MarkHeader.java

/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 24.05.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 *
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&" or "&"
 * "<":  "<" or "<"
 * ">":  ">" or ">"
 * "@":  "@" 
 */
package com.github.junrar.rarfile;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.github.junrar.io.Raw;


/**
 * the header to recognize a file to be a rar archive
 *
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class MarkHeader extends BaseBlock {
	
	private Log logger = LogFactory.getLog(MarkHeader.class.getName());
	private boolean oldFormat = false;
	
	public MarkHeader(BaseBlock bb){
		super(bb);
	}
	public boolean isValid(){
		if(!(getHeadCRC() == 0x6152)){
			return false;
		}
		if(!(getHeaderType() == UnrarHeadertype.MarkHeader)){
			return false;
		}
		if(!(getFlags() == 0x1a21)){
			return false;
		}
		if(!(getHeaderSize() == BaseBlockSize)){
			return false;
		}
		return true;
	}
	
	public boolean isSignature() {
        boolean valid=false;
        byte[] d = new byte[BaseBlock.BaseBlockSize];
        Raw.writeShortLittleEndian(d, 0, headCRC);
        d[2] = headerType;
        Raw.writeShortLittleEndian(d, 3, flags);
        Raw.writeShortLittleEndian(d, 5, headerSize);
        
        if (d[0] == 0x52) {
            if (d[1]==0x45 && d[2]==0x7e && d[3]==0x5e) {
                oldFormat=true;
                valid=true;
            }
            else if (d[1]==0x61 && d[2]==0x72 && d[3]==0x21 && d[4]==0x1a &&
                    d[5]==0x07 && d[6]==0x00) {
                oldFormat=false;
                valid=true;
            }
        }
        return valid;
    }

    public boolean isOldFormat() {
        return oldFormat;
    }
    
	public void print(){
		super.print();
		logger.info("valid: "+isValid());
	}
}