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	/*
	* Copyright (c) 1997, 2011, 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.security.*;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.io.ByteArrayOutputStream;
	import java.util.List;

	/**
	* This class is used to compute digests on sections of the Manifest.
	*/
	public class ManifestDigester {

	public static final String MF_MAIN_ATTRS = "Manifest-Main-Attributes";

	/** the raw bytes of the manifest */
	private byte rawBytes[];

	/** the entries grouped by names */
	private HashMap<String, Entry> entries; // key is a UTF-8 string

	/** state returned by findSection */
	static class Position {
	int endOfFirstLine; // not including newline character

	int endOfSection; // end of section, not including the blank line
	// between sections
	int startOfNext; // the start of the next section
	}

	/**
	* find a section in the manifest.
	*
	* @param offset should point to the starting offset with in the
	* raw bytes of the next section.
	*
	* @pos set by
	*
	* @returns false if end of bytes has been reached, otherwise returns
	* true
	*/
	@SuppressWarnings("fallthrough")
	private boolean findSection(int offset, Position pos)
	{
	int i = offset, len = rawBytes.length;
	int last = offset;
	int next;
	boolean allBlank = true;

	pos.endOfFirstLine = -1;

	while (i < len) {
	byte b = rawBytes[i];
	switch(b) {
	case '\r':
	if (pos.endOfFirstLine == -1)
	pos.endOfFirstLine = i-1;
	if ((i < len) && (rawBytes[i+1] == '\n'))
	i++;
	/* fall through */
	case '\n':
	if (pos.endOfFirstLine == -1)
	pos.endOfFirstLine = i-1;
	if (allBlank \|\| (i == len-1)) {
	if (i == len-1)
	pos.endOfSection = i;
	else
	pos.endOfSection = last;
	pos.startOfNext = i+1;
	return true;
	}
	else {
	// start of a new line
	last = i;
	allBlank = true;
	}
	break;
	default:
	allBlank = false;
	break;
	}
	i++;
	}
	return false;
	}

	public ManifestDigester(byte bytes[])
	{
	rawBytes = bytes;
	entries = new HashMap<String, Entry>();

	ByteArrayOutputStream baos = new ByteArrayOutputStream();

	Position pos = new Position();

	if (!findSection(0, pos))
	return; // XXX: exception?

	// create an entry for main attributes
	entries.put(MF_MAIN_ATTRS, new Entry().addSection(
	new Section(0, pos.endOfSection + 1, pos.startOfNext, rawBytes)));

	int start = pos.startOfNext;
	while(findSection(start, pos)) {
	int len = pos.endOfFirstLine-start+1;
	int sectionLen = pos.endOfSection-start+1;
	int sectionLenWithBlank = pos.startOfNext-start;

	if (len > 6) {
	if (isNameAttr(bytes, start)) {
	StringBuilder nameBuf = new StringBuilder(sectionLen);

	try {
	nameBuf.append(
	new String(bytes, start+6, len-6, "UTF8"));

	int i = start + len;
	if ((i-start) < sectionLen) {
	if (bytes[i] == '\r') {
	i += 2;
	} else {
	i += 1;
	}
	}

	while ((i-start) < sectionLen) {
	if (bytes[i++] == ' ') {
	// name is wrapped
	int wrapStart = i;
	while (((i-start) < sectionLen)
	&& (bytes[i++] != '\n'));
	if (bytes[i-1] != '\n')
	return; // XXX: exception?
	int wrapLen;
	if (bytes[i-2] == '\r')
	wrapLen = i-wrapStart-2;
	else
	wrapLen = i-wrapStart-1;

	nameBuf.append(new String(bytes, wrapStart,
	wrapLen, "UTF8"));
	} else {
	break;
	}
	}

	Entry e = entries.get(nameBuf.toString());
	if (e == null) {
	entries.put(nameBuf.toString(), new Entry()
	.addSection(new Section(start, sectionLen,
	sectionLenWithBlank, rawBytes)));
	} else {
	e.addSection(new Section(start, sectionLen,
	sectionLenWithBlank, rawBytes));
	}

	} catch (java.io.UnsupportedEncodingException uee) {
	throw new IllegalStateException(
	"UTF8 not available on platform");
	}
	}
	}
	start = pos.startOfNext;
	}
	}

	private boolean isNameAttr(byte bytes[], int start)
	{
	return ((bytes[start] == 'N') \|\| (bytes[start] == 'n')) &&
	((bytes[start+1] == 'a') \|\| (bytes[start+1] == 'A')) &&
	((bytes[start+2] == 'm') \|\| (bytes[start+2] == 'M')) &&
	((bytes[start+3] == 'e') \|\| (bytes[start+3] == 'E')) &&
	(bytes[start+4] == ':') &&
	(bytes[start+5] == ' ');
	}

	public static class Entry {

	// One Entry for one name, and one name can have multiple sections.
	// According to the JAR File Specification: "If there are multiple
	// individual sections for the same file entry, the attributes in
	// these sections are merged."
	private List<Section> sections = new ArrayList<>();
	boolean oldStyle;

	private Entry addSection(Section sec)
	{
	sections.add(sec);
	return this;
	}

	public byte[] digest(MessageDigest md)
	{
	md.reset();
	for (Section sec : sections) {
	if (oldStyle) {
	Section.doOldStyle(md, sec.rawBytes, sec.offset, sec.lengthWithBlankLine);
	} else {
	md.update(sec.rawBytes, sec.offset, sec.lengthWithBlankLine);
	}
	}
	return md.digest();
	}

	/** Netscape doesn't include the new line. Intel and JavaSoft do */

	public byte[] digestWorkaround(MessageDigest md)
	{
	md.reset();
	for (Section sec : sections) {
	md.update(sec.rawBytes, sec.offset, sec.length);
	}
	return md.digest();
	}
	}

	private static class Section {
	int offset;
	int length;
	int lengthWithBlankLine;
	byte[] rawBytes;

	public Section(int offset, int length,
	int lengthWithBlankLine, byte[] rawBytes)
	{
	this.offset = offset;
	this.length = length;
	this.lengthWithBlankLine = lengthWithBlankLine;
	this.rawBytes = rawBytes;
	}

	private static void doOldStyle(MessageDigest md,
	byte[] bytes,
	int offset,
	int length)
	{
	// this is too gross to even document, but here goes
	// the 1.1 jar verification code ignored spaces at the
	// end of lines when calculating digests, so that is
	// what this code does. It only gets called if we
	// are parsing a 1.1 signed signature file
	int i = offset;
	int start = offset;
	int max = offset + length;
	int prev = -1;
	while(i <max) {
	if ((bytes[i] == '\r') && (prev == ' ')) {
	md.update(bytes, start, i-start-1);
	start = i;
	}
	prev = bytes[i];
	i++;
	}
	md.update(bytes, start, i-start);
	}
	}

	public Entry get(String name, boolean oldStyle) {
	Entry e = entries.get(name);
	if (e != null)
	e.oldStyle = oldStyle;
	return e;
	}

	public byte[] manifestDigest(MessageDigest md)
	{
	md.reset();
	md.update(rawBytes, 0, rawBytes.length);
	return md.digest();
	}

	}

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