Validator.java

/*
 * Password Management Servlets (PWM)
 * http://www.pwm-project.org
 *
 * Copyright (c) 2006-2009 Novell, Inc.
 * Copyright (c) 2009-2017 The PWM Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package password.pwm.util;

import password.pwm.AppProperty;
import password.pwm.PwmApplication;
import password.pwm.PwmConstants;
import password.pwm.bean.FormNonce;
import password.pwm.config.Configuration;
import password.pwm.config.PwmSetting;
import password.pwm.error.ErrorInformation;
import password.pwm.error.PwmError;
import password.pwm.error.PwmOperationalException;
import password.pwm.error.PwmUnrecoverableException;
import password.pwm.http.PwmRequest;
import password.pwm.http.PwmSession;
import password.pwm.util.logging.PwmLogger;

import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Static utility class for validating parameters, passwords and user input.
 *
 * @author Jason D. Rivard
 */
public class Validator {
// ------------------------------ FIELDS ------------------------------

    private static final PwmLogger LOGGER = PwmLogger.forClass(Validator.class);

    public static final String PARAM_CONFIRM_SUFFIX = "_confirm";



// -------------------------- STATIC METHODS --------------------------


    public static void validatePwmFormID(final PwmRequest pwmRequest)
            throws PwmUnrecoverableException
    {
        final PwmSession pwmSession = pwmRequest.getPwmSession();
        final PwmApplication pwmApplication = pwmRequest.getPwmApplication();

        final String submittedPwmFormID = pwmRequest.readParameterAsString(PwmConstants.PARAM_FORM_ID);

        if (pwmApplication.getConfig().readSettingAsBoolean(PwmSetting.SECURITY_ENABLE_FORM_NONCE)) {
            final FormNonce formNonce = pwmRequest.getPwmApplication().getSecureService().decryptObject(
                    submittedPwmFormID,
                    FormNonce.class
            );
            if (formNonce == null) {
                throw new PwmUnrecoverableException(new ErrorInformation(PwmError.ERROR_INVALID_FORMID,"form nonce missing"));
            }
            if (!pwmSession.getLoginInfoBean().getGuid().equals(formNonce.getSessionGUID())) {
                throw new PwmUnrecoverableException(new ErrorInformation(PwmError.ERROR_INVALID_FORMID,"form nonce incorrect"));
            }
        }
    }

    public static void validatePwmRequestCounter(final PwmRequest pwmRequest)
            throws PwmOperationalException, PwmUnrecoverableException
    {
        final PwmSession pwmSession = pwmRequest.getPwmSession();
        final PwmApplication pwmApplication = pwmRequest.getPwmApplication();

        if (pwmApplication.getConfig().readSettingAsBoolean(PwmSetting.SECURITY_ENABLE_REQUEST_SEQUENCE)) {
            final String requestVerificationKey = String.valueOf(pwmSession.getLoginInfoBean().getReqCounter());

            final String submittedPwmFormID = pwmRequest.readParameterAsString(PwmConstants.PARAM_FORM_ID);
            if (submittedPwmFormID == null || submittedPwmFormID.isEmpty()) {
                return;
            }

            try {
                final FormNonce formNonce = pwmRequest.getPwmApplication().getSecureService().decryptObject(
                        submittedPwmFormID,
                        FormNonce.class
                );
                final String submittedRequestVerificationKey = String.valueOf(formNonce.getReqCounter());
                if (!requestVerificationKey.equals(submittedRequestVerificationKey)) {
                    final String debugMsg = "expectedPageID=" + requestVerificationKey
                            + ", submittedPageID=" + submittedRequestVerificationKey
                            +  ", url=" + pwmRequest.getURL().toString();

                    throw new PwmOperationalException(PwmError.ERROR_INCORRECT_REQ_SEQUENCE, debugMsg);
                }
            } catch (StringIndexOutOfBoundsException | NumberFormatException e) {
                throw new PwmOperationalException(PwmError.ERROR_INCORRECT_REQ_SEQUENCE);
            }
        }
    }


    public static String sanitizeInputValue(
            final Configuration config,
            final String input,
            final int maxLength
    ) {
        String theString = input == null ? "" : input;

        final int max = (maxLength < 1)
                ? 10 * 1024
                : maxLength;

        // strip off any length beyond the specified maxLength.
        if (theString.length() > max) {
            theString = theString.substring(0, max);
        }

        // strip off any disallowed chars.
        if (config != null) {
            final List<String> disallowedInputs = config.readSettingAsStringArray(PwmSetting.DISALLOWED_HTTP_INPUTS);
            for (final String testString : disallowedInputs) {
                final String newString = theString.replaceAll(testString, "");
                if (!newString.equals(theString)) {
                    LOGGER.warn("removing potentially malicious string values from input, converting '" + input + "' newValue=" + newString + "' pattern='" + testString + "'");
                    theString = newString;
                }
            }
        }

        return theString;
    }


    public static String sanitizeHeaderValue(final Configuration configuration, final String input) {
        if (input == null) {
            return null;
        }

        final String regexStripPatternStr = configuration.readAppProperty(AppProperty.SECURITY_HTTP_STRIP_HEADER_REGEX);
        if (regexStripPatternStr != null && !regexStripPatternStr.isEmpty()) {
            final Pattern pattern = Pattern.compile(regexStripPatternStr);
            final Matcher matcher = pattern.matcher(input);
            final String output = matcher.replaceAll("");
            if (!input.equals(output)) {
                LOGGER.warn("stripped potentially harmful chars from value: input=" + input + " strippedOutput=" + output);
            }
            return output;
        }
        return input;
    }
}