(Objective-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.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoRest.h>
#import <CkoWebSocket.h>
#import <NSString.h>

// 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.
// 

CkoRest *rest = [[CkoRest alloc] init];
// ------------------------------------------------------------------
// To use TLS, connect to the TLS port (typically 443) and tell the rest.Connect method
// that it's a TLS connection.
// ------------------------------------------------------------------
BOOL bUseTls = YES;
BOOL success = [rest Connect: @"someserver.com" port: [NSNumber numberWithInt: 443] tls: bUseTls autoReconnect: NO];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

CkoWebSocket *ws = [[CkoWebSocket alloc] init];

// Tell the WebSocket to use this connection.
success = [ws UseConnection: rest];
if (success != YES) {
    NSLog(@"%@",ws.LastErrorText);
    return;
}

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

// Add any additional headers that might be desired.
// Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
[rest AddHeader: @"Sec-WebSocket-Protocol" value: @"x-something"];
[rest AddHeader: @"Origin" value: @"http://someserver.com"];

// Do the open handshake.
NSString *responseBody = [rest FullRequestNoBody: @"GET" uriPath: @"/something"];
if (rest.LastMethodSuccess != YES) {
    NSLog(@"%@",rest.LastErrorText);
    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..)
int statusCode = [rest.ResponseStatusCode intValue];
NSLog(@"%@%d",@"Response status code: ",statusCode);

if (statusCode != 101) {
    NSLog(@"%@",responseBody);
    NSLog(@"%@",@"-- Failed because of unexpected response status code.");
    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 = [ws ValidateServerHandshake];
if (success != YES) {
    NSLog(@"%@",ws.LastErrorText);
    return;
}

NSLog(@"%@",@"WebSocket connection successful.");

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