Form-based authentication in native iOS applications

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This tutorial explains how to implement the client-side of form-based authentication in native iOS.
Prerequisite: Make sure that you read Form-based authentication first.

Implementing the client-side authentication

Create a native iOS application and add the MobileFirst native APIs as explained in Configuring a native iOS application with the MobileFirst Platform SDK.


In your storyboard, add a View Controller containing a login form.

Challenge Handler

  • Create a MyChallengeHandler class as a subclass of ChallengeHandler.

    @interface MyChallengeHandler : ChallengeHandler
  • Call the initWithRealm method:
    @implementation MyChallengeHandler
        self = [self initWithRealm:@"SampleAppRealm"];
        return self;
  • Add implementation of the following ChallengeHandler methods to handle the form-based challenge:
    1. isCustomResponse method:
      The isCustomResponse method is invoked each time a response is received from the MobileFirst Server. It is used to detect whether the response contains data that is related to this challenge handler. It must return either true or false.
      The default login form that returns from the MobileFirst Server contains the j_security_check string. If the response contains the string, the challenge handler returns true.
      @implementation MyChallengeHandler
      -(BOOL) isCustomResponse:(WLResponse *)response {
          if(response && response.responseText){
              if ([response.responseText rangeOfString:@"j_security_check" options:NSCaseInsensitiveSearch].location != NSNotFound) {
                  NSLog(@"Detected j_security_check string - returns true");
                  return true;
          return false;
    2. handleChallenge method:
      If isCustomResponse returns true, the framework calls the handleChallenge method. This function is used to perform required actions, such as hiding the application screen and showing the login screen.

      @implementation MyChallengeHandler
      -(void) handleChallenge:(WLResponse *)response {
          NSLog(@"A login form should appear");
          LoginViewController* loginController = [ instantiateViewControllerWithIdentifier:@"LoginViewController"];
          loginController.challengeHandler = self;
          [ pushViewController:loginController animated:YES];
    3. onSuccess and onFailure methods:
      At the end of the authentication flow, onSuccess or onFailure will be triggered
      Call the submitSuccess method in order to inform the framework that the authentication process completed successfully and for the onSuccess handler of the invocation to be called.
      Call the submitFailure method in order to inform the framework that the authentication process failed and for the onFailure handler of the invocation to be called.

      @implementation MyChallengeHandler
      -(void) onSuccess:(WLResponse *)response {
          NSLog(@"Challenge succeeded");
          [ popViewControllerAnimated:YES];
          [self submitSuccess:response];
      -(void) onFailure:(WLFailResponse *)response {
          NSLog(@"Challenge failed");
          [self submitFailure:response];


In your login View Controller, when the user taps to submit the credentials, call the submitLoginForm method to send the j_security_check string and the credentials to the MobileFirst Server.

@implementation LoginViewController
- (IBAction)login:(id)sender {
    [self.challengeHandler submitLoginForm:@"j_security_check"
         requestParameters:@{@"j_username": self.username.text, @"j_password": self.password.text}

Registering the challenge handler

Before calling the protected adapter, in order to listen to incoming challenges, make sure to register the challenge handler by using the registerChallengeHandler method of the WLClient class.

[[WLClient sharedInstance] registerChallengeHandler:[[MyChallengeHandler alloc] initWithViewController:self] ];

Sample application

Click to download the Studio project.
Click to download the Obj-C project.
Click to download the Swift project.


Last modified on November 09, 2016