websocket stop responding after handshake - websocket

Question

I am building a websocket client (vb.net) with a simple socket.
I'm doing it to have better understanding of it before starting it on embedded project (cc3220).
It seems like i passed the handshake just fine, and after receiving one text frame the data stop to be received.
the websocket server is .net core Azure project works as echo. works great with simple websocket client chrome extension with multiple connections.
here is the log from my VB.NET app, maybe please someone can spot the problem:
--- Sending via socket--
GET http://xxxxxxxx.azurewebsites.net/xxxxxxx HTTP/1.1
Host: xxxxxxxxxx.azurewebsites.net
Connection: Upgrade
Upgrade: WebSocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: gnuE6HbBVfsHzYVNLdxxbQ==
--- New pack received---
total bytes:206
72,84,84,80,47,49,46,49,32,49,48,49,32,83,119,105,116,99,104,105,110,103,32,80,114,111,116,111,99,111,108,115,13,10,85,112,103,114,97,100,101,58,32,119,101,98,115,111,99,107,101,116,13,10,83,101,114,118,101,114,58,32,75,101,115,116,114,101,108,13,10,83,101,99,45,87,101,98,83,111,99,107,101,116,45,65,99,99,101,112,116,58,32,84,101,70,54,79,103,112,48,109,79,106,118,102,105,99,70,82,116,90,48,107,105,52,114,83,49,103,61,13,10,88,45,80,111,119,101,114,101,100,45,66,121,58,32,65,83,80,46,78,69,84,13,10,67,111,110,110,101,99,116,105,111,110,58,32,85,112,103,114,97,100,101,13,10,68,97,116,101,58,32,84,117,101,44,32,49,48,32,65,112,114,32,50,48,49,56,32,50,48,58,51,56,58,53,54,32,71,77,84,13,10,13,10,0,
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Server: Kestrel
Sec-WebSocket-Accept: TeF6Ogp0mOjvficFRtZ0ki4rS1g=
X-Powered-By: ASP.NET
Connection: Upgrade
Date: Tue, 10 Apr 2018 20:38:56 GMT
--- New pack receive---
total bytes:42
129,24,119,101,108,99,111,109,101,32,104,111,119,32,100,111,32,121,111,117,32,100,111,63,13,10,129,14,110,101,119,32,99,111,110,110,101,99,116,105,111,110,32,
welcome how do you do?
new connection
Length: 24 op_code: 1(string data)
-- sending data (string 123) via socket, here there is no respond, the server should echo this ----
Sending string: 123
Sending bytes: 129,3,49,50,51,
Sending string: 123
Sending bytes: 129,3,49,50,51,
--- even when sending data via another websocket client app, the data is not received here, but it does to the third websocket client app ---
VbCode:
Public Class SocketObject
Public socket As Socket = Nothing
Public Const BUFFER_SIZE As Integer = 1024
Public buffer(BUFFER_SIZE) As Byte
End Class 'StateObject
Dim sock As New SocketObject()
Private Sub printbytes(ByVal bytes() As Byte, ByVal size As Int16)
Dim i As Integer = 0
Dim a As String = vbCrLf + "--- New pack receive--- " + vbCrLf + "total bytes:" + size.ToString() + vbCrLf
Dim b As String = ""
For i = 0 To size
a += bytes(i).ToString() + ","
b += Chr(bytes(i))
Next
Dim c As String = ""
If (bytes(0) >= &H0) And (bytes(0) <= &H7F) Then
c = "(0x00 to 0x7F) --> Data... --> 0xFF "
Else
c = "(0x80 to 0xFF) --> Length --> Data..."
c += " Length: " + bytes(1).ToString()
Dim op_code As Byte = bytes(0) And &HF
c += " op_code: " + op_code.ToString()
Select Case op_code
Case 9
c += "(ping) response - Pong"
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = " Pong"
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
bytesSent(0) = &H8A
bytesSent(1) = 4
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
Case 10
c += "(pong)"
Case 1
c += "(string data)"
Case 2
c += "(binary data)"
Case 8
c += "(connection close) - response and close"
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = " "
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
bytesSent(0) = &H8
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
Case Else
c += "(unknown!!)"
