对SslStreamX的一个集成代码。