Symfony 1.4: Custom error message for CSRF in forms

Question

Can anyone tell me where/how to customise the CSRF token error message for forms in Symfony 1.4. I'm using sfDoctrineGuard for logins and in this form particularly, whenever a session runs out and you still have the page open, it throws a very user-unfriendly error: "CSRF attack detected". Something like "This session has expired. Please return to the home page and try again" sounds better.

What's the right way to do this in the form class?

Thanks.

Amortization

Answer 1

The only way seems to be to overwrite sfForm::addCSRFProtection().

In /lib/form/BaseForm.class.php you can add this piece of code:

class BaseForm extends sfFormSymfony
{
    public function addCSRFProtection($secret = null)
    {
        parent::addCSRFProtection($secret);
        if (array_key_exists(self::$CSRFFieldName, $this->getValidatorSchema())) {
            $this->getValidator(self::$CSRFFieldName)->setMessage('csrf_attack', 'This session has expired. Please return to the home page and try again.');
        }
    }
}

After calling the parent method, you retrieve the validator associated with the CSRF field and change the message for the code csrf_attack.

Edit: You also need to check whether or not the validator exists. Some forms might have their CSRF protection disabled!

Hope this helps!

Oligopsony

@naag: thanks very much. Tried a few things but not that, will have a play. Seems like a minor oversight from the symfony guys. – Amortization

I edited my answer to include a check for the existence of the CSRF validator :-) – Oligopsony

Answer 2

None of these answers explain how to remove the "CSRF token:" label that prefixes the error message in a non-hackish way (e.g. changing the token name is a bad idea!).

The only sound way of removing the label is to extend the CSRF validator to throw a global error. While we do this, we can also change the error message.

class myValidatorCSRFToken extends sfValidatorCSRFToken
{
  protected function configure($options = array(), $messages = array())
  {
    parent::configure($options, $messages);
    $this->addMessage('csrf_attack', 'Your session has expired. Please return to the home page and try again.');
  }

  protected function doClean($value)
  {
    try {
      return parent::doClean($value);
    } catch (sfValidatorError $e) {
      throw new sfValidatorErrorSchema($this, array($e));
    }
  }
}

Now, let's set our forms to use this validator by overriding sfForm::addCSRFProtection in BaseForm:

public function addCSRFProtection($secret = null)
{
  parent::addCSRFProtection($secret);
  if (isset($this->validatorSchema[self::$CSRFFieldName])) //addCSRFProtection doesn't always add a validator
  {
    $this->validatorSchema[self::$CSRFFieldName] = new myValidatorCSRFToken(array(
        'token' => $this->validatorSchema[self::$CSRFFieldName]->getOption('token')
    ));
  }
}

Herod

Answer 3

In 1.4.4 I had to modify naag's code like so...

public function addCSRFProtection($secret = null)
{
  parent::addCSRFProtection($secret);
  if (isset($this->validatorSchema[self::$CSRFFieldName])) {
    $this->validatorSchema[self::$CSRFFieldName]->setMessage('csrf_attack', 'This session has expired. Please refresh and try again.');
  }
}

This got it working, the 'csrf token:' bit still appears in the error message though.

Terwilliger

Answer 4

Improving on previous answers, here is the code I use:

public function addCSRFProtection($secret = null)
  {
    parent::addCSRFProtection($secret);
    if (isset($this->validatorSchema[self::$CSRFFieldName])) {
      $this->validatorSchema[self::$CSRFFieldName]->setMessage('csrf_attack', 'This session has expired. Please refresh and try again.');
      $this->getWidgetSchema()->getFormFormatter()->setNamedErrorRowFormatInARow("    <li>%error%</li>\n");
    }
  }

The default value for the NamedErrorRowFormatInARow is "<li>%name%: %error%</li>\n" adding the name and the colon. Be careful because it changes the value for all forms and all global errors.

You can also change the field by creating a custom form formatter and using it in the forms you want. You can go look at the documentation here for more info on this.

Withhold

Answer 5

Use event dispatcher. Check this out http://bluehorn.co.nz/2010/07/15/how-to-change-csrf-attack-message-in-symfony-1-2/

I wrote it for Symfony 1.2, but using event dispatcher, so it still might work for Symfony 1.4.

Cutaway

Answer 6

I suppose the "csrf token:" prefix can be removed or customized by setting the label of the CSRF token field, globally of course.

Retire