com.mobileman.projecth.web.util.PersistentCookieHelper.java Source code

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Here is the source code for com.mobileman.projecth.web.util.PersistentCookieHelper.java

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/*******************************************************************************
 * Copyright 2015 MobileMan GmbH
 * www.mobileman.com
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.mobileman.projecth.web.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;

import com.mobileman.projecth.business.UserService;
import com.mobileman.projecth.domain.user.User;

public class PersistentCookieHelper {

    private static final String COOKIE_NAME = "AutoLogin";
    private static final String SEPARATOR = ",";
    private static final String PATH = "/";

    public void setUser(HttpServletResponse response, User user) {
        String hash = createHash("" + System.currentTimeMillis(), user);
        //save hash to cvookie
        Cookie cookie = new Cookie(COOKIE_NAME, hash);
        cookie.setPath(PATH);
        cookie.setMaxAge(365 * 24 * 3600);

        response.addCookie(cookie);
    }

    public User getUser(UserService userService, HttpServletRequest request, HttpServletResponse response) {
        Cookie[] cookies = request.getCookies();
        boolean removeCookie = false;
        if (cookies != null) {
            for (Cookie c : cookies) {
                if (COOKIE_NAME.equals(c.getName())) {
                    removeCookie = true;
                    String hash = c.getValue();

                    //extract id, salt, hash
                    if (StringUtils.isNotBlank(hash)) {
                        //if not found remove cookie!!!
                        String[] split = hash.split(SEPARATOR);
                        if (split.length == 3) {
                            try {
                                Long id = Long.parseLong(split[0]);
                                //find user
                                User user = userService.findById(id);
                                if (user != null) {
                                    //check hash
                                    String h2 = createHash(split[1], user);
                                    if (hash.equals(h2)) {
                                        return user;
                                    }
                                }
                            } catch (Exception ex) {
                            }
                        }
                    }
                }
            }
        }
        if (removeCookie && response != null) {
            removeUser(request, response);
        }
        return null;
    }

    public void removeUser(HttpServletRequest request, HttpServletResponse response) {
        //remove from request
        Cookie[] cookies = request.getCookies();
        if (cookies != null) {
            for (Cookie c : cookies) {
                if (COOKIE_NAME.equals(c.getName())) {
                    c.setValue("deleted");
                    break;
                }
            }
        }

        //remove from browser
        Cookie cookie = new Cookie(COOKIE_NAME, "1");
        cookie.setPath(PATH);
        cookie.setMaxAge(0); //0 = remove cookie
        response.setContentType("text/html"); //else delete cookie not works
        response.addCookie(cookie);
    }

    private String createHash(String salt, User user) {
        StringBuilder sb = new StringBuilder();

        sb.append(salt);
        sb.append(user.getId());
        sb.append(user.getName().getName());
        sb.append(user.getName().getSurname());
        sb.append(user.getUserAccount().getEmail());

        MessageDigest md;
        try {
            md = MessageDigest.getInstance("SHA-1");
            byte[] src = sb.toString().getBytes("utf-8");
            md.update(src, 0, src.length);
            byte[] sha1hash = new byte[40];
            sha1hash = md.digest();

            String sha1 = convertToHex(sha1hash);

            sb.delete(0, sb.length());

            sb.append(user.getId());
            sb.append(SEPARATOR);
            sb.append(salt);
            sb.append(SEPARATOR);
            sb.append(sha1);

            return sb.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return "";
    }

    private static String convertToHex(byte[] data) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                if ((0 <= halfbyte) && (halfbyte <= 9))
                    buf.append((char) ('0' + halfbyte));
                else
                    buf.append((char) ('a' + (halfbyte - 10)));
                halfbyte = data[i] & 0x0F;
            } while (two_halfs++ < 1);
        }
        return buf.toString();
    }
}