//
// ClientWebSocket.cs
//
-// Author:
-// Martin Baulig <martin.baulig@xamarin.com>
+// Authors:
+// Jérémie Laval <jeremie dot laval at xamarin dot com>
//
-// Copyright (c) 2013 Xamarin Inc. (http://www.xamarin.com)
+// Copyright 2013 Xamarin Inc (http://www.xamarin.com).
+//
+// Lightly inspired from WebSocket4Net distributed under the Apache License 2.0
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
#if NET_4_5
using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Security.Principal;
+using System.Security.Cryptography.X509Certificates;
+using System.Runtime.CompilerServices;
+using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
+using System.Globalization;
+using System.Text;
+using System.Security.Cryptography;
namespace System.Net.WebSockets
{
- [MonoTODO]
- public class ClientWebSocket : WebSocket
+ public class ClientWebSocket : WebSocket, IDisposable
{
- public ClientWebSocketOptions Options {
- get { throw new NotImplementedException (); }
+ const string Magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+ const string VersionTag = "13";
+
+ ClientWebSocketOptions options;
+ WebSocketState state;
+ string subProtocol;
+
+ HttpWebRequest req;
+ WebConnection connection;
+ Socket underlyingSocket;
+
+ Random random = new Random ();
+
+ const int HeaderMaxLength = 14;
+ byte[] headerBuffer;
+ byte[] sendBuffer;
+ long remaining;
+
+ public ClientWebSocket ()
+ {
+ options = new ClientWebSocketOptions ();
+ state = WebSocketState.None;
+ headerBuffer = new byte[HeaderMaxLength];
}
- public Task ConnectAsync (Uri uri, CancellationToken cancellationToken)
+ public override void Dispose ()
{
- throw new NotImplementedException ();
+ if (connection != null)
+ connection.Close (false);
}
- #region implemented abstract members of WebSocket
+ [MonoTODO]
public override void Abort ()
{
throw new NotImplementedException ();
}
- public override Task CloseAsync (WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
+
+ public ClientWebSocketOptions Options {
+ get {
+ return options;
+ }
+ }
+
+ public override WebSocketState State {
+ get {
+ return state;
+ }
+ }
+
+ public override WebSocketCloseStatus? CloseStatus {
+ get {
+ if (state != WebSocketState.Closed)
+ return (WebSocketCloseStatus?)null;
+ return WebSocketCloseStatus.Empty;
+ }
+ }
+
+ public override string CloseStatusDescription {
+ get {
+ return null;
+ }
+ }
+
+ public override string SubProtocol {
+ get {
+ return subProtocol;
+ }
+ }
+
+ public async Task ConnectAsync (Uri uri, CancellationToken cancellationToken)
{
- throw new NotImplementedException ();
+ state = WebSocketState.Connecting;
+ var httpUri = new UriBuilder (uri);
+ if (uri.Scheme == "wss")
+ httpUri.Scheme = "https";
+ else
+ httpUri.Scheme = "http";
+ req = (HttpWebRequest)WebRequest.Create (httpUri.Uri);
+ req.ReuseConnection = true;
+ if (options.Cookies != null)
+ req.CookieContainer = options.Cookies;
+
+ if (options.CustomRequestHeaders.Count > 0) {
+ foreach (var header in options.CustomRequestHeaders)
