Issues relating to password authentication

App Development
1

I have a login system which authenticates the users password to check that it meets the following criteria:

  • 9 characters minimum
  • contains a capital character
  • contains a special character

Here’s my code which is run from my ‘SignUpViewController’

 // Check if the password is secure
    let cleanedPassword = passwordTextField.text!.trimmingCharacters(in: .whitespacesAndNewlines)
    
    if Utilities.isPasswordValid(cleanedPassword) == false {
        
        let alert = UIAlertController(title: "Invalid Password", message: "Please make sure your password is at least 8 characters, contains a special character and a number.", preferredStyle: UIAlertController.Style.alert)

                // add an action (button)
                alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))

                // show the alert
                self.present(alert, animated: true, completion: nil)
        
      
    }
    
    return nil
}

And here is the code which is run from my ‘Utilities.ispasswordvalid’ file:

    static func isPasswordValid(_ password : String) -> Bool {
    
    let passwordTest = NSPredicate(format: "SELF MATCHES %@", "^(?=.*[a-z])(?=.*[$@$#!%*?&])[A-Za-z\\d$@$#!%*?&]{8,}")
    return passwordTest.evaluate(with: password)
}

This previously works, and creates a new user, however when I enter in the required details, the alert popup is displayed for around 1 second and then takes me to the correct view controller. Does anyone know why this alert displaying the ‘Invalid Password’ message appears for a short time, even though everything else works fine?

It doesn’t break anything, but is just quite annoying!!

2

In your sign up view controller why are you returning nil at the end?

It seems like it’s presenting and then goes away because your function is continuing on

3

Hi, I am returning nill at the end as I am using an ‘if loop’ to check the password to see if it is valid or not. When I comment out the ‘return nil’ it just displays the following error:

Missing return in a function expected to return 'String?'
4

You need to write your function in a different way.

func isValidPassword -> Bool
{
   let cleanedPassword = passwordTextField.text!.trimmingCharacters(in: .whitespacesAndNewlines)
    
    if Utilities.isPasswordValid(cleanedPassword) == false { return false }
else { return true}
}

Then in your SignUpVC
Have something calling that function and then put the alert

if !isValidPassword()  {
 // put alertVC here
}

You need to put your password logic in one function (using the regex to check for a valid password.

5

Perfect thank you for your help! I’ve got it working now :slight_smile:

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