org.freeciv.servlet.SaveServlet.java Source code

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Here is the source code for org.freeciv.servlet.SaveServlet.java

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/********************************************************************** 
 Freeciv - Copyright (C) 2013 - Andreas Rsdal   andrearo@pvv.ntnu.no
   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, 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.
***********************************************************************/

package org.freeciv.servlet;

import java.security.MessageDigest;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

import java.sql.*;

import java.util.regex.*;

import javax.sql.*;
import javax.naming.*;

import org.apache.commons.io.*;
import org.apache.commons.codec.digest.DigestUtils;
import java.nio.charset.Charset;
import org.apache.commons.codec.binary.Base64;

/*** The SaveServlet handles savegames, transfering them
  from the freeciv-web server to the localclient storage,
  saving SHA1 hash for security.
*/
public class SaveServlet extends HttpServlet {
    /**
     * Serialization UID.
     */
    private static final long serialVersionUID = 1L;
    String PATTERN_VALIDATE_ALPHA_NUMERIC = "[0-9a-zA-Z\\.]*";
    Pattern p = Pattern.compile(PATTERN_VALIDATE_ALPHA_NUMERIC);

    @SuppressWarnings("unchecked")
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {

        String username = "" + request.getParameter("username");
        if (!p.matcher(username).matches()) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Invalid username");
            return;
        }

        String savename = "" + request.getParameter("savename");

        if (savename.length() == 0 || username.length() == 0 || savename.length() >= 64
                || username.length() >= 32) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Invalid username or savename.");
            return;
        }

        String relativeWebPath = "/savegames/" + username + ".sav.bz2";
        String absoluteDiskPath = getServletContext().getRealPath(relativeWebPath);
        File file = new File(absoluteDiskPath);
        if (!file.exists()) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Savegame file not found!");
            return;

        } else if (file.length() == 0 || file.length() > 5000000) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Invalid file size of savegame.");
            return;

        }

        InputStream in = new FileInputStream(file);
        byte[] compressedFile = IOUtils.toByteArray(in);
        String encodedFile = new String(Base64.encodeBase64(compressedFile));
        String savegameHash = DigestUtils.shaHex(username + savename + encodedFile);

        Connection conn = null;
        try {
            Context env = (Context) (new InitialContext().lookup("java:comp/env"));
            DataSource ds = (DataSource) env.lookup("jdbc/freeciv_mysql");
            conn = ds.getConnection();

            PreparedStatement stmt = conn.prepareStatement("INSERT INTO savegames VALUES (NULL, ?,?,?)");
            stmt.setString(1, username);
            stmt.setString(2, savename);
            stmt.setString(3, savegameHash);
            stmt.executeUpdate();

        } catch (Exception err) {
            err.printStackTrace();
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Savegame digest failed.");
            return;

        } finally {
            if (conn != null)
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
        }

        response.getOutputStream().print(encodedFile);
        in.close();

    }

}