Swift iOS SSL public key pinning

SSLPin.swift

func connection(connection: NSURLConnection, didReceiveAuthenticationChallenge challenge: NSURLAuthenticationChallenge) {
	if(challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust) {
		var localTrust: Unmanaged<SecTrust>?
		let serverTrust = challenge.protectionSpace.serverTrust!
		let serverPublicKey = SecTrustCopyPublicKey(serverTrust).takeRetainedValue();
		let certificateData = NSData(contentsOfFile: NSBundle.mainBundle().pathForResource("pinning-certificate", ofType: "der")!)
		let localCertificate = SecCertificateCreateWithData(kCFAllocatorDefault, certificateData).takeRetainedValue();
		let policy = SecPolicyCreateBasicX509().takeRetainedValue()

		if SecTrustCreateWithCertificates(localCertificate, policy, &localTrust) == errSecSuccess {
			let localTrustRef = localTrust!.takeRetainedValue()
			let localPublicKey = SecTrustCopyPublicKey(localTrustRef)!.takeRetainedValue();
			if (localPublicKey as AnyObject).isEqual(serverPublicKey as AnyObject) {
				println("trusted")
				return challenge.sender.performDefaultHandlingForAuthenticationChallenge!(challenge)
			}
		}
	}
	println("not trusted")
	return challenge.sender.cancelAuthenticationChallenge(challenge)
}