Troubleshooting

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Troubleshooting

How to debug and solve common issues related to the bundle.

TOTP / Google Authenticator code is not accepted

The principle of TOTP/Google Authenticator is that both systems - the server and your device - generate the same authentication code from a shared secret and the current time. If one of those two components isn't in sync, they'll generate a different code. Therefore:

  1. Most common problem: Make sure the server time and the time on your device are in sync with the actual current time
  2. Make sure the secret used in your device matches the secret configured for the account on the server
  3. If you're using TOTP, make sure the app is actually supporting the specific TOTP configuration you're using. The Google Authenticator app supports only one specific TOTP configuration (6-digit code, 30sec window, sha1 algorithm)

The generated authentication code has a time window in which it is valid (30 seconds in Google Authenticator, for TOTP it depends on your configuration). The bigger the time difference between server and device, the smaller the time window, the higher the chance that the codes generated on server and from the app don't match up. When the time difference becomes larger than the time window, it becomes impossible to provide the right code.

To counteract the issue of time differences you could increase the window setting, then more codes around the current time window will be accepted:

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# config/packages/scheb_2fa.yaml
scheb_two_factor:

    # For TOTP
    totp:
        window: 1  # How many codes before/after the current one would be accepted as valid

    # For Google Authenticator
    google:
        window: 1  # How many codes before/after the current one would be accepted as valid

You might want to configure a time synchronization service, such as ntpdate on your server to make sure your server time is always in sync with UTC.

The Google Authenticator app has an option to sync the time of your device. Open the app and select Settings > Time correction for codes > Sync now from the menu. Other apps might have a similar option.

Logout redirects back to the two-factor authentication form

Problem

When the two-factor authentication form is shown, you want to cancel the two-factor authentication process. You click the "cancel" link, which should execute a logout. It does not execute the logout, but redirects back to the two-factor authentication form.

Solution

If you see such behavior, the access_control rules from the security configuration don't allow accessing the logout path. Your logout path must be accessible to user with any authentication state, which is usually done by allowing it for PUBLIC_ACCESS. You're most likely missing a rule under access_control in the security configuration.

The configuration should look similar to this:

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# config/packages/security.yaml
security:
    access_control:
        - { path: ^/logout, role: PUBLIC_ACCESS }
        # More rules here ...

Make sure the rule comes first in the list, since access control rules are evaluated in order.

If you have such a rule and it still doesn't work, for some reason the rule is not matching. Make absolutely sure the path regular expression matches your logout path. If you have additional options, such as host or ip, check that they're matching as well.

Not logged in after completing two-factor authentication

Problem

After you logged in and have successfully passed the two-factor authentication process, you're not logged in. Either you are redirected back to the login page or the page is shown with the authenticated user missing.

Troubleshooting

  1. Disable two-factor authentication by commenting out all two_factor settings in the security firewall configuration. Try to login. Does it work?

    Yes, it works
    Continue with 2)
    No, it does not work

    Your login process is broken.

    Solution: Can't exactly tell what's wrong. Continue debugging the login issue. Solve this issue first, before you re-enable two-factor authentication.

  2. Revert the changes from 1). Debug the security token on the two-factor authentication form page by var_dump-ing it or any other suitable method.

    The token should be of type TwoFactorToken and the field authenticatedToken should contain an authenticated security token. Does that authenticated token have authenticated=false set?

    Yes
    Your authenticated token was flagged as invalid. Follow the solution below.
    No
    Continue with 3)
  3. After completing two-factor authentication, when you end up in the unauthenticated state, check the last request few requests in the Symfony profiler.

    For each of the requests, go to Logs -> Debug.

    Does it say Cannot refresh token because user has changed or Token was deauthenticated after trying to refresh it?

    Yes
    Your authenticated token was flagged as invalid. Follow the solution below.
    No
    Unknown issue. Try to reach out for help by creating an issue and let us know what you've already tested.

Solution to: Your authenticated token was flagged as invalid

Most likely your user entity implements the a serializable interface and not all of the fields relevant to the authentication process are taken by serialize/unserialize. Check which fields are used in methods serialize() and deserialize().

It must be at least the fields that are used in the methods from Symfony\Component\Security\Core\User\UserInterface.

If your user entity implements Symfony\Component\Security\Core\User\AdvancedUserInterface, you also need the fields that are used in isAccountNonExpired(), isAccountNonLocked(), isCredentialsNonExpired() and isEnabled().

Two-factor authentication form is not shown after login

Problem

After successful login, the two-factor authentication form is not shown. Instead, you're either logged in or you see a different page from your application.

