Swift: How to request a URL with a self-signed certificate?

Question

I'm opening an SSL connection to retrieve JSON in Swift, but am testing against my own server with a self-signed certificate. Here's a snippet of the URL request:

var urlPath = "https://myhost.com/get_json"
var url: NSURL = NSURL(string: urlPath)
var request: NSURLRequest = NSURLRequest(URL: url)
var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)        
connection.start()

However, it gets rejected (correctly) because of the certificate:

Opening connection to https://myhost.com/get_json
2014-06-05 09:37:02.543 AppName[44835:3182593] NSURLConnection/CFURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9813)
Connection failed.The certificate for this server is invalid. You might be connecting to a server that is pretending to be “myhost.com” which could put your confidential information at risk.## Heading ##

Answer 1

You will need these additional methods from NSURLConnectionDelegate:

func connection(connection: NSURLConnection, canAuthenticateAgainstProtectionSpace protectionSpace: NSURLProtectionSpace?) -> Bool
{
    return protectionSpace?.authenticationMethod == NSURLAuthenticationMethodServerTrust
}

func connection(connection: NSURLConnection, didReceiveAuthenticationChallenge challenge: NSURLAuthenticationChallenge?)
{
    if challenge?.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust
    {
        if challenge?.protectionSpace.host == "www.myhost.com"
        {
            let credentials = NSURLCredential(forTrust: challenge!.protectionSpace.serverTrust)
            challenge!.sender.useCredential(credentials, forAuthenticationChallenge: challenge)
        }
    }

    challenge?.sender.continueWithoutCredentialForAuthenticationChallenge(challenge)
}

NOTE: This is only possible when using the asynchronous NSURLConnection.