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https://github.com/bertrandmartel/websocket-non-blocking

C++ websocket non-blocking server library for Qt4/Qt5
https://github.com/bertrandmartel/websocket-non-blocking

cpp-library qt websocket websocket-server

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C++ websocket non-blocking server library for Qt4/Qt5

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README 

        
# Websocket non-blocking server library



[![Build Status](https://travis-ci.org/akinaru/websocket-non-blocking.svg?branch=master)](https://travis-ci.org/akinaru/websocket-non-blocking)

[![License](http://img.shields.io/:license-mit-blue.svg)](LICENSE.md)



http://akinaru.github.io/websocket-non-blocking/



C++ websocket non-blocking server library for Qt4/Qt5



## Usage



Start websocket server :

```

WebsocketServer server;



bool success = server.listen(QHostAddress("127.0.0.1"), 8443);

```



Stop websocket server :

```

server.close();

```



## Integrate in your project



* from git submodule



```

git submodule add git://github.com/akinaru/websocket-non-blocking.git

```



and in your `project.pro` :



```

TEMPLATE = subdirs

SUBDIRS = websocket-non-blocking your-app

your-app.depends = websocket-non-blocking

```



with in `your-app.pro` :



```

TARGET = your-app

SOURCES = main.cpp

INCLUDEPATH += $$PWD/../websocket-non-blocking/libwebsocket/release

LIBS += -L$$PWD/../websocket-non-blocking/libwebsocket/release -lwebsocket

DEPENDPATH += $$PWD/../websocket-non-blocking/libwebsocket/release

```



## Monitor clients



Build your own client monitoring class that inherits `IClientEventListener` : 



```

class ClientSocketHandler :  public IClientEventListener

{

public:



    ClientSocketHandler();



    ~ClientSocketHandler();



    void onClientClose(IWebsocketClient &client);



    void onClientConnection(IWebsocketClient &client);



    void onMessageReceivedFromClient(IWebsocketClient &client, std::string message);

};

```



Add listener to server instance : 



```

#include "ClientSockethandler.h"



....



ClientSocketHandler *clientHandler = new ClientSocketHandler();



server.addClientEventListener(clientHandler);

```



In this `ClientSocketHandler` you have 3 callbacks that will notify you on client connection change and arrival of client messages :



* `void onClientClose(IWebsocketClient &client);` notify when client socket close

* `void onClientConnection(IWebsocketClient &client);` notify when client socket connect to server

* `void onMessageReceivedFromClient(IWebsocketClient &client,std::string message);` notify when a socket client send a message to you



You can send a message back with `IWebsocketClient` sent from the same callback with `sendMessage(std::string textToSend)` method :



```

void ClientSocketHandler::onMessageReceivedFromClient(IWebsocketClient &client,string message)

{

    cout << "Client socket message received : " << message.data() << endl;



    client.sendMessage("OK I received your message !");

}

```



Check the client monitoring example [here](./libwebsocket-test/ClientSocketHandler.cpp)



## SSL secured websocket server



```

WebsocketServer server;



server.setSSL(true); // set SSL to true (default is false)

```



Then you set your public/private/ca certificates separately with respective methods : 



```

server.setPublicCert(SslHandler::retrieveCertFromFile(PUBLIC_CERT));

server.setPrivateCert(SslHandler::retrieveKeyCertFile(PRIVATE_CERT,PRIVATE_CERT_PASS));

server.setCaCert(SslHandler::retrieveveCaCertListFromFile(CA_CERTS));

```



You can use static method from [`SslHandler`](./libwebsocket-test/SslHandler.cpp) :



* public cert must be a QSslCertificate : `SslHandler::retrieveCertFromFile(char * filepath)`

* private cert must be a QSslKey : `SslHandler::retrieveKeyCertFile(char * filepath,char * passKey)`

* CA cert must be a QList of QSslCertificate : `SslHandler::retrieveveCaCertListFromFile(char * filepath)`



Eventually add event listener as described above and start websocket server : 



```

server.addClientEventListener(clientHandler);



bool success = server.listen(QHostAddress("127.0.0.1"), 8443);

```



## Troubleshooting SSL errors with local browser JS client



>Bad certificate | Unknown CA errors



This could mean you didn't import your not-trusted-CA certificate into your browser.



>The remote host closed the connection



Just load your URL with "https" : https://127.0.0.1:8443 . Browser will prompt you to accept the certificates and it will probably solve your connection error.



## Debugging SSL connection error



use openssl command line tool to debug ssl connection : 



```

openssl s_client -connect 127.0.0.1:8443

```



## Server-Client key/cert generation



Sample certs are in [libwesocket-test/certs](./libwesocket-test/certs) folder, you will find server,client and ca cert build with easy-rsa :



https://github.com/OpenVPN/easy-rsa



With last release of easy-rsa, you can build your own key with the following : 



* `./build-ca` : generate a new CA for you

* `./build-server-full myServer` : will build for you public cert and private cert signed with CA for server

* `./build-client-full myClient` : will build for you public cert and private cert signed with CA for client



## Build library & examples



```

qmake

make

```



## Run examples



Open a websocket on port 8443 :



```

./libwebsocket-test/release/libwebsocket-test 127.0.0.1 8443

```



Open Javascript clients located in [client-test/js](./client-test/js) :






![client side](./img/clientSide.png)






![server side](./img//serverSide.png)



## Valgrind checking



```

cd libwebsocket-test/release



valgrind --tool=memcheck --leak-check=full --suppressions=../../memcheck.suppress ./libwebsocket-test  



```



## Compatibility



* Qt4

* Qt5



## Specification



* https://tools.ietf.org/html/rfc6455