drupal/modules/user/user.js

// $Id$
(function ($) {

/**
 * Attach handlers to evaluate the strength of any password fields and to check
 * that its confirmation is correct.
 */
Drupal.behaviors.password = {
  attach: function (context, settings) {
    var translate = settings.password;
    $('input.password-field', context).once('password', function () {
      var passwordInput = $(this);
      var innerWrapper = $(this).parent();
      var outerWrapper = $(this).parent().parent();

      // Add the password strength layers.
      var passwordStrength = $('span.password-strength', innerWrapper);
      var passwordResult = $('span.password-result', passwordStrength);
      innerWrapper.addClass('password-parent');

      // Add the description box.
      var passwordMeter = '<div id="password-strength"><div id="password-strength-text"></div><div class="password-strength-title">' + translate.strengthTitle + '</div><div id="password-indicator"><div id="indicator"></div></div></div>';

      $('div.description', outerWrapper).prepend('<div class="password-suggestions"></div>');
      $(innerWrapper).prepend(passwordMeter);
      var passwordDescription = $('div.password-suggestions', outerWrapper).hide();

      // Add the password confirmation layer.
      $('input.password-confirm', outerWrapper).after('<div class="password-confirm">' + translate['confirmTitle'] + ' <span></span></div>').parent().addClass('confirm-parent');
      var confirmInput = $('input.password-confirm', outerWrapper);
      var confirmResult = $('div.password-confirm', outerWrapper);
      var confirmChild = $('span', confirmResult);

      // Check the password strength.
      var passwordCheck = function () {

        // Evaluate the password strength.
        var result = Drupal.evaluatePasswordStrength(passwordInput.val(), settings.password);

        // Update the suggestions for how to improve the password.
        if (passwordDescription.html() != result.message) {
          passwordDescription.html(result.message);
        }

        // Only show the description box if there is a weakness in the password.
        if (result.strength == 100) {
          passwordDescription.hide();
        }
        else {
          passwordDescription.show();
        }

        // Adjust the length of the strength indicator.
        $('#indicator').css('width', result.strength + '%');

        // Update the strength indication text.
        $("#password-strength-text").html(result.indicatorText);

        passwordCheckMatch();
      };

      // Check that password and confirmation inputs match.
      var passwordCheckMatch = function () {

        if (confirmInput.val()) {
          var success = passwordInput.val() === confirmInput.val();

          // Show the confirm result.
          confirmResult.css({ visibility: 'visible' });

          // Remove the previous styling if any exists.
          if (this.confirmClass) {
            confirmChild.removeClass(this.confirmClass);
          }

          // Fill in the success message and set the class accordingly.
          var confirmClass = success ? 'ok' : 'error';
          confirmChild.html(translate['confirm' + (success ? 'Success' : 'Failure')]).addClass(confirmClass);
          this.confirmClass = confirmClass;
        }
        else {
          confirmResult.css({ visibility: 'hidden' });
        }
      };

      // Monitor keyup and blur events.
      // Blur must be used because a mouse paste does not trigger keyup.
      passwordInput.keyup(passwordCheck).focus(passwordCheck).blur(passwordCheck);
      confirmInput.keyup(passwordCheckMatch).blur(passwordCheckMatch);
    });
  }
};

/**
 * Evaluate the strength of a user's password.
 *
 * Returns the estimated strength and the relevant output message.
 */
Drupal.evaluatePasswordStrength = function (password, translate) {
  var weaknesses = 0, strength = 100, msg = [];

  var hasLowercase = password.match(/[a-z]+/);
  var hasUppercase = password.match(/[A-Z]+/);
  var hasNumbers = password.match(/[0-9]+/);
  var hasPunctuation = password.match(/[^a-zA-Z0-9]+/);

  // If there is a username edit box on the page, compare password to that, otherwise
  // use value from the database.
  var usernameBox = $('input.username');
  var username = (usernameBox.length > 0) ? usernameBox.val() : translate.username;

  // Lose 10 points for every character less than 6.
  if (password.length < 6) {
    msg.push(translate.tooShort);
    strength -= (6 - password.length) * 10;
  }

  // Count weaknesses.
  if (!hasLowercase) {
    msg.push(translate.addLowerCase);
    weaknesses++;
  }
  if (!hasUppercase) {
    msg.push(translate.addUpperCase);
    weaknesses++;
  }
  if (!hasNumbers) {
    msg.push(translate.addNumbers);
    weaknesses++;
  }
  if (!hasPunctuation) {
    msg.push(translate.addPunctuation);
    weaknesses++;
  }

  // Apply penalty for each weakness (balanced against length penalty).
  switch (weaknesses) {
    case 1:
      strength -= 12.5;
      break;

    case 2:
      strength -= 25;
      break;

    case 3:
      strength -= 40;
      break;

    case 4:
      strength -= 40;
      break;
  }

  // Check if password is the same as the username.
  if (password !== '' && password.toLowerCase() === username.toLowerCase()) {
    msg.push(translate.sameAsUsername);
    // Passwords the same as username are always very weak.
    strength = 5;
  }

  // Based on the strength, work out what text should be shown by the password strength meter.
  if (strength < 60) {
    indicatorText = translate.weak;
  } else if (strength < 70) {
    indicatorText = translate.fair;
  } else if (strength < 80) {
    indicatorText = translate.good;
  } else if (strength < 100) {
    indicatorText = translate.strong;
  }

  // Assemble the final message.
  msg = translate.hasWeaknesses + '<ul><li>' + msg.join('</li><li>') + '</li></ul>';
  return { strength: strength, message: msg, indicatorText: indicatorText }

};

})(jQuery);