/*
* Copyright (C) 2005 Luca Veltri - University of Parma - Italy
*
* This file is part of MjSip (http://www.mjsip.org)
*
* MjSip 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.
*
* MjSip 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 MjSip; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author(s):
* Luca Veltri (luca.veltri@unipr.it)
*/
package org.zoolu.tools;
/** Class Base64 can be used for base64-encoding a byte array
* and/or for base64-decoding a base64-string.
*
* @author Camilla Ferramola, Univeristy of Parma, Italy - 2004
*/
public class Base64
{
private static final String base64codes ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
private static int[] aux = new int[4];
/** Base64 encoder */
public static String encode(byte[] input)
{
String stringacod = "";
byte[] bin = new byte[3];
int iter = (input.length)/3;
int nzero = (input.length)%3;
int i = 0;
for (i=0; i<iter; i++)
{
bin[0] = input[i*3];
bin[1] = input[i*3+1];
bin[2] = input[i*3+2];
aux[0] = ((bin[0] >>> 2)&63);
aux[1] = ((bin[0] & 3) << 4) + ((bin[1] >>> 4)&15);
aux[2] = ((bin[1] & 15) << 2) + ((bin[2] >>> 6)&3);
aux[3] = (bin[2] & 63);
// uso gli interi memorizzati in aux[] come indice della stringa base64codes
stringacod = stringacod + base64codes.charAt(aux[0])+ base64codes.charAt(aux[1])+
base64codes.charAt(aux[2])+base64codes.charAt(aux[3]);
}
if( i==iter )
{
if ( nzero==0 )
{
}
else
if ( nzero==1 )
{ // l'ultimo pacchetto da analizzare ha 8 bit
// quindi ottengo due caratteri in base64 e due caratteri padding "="
aux[0] = ((input[iter*3] >>> 2) & 63);
aux[1] = (input[iter*3] & 3) << 4;
stringacod = stringacod + base64codes.charAt(aux[0])+base64codes.charAt(aux[1])+"==";
}
else
if (nzero==2)
{ // l'ultimo pacchetto da analizzare ha 16 bit quindi ottengo
// tre caratteri in base 64 e uno di padding "="
aux[0] = ((input[iter*3] >>> 2) & 63) ;
aux[1] = ((input[iter*3] & 3) << 4) + ((input[iter*3+1] >>> 4) & 15);
aux[2] = (input[iter*3+1 ] & 15) << 2;
stringacod = stringacod + base64codes.charAt(aux[0])+ base64codes.charAt(aux[1])+
base64codes.charAt(aux[2])+"=";
}
}
return stringacod;
}
/** Base64 decoder */
public static byte[] decode (String stringacod)
{
// tolgo gli eventuali "=" alla fine della stringa
int uguale = stringacod.indexOf("=");
if ( uguale != -1) stringacod = stringacod.substring(0,uguale);
int[] bin = new int[3];
int iter = (stringacod.length())/4;
int resto = (stringacod.length())%4;
int nzero = 0;
if (resto!=0) nzero = 1;
byte[] output = new byte[iter*3 + nzero*(resto-1)];
int i = 0;
for (i=0; i<iter; i++)
{
aux[0] = base64codes.indexOf(stringacod.charAt(i*4));
aux[1] = base64codes.indexOf(stringacod.charAt(i*4+1));
aux[2] = base64codes.indexOf(stringacod.charAt(i*4+2));
aux[3] = base64codes.indexOf(stringacod.charAt(i*4+3));
bin[0] = (aux[0]<<2) + (aux[1]>>>4);
bin[1] = (aux[1]%16 <<4) + (aux[2]>>>2);
bin[2] = (aux[2]%4 <<6) + aux[3];
output[i*3] = (byte)bin [0];
output[i*3+1] = (byte)bin [1];
output[i*3+2] = (byte)bin [2];
}
if (i==iter)
{
// per come è costruita la codifica a base64
// togliendo gli eventuali caratteri "=" di padding
// il resto può essere 0, 2 o 3
if (resto==0)
{
}
if (resto==2)
{
aux[0] = base64codes.indexOf(stringacod.charAt(i*4));
aux[1] = base64codes.indexOf(stringacod.charAt(i*4+1));
bin[0] = (aux[0]<<2) + (aux[1]>>>4);
output[i*3] = (byte)bin[0];
}
if (resto==3)
{
aux[0] = base64codes.indexOf(stringacod.charAt(i*4));
aux[1] = base64codes.indexOf(stringacod.charAt(i*4+1));
aux[2] = base64codes.indexOf(stringacod.charAt(i*4+2));
bin[0] = (aux[0]<<2) + (aux[1]>>>4);
bin[1] = (aux[1]%16 <<4) + (aux[2]>>>2);
output[i*3] = (byte)bin [0];
output[i*3+1] = (byte)bin [1];
}
}
return output;
}
// ******************************* MAIN *******************************
public static void main (String[] args)
{
String messaggio = args[0];
byte[] bmess = messaggio.getBytes();
String mess64 = encode(bmess);
byte[] decodificato = decode(mess64);
String strdecodificato = "";
try {
strdecodificato = new String (decodificato,"ISO-8859-1");
}
catch (Exception e) { e.printStackTrace();}
}
}