/*
 * $Header: /cvsroot/jboss/jaxrpc/src/main/org/apache/axis/utils/Base64.java,v 1.1.1.1 2004/08/20 18:44:33 tdiesler Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/08/20 18:44:33 $
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "HttpClient", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */

package org.apache.axis.utils;

/**
 * Unceremoniously lifted from
 * jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/Base64.java
 * Revision 1.8 2002/01/05 11:15:59
 * <p/>
 * Eliminates dependency on sun.misc.Base64Encoding,
 * which isn't appreciated by the J2EE security manager.
 * (it's an access exception to load sun.misc.* classes
 * in application code).
 * <p/>
 * <p>Base64 encoder and decoder.</p>
 * <p/>
 * This class provides encoding/decoding methods for
 * the Base64 encoding as defined by RFC 2045,
 * N. Freed and N. Borenstein.
 * RFC 2045: Multipurpose Internet Mail Extensions (MIME)
 * Part One: Format of Internet Message Bodies. Reference
 * 1996. Available at: http://www.ietf.org/rfc/rfc2045.txt
 * </p>
 *
 * @author Jeffrey Rodriguez
 * @version $Revision: 1.1.1.1 $ $Date: 2004/08/20 18:44:33 $
 */
final class Base64
{
   private static final int BASELENGTH = 255;
   private static final int LOOKUPLENGTH = 64;
   private static final int TWENTYFOURBITGROUP = 24;
   private static final int EIGHTBIT = 8;
   private static final int SIXTEENBIT = 16;
   private static final int SIXBIT = 6;
   private static final int FOURBYTE = 4;
   private static final int SIGN = -128;
   private static final byte PAD = (byte)'=';
   private static byte[] base64Alphabet = new byte[BASELENGTH];
   private static byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];

   static
   {

      for (int i = 0; i < BASELENGTH; i++)
      {
         base64Alphabet[i] = -1;
      }
      for (int i = 'Z'; i >= 'A'; i--)
      {
         base64Alphabet[i] = (byte)(i - 'A');
      }
      for (int i = 'z'; i >= 'a'; i--)
      {
         base64Alphabet[i] = (byte)(i - 'a' + 26);
      }

      for (int i = '9'; i >= '0'; i--)
      {
         base64Alphabet[i] = (byte)(i - '0' + 52);
      }

      base64Alphabet['+'] = 62;
      base64Alphabet['/'] = 63;

      for (int i = 0; i <= 25; i++)
      {
         lookUpBase64Alphabet[i] = (byte)('A' + i);
      }

      for (int i = 26, j = 0; i <= 51; i++, j++)
      {
         lookUpBase64Alphabet[i] = (byte)('a' + j);
      }

      for (int i = 52, j = 0; i <= 61; i++, j++)
      {
         lookUpBase64Alphabet[i] = (byte)('0' + j);
      }
      lookUpBase64Alphabet[62] = (byte)'+';
      lookUpBase64Alphabet[63] = (byte)'/';

   }

   static boolean isBase64(String isValidString)
   {
      return (isArrayByteBase64(isValidString.getBytes()));
   }


   static boolean isBase64(byte octect)
   {
      // Should we ignore white space?
      return (octect == PAD || base64Alphabet[octect] != -1);
   }


   static boolean isArrayByteBase64(byte[] arrayOctect)
   {
      int length = arrayOctect.length;
      if (length == 0)
      {
         return true;
      }
      for (int i = 0; i < length; i++)
      {
         if (Base64.isBase64(arrayOctect[i]) == false)
         {
            return false;
         }
      }
      return true;
   }

   /**
    * Encodes hex octects into Base64
    *
    * @param binaryData Array containing binaryData
    * @return Base64-encoded array
    */
   static byte[] encode(byte[] binaryData)
   {

      int lengthDataBits = binaryData.length * EIGHTBIT;
      int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
      int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
      byte encodedData[] = null;


      if (fewerThan24bits != 0)
      {
         //data not divisible by 24 bit
         encodedData = new byte[(numberTriplets + 1) * 4];
      }
      else
      {
         // 16 or 8 bit
         encodedData = new byte[numberTriplets * 4];
      }

      byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;

      int encodedIndex = 0;
      int dataIndex = 0;
      int i = 0;
      for (i = 0; i < numberTriplets; i++)
      {

         dataIndex = i * 3;
         b1 = binaryData[dataIndex];
         b2 = binaryData[dataIndex + 1];
         b3 = binaryData[dataIndex + 2];

