types.java

KeePass for J2ME is a J2ME port of KeePass Password Safe, a free, open source, light-weight and easy

/*
KeePass for J2ME

Copyright 2007 Naomaru Itoi <[e-mail]>

This file was derived from 

Java clone of KeePass - A KeePass file viewer for Java
Copyright 2006 Bill Zwicky <[e-mail]>

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; version 2

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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

package org.phoneid.keepassj2me;

import java.util.Date;

/**
 * Tools for slicing and dicing Java and KeePass data types.
 * 
 * @author Bill Zwicky <[e-mail]>
 */
public class Types {
  /**
   * Read a 32-bit value.
   * 
   * @param buf
   * @param offset
   * @return
   */
  public static int readInt( byte buf[], int offset ) {
    return (buf[offset + 0] & 0xFF) + ((buf[offset + 1] & 0xFF) << 8) + ((buf[offset + 2] & 0xFF) << 16)
           + ((buf[offset + 3] & 0xFF) << 24);
  }



  /**
   * Write a 32-bit value.
   * 
   * @param val
   * @param buf
   * @param offset
   */
  public static void writeInt( int val, byte[] buf, int offset ) {
    buf[offset + 0] = (byte)(val & 0xFF);
    buf[offset + 1] = (byte)((val >>> 8) & 0xFF);
    buf[offset + 2] = (byte)((val >>> 16) & 0xFF);
    buf[offset + 3] = (byte)((val >>> 24) & 0xFF);
  }



  /**
   * Read an unsigned 16-bit value.
   * 
   * @param buf
   * @param offset
   * @return
   */
  public static int readShort( byte[] buf, int offset ) {
    return (buf[offset + 0] & 0xFF) + ((buf[offset + 1] & 0xFF) << 8);
  }



  /** Read an unsigned byte */
  public static int readUByte( byte[] buf, int offset ) {
    return ((int)buf[offset] & 0xFF);
  }



  /**
   * Return len of null-terminated string (i.e. distance to null)
   * within a byte buffer.
   * 
   * @param buf
   * @param offset
   * @return
   */
  public static int strlen( byte[] buf, int offset ) {
    int len = 0;
    while( buf[offset + len] != 0 )
      len++;
    return len;
  }



  /**
   * Copy a sequence of bytes into a new array.
   * 
   * @param b - source array
   * @param offset - first byte
   * @param len - number of bytes
   * @return new byte[len]
   */
  public static byte[] extract( byte[] b, int offset, int len ) {
    byte[] b2 = new byte[len];
    System.arraycopy( b, offset, b2, 0, len );
    return b2;
  }



  /**
   * Unpack date from 5 byte format.
   * The five bytes at 'offset' are unpacked to a java.util.Date instance.
   */
  public static Date readTime( byte[] buf, int offset ) {
    int dw1 = readUByte( buf, offset );
    int dw2 = readUByte( buf, offset + 1 );
    int dw3 = readUByte( buf, offset + 2 );
    int dw4 = readUByte( buf, offset + 3 );
    int dw5 = readUByte( buf, offset + 4 );
  
    // Unpack 5 byte structure to date and time
    int year   =  (dw1 << 6) | (dw2 >> 2);
    int month  = ((dw2 & 0x00000003) << 2) | (dw3 >> 6);
    int day    =  (dw3 >> 1) & 0x0000001F;
    int hour   = ((dw3 & 0x00000001) << 4) | (dw4 >> 4);
    int minute = ((dw4 & 0x0000000F) << 2) | (dw5 >> 6);
    int second =   dw5 & 0x0000003F;
  
    //Calendar time = Calendar.getInstance();
    //time.set( year, month, day, hour, minute, second );
  
    //return time.getTime();

    return null;
  }
}