How could we integrate the Captcha in iOS application?

Question

I googled for integration of Captcha in iOS app but do not found any relevant way to do so. Even i sign up with reCAPTCHA and searched whether the plugins for Captcha are available for iOS or not? I didn't found any plugin for iOS there. Somewhere while RND i come to know that "its not needed for the mobile apps" , But the client wants the Captcha in his application so ,I want to know :-

Whether we can integrate the Captcha in iOS App/Mobile Apps :-
1. If Yes? : Then what would be the relevant way to integrate it.
2. If No? : Then what is the relevant reason .

Explain to the client why it doesn't apply to a mobile app... — Wain, Jan 07 '14 at 13:00
It is relatively simple to create a bot to crawl the web (including web applications) and submit forms. This is where a classic CAPTCHA solution comes in.we didn't need to make captcha in native application. Why we need captcha to avoid spam and unfortunately there are no bots I heard that do spam a native application. — Saad Chaudhry, Jan 08 '14 at 11:36
I'm a penetration tester with 8 years experience working on major projects for very large international companies. I have also developed large web and mobile apps as well as the back-end services for them. I am here to tell you all that the rumour that 'CAPTCHA is not necessary for mobile apps' MUST STOP! The client application, whether HTML/JS in browser or APK on Android, all interact with HTTP services and it is the HTTP services themselves that are vulnerable to the attacks, not the client app that interacts with them! I've personally compromised many APIs in major ways due to this rumour — SomeGuy, Apr 02 '20 at 14:35

score 4 · Answer 1 · answered Dec 01 '18 at 03:40

4

For my I use the following library:

https://github.com/fjcaetano/ReCaptcha

it will use a hidden webview to handle that

answered Dec 01 '18 at 03:40

Developer So far

353
1
11

I am not so sure about this hidden webview ReCaptcha solution, in order for a recaptcha to work, it need to track the user's behavior, with this solution I don't see how this will happen, so I assume that the challenge will show up 99.99% of the times – Waqleh Apr 23 '19 at 14:58
1

@Waqleh the idea of ReCapatcha is to protect your server from spam or irregular hits. Thus, even if you use it with hidden WV, it will not showing a lot for regular users/devices. BTW: I try it, 90% of hits it's not appear at all. – Developer So far Apr 23 '19 at 16:57
good to know that it doesn't always show the challenge, I didnt try this library, I know that recaptcha is used to stop spam and ddos attack... etc. in any case even if it shows 100% of the time it is better than not having one at all. A better solution would be using SMS verification like what telegram and whatsapp..etc do – Waqleh Apr 24 '19 at 08:40
in my opinion, SMS verification not enough, some time hackers can verify using "online fake numbers" and simulate the same query to attack you or access your data, using the token or whatever you give after the SMS verification ,,, good luck bro. – Developer So far Apr 24 '19 at 21:22
1

there is always a way to do an attack, when there is a will there is a way, fake numbers can be detected, gmail, facebook and others already can do this very efficiently, the sms verification is an industry standard, that doesn't mean it is bulletproof, nothing is, you should always try to balance between user experience and security, otherwise you will definitely loose conversion. – Waqleh Apr 25 '19 at 08:18
If you want to verify if it's a mobile device or not, try push notification. You have an authentication process (APNS and Firebase) already there. – Blind Ninja May 20 '19 at 10:45
@HarvantS.Choudhary what if the user don't allow push notification in iOS ? – Developer So far May 24 '19 at 22:59
You can make it mandatory. User can't go further without allowing. Just don't spam user and use silent notification. – Blind Ninja May 25 '19 at 02:14
@BlindNinja ios app will get rejected by the AppStore if you make mandatory the push notifications. – Syed Zahid Shah Feb 26 '20 at 09:08
@SyedZahidShah I have apps on store with mandatory push notifications, I think apple don't have any issue with it until it justify app's functionality. – Blind Ninja Feb 29 '20 at 08:35

score -1 · Accepted Answer · edited Apr 10 '16 at 18:03

Though we do not have any of the API for Captcha in iOS , not even the reCaptcha has provided any plugin for iOS . And even lot of peoples suggested me that there is no need to implement the captcha for mobile applications. I agreed, but as the client was not be able to listen any excuses what i have done is,

simply i created the Random number using

-(NSInteger)randomIntBetween:(NSInteger)min and:(NSInteger)max { return (NSInteger)(min + arc4random_uniform(max + 1 - min)); }

placed that number on label and asked user to enter the same number in in provided textField, If the match is found the captcha's principal is done [The user on the other end is human being is the only principal to integrate captcha], Other wise i regenerate the random number and place it there again on the label asking user to enter same number in provided textField.
Final Result will be like this.