         l = (byte)(b2 & 0x0f);
         k = (byte)(b1 & 0x03);

         encodedIndex = i * 4;
         byte val1 = ((b1 & SIGN) == 0) ? (byte)(b1 >> 2) : (byte)((b1) >> 2 ^ 0xc0);

         byte val2 = ((b2 & SIGN) == 0) ? (byte)(b2 >> 4) : (byte)((b2) >> 4 ^ 0xf0);
         byte val3 = ((b3 & SIGN) == 0) ? (byte)(b3 >> 6) : (byte)((b3) >> 6 ^ 0xfc);

         encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
         encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
         encodedData[encodedIndex + 2] = lookUpBase64Alphabet[(l << 2) | val3];
         encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
      }

      // form integral number of 6-bit groups
      dataIndex = i * 3;
      encodedIndex = i * 4;
      if (fewerThan24bits == EIGHTBIT)
      {
         b1 = binaryData[dataIndex];
         k = (byte)(b1 & 0x03);
         byte val1 = ((b1 & SIGN) == 0) ? (byte)(b1 >> 2) : (byte)((b1) >> 2 ^ 0xc0);
         encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
         encodedData[encodedIndex + 1] = lookUpBase64Alphabet[k << 4];
         encodedData[encodedIndex + 2] = PAD;
         encodedData[encodedIndex + 3] = PAD;
      }
      else if (fewerThan24bits == SIXTEENBIT)
      {
         b1 = binaryData[dataIndex];
         b2 = binaryData[dataIndex + 1];
         l = (byte)(b2 & 0x0f);
         k = (byte)(b1 & 0x03);

         byte val1 = ((b1 & SIGN) == 0) ? (byte)(b1 >> 2) : (byte)((b1) >> 2 ^ 0xc0);
         byte val2 = ((b2 & SIGN) == 0) ? (byte)(b2 >> 4) : (byte)((b2) >> 4 ^ 0xf0);

         encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
         encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
         encodedData[encodedIndex + 2] = lookUpBase64Alphabet[l << 2];
         encodedData[encodedIndex + 3] = PAD;
      }
      return encodedData;
   }


   /**
    * Decodes Base64 data into octects
    *
    * @param base64Data Byte array containing Base64 data
    * @return Array containing decoded data.
    */
   static byte[] decode(byte[] base64Data)
   {
      // Should we throw away anything not in base64Data ?

      // handle the edge case, so we don't have to worry about it later
      if (base64Data.length == 0)
      {
         return new byte[0];
      }

      int numberQuadruple = base64Data.length / FOURBYTE;
      byte decodedData[] = null;
      byte b1 = 0, b2 = 0, b3 = 0, b4 = 0, marker0 = 0, marker1 = 0;

      int encodedIndex = 0;
      int dataIndex = 0;
      {
         // this block sizes the output array properly - rlw
         int lastData = base64Data.length;
         // ignore the '=' padding
         while (base64Data[lastData - 1] == PAD)
         {
            if (--lastData == 0)
            {
               return new byte[0];
            }
         }
         decodedData = new byte[lastData - numberQuadruple];
      }

      for (int i = 0; i < numberQuadruple; i++)
      {
         dataIndex = i * 4;
         marker0 = base64Data[dataIndex + 2];
         marker1 = base64Data[dataIndex + 3];

         b1 = base64Alphabet[base64Data[dataIndex]];
         b2 = base64Alphabet[base64Data[dataIndex + 1]];

         if (marker0 != PAD && marker1 != PAD)
         {     //No PAD e.g 3cQl
            b3 = base64Alphabet[marker0];
            b4 = base64Alphabet[marker1];

            decodedData[encodedIndex] = (byte)(b1 << 2 | b2 >> 4);
            decodedData[encodedIndex + 1] = (byte)(((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
            decodedData[encodedIndex + 2] = (byte)(b3 << 6 | b4);
         }
         else if (marker0 == PAD)
         {               //Two PAD e.g. 3c[Pad][Pad]
            decodedData[encodedIndex] = (byte)(b1 << 2 | b2 >> 4);
         }
         else if (marker1 == PAD)
         {              //One PAD e.g. 3cQ[Pad]
            b3 = base64Alphabet[marker0];

            decodedData[encodedIndex] = (byte)(b1 << 2 | b2 >> 4);
            decodedData[encodedIndex + 1] = (byte)(((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
         }
         encodedIndex += 3;
      }
      return decodedData;
   }

}