End Select
End If
Me.Dispatcher.Invoke(Windows.Threading.DispatcherPriority.Background, New Delegate_LableAddText(AddressOf LableAddText), a + vbCrLf + b + vbCrLf + c + vbCrLf + vbCrLf)
End Sub
Public Sub Read_Callback(ar As IAsyncResult)
Dim so As SocketObject = CType(ar.AsyncState, SocketObject)
Dim s As Socket = so.socket
Try
Dim read As Integer = s.EndReceive(ar)
If read > 0 Then
Dim frameCount = 2
Dim bytes As Byte() = so.buffer
printbytes(bytes, read)
End If
If (s.Connected = True) Then
s.BeginReceive(so.buffer, 0, SocketObject.BUFFER_SIZE, 0, New AsyncCallback(AddressOf Read_Callback), so)
Else
Me.Dispatcher.Invoke(Windows.Threading.DispatcherPriority.Background, New Delegate_LableAddText(AddressOf LableAddText), "-close-")
End If
Catch
End Try
End Sub
Public Delegate Sub Delegate_LableAddText(ByVal str As String)
''' <summary>
''' Check the received data and see if there is command from the device to check
''' </summary>
''' <param name="str"></param>
Public Sub LableAddText(ByVal str As String)
LblSock.Text += str
End Sub
Private Sub Button3_Click(sender As Object, e As RoutedEventArgs)
sock.socket.Close()
End Sub
Private Function random_sc_key() As String
Dim s As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
Dim r As New Random
Dim sb As New StringBuilder
For i As Integer = 0 To "gnuE6HbBVfsHzYVNLdxxbQ==".Length
Dim idx As Integer = r.Next(0, 35)
sb.Append(s.Substring(idx, 1))
Next
Dim a As String = sb.ToString()
Return "gnuE6HbBVfsHzYVNLdxxbQ=="
End Function
Private Sub BtnConnect_Click(sender As Object, e As RoutedEventArgs)
LblSock.Text = ""
'Set up variables and String to write to the server.
Dim ascii As Encoding = Encoding.UTF8
Dim request As String = "GET http://xxxxxxxxx.azurewebsites.net/xxxxxxxxx HTTP/1.1" + ControlChars.Cr + ControlChars.Lf + "Host: xxxxxxxxx.azurewebsites.net" + ControlChars.Cr + ControlChars.Lf + "Connection: Upgrade" + ControlChars.Cr + ControlChars.Lf + "Upgrade: WebSocket" + ControlChars.Cr + ControlChars.Lf + "Sec-WebSocket-Version: 13" + ControlChars.Cr + ControlChars.Lf + "Sec-WebSocket-Key: " + random_sc_key() + vbCrLf + vbCrLf
Dim bytesSent As [Byte]() = ascii.GetBytes(request)
Dim bytesReceived(255) As [Byte]
Dim hostEntry As IPHostEntry = Nothing
' Get host related information.
hostEntry = Dns.GetHostEntry("xxxxxxxxx.azurewebsites.net")
Dim address As IPAddress
For Each address In hostEntry.AddressList
Dim endPoint As New IPEndPoint(address, 80)
Dim tempSocket As New Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp)
tempSocket.Connect(endPoint)
If tempSocket.Connected Then
sock.socket = tempSocket
Exit For
End If
Next address
If sock.socket Is Nothing Then
MessageBox.Show("Connection failed")
Exit Sub
End If
LblSock.Text += "Sending: " + request
' Send request to the server.
sock.socket.Send(bytesSent, bytesSent.Length, 0)
LblSock.Text += "BeginReceive" + vbCrLf
sock.socket.BeginReceive(sock.buffer, 0, SocketObject.BUFFER_SIZE, 0, New AsyncCallback(AddressOf Read_Callback), sock)
End Sub
Private Sub BtnSendString1_Click(sender As Object, e As RoutedEventArgs)
If (sock.socket.Connected = False) Then
LblSock.Text += vbCrLf + "connection closed" + vbCrLf
Exit Sub
End If
Dim request As String = txtsock.Text
request = "11" & request
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = &H81
bytesSent(1) = txtsock.Text.Length
LblSock.Text += vbCrLf + "Sending string: " + txtsock.Text
LblSock.Text += vbCrLf + "Sending bytes: "
Dim i As Int16
For i = 0 To bytesSent.Length - 1
LblSock.Text += bytesSent(i).ToString() + ","
Next
sock.socket.Send(bytesSent)
End Sub
Private Sub BtnCloseSock_Click(sender As Object, e As RoutedEventArgs)
If (sock.socket.Connected = False) Then
LblSock.Text += vbCrLf + "connection closed" + vbCrLf
Exit Sub
End If
Dim request As String = txtsock.Text
request = "1" & request & "1"
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = 0
'bytesSent(1) = txtsock.Text.Length
bytesSent(bytesSent.Length - 1) = &HFF
sock.socket.Send(bytesSent)
End Sub

Answer 1

Thanks to Myst that point me to the MASK issue.
