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	/*
	* reserved comment block
	* DO NOT REMOVE OR ALTER!
	*/
	/**
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package com.sun.org.apache.xml.internal.security.utils;

	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.math.BigInteger;

	import com.sun.org.apache.xml.internal.security.exceptions.Base64DecodingException;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.Node;
	import org.w3c.dom.Text;

	/**
	* Implementation of MIME's Base64 encoding and decoding conversions.
	* Optimized code. (raw version taken from oreilly.jonathan.util,
	* and currently org.apache.xerces.ds.util.Base64)
	*
	* @see <A HREF="ftp://ftp.isi.edu/in-notes/rfc2045.txt">RFC 2045</A>
	* @see com.sun.org.apache.xml.internal.security.transforms.implementations.TransformBase64Decode
	*/
	@Deprecated
	public final class Base64 {

	/** Field BASE64DEFAULTLENGTH */
	public static final int BASE64DEFAULTLENGTH = 76;

	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 FOURBYTE = 4;
	private static final int SIGN = -128;
	private static final char PAD = '=';
	private static final byte [] base64Alphabet = new byte[BASELENGTH];
	private static final char [] lookUpBase64Alphabet = new char[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] = (char)('A' + i);
	}

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

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

	private Base64() {
	// we don't allow instantiation
	}

	/**
	* Returns a byte-array representation of a <code>{@link BigInteger}<code>.
	* No sign-bit is output.
	*
	* <b>N.B.:</B> <code>{@link BigInteger}<code>'s toByteArray
	* returns eventually longer arrays because of the leading sign-bit.
	*
	* @param big {@code BigInteger} to be converted
	* @param bitlen {@code int} the desired length in bits of the representation
	* @return a byte array with {@code bitlen} bits of {@code big}
	*/
	static final byte[] getBytes(BigInteger big, int bitlen) {

	//round bitlen
	bitlen = ((bitlen + 7) >> 3) << 3;

	if (bitlen < big.bitLength()) {
	throw new IllegalArgumentException(I18n.translate("utils.Base64.IllegalBitlength"));
	}

	byte[] bigBytes = big.toByteArray();

	if (big.bitLength() % 8 != 0
	&& big.bitLength() / 8 + 1 == bitlen / 8) {
	return bigBytes;
	}

	// some copying needed
	int startSrc = 0; // no need to skip anything
	int bigLen = bigBytes.length; //valid length of the string

	if (big.bitLength() % 8 == 0) { // correct values
	startSrc = 1; // skip sign bit

	bigLen--; // valid length of the string
	}

	int startDst = bitlen / 8 - bigLen; //pad with leading nulls
	byte[] resizedBytes = new byte[bitlen / 8];

	System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, bigLen);

	return resizedBytes;
	}

	/**
	* Encode in Base64 the given {@code {@link BigInteger}}.
	*
	* @param big
	* @return String with Base64 encoding
	*/
	public static final String encode(BigInteger big) {
	byte[] bytes = XMLUtils.getBytes(big, big.bitLength());
	return XMLUtils.encodeToString(bytes);
	}

	/**
	* Returns a byte-array representation of a {@code {@link BigInteger}}.
	* No sign-bit is output.
	*
	* <b>N.B.:</B> {@code {@link BigInteger}}'s toByteArray
	* returns eventually longer arrays because of the leading sign-bit.
	*
	* @param big {@code BigInteger} to be converted
	* @param bitlen {@code int} the desired length in bits of the representation
	* @return a byte array with {@code bitlen} bits of {@code big}
	*/
	public static final byte[] encode(BigInteger big, int bitlen) {

	//round bitlen
	bitlen = ((bitlen + 7) >> 3) << 3;

	if (bitlen < big.bitLength()) {
	throw new IllegalArgumentException(I18n.translate("utils.Base64.IllegalBitlength"));
	}

	byte[] bigBytes = big.toByteArray();

	if (big.bitLength() % 8 != 0
	&& big.bitLength() / 8 + 1 == bitlen / 8) {
	return bigBytes;
	}

	// some copying needed
	int startSrc = 0; // no need to skip anything
	int bigLen = bigBytes.length; //valid length of the string

	if (big.bitLength() % 8 == 0) { // correct values
	startSrc = 1; // skip sign bit

	bigLen--; // valid length of the string
	}

	int startDst = bitlen / 8 - bigLen; //pad with leading nulls
	byte[] resizedBytes = new byte[bitlen / 8];

