eu.trentorise.smartcampus.permissionprovider.auth.google.GoogleController.java Source code

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Here is the source code for eu.trentorise.smartcampus.permissionprovider.auth.google.GoogleController.java

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/*******************************************************************************
 * Copyright 2012-2013 Trento RISE
 * 
 * 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 eu.trentorise.smartcampus.permissionprovider.auth.google;

import java.io.IOException;
import java.net.URLEncoder;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeRequestUrl;

/**
 * Google controller connects to google and retrieve user data.
 * 
 * @author Giulia Canobbio
 * 
 */
@Controller
@RequestMapping(value = "/auth/google-oauth")
public class GoogleController {

    private static final Logger logger = LoggerFactory.getLogger(GoogleController.class);

    private static final String SESSION_ATTR_STATE = "state";
    /**
     * Instance of {@link GoogleAuthHelper} for oauth google
     */
    @Autowired
    private GoogleAuthHelper auth;

    /**
     * This rest web services sends an authentication request to Google. First
     * it creates state token and then it builds login url for Google. After
     * that state token is saved in current session.
     * 
     * @param response
     *            : instance of {@link HttpServletResponse}
     * @param request
     *            : instance of {@link HttpServletRequest}
     * @return {@link ResponseObject} with redirect google login url, status
     *         (OK)
     */
    @RequestMapping(method = RequestMethod.GET)
    public String socialGooglePlus(HttpServletResponse response, HttpServletRequest request) {
        GoogleAuthorizationCodeRequestUrl googleCodeURL = auth.buildLoginUrl();
        request.getSession().setAttribute(SESSION_ATTR_STATE, googleCodeURL.getState());
        return "redirect:" + googleCodeURL.build();

    }

    /**
     * This rest web service is the one that google called after login (callback
     * url). First it retrieve code and token that google sends back. It checks
     * if code and token are not null, then if token is the same that was saved
     * in session. If it is not response status is UNAUTHORIZED, otherwise it
     * retrieves user data. If user is not already saved in db, then user is
     * added in db, iff email is not already used, otherwise it sends an
     * UNAUTHORIZED status and redirect user to home page without authenticating
     * him/her. If it is all ok, then it authenticates user in spring security
     * and create cookie user. Then redirects authenticated user to home page
     * where user can access protected resources.
     * 
     * @param request
     *            : instance of {@link HttpServletRequest}
     * @param response
     *            : instance of {@link HttpServletResponse}
     * @return redirect to home page
     */
    @RequestMapping(value = "/callback", method = RequestMethod.GET)
    public String confirmStateToken(HttpServletRequest request, HttpServletResponse response) {

        String code = request.getParameter("code");
        String token = request.getParameter("state");
        String sessionStateToken = "";
        if (request.getSession().getAttribute(SESSION_ATTR_STATE) != null) {
            sessionStateToken = request.getSession().getAttribute(SESSION_ATTR_STATE).toString();
        }

        // compare state token in session and state token in response of google
        // if equals return to home
        // if not error page
        if ((code == null || token == null) && (!token.equals(sessionStateToken))) {
            logger.error("Error in google authentication flow");
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return "";
        } else {
            try {
                GoogleUser userInfo = auth.getUserInfoJson(code);
                response.setStatus(HttpServletResponse.SC_OK);
                request.getSession().setAttribute(GoogleAuthHelper.SESSION_GOOGLE_CHECK, "true");
                return String.format(
                        "redirect:/eauth/google?target=%s&OIDC_CLAIM_email=%s&OIDC_CLAIM_given_name=%s&OIDC_CLAIM_family_name=%s",
                        URLEncoder.encode((String) request.getSession().getAttribute("redirect"), "UTF8"),
                        userInfo.getEmail(), userInfo.getGivenName(), userInfo.getFamilyName());

            } catch (IOException e) {
                logger.error("IOException .. Problem in reading user data.", e);
                response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            }
        }

        return "redirect:/";
    }
}