RecordStream.cs :  » PDF » iTextSharp » Org » BouncyCastle » Crypto » Tls » C# / CSharp Open Source

using System;
using System.IO;

namespace Org.BouncyCastle.Crypto.Tls{
  /// <remarks>An implementation of the TLS 1.0 record layer.</remarks>
  internal class RecordStream
  {
    private TlsProtocolHandler handler;
    private Stream inStr;
    private Stream outStr;
    internal CombinedHash hash1;
    internal CombinedHash hash2;
    internal CombinedHash hash3;
    internal TlsCipherSuite readSuite = null;
    internal TlsCipherSuite writeSuite = null;

    internal RecordStream(
      TlsProtocolHandler  handler,
      Stream        inStr,
      Stream        outStr)
    {
      this.handler = handler;
      this.inStr = inStr;
      this.outStr = outStr;
      this.hash1 = new CombinedHash();
      this.hash2 = new CombinedHash();
      this.hash3 = new CombinedHash();
      this.readSuite = new TlsNullCipherSuite();
      this.writeSuite = this.readSuite;
    }

    public void ReadData()
    {
      short type = TlsUtilities.ReadUint8(inStr);
      TlsUtilities.CheckVersion(inStr, handler);
      int size = TlsUtilities.ReadUint16(inStr);
      byte[] buf = DecodeAndVerify(type, inStr, size);
      handler.ProcessData(type, buf, 0, buf.Length);

    }

    internal byte[] DecodeAndVerify(
      short  type,
      Stream  inStr,
      int    len)
    {
      byte[] buf = new byte[len];
      TlsUtilities.ReadFully(buf, inStr);
      return readSuite.DecodeCiphertext(type, buf, 0, buf.Length);
    }

    internal void WriteMessage(
      short  type,
      byte[]  message,
      int    offset,
      int    len)
    {
      if (type == 22)
      {
        UpdateHandshakeData(message, offset, len);
      }
      byte[] ciphertext = writeSuite.EncodePlaintext(type, message, offset, len);
      byte[] writeMessage = new byte[ciphertext.Length + 5];
      TlsUtilities.WriteUint8(type, writeMessage, 0);
      TlsUtilities.WriteUint8((short)3, writeMessage, 1);
      TlsUtilities.WriteUint8((short)1, writeMessage, 2);
      TlsUtilities.WriteUint16(ciphertext.Length, writeMessage, 3);
      Array.Copy(ciphertext, 0, writeMessage, 5, ciphertext.Length);
      outStr.Write(writeMessage, 0, writeMessage.Length);
      outStr.Flush();
    }

    internal void UpdateHandshakeData(
      byte[]  message,
      int    offset,
      int    len)
    {
      hash1.BlockUpdate(message, offset, len);
      hash2.BlockUpdate(message, offset, len);
      hash3.BlockUpdate(message, offset, len);
    }

    internal void Close()
    {
      IOException e = null;
      try
      {
        inStr.Close();
      }
      catch (IOException ex)
      {
        e = ex;
      }

      try
      {
        // NB: This is harmless if outStr == inStr
        outStr.Close();
      }
      catch (IOException ex)
      {
        e = ex;
      }

      if (e != null)
      {
        throw e;
      }
    }

    internal void Flush()
    {
      outStr.Flush();
    }
  }
}