public async ValueTask ConnectAsync(Socket socket, EndPoint endpoint, CancellationToken cancel)
{
// HTTP connect request
string addr = endpoint.ToString() !;
var sb = new System.Text.StringBuilder();
sb.Append("CONNECT ");
sb.Append(addr);
sb.Append(" HTTP/1.1\r\nHost: ");
sb.Append(addr);
sb.Append("\r\n\r\n");
// Send the connect request.
await socket.SendAsync(System.Text.Encoding.ASCII.GetBytes(sb.ToString()),
SocketFlags.None,
cancel).ConfigureAwait(false);
// Read the HTTP response, reserve enough space for reading at least HTTP1.1
byte[] buffer = new byte[256];
int received = 0;
while (true)
{
received += await socket.ReceiveAsync(buffer.AsMemory(received),
SocketFlags.None,
cancel).ConfigureAwait(false);
// Check if we received the full HTTP response, if not, continue reading otherwise we're done.
int end = HttpParser.IsCompleteMessage(buffer.AsSpan(0, received));
if (end < 0 && received == buffer.Length)
{
// We need to allocate a new buffer
byte[] newBuffer = new byte[buffer.Length * 2];
Buffer.BlockCopy(buffer, 0, newBuffer, 0, received);
buffer = newBuffer;
}
else
{
break;
}
}
var parser = new HttpParser();
parser.Parse(buffer);
if (parser.Status() != 200)
{
// TODO the retry always use the same proxy address
throw new ConnectFailedException(RetryPolicy.AfterDelay(TimeSpan.Zero));
}
}
public async ValueTask InitializeAsync(CancellationToken cancel)
{
await _underlying.InitializeAsync(cancel).ConfigureAwait(false);
try
{
// The server waits for the client's upgrade request, the client sends the upgrade request.
if (!_incoming)
{
// Compose the upgrade request.
var sb = new StringBuilder();
sb.Append("GET " + _resource + " HTTP/1.1\r\n");
sb.Append("Host: " + _host + "\r\n");
sb.Append("Upgrade: websocket\r\n");
sb.Append("Connection: Upgrade\r\n");
sb.Append("Sec-WebSocket-Protocol: " + IceProtocol + "\r\n");
sb.Append("Sec-WebSocket-Version: 13\r\n");
sb.Append("Sec-WebSocket-Key: ");
// The value for Sec-WebSocket-Key is a 16-byte random number, encoded with Base64.
byte[] key = new byte[16];
_rand.NextBytes(key);
_key = Convert.ToBase64String(key);
sb.Append(_key + "\r\n\r\n"); // EOM
byte[] data = _utf8.GetBytes(sb.ToString());
_sendBuffer.Add(data);
await _underlying.SendAsync(_sendBuffer, cancel).ConfigureAwait(false);
}
_sendBuffer.Clear();
// Try to read the client's upgrade request or the server's response.
var httpBuffer = new ArraySegment <byte>();
while (true)
{
ReadOnlyMemory <byte> buffer = await _underlying.ReceiveAsync(0, cancel).ConfigureAwait(false);
if (httpBuffer.Count + buffer.Length > _communicator.IncomingFrameSizeMax)
{
throw new InvalidDataException(
"WebSocket frame size is greater than the configured IncomingFrameSizeMax value");
}
ArraySegment <byte> tmpBuffer = new byte[httpBuffer.Count + buffer.Length];
if (httpBuffer.Count > 0)
{
httpBuffer.CopyTo(tmpBuffer);
}
buffer.CopyTo(tmpBuffer.Slice(httpBuffer.Count));
httpBuffer = tmpBuffer;
// Check if we have enough data for a complete frame.
int endPos = HttpParser.IsCompleteMessage(httpBuffer);
if (endPos != -1)
{
// Add back the un-consumed data to the buffer.
_underlying.Rewind(httpBuffer.Count - endPos);
httpBuffer = httpBuffer.Slice(0, endPos);
break; // Done
}
}
try
{
if (_parser.Parse(httpBuffer))
{
if (_incoming)
{
(bool addProtocol, string key) = ReadUpgradeRequest();
// Compose the response.
var sb = new StringBuilder();
sb.Append("HTTP/1.1 101 Switching Protocols\r\n");
sb.Append("Upgrade: websocket\r\n");
sb.Append("Connection: Upgrade\r\n");
if (addProtocol)
{
sb.Append($"Sec-WebSocket-Protocol: {IceProtocol}\r\n");
}
// The response includes:
//
// "A |Sec-WebSocket-Accept| header field. The value of this header field is constructed
// by concatenating /key/, defined above in step 4 in Section 4.2.2, with the string
// "258EAFA5-E914-47DA-95CA-C5AB0DC85B11", taking the SHA-1 hash of this concatenated value
// to obtain a 20-byte value and base64-encoding (see Section 4 of [RFC4648]) this 20-byte
// hash.
sb.Append("Sec-WebSocket-Accept: ");
string input = key + WsUUID;
#pragma warning disable CA5350 // Do Not Use Weak Cryptographic Algorithms
using var sha1 = SHA1.Create();
byte[] hash = sha1.ComputeHash(_utf8.GetBytes(input));
#pragma warning restore CA5350 // Do Not Use Weak Cryptographic Algorithms
sb.Append(Convert.ToBase64String(hash) + "\r\n" + "\r\n"); // EOM
Debug.Assert(_sendBuffer.Count == 0);
byte[] data = _utf8.GetBytes(sb.ToString());
_sendBuffer.Add(data);
await _underlying.SendAsync(_sendBuffer, cancel).ConfigureAwait(false);
_sendBuffer.Clear();
}
else
{
ReadUpgradeResponse();
}
}
else
{
throw new InvalidDataException("incomplete WebSocket request frame");
}
}
catch (WebSocketException ex)
{
throw new InvalidDataException(ex.Message, ex);
}
}
catch (Exception ex)
{
if (_communicator.TraceLevels.Transport >= 2)
{
_communicator.Logger.Trace(TraceLevels.TransportCategory,
$"{_transportName} connection HTTP upgrade request failed\n{this}\n{ex}");
}
throw;
}
if (_communicator.TraceLevels.Transport >= 1)
{
if (_incoming)
{
_communicator.Logger.Trace(TraceLevels.TransportCategory,
$"accepted {_transportName} connection HTTP upgrade request\n{this}");
}
else
{
_communicator.Logger.Trace(TraceLevels.TransportCategory,
$"{_transportName} connection HTTP upgrade request accepted\n{this}");
}
}
}