+ req.Headers[header.Key] = header.Value;
+ }
+
+ var secKey = Convert.ToBase64String (Encoding.ASCII.GetBytes (Guid.NewGuid ().ToString ().Substring (0, 16)));
+ string expectedAccept = Convert.ToBase64String (SHA1.Create ().ComputeHash (Encoding.ASCII.GetBytes (secKey + Magic)));
+
+ req.Headers["Upgrade"] = "WebSocket";
+ req.Headers["Sec-WebSocket-Version"] = VersionTag;
+ req.Headers["Sec-WebSocket-Key"] = secKey;
+ req.Headers["Sec-WebSocket-Origin"] = uri.Host;
+ if (options.SubProtocols.Count > 0)
+ req.Headers["Sec-WebSocket-Protocol"] = string.Join (",", options.SubProtocols);
+
+ if (options.Credentials != null)
+ req.Credentials = options.Credentials;
+ if (options.ClientCertificates != null)
+ req.ClientCertificates = options.ClientCertificates;
+ if (options.Proxy != null)
+ req.Proxy = options.Proxy;
+ req.UseDefaultCredentials = options.UseDefaultCredentials;
+ req.Connection = "Upgrade";
+
+ HttpWebResponse resp = null;
+ try {
+ resp = (HttpWebResponse)(await req.GetResponseAsync ().ConfigureAwait (false));
+ } catch (Exception e) {
+ throw new WebSocketException (WebSocketError.Success, e);
+ }
+
+ connection = req.StoredConnection;
+ underlyingSocket = connection.socket;
+
+ if (resp.StatusCode != HttpStatusCode.SwitchingProtocols)
+ throw new WebSocketException ("The server returned status code '" + (int)resp.StatusCode + "' when status code '101' was expected");
+ if (!string.Equals (resp.Headers["Upgrade"], "WebSocket", StringComparison.OrdinalIgnoreCase)
+ || !string.Equals (resp.Headers["Connection"], "Upgrade", StringComparison.OrdinalIgnoreCase)
+ || !string.Equals (resp.Headers["Sec-WebSocket-Accept"], expectedAccept))
+ throw new WebSocketException ("HTTP header error during handshake");
+ if (resp.Headers["Sec-WebSocket-Protocol"] != null) {
+ if (!options.SubProtocols.Contains (resp.Headers["Sec-WebSocket-Protocol"]))
+ throw new WebSocketException (WebSocketError.UnsupportedProtocol);
+ subProtocol = resp.Headers["Sec-WebSocket-Protocol"];
+ }
+
+ state = WebSocketState.Open;
}
- public override Task CloseOutputAsync (WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
+
+ public override Task SendAsync (ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
{
- throw new NotImplementedException ();
+ EnsureWebSocketConnected ();
+ ValidateArraySegment (buffer);
+ if (connection == null)
+ throw new WebSocketException (WebSocketError.Faulted);
+ var count = Math.Max (options.SendBufferSize, buffer.Count) + HeaderMaxLength;
+ if (sendBuffer == null || sendBuffer.Length != count)
+ sendBuffer = new byte[count];
+ return Task.Run (() => {
+ EnsureWebSocketState (WebSocketState.Open, WebSocketState.CloseReceived);
+ var maskOffset = WriteHeader (messageType, buffer, endOfMessage);
+
+ if (buffer.Count > 0)
+ MaskData (buffer, maskOffset);
+ //underlyingSocket.Send (headerBuffer, 0, maskOffset + 4, SocketFlags.None);
+ var headerLength = maskOffset + 4;
+ Array.Copy (headerBuffer, sendBuffer, headerLength);
+ underlyingSocket.Send (sendBuffer, 0, buffer.Count + headerLength, SocketFlags.None);
