(C) WebSocket over TLS

Establishing a WebSocket connection over TLS is exactly the same as for TCP, except for a few arguments passed to the Connect method.

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#include <C_CkRest.h>
#include <C_CkWebSocket.h>

void ChilkatSample(void)
    {
    HCkRest rest;
    BOOL bUseTls;
    BOOL success;
    HCkWebSocket ws;
    const char *responseBody;
    int statusCode;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  --------------------------------------------------
    //  A WebSocket connection begins life as an HTTP GET request containing a few special header fields,
    //  such as "Upgrade: websocket".

    //  Your application will use the Chilkat Rest class to send the initial HTTP GET.  This allows you
    //  to use the full capability of the Chilkat Rest class to customize the GET for any particular situation.
    //  For example:
    // 
    //    - If custom HTTP request header fields must be added.
    //    - If authentication is required, such as OAuth2, OAuth1, Basic HTTP Auth, etc.
    //    - If HTTPS, SSH Tunneling, Proxies (HTTP or SOCKS), or other advanced connection or TLS features are required.
    // 

    rest = CkRest_Create();
    //  ------------------------------------------------------------------
    //  To use TLS, connect to the TLS port (typically 443) and tell the rest.Connect method
    //  that it's a TLS connection.
    //  ------------------------------------------------------------------
    bUseTls = TRUE;
    success = CkRest_Connect(rest,"someserver.com",443,bUseTls,FALSE);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        return;
    }

    ws = CkWebSocket_Create();

    //  Tell the WebSocket to use this connection.
    success = CkWebSocket_UseConnection(ws,rest);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

    //  Add the standard WebSocket open handshake headers that will be needed.
    //  (This adds the required HTTP request headers to the rest object.)
    CkWebSocket_AddClientHeaders(ws);

    //  Add any additional headers that might be desired.
    //  Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    CkRest_AddHeader(rest,"Sec-WebSocket-Protocol","x-something");
    CkRest_AddHeader(rest,"Origin","http://someserver.com");

    //  Do the open handshake.
    responseBody = CkRest_fullRequestNoBody(rest,"GET","/something");
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

    //  If successful, the HTTP response status code should be 101,
    //  and the response body will be empty. (If it failed, we'll have a look
    //  at the response body..)
    statusCode = CkRest_getResponseStatusCode(rest);
    printf("Response status code: %d\n",statusCode);

    if (statusCode != 101) {
        printf("%s\n",responseBody);
        printf("-- Failed because of unexpected response status code.\n");
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

    //  We have the expected 101 response, so let's now validate the
    //  contents of the response, such as the value sent by the server in the
    //  Sec-WebSocket-Accept header.
    success = CkWebSocket_ValidateServerHandshake(ws);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkWebSocket_Dispose(ws);
        return;
    }

    printf("WebSocket connection successful.\n");

    //  The application may now begin sending and receiving frames on the WebSocket connection.
    //  (At this point, we're done with the rest object...)


    CkRest_Dispose(rest);
    CkWebSocket_Dispose(ws);

    }