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	/*
	* Copyright (c) 1995, 2015, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/


	package sun.security.util;

	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.InputStream;
	import java.io.PrintStream;
	import java.io.OutputStream;
	import java.io.IOException;
	import java.nio.ByteBuffer;

	/**
	* This class encodes a buffer into the classic: "Hexadecimal Dump" format of
	* the past. It is useful for analyzing the contents of binary buffers.
	* The format produced is as follows:
	* <pre>
	* xxxx: 00 11 22 33 44 55 66 77 88 99 aa bb cc dd ee ff ................
	* </pre>
	* Where xxxx is the offset into the buffer in 16 byte chunks, followed
	* by ascii coded hexadecimal bytes followed by the ASCII representation of
	* the bytes or '.' if they are not valid bytes.
	*
	* @author Chuck McManis
	*/

	public class HexDumpEncoder {

	private int offset;
	private int thisLineLength;
	private int currentByte;
	private byte thisLine[] = new byte[16];

	static void hexDigit(PrintStream p, byte x) {
	char c;

	c = (char) ((x >> 4) & 0xf);
	if (c > 9)
	c = (char) ((c-10) + 'A');
	else
	c = (char)(c + '0');
	p.write(c);
	c = (char) (x & 0xf);
	if (c > 9)
	c = (char)((c-10) + 'A');
	else
	c = (char)(c + '0');
	p.write(c);
	}

	protected int bytesPerAtom() {
	return (1);
	}

	protected int bytesPerLine() {
	return (16);
	}

	protected void encodeBufferPrefix(OutputStream o) throws IOException {
	offset = 0;
	pStream = new PrintStream(o);
	}

	protected void encodeLinePrefix(OutputStream o, int len) throws IOException {
	hexDigit(pStream, (byte)((offset >>> 8) & 0xff));
	hexDigit(pStream, (byte)(offset & 0xff));
	pStream.print(": ");
	currentByte = 0;
	thisLineLength = len;
	}

	protected void encodeAtom(OutputStream o, byte buf[], int off, int len) throws IOException {
	thisLine[currentByte] = buf[off];
	hexDigit(pStream, buf[off]);
	pStream.print(" ");
	currentByte++;
	if (currentByte == 8)
	pStream.print(" ");
	}

	protected void encodeLineSuffix(OutputStream o) throws IOException {
	if (thisLineLength < 16) {
	for (int i = thisLineLength; i < 16; i++) {
	pStream.print(" ");
	if (i == 7)
	pStream.print(" ");
	}
	}
	pStream.print(" ");
	for (int i = 0; i < thisLineLength; i++) {
	if ((thisLine[i] < ' ') \|\| (thisLine[i] > 'z')) {
	pStream.print(".");
	} else {
	pStream.write(thisLine[i]);
	}
	}
	pStream.println();
	offset += thisLineLength;
	}

	/** Stream that understands "printing" */
	protected PrintStream pStream;

	/**
	* This method works around the bizarre semantics of BufferedInputStream's
	* read method.
	*/
	protected int readFully(InputStream in, byte buffer[])
	throws java.io.IOException {
	for (int i = 0; i < buffer.length; i++) {
	int q = in.read();
	if (q == -1)
	return i;
	buffer[i] = (byte)q;
	}
	return buffer.length;
	}

	/**
	* Encode bytes from the input stream, and write them as text characters
	* to the output stream. This method will run until it exhausts the
	* input stream, but does not print the line suffix for a final
	* line that is shorter than bytesPerLine().
	*/
	public void encode(InputStream inStream, OutputStream outStream)
	throws IOException
	{
	int j;
	int numBytes;
	byte tmpbuffer[] = new byte[bytesPerLine()];

	encodeBufferPrefix(outStream);

	while (true) {
	numBytes = readFully(inStream, tmpbuffer);
	if (numBytes == 0) {
	break;
	}
	encodeLinePrefix(outStream, numBytes);
	for (j = 0; j < numBytes; j += bytesPerAtom()) {

	if ((j + bytesPerAtom()) <= numBytes) {
	encodeAtom(outStream, tmpbuffer, j, bytesPerAtom());
	} else {
	encodeAtom(outStream, tmpbuffer, j, (numBytes)- j);
	}
	}
	if (numBytes < bytesPerLine()) {
	break;
	} else {
	encodeLineSuffix(outStream);
	}
	}
	}

