javascriptfilter.java

java 开发的一个电子邮局,挺实用的

/* CVS ID: $Id: JavaScriptFilter.java,v 1.2 2000/04/06 08:02:02 wastl Exp $ */
package net.wastl.webmail.ui.html;

import gnu.regexp.*;

/*
 * JavaScriptFilter.java
 *
 * Created: Thu Oct 14 12:08:28 1999
 *
 * Copyright (C) 1999-2000 Sebastian Schaffert
 * 
 * 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.
 */

/**
 * Filter JavaScript content from HTML messages to avoid security problems.
 *
 * @author Sebastian Schaffert
 * @version
 */

public class JavaScriptFilter  {

    private static RE jscriptfil1=null; 
    private static RE jscriptfil2=null;
    private static RE jscriptfil3=null;

    private static boolean initialized=false;
    
    public JavaScriptFilter() {
	
    }

    public static void init() {
	try {
	    jscriptfil1=new RE("<\\s*SCRIPT[^>]*>",RE.REG_ICASE);
	    jscriptfil2=new RE("<\\s*\\/SCRIPT[^>]*>",RE.REG_ICASE);
	    jscriptfil3=new RE("<\\s*A +HREF *=.*\"(javascript:[^\"]*)\"[^>]*>([^<]+)</A>",RE.REG_ICASE);
	    // Link highlighting
	    //uri=new RE("http\\:\\/\\/(.+)(html|\\/)(\\S|\\-|\\+|\\.|\\\|\\:)");
	    initialized=true;
	} catch(Exception e) {
	    e.printStackTrace();
	}
    }

    public static String apply(String s) {
	if(!initialized) {
	    init();
	}
	String retval=s;
	retval=jscriptfil1.substituteAll(retval,"<P><FONT color=\"red\">WebMail security: JavaScript filtered</FONT>:<BR>\n<HR>\n<FONT COLOR=\"orange\"><PRE>");
	retval=jscriptfil2.substituteAll(retval,"</PRE></FONT><HR><FONT color=\"red\">JavaScript end</FONT><P>");
	retval=jscriptfil3.substituteAll(retval,"<FONT COLOR=\"red\">WebMail security: JavaScript link filtered:</FONT> <FONT COLOR=\"orange\">$1</FONT> $2 ");
	return retval;
    }
    
} // JavaScriptFilter