+ });
+ }
+
+ const int messageTypeText = 1;
+ const int messageTypeBinary = 2;
+ const int messageTypeClose = 8;
+
+ static WebSocketMessageType WireToMessageType (byte msgType)
+ {
+
+ if (msgType == messageTypeText)
+ return WebSocketMessageType.Text;
+ if (msgType == messageTypeBinary)
+ return WebSocketMessageType.Binary;
+ return WebSocketMessageType.Close;
}
+
+ static byte MessageTypeToWire (WebSocketMessageType type)
+ {
+ if (type == WebSocketMessageType.Text)
+ return messageTypeText;
+ if (type == WebSocketMessageType.Binary)
+ return messageTypeBinary;
+ return messageTypeClose;
+ }
+
public override Task<WebSocketReceiveResult> ReceiveAsync (ArraySegment<byte> buffer, CancellationToken cancellationToken)
{
- throw new NotImplementedException ();
+ EnsureWebSocketConnected ();
+ ValidateArraySegment (buffer);
+ return Task.Run (() => {
+ EnsureWebSocketState (WebSocketState.Open, WebSocketState.CloseSent);
+
+ bool isLast;
+ WebSocketMessageType type;
+ long length;
+
+ if (remaining == 0) {
+ // First read the two first bytes to know what we are doing next
+ connection.Read (req, headerBuffer, 0, 2);
+ isLast = (headerBuffer[0] >> 7) > 0;
+ var isMasked = (headerBuffer[1] >> 7) > 0;
+ int mask = 0;
+ type = WireToMessageType ((byte)(headerBuffer[0] & 0xF));
+ length = headerBuffer[1] & 0x7F;
+ int offset = 0;
+ if (length == 126) {
+ offset = 2;
+ connection.Read (req, headerBuffer, 2, offset);
+ length = (headerBuffer[2] << 8) | headerBuffer[3];
+ } else if (length == 127) {
+ offset = 8;
+ connection.Read (req, headerBuffer, 2, offset);
+ length = 0;
+ for (int i = 2; i <= 9; i++)
+ length = (length << 8) | headerBuffer[i];
+ }
+
+ if (isMasked) {
+ connection.Read (req, headerBuffer, 2 + offset, 4);
+ for (int i = 0; i < 4; i++) {
+ var pos = i + offset + 2;
+ mask = (mask << 8) | headerBuffer[pos];
+ }
+ }
+ } else {
+ isLast = (headerBuffer[0] >> 7) > 0;
+ type = WireToMessageType ((byte)(headerBuffer[0] & 0xF));
+ length = remaining;
+ }
+
+ if (type == WebSocketMessageType.Close) {
+ state = WebSocketState.Closed;
+ var tmpBuffer = new byte[length];
+ connection.Read (req, tmpBuffer, 0, tmpBuffer.Length);
+ var closeStatus = (WebSocketCloseStatus)(tmpBuffer[0] << 8 | tmpBuffer[1]);
+ var closeDesc = tmpBuffer.Length > 2 ? Encoding.UTF8.GetString (tmpBuffer, 2, tmpBuffer.Length - 2) : string.Empty;
+ return new WebSocketReceiveResult ((int)length, type, isLast, closeStatus, closeDesc);
+ } else {
+ var readLength = (int)(buffer.Count < length ? buffer.Count : length);
+ connection.Read (req, buffer.Array, buffer.Offset, readLength);
+ remaining = length - readLength;
+
+ return new WebSocketReceiveResult ((int)readLength, type, isLast && remaining == 0);
+ }
+ });
}
- public override Task SendAsync (ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
+
+ // The damn difference between those two methods is that CloseAsync will wait for server acknowledgement before completing
+ // while CloseOutputAsync will send the close packet and simply complete.
