/// <summary>
/// Perform WebSocket client upgrade
/// </summary>
/// <param name="response">WebSocket upgrade HTTP response</param>
/// <returns>'true' if the WebSocket was successfully upgrade, 'false' if the WebSocket was not upgrade</returns>
public bool PerformClientUpgrade(HttpResponse response)
{
if (response.Status != 101)
{
return(false);
}
bool error = false;
bool accept = false;
bool connection = false;
bool upgrade = false;
// Validate WebSocket handshake headers
for (int i = 0; i < response.Headers; i++)
{
var header = response.Header(i);
var key = header.Item1;
var value = header.Item2;
if (string.Compare(key, "Connection", StringComparison.OrdinalIgnoreCase) == 0)
{
if (string.Compare(value, "Upgrade", StringComparison.OrdinalIgnoreCase) != 0)
{
error = true;
_wsHandler.OnWsError("Invalid WebSocket handshaked response: 'Connection' header value must be 'Upgrade'");
break;
}
connection = true;
}
else if (string.Compare(key, "Upgrade", StringComparison.OrdinalIgnoreCase) == 0)
{
if (string.Compare(value, "websocket", StringComparison.OrdinalIgnoreCase) != 0)
{
error = true;
_wsHandler.OnWsError("Invalid WebSocket handshaked response: 'Upgrade' header value must be 'websocket'");
break;
}
upgrade = true;
}
else if (string.Compare(key, "Sec-WebSocket-Accept", StringComparison.OrdinalIgnoreCase) == 0)
{
// Calculate the original WebSocket hash
string wskey = Convert.ToBase64String(WsNonce) + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
string wshash;
using (SHA1Managed sha1 = new SHA1Managed())
{
wshash = Encoding.UTF8.GetString(sha1.ComputeHash(Encoding.UTF8.GetBytes(wskey)));
}
// Get the received WebSocket hash
wskey = Encoding.UTF8.GetString(Convert.FromBase64String(value));
// Compare original and received hashes
if (string.Compare(wskey, wshash, StringComparison.InvariantCulture) != 0)
{
error = true;
_wsHandler.OnWsError("Invalid WebSocket handshaked response: 'Sec-WebSocket-Accept' value validation failed");
break;
}
accept = true;
}
}
// Failed to perform WebSocket handshake
if (!accept || !connection || !upgrade)
{
if (!error)
{
_wsHandler.OnWsError("Invalid WebSocket response");
}
return(false);
}
// WebSocket successfully handshaked!
WsHandshaked = true;
WsRandom.NextBytes(WsSendMask);
_wsHandler.OnWsConnected(response);
return(true);
}
