I am relatively new to Qt and have no experience in network programming. I am trying to write a minimal TCP-client-server connection with TLS encryption in Qt using the QSslSocket class. So far I established a connection between server and client both running on localhost without encryption. For TLS encryption I found this example on gitHub: https://github.com/GuiTeK/Qt-SslServer
and followed carefully the given instructions (including the OpenSSL installation). Nevertheless I can not establish a connection between client and server (even if I set timeout to -1). The error messages for the server and client are depicted below.
Can anybody help me with that ? If someone has complete code examples in Qt for client and server which exchange data via TCP using encryption SSL encryption I would highly appreciate. I am working with QtCreator running Qt 5.5.0 MSVC2013 64 bit.
Launch Qt Creator. On Welcome screen hit "Examples" button. Then at search box write "ssl". You will see several fully working Qt examples for ssl clients and servers. This is the good place for start. Also read this link.
Related
I am trying to write a c++ websocket server and have browser/chrome clients connect over websockets, for a multiplayer game. The websocket c++ library I'm using atm is websocketpp or websocket++. I wrote an app that allows clients to connect over ws and localhost, but when I add an ip for the address, connections don't occur at all. Now I think I have to use ssl and wss for ip connection? I tried it and there is some connection activity, but then the handshake times out. Could I be experiencing cross-orgin issues, or what, do i need ssl? I am new to websockets. Could the problem be my ssl certs I made with openssl? I can post code, or if you are familiar with a c++ library to do websockets, what is it? Is this even a possible thing to do?
There could be multiple reasons why it won't connect over ip.
The first is port forwarding. On a local network it's not necessary but running a server over a remote network, portforwarding has to be done. You can just run your server then use a simple port checker (there's many websites for them) to see if a connection can be established.
The other reason could be as you said ssl. If you are running your client on a web host, the host may require a connection to be made over ssl/wss for websockets. If your server isn't running a valid ssl certificate then this could prevent the client from connecting to your server. I know for exampe Github pages requires the server to be running wss or valid ssl certificates on the server side in order for a client connection to be established; however, if you use a custom domain name for Github pages then you can disable the need for ssl.
In order to get valid ssl certificates you would need to register a domain for your ip address then either buy certificates or use free certificates from zerossl or other distributors.
Here is a game I have written which connects to a c++ server which I'm running on my own machine with its own domain with valid ssl certificates and the client is running on github pages with a custom domain I have registered.
It's basically multiplayer minesweeper where the objective is to locate the flags rather than avoid them.
I just developed an Application in Qt that uses a WebSocket Server (QWebSocketServer). I did this under Linux and everything worked great, but when I ran the code on Mac OS I was unable to connect to the server from a webpage on Chrome.
The connection took ages, and I got WebSocket opening handshake timed out from Chrome after a few minutes.
In the end I went back to basics and tried Qt's example:
http://doc.qt.io/qt-5/qtwebsockets-sslechoserver-example.html
Exactly the same.
edit:
After removing SSL and using non-secure websockets it works, even on the same port.
Chrome on the Mac can access a secure Qt WebSocket server on a remote (non-Mac) computer, but Chrome on a remote computer times out while connecting to the Mac (securely) - so it would appear to be something wrong with the Qt QWebSocketServer example. It works fine on both Linux and Windows.
There is a connection being made (because the web browser fails instantly if the application isn't running or is closed), but for whatever reason it isn't completing.
Any idea what this might be, or how I can go about trying to track it down?
thanks!
As qt document(http://doc.qt.io/qt-5/qsslsocket.html) says:
Note: Secure Transport SSL backend on macOS may update the default keychain (the default is probably your login keychain) by importing your local certificates and keys. This can also result in system dialogs showing up and asking for permission when your application is using these private keys. If such behavior is undesired, set the QT_SSL_USE_TEMPORARY_KEYCHAIN environment variable to a non-zero value; this will prompt QSslSocket to use its own temporary keychain.
The issue here seems to be some interaction with MacOS's permissions system.
The first time you run the application and connect, the app will pop up a window asking for permissions to access your keychain (I guess to install the certificate).
If you close the dialog at that point, it won't come back, and it seems no QtWebSocketServer based programs will function from then on, until your reboot!
I am trying to use libvnc to write client application for VMware ESXi 6 vm's consoles.
From ESXi 6 VMware provides websocket for this purpose. They are also released basic HTML5 client for this.
ESXi websocket VNC uses connection path to authorize.
When HTML5 client trying to connect it making request like this:
wss://esxi_host_ip/ticket/secret_token
From my research I know that this method also works with noVNC Client
(https://github.com/kanaka/noVNC)
This client passes "path" parameter to RFB implementation.
From libvnc website I know that it support websockets but I don't know if it is supported on client side and if the answer is YES, how can I do that ?
Finally the answer is NO but simple hack is possible.
Connection to websocket vnc server from libvnc is not directly possible.
As solution for my problem I used custom made tcp to websocket proxy where I firstly negotiating websocket connection and then connecting standard tcp vnc client.
Is it possible with Qt to upgrade a HTTP connection that handles the normal HTTP requests to a Websocket with the same connection?
I'm thinking about something like this with Poco libraries, but all done in Qt similar to QtWebApp.
The simple answer is no and that is mostly because of specifics of the server side. And Qt just follows the protocol available and exposed by the server (HTTP/WebSocket) as mostly the client-side development framework and AFAIK won't be able to do the kind of transformation you want of going from HTTP to Websocket that are two different protocols. But of course, theoretically that can be done as long as both protocols able to use IP port 80. But that implies new unique sever and new unique client implementations.
We use both WebSocket and REST in our app. And WebSocket is for triggering the client by the server to do something. Client gets the "poke" from the server and starts normal JSON HTTP-based exchange with the server.
Somewhat relative link: https://softwareengineering.stackexchange.com/questions/276253/mixing-rest-and-websocket-in-the-same-api
Im new in C++.
I need to listen HTTP requests.
Please advice me some good tutorials or examples
Thanks
update:
Platform: Windows
Language: C++
I will explain more clearly what i need
when user clicks row on this page: http://ucp-anticheat.org/monitor.html applications is automatically starts on client machine.
I want to make same thing.
I think on client side is service which listens http requests and if url starts with steam:// service automatically runs application...
Do i need to listen http requests?
What is best solution for my problem?
You can listen to http requests through a web server like mongoose , which can be easily used in C++ http://code.google.com/p/mongoose/ , and here is a good example of using mongoose web server http://code.google.com/p/mongoose/source/browse/examples/hello.c
I m not sure what you mean 'client side', if you are meaning Browser as your client, you can't control nothing outside your browser. If you want to control a machine, you need your client machine to run your exe, that has the code to act based on your server instructions.
You should create a simple server program, create a SOCKET listening on default http, https etc, ports. Usually we do it inside a loop (at each one you make a read).
Now... would be easer if you specified if you are on Unix like OS or Windows, but from now on you can google it. Like sys/socket.h or try "man 7 socket" on almost all linux (at least the ones I know).
If you want to sniff something you can google some specific apps around web.
If i get your question right, you want to be able to launch an application when someone clicks a link with a custom protocol, like steam:// or telnet://. You are looking for an Protocol Handler.
A simple way to register such an application is using the ftype program, as described here.