	System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, bigLen);

	return resizedBytes;
	}

	/**
	* Method decodeBigIntegerFromElement
	*
	* @param element
	* @return the biginteger obtained from the node
	* @throws Base64DecodingException
	*/
	public static final BigInteger decodeBigIntegerFromElement(Element element)
	throws Base64DecodingException {
	return new BigInteger(1, Base64.decode(element));
	}

	/**
	* Decode a base 64 string into a {@link BigInteger}
	* @param text Base 64 encoded text.
	* @return a decoded BigInteger
	* @throws Base64DecodingException
	*/
	public static final BigInteger decodeBigIntegerFromText(Text text)
	throws Base64DecodingException {
	return new BigInteger(1, Base64.decode(text.getData()));
	}

	/**
	* This method takes an (empty) Element and a BigInteger and adds the
	* base64 encoded BigInteger to the Element.
	*
	* @param element
	* @param biginteger
	*/
	public static final void fillElementWithBigInteger(Element element, BigInteger biginteger) {

	String encodedInt = encode(biginteger);

	if (!XMLUtils.ignoreLineBreaks() && encodedInt.length() > BASE64DEFAULTLENGTH) {
	encodedInt = "\n" + encodedInt + "\n";
	}

	Document doc = element.getOwnerDocument();
	Text text = doc.createTextNode(encodedInt);

	element.appendChild(text);
	}

	/**
	* Method decode
	*
	* Takes the {@code Text} children of the Element and interprets
	* them as input for the {@code Base64.decode()} function.
	*
	* @param element
	* @return the byte obtained of the decoding the element
	* $todo$ not tested yet
	* @throws Base64DecodingException
	*/
	public static final byte[] decode(Element element) throws Base64DecodingException {

	Node sibling = element.getFirstChild();
	StringBuilder sb = new StringBuilder();

	while (sibling != null) {
	if (sibling.getNodeType() == Node.TEXT_NODE) {
	Text t = (Text) sibling;

	sb.append(t.getData());
	}
	sibling = sibling.getNextSibling();
	}

	return decode(sb.toString());
	}

	/**
	* Method encodeToElement
	*
	* @param doc
	* @param localName
	* @param bytes
	* @return an Element with the base64 encoded in the text.
	*
	*/
	public static final Element encodeToElement(Document doc, String localName, byte[] bytes) {
	Element el = XMLUtils.createElementInSignatureSpace(doc, localName);
	Text text = doc.createTextNode(encode(bytes));

	el.appendChild(text);

	return el;
	}

	/**
	* Method decode
	*
	* @param base64
	* @return the UTF bytes of the base64
	* @throws Base64DecodingException
	*
	*/
	public static final byte[] decode(byte[] base64) throws Base64DecodingException {
	return decodeInternal(base64, -1);
	}

	/**
	* Encode a byte array and fold lines at the standard 76th character unless
	* ignore line breaks property is set.
	*
	* @param binaryData {@code byte[]} to be base64 encoded
	* @return the {@code String} with encoded data
	*/
	public static final String encode(byte[] binaryData) {
	return XMLUtils.ignoreLineBreaks()
	? encode(binaryData, Integer.MAX_VALUE)
	: encode(binaryData, BASE64DEFAULTLENGTH);
	}

	/**
	* Base64 decode the lines from the reader and return an InputStream
	* with the bytes.
	*
	* @param reader
	* @return InputStream with the decoded bytes
	* @exception IOException passes what the reader throws
	* @throws IOException
	* @throws Base64DecodingException
	*/
	public static final byte[] decode(BufferedReader reader)
	throws IOException, Base64DecodingException {

	byte[] retBytes = null;
	UnsyncByteArrayOutputStream baos = new UnsyncByteArrayOutputStream();
	try {
	String line;
	while (null != (line = reader.readLine())) {
	byte[] bytes = decode(line);
	baos.write(bytes);
	}
	retBytes = baos.toByteArray();
	} finally {
	baos.close();
	}

	return retBytes;
	}

	protected static final boolean isWhiteSpace(byte octet) {
	return octet == 0x20 \|\| octet == 0xd \|\| octet == 0xa \|\| octet == 0x9;
	}

