attachmentscanner.java

spam source codejasen-0.9jASEN - java Anti Spam ENgine.zip 如标题所示

/*
 * @(#)AttachmentScanner.java	30/10/2004
 *
 * Copyright (c) 2004, 2005  jASEN.org
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in
 *      the documentation and/or other materials provided with the distribution.
 *
 *   3. The names of the authors may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *   4. Any modification or additions to the software must be contributed back
 *      to the project.
 *
 *   5. Any investigation or reverse engineering of source code or binary to
 *      enable emails to bypass the filters, and hence inflict spam and or viruses
 *      onto users who use or do not use jASEN could subject the perpetrator to
 *      criminal and or civil liability.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JASEN.ORG,
 * OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
package org.jasen.plugins;

import java.util.Arrays;
import java.util.Properties;

import javax.mail.internet.MimeMessage;

import org.jasen.core.PointTestResult;
import org.jasen.core.engine.Jasen;
import org.jasen.error.JasenException;
import org.jasen.interfaces.JasenMessage;
import org.jasen.interfaces.JasenPlugin;
import org.jasen.interfaces.JasenTestResult;
import org.jasen.interfaces.ParserData;
import org.jasen.interfaces.ReceivedHeaderParser;

/**
 * <P>
 *  Looks for attachment types which may indicate spam, viruses or trojens.
 * </P>
 * @author Jason Polites
 */
public class AttachmentScanner implements JasenPlugin
{
    private String[] extensions = null;

    private float min = 0.5f;
    private float max = 0.9f;
    private int threshold = 1;


    /**
     *
     */
    public AttachmentScanner() {
        super ();
    }

    /*
     * (non-Javadoc)
     * @see org.jasen.interfaces.JasenPlugin#destroy()
     */
    public void destroy() throws JasenException {}

    /*
     * (non-Javadoc)
     * @see org.jasen.interfaces.JasenPlugin#test(org.jasen.core.Jasen, javax.mail.internet.MimeMessage, org.jasen.interfaces.JasenMessage, org.jasen.interfaces.ParserData, org.jasen.interfaces.ReceivedHeaderParser)
     */
    public JasenTestResult test(Jasen engine, MimeMessage rawMessage, JasenMessage parsedMessage, ParserData data, ReceivedHeaderParser parser) throws JasenException {
        PointTestResult result = new PointTestResult();

        result.setMin(min);
        result.setMax(max);
        result.setThreshold(threshold);

        String[] names = parsedMessage.getAttachmentNames();

        if(names != null) {

            String ext;

            for (int i = 0; i < names.length; i++)
            {
                ext = getFileExtension(names[i]);

                if(ext != null) {
                    if(Arrays.binarySearch(extensions, ext) > -1) {
                        result.setAbsolute(true);
                        break;
                    }
                }
            }
        }

        return result;
    }

    /*
     * (non-Javadoc)
     * @see org.jasen.interfaces.JasenPlugin#init(java.util.Properties)
     */
    public void init(Properties properties) throws JasenException {
        if(properties != null) {
            // Get the extension list
            String ext = properties.getProperty("extensions");

            if(ext != null) {
                extensions = ext.split(",\\s*?");
                Arrays.sort(extensions);
            }

            String strMin = properties.getProperty("min");
            String strMax = properties.getProperty("max");
            String strThresh = properties.getProperty("threshold");

            if(strMin != null) {
                min = Float.parseFloat(strMin);
            }

            if(strMax != null) {
                max = Float.parseFloat(strMax);
            }

            if(strThresh != null) {
                threshold = Integer.parseInt(strThresh);
            }
        }
    }

    private String getFileExtension(String filename) {
        if(filename != null) {
            int index =  filename.lastIndexOf('.');

            if(index == -1 || index == filename.length() - 1) {
                return null;
            }
            else
            {
                return filename.substring(index + 1, filename.length());
            }
        }
        else
        {
            return null;
        }
    }
}