It Will Look Something Like This

Now the idea might be more clear to you, Simply assign the output of the function "randomIntBetween" to the label on which the number is displayed, and when the user will press the login button authenticate whether the text in the textField(Named: Enter number) is matches with the label on its left, if it matches allow the user to login if not then clear then text of text field and also the text on label then assign the new random number to the label on left by calling the method "randomIntBetween:" and ask user to enter the text in the enter number text field.

This is not a CAPTCHA. It _looks_ like a CAPTCHA, but provides none of the protection. — , Feb 14 '17 at 00:30

Manab Kumar Mal · Answer 3 · 2016-05-07T08:17:01.537

Though there is no Need to add Captcha in some Application, as Applications are not as like Web, So, as per my thinking there is no Need to attach the Captcha in some Application to prevent the Bots, Still if you need to embed it... Yes, Here is the Possible way, Please check the following codes:

Take these outlets and variables:

NSArray *arrCapElements;
IBOutlet UILabel *Captcha_label;
IBOutlet UITextField *Captcha_field;
IBOutlet UILabel *Status_label;

and IBActions as:

- (IBAction)Reload_Action:(id)sender;
- (IBAction)Submit_Action:(id)sender;

In storyboard choose the font name as Chalkduster 30.0 for the Captcha_label.

Now assign arrCapElements in viewDidLoad() as

arrCapElements = [[NSArray alloc]initWithObjects:@"0",@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",@"i",@"j",@"k",@"l",@"m",@"n",@"o",@"p",@"q",@"r",@"s",@"t",@"u",@"v",@"w",@"x",@"y",@"z",@"A",@"B",@"C",@"D",@"E",@"F",@"G",@"H",@"I",@"J",@"K",@"L",@"M",@"N",@"O",@"P",@"Q",@"R",@"S",@"T",@"U",@"V",@"W",@"X",@"Y",@"Z", nil];

Code for load the Captcha:

-(void)load_captcha{
    @try {
        CGFloat hue = ( arc4random() % 256 / 256.0 );  //  0.0 to 1.0
        CGFloat saturation = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from white
        CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from black
        Captcha_label.backgroundColor = [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1];
        //Captcha_label.textColor=[UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1];
        NSUInteger elmt1,elmt2,elmt3,elmt4,elmt5,elmt6;
        elmt1 = arc4random() % [arrCapElements count];
        elmt2= arc4random() % [arrCapElements count];
        elmt3 = arc4random() % [arrCapElements count];
        elmt4 = arc4random() % [arrCapElements count];
        elmt5 = arc4random() % [arrCapElements count];
        elmt6 = arc4random() % [arrCapElements count];

        NSString *Captcha_string = [NSString stringWithFormat:@"%@%@%@%@%@%@",arrCapElements[elmt1-1],arrCapElements[elmt2-1],arrCapElements[elmt3-1],arrCapElements[elmt4-1],arrCapElements[elmt5-1],arrCapElements[elmt6-1]];
        //NSLog(@" Captcha String : %@",Captcha_string);
        Captcha_label.text = Captcha_string;
    }
    @catch (NSException *exception) {
        NSLog(@"%@",exception);
    }
}

Reload Action:

- (IBAction)Reload_Action:(id)sender {

    [self load_captcha];
}

Check the captcha Correct or not:

- (IBAction)Submit_Action:(id)sender {

    NSLog(@"%@ = %@",Captcha_label.text,Captcha_field.text);
    if([Captcha_label.text isEqualToString: Captcha_field.text]){
        [self.view endEditing:YES];
        Status_label.text =@"Success";
        Status_label.textColor = [UIColor greenColor];
    }else{
        Status_label.text =@"Faild";
        Status_label.textColor = [UIColor redColor];
    }
}

It will be shown like this:

Help taken from: Captcha Generator for iOS

This is not a CAPTCHA. It _looks_ like a CAPTCHA, but provides none of the protection. — , Feb 14 '17 at 00:30
reCAPTCHA should be validated on the server, I couldn’t see it in your answer — Michael Freidgeim, Sep 10 '19 at 20:53

How could we integrate the Captcha in iOS application?

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