Basic checks

  • Your login page belongs to the firewall, which has two-factor authentication configured.
  • The paths of login page, login check, 2fa and 2fa check are all located with the firewall's path pattern.
  • Your user entity has the interfaces implemented, which are necessary for the two-factor authentication method.
  • Your user entity fulfills the requirements of at least one two-factor authentication method:

    • The is*Enabled() method returns true
    • Additional data for the authentication method is returned, e.g. for Google Authenticator to work the getGoogleAuthenticatorSecret() method must return a secret code.

Is access_control configured properly?

To make the two-factor authentication form accessible during the two-factor authentication process, you have to configure a access_control rule for the 2fa routes:

The configuration should look similar to this:

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# config/packages/security.yaml
security:
    # IMPORTANT: THE ACCESS CONTROL RULE NEEDS TO BE AT THE VERY TOP OF THE LIST!
    access_control:
        # This ensures that the form can only be accessed when two-factor authentication is in progress.
        # The path may be different, depending on how you've configured the route.
        - { path: ^/2fa, role: IS_AUTHENTICATED_2FA_IN_PROGRESS }
        # Other rules may follow here...

Make sure the rule comes first in the list, since access control rules are evaluated in order.

If you already have such a rule at the top of the list, make sure the path regular expression matches your two-factor authentication form path. If you have additional options, such as host or ip, check that they're matching as well.

Is there something special about your security setup?

Often issues originate from a customization in the application's security setup, which is usually related to how roles are granted. Examples of such issue are:

For 2fa to work properly, there must be two things fulfilled: A TwoFactorToken must be present after login and within that intermediate "2fa incomplete" state no roles must be granted. That later one is achieved by TwoFactorToken not returning any roles on the getRoleNames() call. But if you grant roles differently other than through the token, things will break.

The solution to this problem is usually to skip any customization for a security token of type TwoFactorTokenInterface.

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use Scheb\TwoFactorBundle\Security\Authentication\Token\TwoFactorTokenInterface;

if (!($token instanceof TwoFactorTokenInterface)) {
    // Your customization here
}

Troubleshooting

  1. Is a TwoFactorToken present after the login?

    Yes
    Continue with 2)
    No
    Continue with 3)
  2. Try accessing a page that requires the user to be authenticated. Does it redirect to the two-factor authentication form?

    Yes
    Solution: The page you've seen after login doesn't require a fully authenticated user. Most likely that path is accessible to PUBLIC_ACCESS via your security access_control configuration. Either change your access_control configuration or after login force-redirect to user to a page that requires full authentication.
    No
    Unknown issue. Try to reach out for help by creating an issue and let us know what you've already tested.
  3. On login, do you reach the end (return statement) of method Scheb\TwoFactorBundle\Security\Authentication\Provider\AuthenticationProviderDecorator::authenticate()?

    Yes
    Continue with 4)
    No
    Something is wrong with the integration of the bundle. Try to reach out for help by creating an issue`_ and let us know what you've already tested.
  4. On login, is method Scheb\TwoFactorBundle\Security\TwoFactor\Handler\TwoFactorProviderInitiator::getActiveTwoFactorProviders() called?

    Yes, it's called
    Continue with 5)
    No it's not called
    Solution: Two-factor authentication is skipped, either because of the IP whitelist or because of a trusted device token. IP whitelist is part of the bundle's configuration. Maybe you have whitelisted "localhost" or "127.0.0.1"? The trusted device cookie can be removed with your browser's developer tools.
  5. Does Scheb\TwoFactorBundle\Security\TwoFactor\Handler\TwoFactorProviderInitiator::getActiveTwoFactorProviders() return any values?

    Yes, it returns an array of strings
    Unknown issue. Try to reach out for help by creating an issue and let us know what you've already tested.
    No, it returns an empty array
    Solution: our user doesn't have an active two-factor authentication method. Either the is*Enabled method returns false or an essential piece of data (e.g. Google Authenticator secret) is missing.

Problem

After you have completed 2fa, you expect that device to be flagged as a "trusted device", but the trusted device cookie is not set.

Basic checks

  • 2fa was completed with that call and you've been fully authenticated afterwards.
  • Together with the 2fa code, you have sent the trusted parameter (default _trusted) with a true-like value. (Background information: Devices are not automatically flagged as trusted. The user has to choose if they can trust that device. That's why this extra parameter has to be sent over.)

Troubleshooting

Have a look at the response of the HTTP call when you sent the 2fa and the trusted parameter. Do you see a cookie being set (Set-Cookie header)?

Yes
Please validate the cookie's parameters. Make sure everything is fine for that cookie: the path, domain, and other cookie options. Did you maybe try to set it for a top level domain ?
No, there's no cookie set
Unknown issue. Try to reach out for help by creating an issue and let us know what you've already tested.
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.