	protected static final boolean isPad(byte octet) {
	return octet == PAD;
	}

	/**
	* Encodes hex octets into Base64
	*
	* @param binaryData Array containing binaryData
	* @return Encoded Base64 array
	*/
	/**
	* Encode a byte array in Base64 format and return an optionally
	* wrapped line.
	*
	* @param binaryData {@code byte[]} data to be encoded
	* @param length {@code int} length of wrapped lines; No wrapping if less than 4.
	* @return a {@code String} with encoded data
	*/
	public static final String encode(byte[] binaryData, int length) {
	if (length < 4) {
	length = Integer.MAX_VALUE;
	}

	if (binaryData == null) {
	return null;
	}

	long lengthDataBits = ((long) binaryData.length) * ((long) EIGHTBIT);
	if (lengthDataBits == 0L) {
	return "";
	}

	long fewerThan24bits = lengthDataBits % (TWENTYFOURBITGROUP);
	int numberTriplets = (int) (lengthDataBits / TWENTYFOURBITGROUP);
	int numberQuartet = fewerThan24bits != 0L ? numberTriplets + 1 : numberTriplets;
	int quartesPerLine = length / 4;
	int numberLines = (numberQuartet - 1) / quartesPerLine;
	char[] encodedData = null;

	encodedData = new char[numberQuartet * 4 + numberLines * 2];

	byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
	int encodedIndex = 0;
	int dataIndex = 0;
	int i = 0;

	for (int line = 0; line < numberLines; line++) {
	for (int quartet = 0; quartet < 19; quartet++) {
	b1 = binaryData[dataIndex++];
	b2 = binaryData[dataIndex++];
	b3 = binaryData[dataIndex++];

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


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

	i++;
	}
	encodedData[encodedIndex++] = 0xd;
	encodedData[encodedIndex++] = 0xa;
	}

	for (; i < numberTriplets; i++) {
	b1 = binaryData[dataIndex++];
	b2 = binaryData[dataIndex++];
	b3 = binaryData[dataIndex++];

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


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

	// form integral number of 6-bit groups
	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++] = lookUpBase64Alphabet[k << 4];
	encodedData[encodedIndex++] = PAD;
	encodedData[encodedIndex++] = 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++] = lookUpBase64Alphabet[val2 \| (k << 4)];
	encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];
	encodedData[encodedIndex++] = PAD;
	}

	//encodedData[encodedIndex] = 0xa;

	return new String(encodedData);
	}

	/**
	* Decodes Base64 data into octets
	*
	* @param encoded String containing base64 encoded data
	* @return byte array containing the decoded data
	* @throws Base64DecodingException if there is a problem decoding the data
	*/
	public static final byte[] decode(String encoded) throws Base64DecodingException {
	if (encoded == null) {
	return null;
	}
	byte[] bytes = new byte[encoded.length()];
	int len = getBytesInternal(encoded, bytes);
	return decodeInternal(bytes, len);
	}

	protected static final int getBytesInternal(String s, byte[] result) {
	int length = s.length();

	int newSize = 0;
	for (int i = 0; i < length; i++) {
	byte dataS = (byte)s.charAt(i);
	if (!isWhiteSpace(dataS)) {
	result[newSize++] = dataS;
	}
	}
	return newSize;
	}

	protected static final byte[] decodeInternal(byte[] base64Data, int len)
	throws Base64DecodingException {
	// remove white spaces
	if (len == -1) {
	len = removeWhiteSpace(base64Data);
	}

	if (len % FOURBYTE != 0) {
	throw new Base64DecodingException("decoding.divisible.four");
	//should be divisible by four
	}

	int numberQuadruple = len / FOURBYTE;

	if (numberQuadruple == 0) {
	return new byte[0];
	}

	byte[] decodedData = null;
	byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;

	int i = 0;
	int encodedIndex = 0;
	int dataIndex = 0;

