/**
   * Validates a number of password policy state constraints for the user. This will be called
   * before the offered credentials are checked.
   *
   * @param userEntry The entry for the user that is authenticating.
   * @param saslHandler The SASL mechanism handler if this is a SASL bind, or {@code null} for a
   *     simple bind.
   * @throws DirectoryException If a problem occurs that should cause the bind to fail.
   */
  protected void checkUnverifiedPasswordPolicyState(
      Entry userEntry, SASLMechanismHandler<?> saslHandler) throws DirectoryException {
    PasswordPolicyState pwPolicyState = (PasswordPolicyState) authPolicyState;
    PasswordPolicy policy = pwPolicyState.getAuthenticationPolicy();

    boolean isSASLBind = saslHandler != null;

    // If the password policy is configured to track authentication failures or
    // keep the last login time and the associated backend is disabled, then we
    // may need to reject the bind immediately.
    if ((policy.getStateUpdateFailurePolicy()
            == PasswordPolicyCfgDefn.StateUpdateFailurePolicy.PROACTIVE)
        && ((policy.getLockoutFailureCount() > 0)
            || ((policy.getLastLoginTimeAttribute() != null)
                && (policy.getLastLoginTimeFormat() != null)))
        && ((DirectoryServer.getWritabilityMode() == WritabilityMode.DISABLED)
            || (backend.getWritabilityMode() == WritabilityMode.DISABLED))) {
      // This policy isn't applicable to root users, so if it's a root
      // user then ignore it.
      if (!DirectoryServer.isRootDN(userEntry.getName())) {
        throw new DirectoryException(
            ResultCode.INVALID_CREDENTIALS,
            ERR_BIND_OPERATION_WRITABILITY_DISABLED.get(userEntry.getName()));
      }
    }

    // Check to see if the authentication must be done in a secure
    // manner.  If so, then the client connection must be secure.
    if (policy.isRequireSecureAuthentication() && !clientConnection.isSecure()) {
      if (isSASLBind) {
        if (!saslHandler.isSecure(saslMechanism)) {
          throw new DirectoryException(
              ResultCode.INVALID_CREDENTIALS,
              ERR_BIND_OPERATION_INSECURE_SASL_BIND.get(saslMechanism, userEntry.getName()));
        }
      } else {
        throw new DirectoryException(
            ResultCode.INVALID_CREDENTIALS, ERR_BIND_OPERATION_INSECURE_SIMPLE_BIND.get());
      }
    }
  }
  /**
   * Performs the processing necessary for a simple bind operation.
   *
   * @return {@code true} if processing should continue for the operation, or {@code false} if not.
   * @throws DirectoryException If a problem occurs that should cause the bind operation to fail.
   */
  protected boolean processSimpleBind() throws DirectoryException {
    // See if this is an anonymous bind.  If so, then determine whether
    // to allow it.
    ByteString simplePassword = getSimplePassword();
    if (simplePassword == null || simplePassword.length() == 0) {
      return processAnonymousSimpleBind();
    }

    // See if the bind DN is actually one of the alternate root DNs
    // defined in the server.  If so, then replace it with the actual DN
    // for that user.
    DN actualRootDN = DirectoryServer.getActualRootBindDN(bindDN);
    if (actualRootDN != null) {
      bindDN = actualRootDN;
    }

    Entry userEntry;
    try {
      userEntry = backend.getEntry(bindDN);
    } catch (DirectoryException de) {
      logger.traceException(de);

      userEntry = null;

      if (de.getResultCode() == ResultCode.REFERRAL) {
        // Re-throw referral exceptions - these should be passed back
        // to the client.
        throw de;
      } else {
        // Replace other exceptions in case they expose any sensitive
        // information.
        throw new DirectoryException(ResultCode.INVALID_CREDENTIALS, de.getMessageObject());
      }
    }

    if (userEntry == null) {
      throw new DirectoryException(
          ResultCode.INVALID_CREDENTIALS, ERR_BIND_OPERATION_UNKNOWN_USER.get());
    } else {
      setUserEntryDN(userEntry.getName());
    }

