How to remove NSURLCredential storage for https authentication in iOS

Question

I need to remove the NSURLCredential storage everytime after response received for every https request. That is not happening in my case. The below method is executed only for the first time request, for next requests it is not called. When i relaunch the App, then it is called. I tried lot of suggestions in SO, but didn't help. How can i fix this?

    - (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
    SecTrustRef trust = challenge.protectionSpace.serverTrust;
    NSURLCredential *cred;
    cred = [NSURLCredential credentialForTrust:trust];
    [challenge.sender useCredential:cred forAuthenticationChallenge:challenge];
}

Answer 1

Set the credential's persistence property to NSURLCredentialPersistenceNone. That should ensure that the credential is never stored for future use (assuming you aren't still building for iOS 2).