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JBroFuzz is a stateless web application fuzzer for requests being made over HTTP and/or HTTPS. Its purpose is to provide a single, portable application that offers stable web protocol fuzzing capabilities. As a tool, it emerged from the needs of penetration testing.
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/**
 * JbroFuzz 2.5
 *
 * JBroFuzz - A stateless network protocol fuzzer for web applications.
 * 
 * Copyright (C) 2007 - 2010 [email protected]
 *
 * This file is part of JBroFuzz.
 * 
 * JBroFuzz 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 3 of the License, or
 * (at your option) any later version.
 * 
 * JBroFuzz 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 JBroFuzz.  If not, see .
 * Alternatively, write to the Free Software Foundation, Inc., 51 
 * Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 * 
 * Verbatim copying and distribution of this entire program file is 
 * permitted in any medium without royalty provided this notice 
 * is preserved. 
 * 
 */
package org.owasp.jbrofuzz.encode;

/**
* Base32 - encodes and decodes 'Canonical' Base32
* @author  Robert Kaye & Gordon Mohr
* 
*/
public class Base32 {
   private static final String BASE32CHARS =
       "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
   
   private static final int[] base32Lookup =
   { 0xFF,0xFF,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F, // '0', '1', '2', '3', '4', '5', '6', '7'
     0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, // '8', '9', ':', ';', '<', '=', '>', '?'
     0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, // '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G'
     0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, // 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O'
     0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, // 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W'
     0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF, // 'X', 'Y', 'Z', '[', '\', ']', '^', '_'
     0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, // '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g'
     0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, // 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o'
     0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, // 'p', 'q', 'r', 's', 't', 'u', 'v', 'w'
     0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF  // 'x', 'y', 'z', '{', '|', '}', '~', 'DEL'
   };

    static public String encode(final byte[] bytes)
   {
       int i =0, index = 0, digit = 0;
       int currByte, nextByte;

       // begin fix
       // added by [email protected], Feb 13, 2005
       // according to RFC 3548, the encoding must also contain paddings in some cases
       int add=0;
       switch (bytes.length) {
           case 1: add=6; break;
           case 2: add=4; break;
           case 3: add=3; break;
           case 4: add=1; break;
       }
       // end fix

       final StringBuffer base32 = new StringBuffer(((bytes.length+7)*8/5)+add);

       while(i < bytes.length)
       {
           currByte = (bytes[i]>=0) ? bytes[i] : (bytes[i]+256); // unsign

           /* Is the current digit going to span a byte boundary? */
           if (index > 3)
           {
               if ((i+1)=0) ? bytes[i+1] : (bytes[i+1]+256);
               else
                   nextByte = 0;

               digit = currByte & (0xFF >> index);
               index = (index + 5) % 8;
               digit <<= index;
               digit |= nextByte >> (8 - index);
               i++;
           }
           else
           {
               digit = (currByte >> (8 - (index + 5))) & 0x1F;
               index = (index + 5) % 8;
               if (index == 0)
                   i++;
           }
           base32.append(BASE32CHARS.charAt(digit));
       }

       // begin fix
       // added by [email protected], Feb 13, 2005
       // according to RFC 3548, the encoding must also contain paddings in some cases
       switch (bytes.length) {
           case 1: base32.append("======"); break;
           case 2: base32.append("===="); break;
           case 3: base32.append("==="); break;
           case 4: base32.append("="); break;
       }
       // end fix

       return base32.toString();
   }

   static public byte[] decode(final String base32)
   {
       int    i, index, lookup, offset, digit;
       final byte[] bytes = new byte[base32.length()*5/8];

       for(i = 0, index = 0, offset = 0; i < base32.length(); i++)
       {
           lookup = base32.charAt(i) - '0';

           /* Skip chars outside the lookup table */
           if ( lookup < 0 || lookup >= base32Lookup.length)
               continue;

           digit = base32Lookup[lookup];

           /* If this digit is not in the table, ignore it */
           if (digit == 0xFF)
               continue;

           if (index <= 3)
           {
               index = (index + 5) % 8;
               if (index == 0)
               {
                  bytes[offset] |= digit;
                  offset++;
                  if(offset>=bytes.length) break;
               }
               else
                  bytes[offset] |= digit << (8 - index);
           }
           else
           {
               index = (index + 5) % 8;
               bytes[offset] |= (digit >>> index);
               offset++;

               if(offset>=bytes.length) break;
               bytes[offset] |= digit << (8 - index);
           }
       }
       return bytes;
   }

   
}