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// Copyright 2003-2009 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
// www.source-code.biz, www.inventec.ch/chdh
//
// This module is multi-licensed and may be used under the terms
// of any of the following licenses:
//
//  EPL, Eclipse Public License, http://www.eclipse.org/legal
//  LGPL, GNU Lesser General Public License, http://www.gnu.org/licenses/lgpl.html
//  AL, Apache License, http://www.apache.org/licenses
//  BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php
//
// Please contact the author if you need another license.
// This module is provided "as is", without warranties of any kind.

package biz.source_code.base64Coder;

/**
* A Base64 Encoder/Decoder.
*
* 
* This class is used to encode and decode data in Base64 format as described in RFC 1521.
*
* 

* Home page: www.source-code.biz

* Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland

* Multi-licensed: EPL/LGPL/AL/BSD.
*
* 
* Version history:

* 2003-07-22 Christian d'Heureuse (chdh): Module created.

* 2005-08-11 chdh: Lincense changed from GPL to LGPL.

* 2006-11-21 chdh:

*    Method encode(String) renamed to encodeString(String).

*    Method decode(String) renamed to decodeString(String).

*    New method encode(byte[],int) added.

*    New method decode(String) added.

* 2009-07-16: Additional licenses (EPL/AL) added.

* 2009-09-16: Additional license (BSD) added.

* 2009-09-16: Additional license (BSD) added.

* 2010-01-27: Package name added.

*/

public class Base64Coder {

	// Mapping table from 6-bit nibbles to Base64 characters.
	private static char[]    map1 = new char[64];
	   static {
	      int i=0;
	      for (char c='A'; c<='Z'; c++) map1[i++] = c;
	      for (char c='a'; c<='z'; c++) map1[i++] = c;
	      for (char c='0'; c<='9'; c++) map1[i++] = c;
	      map1[i++] = '+'; map1[i++] = '/'; }
	
	// Mapping table from Base64 characters to 6-bit nibbles.
	private static byte[]    map2 = new byte[128];
	   static {
	      for (int i=0; iin.
	* @return     A character array with the Base64 encoded data.
	*/
	public static char[] encode (byte[] in, int iLen) {
	   int oDataLen = (iLen*4+2)/3;       // output length without padding
	   int oLen = ((iLen+2)/3)*4;         // output length including padding
	   char[] out = new char[oLen];
	   int ip = 0;
	   int op = 0;
	   while (ip < iLen) {
	      int i0 = in[ip++] & 0xff;
	      int i1 = ip < iLen ? in[ip++] & 0xff : 0;
	      int i2 = ip < iLen ? in[ip++] & 0xff : 0;
	      int o0 = i0 >>> 2;
	      int o1 = ((i0 &   3) << 4) | (i1 >>> 4);
	      int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
	      int o3 = i2 & 0x3F;
	      out[op++] = map1[o0];
	      out[op++] = map1[o1];
	      out[op] = op < oDataLen ? map1[o2] : '='; op++;
	      out[op] = op < oDataLen ? map1[o3] : '='; op++; }
	   return out; }
	
	/**
	* Decodes a string from Base64 format.
	* @param s  a Base64 String to be decoded.
	* @return   A String containing the decoded data.
	* @throws   IllegalArgumentException if the input is not valid Base64 encoded data.
	*/
	public static String decodeString (String s) {
	   return new String(decode(s)); }
	
	/**
	* Decodes a byte array from Base64 format.
	* @param s  a Base64 String to be decoded.
	* @return   An array containing the decoded data bytes.
	* @throws   IllegalArgumentException if the input is not valid Base64 encoded data.
	*/
	public static byte[] decode (String s) {
	   return decode(s.toCharArray()); }
	
	/**
	* Decodes a byte array from Base64 format.
	* No blanks or line breaks are allowed within the Base64 encoded data.
	* @param in  a character array containing the Base64 encoded data.
	* @return    An array containing the decoded data bytes.
	* @throws    IllegalArgumentException if the input is not valid Base64 encoded data.
	*/
	public static byte[] decode (char[] in) {
	   int iLen = in.length;
	   if (iLen%4 != 0) throw new IllegalArgumentException ("Length of Base64 encoded input string is not a multiple of 4.");
	   while (iLen > 0 && in[iLen-1] == '=') iLen--;
	   int oLen = (iLen*3) / 4;
	   byte[] out = new byte[oLen];
	   int ip = 0;
	   int op = 0;
	   while (ip < iLen) {
	      int i0 = in[ip++];
	      int i1 = in[ip++];
	      int i2 = ip < iLen ? in[ip++] : 'A';
	      int i3 = ip < iLen ? in[ip++] : 'A';
	      if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)
	         throw new IllegalArgumentException ("Illegal character in Base64 encoded data.");
	      int b0 = map2[i0];
	      int b1 = map2[i1];
	      int b2 = map2[i2];
	      int b3 = map2[i3];
	      if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
	         throw new IllegalArgumentException ("Illegal character in Base64 encoded data.");
	      int o0 = ( b0       <<2) | (b1>>>4);
	      int o1 = ((b1 & 0xf)<<4) | (b2>>>2);
	      int o2 = ((b2 &   3)<<6) |  b3;
	      out[op++] = (byte)o0;
	      if (op