	//decodedData = new byte[ (numberQuadruple)*3];
	dataIndex = (numberQuadruple - 1) * 4;
	encodedIndex = (numberQuadruple - 1) * 3;
	//first last bits.
	b1 = base64Alphabet[base64Data[dataIndex++]];
	b2 = base64Alphabet[base64Data[dataIndex++]];
	if (b1 == -1 \|\| b2 == -1) {
	//if found "no data" just return null
	throw new Base64DecodingException("decoding.general");
	}


	byte d3, d4;
	b3 = base64Alphabet[d3 = base64Data[dataIndex++]];
	b4 = base64Alphabet[d4 = base64Data[dataIndex++]];
	if (b3 == -1 \|\| b4 == -1) {
	//Check if they are PAD characters
	if (isPad(d3) && isPad(d4)) { //Two PAD e.g. 3c[Pad][Pad]
	if ((b2 & 0xf) != 0) { //last 4 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	decodedData = new byte[encodedIndex + 1];
	decodedData[encodedIndex] = (byte)(b1 << 2 \| b2 >> 4) ;
	} else if (!isPad(d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
	if ((b3 & 0x3) != 0) { //last 2 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	decodedData = new byte[encodedIndex + 2];
	decodedData[encodedIndex++] = (byte)(b1 << 2 \| b2 >> 4);
	decodedData[encodedIndex] = (byte)(((b2 & 0xf) << 4) \|((b3 >> 2) & 0xf));
	} else {
	//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
	throw new Base64DecodingException("decoding.general");
	}
	} else {
	//No PAD e.g 3cQl
	decodedData = new byte[encodedIndex+3];
	decodedData[encodedIndex++] = (byte)(b1 << 2 \| b2 >> 4) ;
	decodedData[encodedIndex++] = (byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf));
	decodedData[encodedIndex++] = (byte)(b3 << 6 \| b4);
	}
	encodedIndex = 0;
	dataIndex = 0;
	//the begin
	for (i = numberQuadruple - 1; i > 0; i--) {
	b1 = base64Alphabet[base64Data[dataIndex++]];
	b2 = base64Alphabet[base64Data[dataIndex++]];
	b3 = base64Alphabet[base64Data[dataIndex++]];
	b4 = base64Alphabet[base64Data[dataIndex++]];

	if (b1 == -1 \|\| b2 == -1 \|\| b3 == -1 \|\| b4 == -1) {
	//if found "no data" just return null
	throw new Base64DecodingException("decoding.general");
	}

	decodedData[encodedIndex++] = (byte)(b1 << 2 \| b2 >> 4) ;
	decodedData[encodedIndex++] = (byte)(((b2 & 0xf) << 4) \|((b3 >> 2) & 0xf));
	decodedData[encodedIndex++] = (byte)(b3 << 6 \| b4 );
	}
	return decodedData;
	}

	/**
	* Decodes Base64 data into outputstream
	*
	* @param base64Data String containing Base64 data
	* @param os the outputstream
	* @throws IOException
	* @throws Base64DecodingException
	*/
	public static final void decode(String base64Data, OutputStream os)
	throws Base64DecodingException, IOException {
	byte[] bytes = new byte[base64Data.length()];
	int len = getBytesInternal(base64Data, bytes);
	decode(bytes, os, len);
	}

	/**
	* Decodes Base64 data into outputstream
	*
	* @param base64Data Byte array containing Base64 data
	* @param os the outputstream
	* @throws IOException
	* @throws Base64DecodingException
	*/
	public static final void decode(byte[] base64Data, OutputStream os)
	throws Base64DecodingException, IOException {
	decode(base64Data, os, -1);
	}

	protected static final void decode(byte[] base64Data, OutputStream os, int len)
	throws Base64DecodingException, IOException {
	// remove white spaces
	if (len == -1) {
	len = removeWhiteSpace(base64Data);
	}

	if (len % FOURBYTE != 0) {
	throw new Base64DecodingException("decoding.divisible.four");
	//should be divisible by four
	}

	int numberQuadruple = len / FOURBYTE;

	if (numberQuadruple == 0) {
	return;
	}

	//byte[] decodedData = null;
	byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;

	int i = 0;
	int dataIndex = 0;

	//the begin
	for (i = numberQuadruple - 1; i > 0; i--) {
	b1 = base64Alphabet[base64Data[dataIndex++]];
	b2 = base64Alphabet[base64Data[dataIndex++]];
	b3 = base64Alphabet[base64Data[dataIndex++]];
	b4 = base64Alphabet[base64Data[dataIndex++]];
	if (b1 == -1 \|\| b2 == -1 \|\| b3 == -1 \|\| b4 == -1) {
	//if found "no data" just return null
	throw new Base64DecodingException("decoding.general");
	}