    // Check to see if the user has a password. If not, then fail.
    // FIXME -- We need to have a way to enable/disable debugging.
    authPolicyState = AuthenticationPolicyState.forUser(userEntry, false);
    if (authPolicyState.isPasswordPolicy()) {
      // Account is managed locally.
      PasswordPolicyState pwPolicyState = (PasswordPolicyState) authPolicyState;
      PasswordPolicy policy = pwPolicyState.getAuthenticationPolicy();

      AttributeType pwType = policy.getPasswordAttribute();
      List<Attribute> pwAttr = userEntry.getAttribute(pwType);
      if (pwAttr == null || pwAttr.isEmpty()) {
        throw new DirectoryException(
            ResultCode.INVALID_CREDENTIALS, ERR_BIND_OPERATION_NO_PASSWORD.get());
      }

      // Perform a number of password policy state checks for the
      // non-authenticated user.
      checkUnverifiedPasswordPolicyState(userEntry, null);

      // Invoke pre-operation plugins.
      if (!invokePreOpPlugins()) {
        return false;
      }

      // Determine whether the provided password matches any of the stored
      // passwords for the user.
      if (pwPolicyState.passwordMatches(simplePassword)) {
        setResultCode(ResultCode.SUCCESS);

        checkVerifiedPasswordPolicyState(userEntry, null);

        if (DirectoryServer.lockdownMode()
            && !ClientConnection.hasPrivilege(userEntry, BYPASS_LOCKDOWN)) {
          throw new DirectoryException(
              ResultCode.INVALID_CREDENTIALS, ERR_BIND_REJECTED_LOCKDOWN_MODE.get());
        }
        setAuthenticationInfo(
            new AuthenticationInfo(
                userEntry, getBindDN(), DirectoryServer.isRootDN(userEntry.getName())));

        // Set resource limits for the authenticated user.
        setResourceLimits(userEntry);

        // Perform any remaining processing for a successful simple
        // authentication.
        pwPolicyState.handleDeprecatedStorageSchemes(simplePassword);
        pwPolicyState.clearFailureLockout();

        if (isFirstWarning) {
          pwPolicyState.setWarnedTime();

          int numSeconds = pwPolicyState.getSecondsUntilExpiration();
          LocalizableMessage m = WARN_BIND_PASSWORD_EXPIRING.get(secondsToTimeString(numSeconds));

          pwPolicyState.generateAccountStatusNotification(
              AccountStatusNotificationType.PASSWORD_EXPIRING,
              userEntry,
              m,
              AccountStatusNotification.createProperties(
                  pwPolicyState, false, numSeconds, null, null));
        }

        if (isGraceLogin) {
          pwPolicyState.updateGraceLoginTimes();
        }

        pwPolicyState.setLastLoginTime();
      } else {
        setResultCode(ResultCode.INVALID_CREDENTIALS);
        setAuthFailureReason(ERR_BIND_OPERATION_WRONG_PASSWORD.get());

        if (policy.getLockoutFailureCount() > 0) {
          generateAccountStatusNotificationForLockedBindAccount(userEntry, pwPolicyState);
        }
      }
    } else {
      // Check to see if the user is administratively disabled or locked.
      if (authPolicyState.isDisabled()) {
        throw new DirectoryException(
            ResultCode.INVALID_CREDENTIALS, ERR_BIND_OPERATION_ACCOUNT_DISABLED.get());
      }

      // Invoke pre-operation plugins.
      if (!invokePreOpPlugins()) {
        return false;
      }

      if (authPolicyState.passwordMatches(simplePassword)) {
        setResultCode(ResultCode.SUCCESS);

        if (DirectoryServer.lockdownMode()
            && !ClientConnection.hasPrivilege(userEntry, BYPASS_LOCKDOWN)) {
          throw new DirectoryException(
              ResultCode.INVALID_CREDENTIALS, ERR_BIND_REJECTED_LOCKDOWN_MODE.get());
        }
        setAuthenticationInfo(
            new AuthenticationInfo(
                userEntry, getBindDN(), DirectoryServer.isRootDN(userEntry.getName())));

        // Set resource limits for the authenticated user.
        setResourceLimits(userEntry);
      } else {
        setResultCode(ResultCode.INVALID_CREDENTIALS);
        setAuthFailureReason(ERR_BIND_OPERATION_WRONG_PASSWORD.get());
      }
    }

    return true;
  }