+
+ public async override Task CloseAsync (WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
{
- throw new NotImplementedException ();
+ EnsureWebSocketConnected ();
+ await SendCloseFrame (closeStatus, statusDescription, cancellationToken).ConfigureAwait (false);
+ state = WebSocketState.CloseSent;
+ // TODO: figure what's exceptions are thrown if the server returns something faulty here
+ await ReceiveAsync (new ArraySegment<byte> (new byte[0]), cancellationToken).ConfigureAwait (false);
+ state = WebSocketState.Closed;
}
- public override void Dispose ()
+
+ public async override Task CloseOutputAsync (WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
{
- throw new NotImplementedException ();
+ EnsureWebSocketConnected ();
+ await SendCloseFrame (closeStatus, statusDescription, cancellationToken).ConfigureAwait (false);
+ state = WebSocketState.CloseSent;
}
- public override WebSocketCloseStatus? CloseStatus {
- get {
- throw new NotImplementedException ();
- }
+
+ async Task SendCloseFrame (WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
+ {
+ var statusDescBuffer = string.IsNullOrEmpty (statusDescription) ? new byte[2] : new byte[2 + Encoding.UTF8.GetByteCount (statusDescription)];
+ statusDescBuffer[0] = (byte)(((ushort)closeStatus) >> 8);
+ statusDescBuffer[1] = (byte)(((ushort)closeStatus) & 0xFF);
+ if (!string.IsNullOrEmpty (statusDescription))
+ Encoding.UTF8.GetBytes (statusDescription, 0, statusDescription.Length, statusDescBuffer, 2);
+ await SendAsync (new ArraySegment<byte> (statusDescBuffer), WebSocketMessageType.Close, true, cancellationToken).ConfigureAwait (false);
}
- public override string CloseStatusDescription {
- get {
- throw new NotImplementedException ();
+
+ int WriteHeader (WebSocketMessageType type, ArraySegment<byte> buffer, bool endOfMessage)
+ {
+ var opCode = MessageTypeToWire (type);
+ var length = buffer.Count;
+
+ headerBuffer[0] = (byte)(opCode | (endOfMessage ? 0x80 : 0));
+ if (length < 126) {
+ headerBuffer[1] = (byte)length;
+ } else if (length <= ushort.MaxValue) {
+ headerBuffer[1] = (byte)126;
+ headerBuffer[2] = (byte)(length / 256);
+ headerBuffer[3] = (byte)(length % 256);
+ } else {
+ headerBuffer[1] = (byte)127;
+
+ int left = length;
+ int unit = 256;
+
+ for (int i = 9; i > 1; i--) {
+ headerBuffer[i] = (byte)(left % unit);
+ left = left / unit;
+ }
}
+
+ var l = Math.Max (0, headerBuffer[1] - 125);
+ var maskOffset = 2 + l * l * 2;
+ GenerateMask (headerBuffer, maskOffset);
+
+ // Since we are client only, we always mask the payload
+ headerBuffer[1] |= 0x80;
+
+ return maskOffset;
}
- public override WebSocketState State {
- get {
- throw new NotImplementedException ();
- }
+
+ void GenerateMask (byte[] mask, int offset)
+ {
+ mask[offset + 0] = (byte)random.Next (0, 255);
+ mask[offset + 1] = (byte)random.Next (0, 255);
+ mask[offset + 2] = (byte)random.Next (0, 255);
+ mask[offset + 3] = (byte)random.Next (0, 255);
}
- public override string SubProtocol {
- get {
- throw new NotImplementedException ();
- }
+
+ void MaskData (ArraySegment<byte> buffer, int maskOffset)
+ {
+ var sendBufferOffset = maskOffset + 4;
+ for (var i = 0; i < buffer.Count; i++)
+ sendBuffer[i + sendBufferOffset] = (byte)(buffer.Array[buffer.Offset + i] ^ headerBuffer[maskOffset + (i % 4)]);
+ }
+
+ void EnsureWebSocketConnected ()
+ {
+ if (state < WebSocketState.Open)
+ throw new InvalidOperationException ("The WebSocket is not connected");
+ }
+
+ void EnsureWebSocketState (params WebSocketState[] validStates)
+ {
+ foreach (var validState in validStates)
+ if (state == validState)
+ return;
+ throw new WebSocketException ("The WebSocket is in an invalid state ('" + state + "') for this operation. Valid states are: " + string.Join (", ", validStates));
+ }
+
+ void ValidateArraySegment (ArraySegment<byte> segment)
+ {
+ if (segment.Array == null)
+ throw new ArgumentNullException ("buffer.Array");
+ if (segment.Offset < 0)
+ throw new ArgumentOutOfRangeException ("buffer.Offset");
+ if (segment.Offset + segment.Count > segment.Array.Length)
+ throw new ArgumentOutOfRangeException ("buffer.Count");
}
- #endregion
}
}
#endif
-