NSURLSession didReceiveChallenge called for each request - ios

Question

I am using this custom class to download data from Server(ASP.NET IIS 7.5) using a certificate. It works just fine except that on every request the didReceiveChallenge method is called every time and credentials has to be applied again and again. The performance suffers greatly.
How can we avoid this?
Thanks.
#import "ServerRequest.h"
#import <UIKit/UIKit.h>
#implementation ServerRequest{
NSMutableData * recievedData;
NSString * operationName;
NSString * operationParameters;
DataOperationType operationType;
NSURL* downloadURL;
NSData * HTTPBodyData;
UIView * waitView;
UIProgressView * progressView;
}
- (instancetype)init{
if(self = [super init]) {
}
return self;
}
- (NSURLSession *)normalSession{
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLProtectionSpace * protectionSpace = [[NSURLProtectionSpace alloc] initWithHost:[Config getBaseURL] port:443 protocol:#"https" realm:nil authenticationMethod:NSURLAuthenticationMethodClientCertificate];
[configuration.URLCredentialStorage setDefaultCredential:[Helper getCredential] forProtectionSpace:protectionSpace];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:[NSOperationQueue mainQueue]];
return session;
}
- (instancetype)initWithRequest:(NSString *)request
{
if(self = [super init]) {
operationType = DataOperationTypeData;
downloadURL = [NSURL URLWithString:request];
NSLog(#"Created download operation for URL: %#", [downloadURL absoluteString]);
}
return self;
}
- (instancetype)initWithRequest:(NSString *)request Dicionary:(NSString *) dataDictionary{
if(self = [super init]) {
operationType = DataOperationTypeHTMLFrom;
downloadURL = [NSURL URLWithString:request];
NSLog(#"Created download operation for URL: %#", [downloadURL absoluteString]);
operationParameters = dataDictionary;
}
return self;
}
- (instancetype)initWithRequest:(NSString *)request data:(NSData *) bodyData{
if(self = [super init]) {
operationType = DataOperationTypeBodyData;
downloadURL = [NSURL URLWithString:request];
NSLog(#"Created download operation for URL: %#", [downloadURL absoluteString]);
HTTPBodyData = bodyData;
}
return self;
}
- (void) performOperationWithCompletion:(ServerRequestCompletion)onCompletion error:(ServerRequestError)onError{
if (self.showProgressView){
[self configureProgressView];
}
if (self.parentView) {
waitView = [Config createWaitView:self.parentView];
}
self.completion = onCompletion;
self.error = onError;
NSMutableURLRequest *request;
request = [NSMutableURLRequest requestWithURL:downloadURL];
[request setHTTPMethod:#"POST"];
[request setValue:#"utf-8" forHTTPHeaderField:#"Accept-Charset"];
if (operationType == DataOperationTypeHTMLFrom) {
NSData *postData = [operationParameters dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPMethod:#"POST"];
[request setValue:#"utf-8" forHTTPHeaderField:#"Accept-Charset"];
[request setValue:[NSString stringWithFormat:#"%ld", (unsigned long)postData.length] forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded charset=utf-8" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
}
else if (operationType == DataOperationTypeBodyData) {
[request setHTTPMethod:#"POST"];
[request setValue:[NSString stringWithFormat:#"%ld", (unsigned long)HTTPBodyData.length] forHTTPHeaderField:#"Content-Length"];
[request addValue: #"multipart/form-data; charset=utf-8" forHTTPHeaderField: #"Content-Type"];
[request setHTTPBody:HTTPBodyData];
}
else{
[request setValue:#"application/x-www-form-urlencoded charset=utf-8" forHTTPHeaderField:#"Content-Type"];
}
NSURLSession * defaultSession = [self normalSession];
NSURLSessionTask * dataTask = [defaultSession dataTaskWithRequest:request];
if (!dataTask) {
self.error([EXError errorWithDomain:[[NSBundle mainBundle] bundleIdentifier] code:-1 userInfo:#{NSLocalizedDescriptionKey: #"Could not initialize connection"}]);
}else{
if (self.showProgressView) {
dispatch_async(dispatch_get_main_queue(), ^{
// AppDelegate_Shared * appDelegate = (AppDelegate_Shared *)([UIApplication sharedApplication]).delegate;
// [appDelegate.progressView setHidden:NO];
// [appDelegate.progressView setProgress:0];
});
}
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
[dataTask resume];
}
}
- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler{
//NSURLProtectionSpace *protectionSpace = [challenge protectionSpace];
NSURLCredential *credential = [Helper getCredential];
if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodNTLM])
{
if (challenge.previousFailureCount >= 3)
{
// handle the fact that the previous attempt failed
EXError* error = [EXError errorWithDomain:NSURLErrorDomain code:403 userInfo: #{NSLocalizedDescriptionKey: #"Unable to verify account information."}];
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
self.error(error);
}else{
NSURLCredentialPersistence persistence = NSURLCredentialPersistenceForSession;
NSString * userName = [Config getUserName];
NSString * password = [Config getPassword];
NSURLCredential *loginCredential = [NSURLCredential credentialWithUser:userName password:password persistence:persistence];
completionHandler(NSURLSessionAuthChallengeUseCredential, loginCredential);
[self removeWaitView];
}
}
else if([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust])
{
completionHandler(NSURLSessionAuthChallengeUseCredential, [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust]);
//completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
[self removeWaitView];
}
else if ([[challenge protectionSpace] authenticationMethod] == NSURLAuthenticationMethodClientCertificate)
{ NSLog(#"\n______________________________________________________ Authentication Method Client Certificate _________________________________________________");
completionHandler(NSURLSessionAuthChallengeUseCredential, credential);
[self removeWaitView];
}
else{
completionHandler(NSURLSessionAuthChallengeRejectProtectionSpace, nil);
[self removeWaitView];
}
}
-(void) configureProgressView{
UIViewController * topController = [Helper currentTopViewController];
if (![topController isKindOfClass:[UINavigationController class]]) {
return;
}
UINavigationController * navigationController = (UINavigationController *)topController;
UINavigationBar * navigationBar = [navigationController navigationBar];
progressView = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
progressView.frame = CGRectMake(navigationBar.frame.origin.x, navigationBar.frame.size.height - 5, navigationBar.frame.size.width, 5);
[navigationBar addSubview:progressView];
}
-(void) removeWaitView{
[waitView removeFromSuperview];
waitView = nil;
}
- (void)URLSession:(NSURLSession *)session didBecomeInvalidWithError:(NSError *)error{
}
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask
didReceiveResponse:(NSURLResponse *)response
completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))completionHandler
{
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
NSDictionary *responseHeaders = ((NSHTTPURLResponse *)response).allHeaderFields;
NSLog(#"headers: %#", responseHeaders.description);
if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
if (httpResponse.statusCode >= 400) { // Client/Server Error
EXError * error = [EXError errorWithDomain:[[NSBundle mainBundle] bundleIdentifier] code:httpResponse.statusCode userInfo:#{NSLocalizedDescriptionKey: [NSHTTPURLResponse localizedStringForStatusCode:httpResponse.statusCode]}];
self.error(error);
NSLog(#"Failed with Error %ld : %#", (long)httpResponse.statusCode, [NSHTTPURLResponse localizedStringForStatusCode:httpResponse.statusCode]);
completionHandler(NSURLSessionResponseAllow);
[self removeWaitView];
return;
}
}
completionHandler(NSURLSessionResponseAllow);
[self removeWaitView];
}
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data{
if (!recievedData) {
recievedData = [NSMutableData new];
}
[recievedData appendData:data];
if ([dataTask countOfBytesExpectedToReceive] !=NSURLSessionTransferSizeUnknown) {
double progress = (double)[dataTask countOfBytesReceived] / (double) [dataTask countOfBytesExpectedToReceive];
if (self.showProgressView) {
dispatch_async(dispatch_get_main_queue(), ^{
[progressView setProgress:progress animated:YES];
});
}
}
// DLog(#"progress : %lld", [dataTask countOfBytesExpectedToReceive]);
}
//- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task
// didSendBodyData:(int64_t)bytesSent
// totalBytesSent:(int64_t)totalBytesSent
// totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend{
// // DLog(#"Did Sent %f", (double)totalBytesSent);
//
// if (self.showProgressView) {
//
// dispatch_async(dispatch_get_main_queue(), ^{
//
// AppDelegate_Shared * appDelegate = (AppDelegate_Shared *)([UIApplication sharedApplication]).delegate;
// [appDelegate.progressView setProgress:
// (double)totalBytesSent /
// (double)totalBytesExpectedToSend animated:YES];
//
// });
// }
//}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
if (self.showProgressView) {
dispatch_async(dispatch_get_main_queue(), ^{
[progressView setHidden:YES];
});
}
// NSString *myString = [[NSString alloc] initWithData:recievedData encoding:NSUTF8StringEncoding];
//
// NSLog(#"%#", myString);
if(error == nil)
{
// SBJSON *json = [SBJSON new];
// NSString *responseString = [[NSString alloc] initWithData:recievedData encoding:NSUTF8StringEncoding];
//
// //NSLog(#"Finished (%#) %d bytes. %#", [downloadURL absoluteString], [data length], responseString);
//
// NSDictionary *dataSet = [json objectWithString:responseString];
NSDictionary* dataSet = [NSJSONSerialization
JSONObjectWithData:recievedData
options:kNilOptions
error:&error];
self.completion(dataSet);
}
else{
// if (error.code == -999) {
// return;
// }
// NSString * httpBody = [[NSString alloc] initWithData:task.currentRequest.HTTPBody encoding:NSUTF8StringEncoding];
//
// httpBody = [NSString stringWithFormat:#"%s\n%#", __PRETTY_FUNCTION__, httpBody];
// [Helper MsgBox:httpBody];
EXError * exError = [EXError errorWithDomain:error.domain code:error.code userInfo:#{NSLocalizedDescriptionKey: [NSHTTPURLResponse localizedStringForStatusCode:error.code]}];
self.error(exError);
// DLog(#"Error %#", [error localizedDescription]);
}
}
#end

Answer 1

One of the reasons can be a check of HTTPS the certificate.
Apple Documentation
This instance contains a protectionSpace property whose authenticationMethod property indicates the kind of challenge being issued (such as a request for a username and password, or a client certificate). You use this value to determine whether you can handle the challenge.
Adding this precondition can check the authentication method and call the handler.
if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]) {
completionHandler(NSURLSessionAuthChallengeUseCredential, nil);
return;
}
You can find authentication methods constants here