here is the fixed code to preform simple text transmit to the server from the client:
Private Sub BtnSendString1_Click(sender As Object, e As RoutedEventArgs)
If (sock.socket.Connected = False) Then
LblSock.Text += vbCrLf + "connection closed" + vbCrLf
Exit Sub
End If
Dim rand As Random = New Random()
Dim masking_key(4) As Byte
Dim i As Integer
masking_key(0) = Convert.ToByte(rand.Next(0, 250))
masking_key(1) = Convert.ToByte(rand.Next(0, 250))
masking_key(2) = Convert.ToByte(rand.Next(0, 250))
masking_key(3) = Convert.ToByte(rand.Next(0, 250))
Dim request As String = txtsock.Text
If (txtsock.Text.Length <= 125) Then
request = "112222" & request
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = &H80 Or 1
bytesSent(1) = txtsock.Text.Length Or &H80
bytesSent(2) = masking_key(0)
bytesSent(3) = masking_key(1)
bytesSent(4) = masking_key(2)
bytesSent(5) = masking_key(3)
Dim s As Integer = 0
For i = 6 To bytesSent.Length - 1
bytesSent(i) = bytesSent(i) Xor masking_key(s)
s += 1
If s = 4 Then s = 0
Next
LblSock.Text += vbCrLf + "Sending string: " + txtsock.Text
LblSock.Text += vbCrLf + "Sending bytes: "
For i = 0 To bytesSent.Length - 1
LblSock.Text += bytesSent(i).ToString() + ","
Next
sock.socket.Send(bytesSent)
ElseIf (txtsock.Text.Length <= 65535) Then
request = "11111111" & request
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = &H80 Or 1
bytesSent(1) = 126 Or &H80
bytesSent(2) = BitConverter.GetBytes(txtsock.Text.Length)(1)
bytesSent(3) = BitConverter.GetBytes(txtsock.Text.Length)(0)
bytesSent(4) = masking_key(0)
bytesSent(5) = masking_key(1)
bytesSent(6) = masking_key(2)
bytesSent(7) = masking_key(3)
Dim s As Integer = 0
For i = 8 To bytesSent.Length - 1
bytesSent(i) = bytesSent(i) Xor masking_key(s)
s += 1
If s = 4 Then s = 0
Next
LblSock.Text += vbCrLf + "Sending string: " + txtsock.Text
LblSock.Text += vbCrLf + "Sending bytes: "
For i = 0 To bytesSent.Length - 1
LblSock.Text += bytesSent(i).ToString() + ","
Next
sock.socket.Send(bytesSent)
Else
request = "1111111112222" & request
Dim ascii As Encoding = Encoding.UTF8
Dim bytesSent As Byte() = ascii.GetBytes(request)
bytesSent(0) = &H80 Or 1
bytesSent(1) = 126 Or &H80
bytesSent(2) = BitConverter.GetBytes(txtsock.Text.Length)(0)
bytesSent(3) = BitConverter.GetBytes(txtsock.Text.Length)(1)
bytesSent(4) = BitConverter.GetBytes(txtsock.Text.Length)(2)
bytesSent(5) = BitConverter.GetBytes(txtsock.Text.Length)(3)
bytesSent(6) = BitConverter.GetBytes(txtsock.Text.Length)(4)
bytesSent(7) = BitConverter.GetBytes(txtsock.Text.Length)(5)
bytesSent(8) = BitConverter.GetBytes(txtsock.Text.Length)(6)
bytesSent(9) = BitConverter.GetBytes(txtsock.Text.Length)(7)
bytesSent(10) = masking_key(0)
bytesSent(11) = masking_key(1)
bytesSent(12) = masking_key(2)
bytesSent(13) = masking_key(3)
Dim s As Integer = 0
For i = 13 To bytesSent.Length - 1
bytesSent(i) = bytesSent(i) Xor masking_key(s)
s += 1
If s = 4 Then s = 0
Next
LblSock.Text += vbCrLf + "Sending string: " + txtsock.Text
LblSock.Text += vbCrLf + "Sending bytes: "
For i = 0 To bytesSent.Length - 1
LblSock.Text += bytesSent(i).ToString() + ","
Next
sock.socket.Send(bytesSent)
End If
LblSock.ScrollToEnd()
End Sub