com.chaosinmotion.securechat.server.commands.AddDevice.java Source code

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Here is the source code for com.chaosinmotion.securechat.server.commands.AddDevice.java

Source

/*   SecureChat: A secure chat system which permits secure communications 
 *  between iOS devices and a back-end server.
 *
 *   Copyright  2016 by William Edward Woody
 *
 *   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 3 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, see <http://www.gnu.org/licenses/>
 */

package com.chaosinmotion.securechat.server.commands;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.json.JSONObject;
import com.chaosinmotion.securechat.server.database.Database;

public class AddDevice {
    /**
     * Add device request. Takes parameters for deviceid, pubkey, as well as
     * the user info.
     * @param userinfo
     * @param requestParams
     * @return
     * @throws IOException 
     * @throws SQLException 
     * @throws ClassNotFoundException 
     */
    public static boolean processRequest(Login.UserInfo userinfo, JSONObject requestParams)
            throws ClassNotFoundException, SQLException, IOException {
        String deviceid = requestParams.optString("deviceid");
        String pubkey = requestParams.optString("pubkey");

        /*
         * Attempt to insert a new user into the database
         */

        Connection c = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        try {
            c = Database.get();

            /*
                * We now have the user index. Insert the device. Note that it is
                * highly unlikely we will have a UUID collision, but we verify
                * we don't by deleting any rows in the device table with the
                * specified UUID. The worse case scenario is a collision which
                * knocks someone else off the air. (The alternative would be
                * to accidentally send the wrong person duplicate messages.)
                * 
                * Note that we don't actually use a device-identifying identifer,
                * choosing instead to pick a UUID, so we need to deal with
                * the possibility (however remote) of duplicate UUIDs.
                * 
                * In the off chance we did have a collision, we also delete all
                * old messages to the device; that prevents messages from being
                * accidentally delivered.
                */

            ps = c.prepareStatement("DELETE FROM Messages " + "WHERE messageid IN "
                    + "    (SELECT Messages.messageid " + "     FROM Messages, Devices "
                    + "     WHERE Messages.deviceid = Devices.deviceid " + "     AND Devices.deviceuuid = ?)");
            ps.setString(1, deviceid);
            ps.execute();
            ps.close();
            ps = null;

            ps = c.prepareStatement("DELETE FROM Devices WHERE deviceuuid = ?");
            ps.setString(1, deviceid);
            ps.execute();
            ps.close();
            ps = null;

            ps = c.prepareStatement("INSERT INTO Devices " + "    ( userid, deviceuuid, publickey ) " + "VALUES "
                    + "    ( ?, ?, ?)");
            ps.setInt(1, userinfo.getUserID());
            ps.setString(2, deviceid);
            ps.setString(3, pubkey);
            ps.execute();

            /*
             * Complete; return result
             */

            return true;
        } finally {
            if (rs != null)
                rs.close();
            if (ps != null)
                ps.close();
            if (c != null)
                c.close();
        }
    }
}