	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write((byte)(((b2 & 0xf) << 4 ) \| ((b3 >> 2) & 0xf)));
	os.write((byte)(b3 << 6 \| b4));
	}
	b1 = base64Alphabet[base64Data[dataIndex++]];
	b2 = base64Alphabet[base64Data[dataIndex++]];

	// first last bits.
	if (b1 == -1 \|\| b2 == -1) {
	//if found "no data" just return null
	throw new Base64DecodingException("decoding.general");
	}

	byte d3, d4;
	b3 = base64Alphabet[d3 = base64Data[dataIndex++]];
	b4 = base64Alphabet[d4 = base64Data[dataIndex++]];
	if (b3 == -1 \|\| b4 == -1) { //Check if they are PAD characters
	if (isPad(d3) && isPad(d4)) { //Two PAD e.g. 3c[Pad][Pad]
	if ((b2 & 0xf) != 0) { //last 4 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	os.write((byte)(b1 << 2 \| b2 >> 4));
	} else if (!isPad(d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
	if ((b3 & 0x3 ) != 0) { //last 2 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write((byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf)));
	} else {
	//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
	throw new Base64DecodingException("decoding.general");
	}
	} else {
	//No PAD e.g 3cQl
	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write( (byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf)));
	os.write((byte)(b3 << 6 \| b4));
	}
	}

	/**
	* Decodes Base64 data into outputstream
	*
	* @param is containing Base64 data
	* @param os the outputstream
	* @throws IOException
	* @throws Base64DecodingException
	*/
	public static final void decode(InputStream is, OutputStream os)
	throws Base64DecodingException, IOException {
	//byte[] decodedData = null;
	byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;

	int index = 0;
	byte[] data = new byte[4];
	int read;
	//the begin
	while ((read = is.read()) > 0) {
	byte readed = (byte)read;
	if (isWhiteSpace(readed)) {
	continue;
	}
	if (isPad(readed)) {
	data[index++] = readed;
	if (index == 3) {
	data[index++] = (byte)is.read();
	}
	break;
	}

	if ((data[index++] = readed) == -1) {
	//if found "no data" just return null
	throw new Base64DecodingException("decoding.general");
	}

	if (index != 4) {
	continue;
	}
	index = 0;
	b1 = base64Alphabet[data[0]];
	b2 = base64Alphabet[data[1]];
	b3 = base64Alphabet[data[2]];
	b4 = base64Alphabet[data[3]];

	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write((byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf)));
	os.write((byte)(b3 << 6 \| b4));
	}

	byte d1 = data[0], d2 = data[1], d3 = data[2], d4 = data[3];
	b1 = base64Alphabet[d1];
	b2 = base64Alphabet[d2];
	b3 = base64Alphabet[d3];
	b4 = base64Alphabet[d4];
	if (b3 == -1 \|\| b4 == -1) { //Check if they are PAD characters
	if (isPad(d3) && isPad(d4)) { //Two PAD e.g. 3c[Pad][Pad]
	if ((b2 & 0xf) != 0) { //last 4 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	os.write((byte)(b1 << 2 \| b2 >> 4));
	} else if (!isPad(d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
	b3 = base64Alphabet[d3];
	if ((b3 & 0x3) != 0) { //last 2 bits should be zero
	throw new Base64DecodingException("decoding.general");
	}
	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write((byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf)));
	} else {
	//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
	throw new Base64DecodingException("decoding.general");
	}
	} else {
	//No PAD e.g 3cQl
	os.write((byte)(b1 << 2 \| b2 >> 4));
	os.write((byte)(((b2 & 0xf) << 4) \| ((b3 >> 2) & 0xf)));
	os.write((byte)(b3 << 6 \| b4));
	}
	}

	/**
	* remove WhiteSpace from MIME containing encoded Base64 data.
	*
	* @param data the byte array of base64 data (with WS)
	* @return the new length
	*/
	protected static final int removeWhiteSpace(byte[] data) {
	if (data == null) {
	return 0;
	}

	// count characters that's not whitespace
	int newSize = 0;
	int len = data.length;
	for (int i = 0; i < len; i++) {
	byte dataS = data[i];
	if (!isWhiteSpace(dataS)) {
	data[newSize++] = dataS;
	}
	}
	return newSize;
	}
	}

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