	/**
	* A 'streamless' version of encode that simply takes a buffer of
	* bytes and returns a string containing the encoded buffer.
	*/
	public String encode(byte aBuffer[]) {
	ByteArrayOutputStream outStream = new ByteArrayOutputStream();
	ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
	String retVal = null;
	try {
	encode(inStream, outStream);
	// explicit ascii->unicode conversion
	retVal = outStream.toString("ISO-8859-1");
	} catch (Exception IOException) {
	// This should never happen.
	throw new Error("CharacterEncoder.encode internal error");
	}
	return (retVal);
	}

	/**
	* Return a byte array from the remaining bytes in this ByteBuffer.
	* <P>
	* The ByteBuffer's position will be advanced to ByteBuffer's limit.
	* <P>
	* To avoid an extra copy, the implementation will attempt to return the
	* byte array backing the ByteBuffer. If this is not possible, a
	* new byte array will be created.
	*/
	private byte [] getBytes(ByteBuffer bb) {
	/*
	* This should never return a BufferOverflowException, as we're
	* careful to allocate just the right amount.
	*/
	byte [] buf = null;

	/*
	* If it has a usable backing byte buffer, use it. Use only
	* if the array exactly represents the current ByteBuffer.
	*/
	if (bb.hasArray()) {
	byte [] tmp = bb.array();
	if ((tmp.length == bb.capacity()) &&
	(tmp.length == bb.remaining())) {
	buf = tmp;
	bb.position(bb.limit());
	}
	}

	if (buf == null) {
	/*
	* This class doesn't have a concept of encode(buf, len, off),
	* so if we have a partial buffer, we must reallocate
	* space.
	*/
	buf = new byte[bb.remaining()];

	/*
	* position() automatically updated
	*/
	bb.get(buf);
	}

	return buf;
	}

	/**
	* A 'streamless' version of encode that simply takes a ByteBuffer
	* and returns a string containing the encoded buffer.
	* <P>
	* The ByteBuffer's position will be advanced to ByteBuffer's limit.
	*/
	public String encode(ByteBuffer aBuffer) {
	byte [] buf = getBytes(aBuffer);
	return encode(buf);
	}

	/**
	* Encode bytes from the input stream, and write them as text characters
	* to the output stream. This method will run until it exhausts the
	* input stream. It differs from encode in that it will add the
	* line at the end of a final line that is shorter than bytesPerLine().
	*/
	public void encodeBuffer(InputStream inStream, OutputStream outStream)
	throws IOException
	{
	int j;
	int numBytes;
	byte tmpbuffer[] = new byte[bytesPerLine()];

	encodeBufferPrefix(outStream);

	while (true) {
	numBytes = readFully(inStream, tmpbuffer);
	if (numBytes == 0) {
	break;
	}
	encodeLinePrefix(outStream, numBytes);
	for (j = 0; j < numBytes; j += bytesPerAtom()) {
	if ((j + bytesPerAtom()) <= numBytes) {
	encodeAtom(outStream, tmpbuffer, j, bytesPerAtom());
	} else {
	encodeAtom(outStream, tmpbuffer, j, (numBytes)- j);
	}
	}
	encodeLineSuffix(outStream);
	if (numBytes < bytesPerLine()) {
	break;
	}
	}
	}

	/**
	* Encode the buffer in <i>aBuffer</i> and write the encoded
	* result to the OutputStream <i>aStream</i>.
	*/
	public void encodeBuffer(byte aBuffer[], OutputStream aStream)
	throws IOException
	{
	ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
	encodeBuffer(inStream, aStream);
	}

	/**
	* A 'streamless' version of encode that simply takes a buffer of
	* bytes and returns a string containing the encoded buffer.
	*/
	public String encodeBuffer(byte aBuffer[]) {
	ByteArrayOutputStream outStream = new ByteArrayOutputStream();
	ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
	try {
	encodeBuffer(inStream, outStream);
	} catch (Exception IOException) {
	// This should never happen.
	throw new Error("CharacterEncoder.encodeBuffer internal error");
	}
	return (outStream.toString());
	}

	/**
	* Encode the <i>aBuffer</i> ByteBuffer and write the encoded
	* result to the OutputStream <i>aStream</i>.
	* <P>
	* The ByteBuffer's position will be advanced to ByteBuffer's limit.
	*/
	public void encodeBuffer(ByteBuffer aBuffer, OutputStream aStream)
	throws IOException
	{
	byte [] buf = getBytes(aBuffer);
	encodeBuffer(buf, aStream);
	}

	}

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