/// <summary>
/// Waits until the connected client sends a SOCKS5 request.
/// </summary>
/// <returns>The SOCKS5 request sent by the client.</returns>
/// <exception cref="Socks5Exception">The data sent by the client
/// is not a valid SOCKS5 request.</exception>
private SocksRequest WaitForRequest()
{
ByteBuilder b = new ByteBuilder();
using (var r = new BinaryReader(stream, Encoding.UTF8, true))
{
byte[] bytes = r.ReadBytes(4);
b.Append(bytes);
ATyp atyp = (ATyp)bytes[3];
switch (atyp)
{
case ATyp.IPv4:
case ATyp.IPv6:
b.Append(r.ReadBytes(atyp == ATyp.IPv4 ? 4 : 16));
break;
case ATyp.Domain:
byte length = r.ReadByte();
b.Append(length).Append(r.ReadBytes(length));
break;
}
b.Append(r.ReadBytes(2));
}
try
{
return(SocksRequest.Deserialize(b.ToArray()));
}
catch (Exception e)
{
throw new Socks5Exception("The request could not be serialized.", e);
}
}
/// <summary>
/// Performs the specified SOCKS5 request.
/// </summary>
/// <param name="request">The SOCKS5 request to issue to the server.</param>
/// <returns>The SOCKS5 reply sent by the server.</returns>
/// <exception cref="ArgumentNullException">The request parameter is
/// null.</exception>
/// <exception cref="ObjectDisposedException">The object has been
/// disposed.</exception>
/// <exception cref="Socks5Exception">The request could not be performed.
/// Consult the InnerException property of the Socks5Exception to learn
/// the reason.</exception>
public SocksReply Request(SocksRequest request)
{
request.ThrowIfNull("request");
AssertValid();
try
{
byte[] bytes = request.Serialize();
stream.Write(bytes, 0, bytes.Length);
ByteBuilder b = new ByteBuilder();
using (var r = new BinaryReader(stream, Encoding.UTF8, true))
{
bytes = r.ReadBytes(4);
b.Append(bytes);
ATyp atyp = (ATyp)bytes[3];
switch (atyp)
{
case ATyp.IPv4:
case ATyp.IPv6:
b.Append(r.ReadBytes(atyp == ATyp.IPv4 ? 4 : 16));
break;
case ATyp.Domain:
byte length = r.ReadByte();
b.Append(length).Append(r.ReadBytes(length));
break;
}
b.Append(r.ReadBytes(2));
}
return(SocksReply.Deserialize(b.ToArray()));
}
catch (Exception e)
{
throw new Socks5Exception("The request could not be performed.", e);
}
}
/// <summary>
/// Serializes the instance into an array of bytes.
/// </summary>
/// <returns>An array of bytes representing the instance of the
/// ClientGreeting class.</returns>
public byte[] Serialize()
{
ByteBuilder b = new ByteBuilder()
.Append(version)
.Append((byte)methods.Count);
foreach (AuthMethod m in Methods)
{
b.Append((byte)m);
}
return(b.ToArray());
}
/// <summary>
/// Performs the initial greeting.
/// </summary>
/// <exception cref="Socks5Exception">The client sent invalid data, or
/// requires authentication.</exception>
/// <exception cref="IOException">The stream could not be read, or the
/// operation timed out.</exception>
private void PerformGreeting()
{
ByteBuilder b = new ByteBuilder();
using (var r = new BinaryReader(stream, Encoding.UTF8, true))
{
byte[] bytes = r.ReadBytes(2);
b.Append(bytes);
// The number of method-bytes following is contained in the second byte.
b.Append(r.ReadBytes(bytes[1]));
}
ClientGreeting greeting = ClientGreeting.Deserialize(b.ToArray());
// We only accept an authentication method of 'none'.
if (!greeting.Methods.Contains(AuthMethod.None))
{
Dispose();
throw new Socks5Exception("Client requires authentication.");
}
// Send back our greeting response.
var response = new ServerGreeting(AuthMethod.None).Serialize();
stream.Write(response, 0, response.Length);
}
