NSURLConnection only authenticates on second attempt - ios

Question

I am trying to load a secure website in a UIWebView my basic approach is to create a NSURL, the n a NSURLRequest, then a NSURLConnection, then to load the NSURLRequest in the UIWebView. When the website is loaded I receive
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
I respond to the challenge sender with
- (void)useCredential:(NSURLCredential *)credential forAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
But after that I get nothing... it just hangs. I put in break points so I know that
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
is being called. If I wait till I am sure that the NSURLConnection is not going to complete then reload the view no authentication challenge is sent but the view will load. I do not have any control over the server. I am open to using AFNetworking, but only if necessary.
The full listing of source code is provided below:
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:
(NSURLAuthenticationChallenge *)challenge
{
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
if ([challenge previousFailureCount] == 0)
{
NSString *username = #"username";
NSString *password = #"passsword";
NSURLCredential * cred = [NSURLCredential credentialWithUser:username
password:password
persistence:NSURLCredentialPersistenceForSession];
[[challenge sender] useCredential:cred forAuthenticationChallenge:challenge];
}
else
{
}
}
-(void)updateCard
{
NSURL * url = [NSURL URLWithString:#"https://ssl.letu.edu/applications/chapelattendance/attendance.html"];
NSURLRequest * request = [NSURLRequest requestWithURL:url
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:50.0];
self.webView =[[UIWebView alloc] initWithFrame:self.bounds];
self.webView.delegate = self;
[self.webView loadRequest:request];
self.connection = [[ NSURLConnection alloc]initWithRequest:request delegate:self];
[self.connection start];
}
Where did I go wrong?

Answer 1

You need to first retrieve the "authentication method" the server is requesting for:
[[challenge protectionSpace] authenticationMethod]
These are the authentication methods (which are string constants) which the expression above returns:
NSURLAuthenticationMethodDefault
NSURLAuthenticationMethodHTTPBasic
NSURLAuthenticationMethodHTTPDigest
NSURLAuthenticationMethodHTMLForm
NSURLAuthenticationMethodNegotiate
NSURLAuthenticationMethodNTLM
NSURLAuthenticationMethodClientCertificate
NSURLAuthenticationMethodServerTrust
Then, you have these options:
If you want to provide the credentials for the given authentication method, you invoke
useCredential:forAuthenticationChallenge:
If you don't want to handle that authentication method yourself and want the system try
to authenticate, you may invoke performDefaultHandlingForAuthenticationChallenge:
which may then fail or not, depending whether the system is capable to handle that type
of authentication and whether it can find credentials in well known storages.
If you cant handle that authentication method -- say authentication method
NSURLAuthenticationMethodNTLM for example -- you can skip this protection
space and try another protection space if another one
exists in this authentication challenge. Then you may possibly get an
authentication method NSURLAuthenticationMethodHTTPBasic which you
are capable to handle.
In order to reject the current protection space you send method
rejectProtectionSpaceAndContinueWithChallenge: to the
authentication challenge sender. Then, NSURLConnection will send
once again willSendRequestForAuthenticationChallenge: to your
delegate with another protection space if any further exists.
You may try to continue without providing credentials at all.
Likely, the authentication will fail. You can try it through
sending message continueWithoutCredentialForAuthenticationChallenge:
to the authentication challenge sender.
And finally, you can cancel the request through canceling the
authentication challenge: send cancelAuthenticationChallenge: to
the authentication challenge sender.
Note: NSURLAuthenticationMethodHTTPBasic and NSURLAuthenticationMethodHTTPDigest authentication methods can be handled with the same NSURLCredential object created with +credentialWithUser:password:persistence:

Answer 2

If anyone comes along and has the same problem be sure I want to share the solution I found. Use AFNetworking.
Here is the revised code:
-(void)updateCard
{
if(!self.webView)
{
self.webView =[[UIWebView alloc] initWithFrame:self.bounds];
self.webView.delegate = self;
}
NSUserDefaults * userDefaults = [NSUserDefaults standardUserDefaults];
NSString *username = #"username";
NSString *password = #"password";
NSURL *url = [NSURL URLWithString:#"https://ssl.letu.edu/"];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL: url];
[client setAuthorizationHeaderWithUsername:username password:password];
NSMutableURLRequest *request = [client requestWithMethod:#"GET" path:#"applications/chapelattendance/attendance.html"
parameters:nil];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject)
{
[self.webView loadRequest:request];
}
failure: ^(AFHTTPRequestOperation *operation, NSError *error)
{
NSLog(#"Could not load chapel attendance");
}];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[queue addOperation:operation];
}

Answer 3

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:urlRequest];
operation.securityPolicy.allowInvalidCertificates = YES;

Answer 4

You need to send the username and password combination with the http header to authenticate the request while sending the same.
NSData *authData = [#"username:password" dataUsingEncoding:NSASCIIStringEncoding];
NSString *authorization = [NSString stringWithFormat:#"Basic %#", [authData base64Encoding]];
[mutableRequest addValue:authorization forHTTPHeaderField:#"Authorization"];