/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.jboss.security; // for the time being ...

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * BASE64 encoder implementation.
 * Provides encoding methods, using the BASE64 encoding rules, as defined
 * in the MIME specification, <a href="http://ietf.org/rfc/rfc1521.txt">rfc1521</a>.
 *
 *
 * This class is a modified version based on code
 * obtained from the w3 consortium website,
 * which is subject to their generic copyright notice:
 *
 * <dl>
 * <dd><a href="http://www.w3.org/Consortium/Legal/">Copyright</a> © [$date-of-software] <a
 * HREF="http://www.w3.org/">World Wide Web Consortium</a>, (<a
 * HREF="http://www.lcs.mit.edu/">Massachusetts Institute of Technology</a>, <a
 * HREF="http://www.inria.fr/">Institut National de Recherche en Informatique et en
 * Automatique</a>, <a HREF="http://www.keio.ac.jp/">Keio University</a>). All Rights
 *    Reserved. This program is distributed under the <a
 * HREF="http://www.w3.org/Consortium/Legal/copyright-software-19980720.html">W3C's Software
 *    Intellectual Property License</a>. 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 W3C License <a
 * href="http://www.w3.org/Consortium/Legal/">http://www.w3.org/Consortium/Legal/</a> for
 *    more details. </dd>
 *</dl>
 *
 *
 */
public final class Base64Encoder
{
   private static final int BUFFER_SIZE = 1024 ;
   private static final byte encoding[] =
   {
      (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D',
      (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H',		// 0-7
      (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L',
      (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P',		// 8-15
      (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T',
      (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', 	// 16-23
      (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b',
      (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f',		// 24-31
      (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j',
      (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n',		// 32-39
      (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r',
      (byte) 's', (byte) 't', (byte) 'u', (byte) 'v',		// 40-47
      (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z',
      (byte) '0', (byte) '1', (byte) '2', (byte) '3',		// 48-55
      (byte) '4', (byte) '5', (byte) '6', (byte) '7',
      (byte) '8', (byte) '9', (byte) '+', (byte) '/',		// 56-63
      (byte) '='						  // 64
   };


  /**
   * Encodes data from supplied input to output.
   * @param in The input stream to be encoded.
   * @param out The output stream, to write encoded data to.
   */
   public static void encode(InputStream in, OutputStream out) throws IOException
   {
      process(in, out);
   }

  /**
   * Encode the supplied byte array and write the encoded
   * data to the OutputStream <i>out</i>.
   */
   public static void encode(byte input[], OutputStream out) throws IOException
   {
      ByteArrayInputStream in = new ByteArrayInputStream(input);
      process(in, out);
   }

  /**
   * Encode the given string,and return the encoded version as a string.
   *
   * @return A String, representing the encoded content of the input String.
   */
   public static String encode(String input) throws IOException
   {
	   byte bytes[] ;
      bytes = input.getBytes("ISO-8859-1");
      return encode (bytes);
   }

  /**
   * Encode the given byte array and return the result as a string.
   */
   public static String encode(byte bytes[]) throws IOException
   {
      ByteArrayInputStream in = new ByteArrayInputStream(bytes);
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      process(in, out);
      return out.toString("ISO-8859-1");
   }

  /**
   * Run with one argument, prints the encoded version of it.
   * With two, the second is assumed to be the name of a MessageDigest to
   * be applied to the string before encoding (useful for generating
   * password hashes).
   * <p>
   * Alternatively, use the openssl utility, for example:
   * <p>
   * echo -n "password" | openssl dgst -sha1 -binary | openssl base64
   * 
   */
   public static void main (String args[]) throws Exception
   {
      if(args.length == 1)
      {
         System.out.println ("["+ Base64Encoder.encode(args[0])+"]");
      // joe:eoj -> am9lOmVvag==
      // 12345678:87654321 -> MTIzNDU2Nzg6ODc2NTQzMjE=
      }
      else if (args.length == 2)
      {
         byte[] hash = java.security.MessageDigest.getInstance(args[1]).digest(args[0].getBytes());
         System.out.println ("["+ Base64Encoder.encode(hash)+"]");
      }
      else
      {
         System.out.println("Usage: Base64Encoder <string> <optional hash algorithm>");
      }
   }

// Private ----------------------------------------------------------------

   private static int get1(byte buf[], int off)
   {
      return (buf[off] & 0xfc) >> 2 ;
   }

   private static int get2(byte buf[], int off)
   {
      return ((buf[off]&0x3) << 4) | ((buf[off+1]&0xf0) >>> 4) ;
   }

   private static int get3(byte buf[], int off)
   {
      return ((buf[off+1] & 0x0f) << 2) | ((buf[off+2] & 0xc0) >>> 6) ;
   }

   private static int get4(byte buf[], int off)
   {
      return buf[off+2] & 0x3f ;
   }

  /**
   * Process the data: encode the input stream to the output stream.
   * This method runs through the input stream, encoding it to the output
   * stream.
   * @exception IOException If we weren't able to access the input stream or
   *    the output stream.
   */
   private static void process(InputStream in, OutputStream out) throws IOException
   {
      byte buffer[] = new byte[BUFFER_SIZE] ;
      int  got      = -1 ;
      int  off      = 0 ;
      int  count    = 0 ;
      while ((got = in.read(buffer, off, BUFFER_SIZE-off)) > 0)
      {
         if ( got >= 3 )
         {
            got += off;
            off  = 0;
            while (off + 3 <= got)
            {
                int c1 = get1(buffer,off);
                int c2 = get2(buffer,off);
                int c3 = get3(buffer,off);
                int c4 = get4(buffer,off);
                switch (count)
                {
                    case 73:
                       out.write(encoding[c1]);
                       out.write(encoding[c2]);
                       out.write(encoding[c3]);
                       out.write ('\n') ;
                       out.write(encoding[c4]);
                       count = 1 ;
                       break ;
                     case 74:
                       out.write(encoding[c1]);
                       out.write(encoding[c2]);
                       out.write ('\n') ;
                       out.write(encoding[c3]);
                       out.write(encoding[c4]) ;
                       count = 2 ;
                       break ;
                     case 75:
                       out.write(encoding[c1]);
                       out.write ('\n') ;
                       out.write(encoding[c2]);
                       out.write(encoding[c3]);
                       out.write(encoding[c4]) ;
                       count = 3 ;
                       break ;
                     case 76:
                       out.write('\n') ;
                       out.write(encoding[c1]);
                       out.write(encoding[c2]);
                       out.write(encoding[c3]);
                       out.write(encoding[c4]);
                       count = 4;
                       break;
                     default:
                       out.write(encoding[c1]);
                       out.write(encoding[c2]);
                       out.write(encoding[c3]);
                       out.write(encoding[c4]);
                       count += 4;
                       break;
                }
                off += 3;
            }
            // Copy remaining bytes to beginning of buffer:
            for ( int i = 0 ; i < 3 ;i++)
                buffer[i] = (i < got-off) ? buffer[off+i] : ((byte) 0);
            off = got-off ;
         }
         else
         {
            // Total read amount is less then 3 bytes:
            off += got;
         }
      }
      // Manage the last bytes, from 0 to off:
      switch (off) {
        case 1:
            out.write(encoding[get1(buffer, 0)]);
            out.write(encoding[get2(buffer, 0)]);
            out.write('=');
            out.write('=');
            break ;
        case 2:
            out.write(encoding[get1(buffer, 0)]);
            out.write(encoding[get2(buffer, 0)]);
            out.write(encoding[get3(buffer, 0)]);
            out.write('=');
      }
      return;
   }
}

