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Authentication mechanism absence or evasion - Security Image

Need​

Implementation of a robust authentication mechanism

Context​

  • Usage of Swift for iOS and macOS app development
  • Usage of UIKit for building modern and responsive user interfaces

Description​

Non compliant code​

import UIKit

class LoginViewController: UIViewController {

    @IBOutlet weak var usernameTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!

    @IBAction func loginButtonTapped(_ sender: UIButton) {
        let username = usernameTextField.text
        let password = passwordTextField.text

        if !username.isEmpty && !password.isEmpty {
            // Proceed with the authentication
            authenticateUser(username: username!, password: password!)
        }
    }

    func authenticateUser(username: String, password: String) {
        // Authentication logic here
    }
}

This Swift code represents a simple login interface for a mobile application built for iOS. The LoginViewController class contains two text fields, usernameTextField and passwordTextField, for users to input their username and password respectively.

When the login button is tapped, the loginButtonTapped function is called. This function checks if the username and password fields are not empty, and if they aren't, it calls the authenticateUser function with the username and password as parameters.

The vulnerability lies in the absence of any additional authentication mechanism, such as a security image or phrase. The application only relies on the username and password for authentication, which makes it susceptible to brute force attacks. If a malicious user makes multiple attempts to guess a user's password, the application does not provide any additional layer of security to prevent this.

An additional security measure, such as a security image or phrase, could be used to verify that the user is not a bot. This would add an extra layer of security to the authentication process and help protect against brute force attacks.

Steps​

  • Implement a secure authentication mechanism that includes the use of a security image and phrase.
  • Add a security image and phrase to the login screen.
  • Modify the authentication logic to validate the security image and phrase along with the username and password.
  • Ensure that the security image and phrase are securely stored and transmitted.
  • Consider implementing additional security measures such as multi-factor authentication or biometric authentication.

Compliant code​

import UIKit

class LoginViewController: UIViewController {

    @IBOutlet weak var usernameTextField: UITextField!
    @IBOutlet weak var passwordTextField: UITextField!
    @IBOutlet weak var securityImage: UIImageView!
    @IBOutlet weak var securityPhraseTextField: UITextField!

    @IBAction func loginButtonTapped(_ sender: UIButton) {
        let username = usernameTextField.text
        let password = passwordTextField.text
        let securityPhrase = securityPhraseTextField.text

        if !username.isEmpty && !password.isEmpty && !securityPhrase.isEmpty {
            // Proceed with the authentication
            authenticateUser(username: username!, password: password!, securityPhrase: securityPhrase!)
        }
    }

    func authenticateUser(username: String, password: String, securityPhrase: String) {
        // Authentication logic here
        // This should include validation of the security image and phrase
    }
}

The updated code includes a security image and phrase as part of the login process. The securityImage and securityPhraseTextField outlets are connected to the corresponding UI elements on the login screen.

The loginButtonTapped function now checks that the security phrase is not empty in addition to the username and password. If all fields are filled, it calls the authenticateUser function with the security phrase as an additional parameter.

The authenticateUser function should be updated to include validation of the security image and phrase. This could involve comparing the entered phrase to a stored value, and/or using the security image as a form of captcha or other verification method.

This change helps to mitigate the risk of authentication evasion by adding an additional layer of security to the login process. For even greater security, consider implementing multi-factor or biometric authentication.

References​

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