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	/*
	* Copyright (c) 2016, 2021, 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 org.jcp.xml.dsig.internal.dom;

	import java.net.URI;
	import java.net.URISyntaxException;
	import java.security.AccessController;
	import java.security.AccessController;
	import java.security.PrivilegedAction;
	import java.security.Security;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Set;

	/**
	* The secure validation policy as specified by the
	* jdk.xml.dsig.secureValidationPolicy security property.
	*/
	public final class Policy {

	// all restrictions are initialized to be unconstrained
	private static Set<URI> disallowedAlgs = new HashSet<>();
	private static int maxTrans = Integer.MAX_VALUE;
	private static int maxRefs = Integer.MAX_VALUE;
	private static Set<String> disallowedRefUriSchemes = new HashSet<>();
	private static Map<String, Integer> minKeyMap = new HashMap<>();
	private static boolean noDuplicateIds = false;
	private static boolean noRMLoops = false;

	static {
	try {
	initialize();
	} catch (Exception e) {
	throw new SecurityException(
	"Cannot initialize the secure validation policy", e);
	}
	}

	private Policy() {}

	private static void initialize() {
	@SuppressWarnings("removal")
	String prop =
	AccessController.doPrivileged((PrivilegedAction<String>) () ->
	Security.getProperty("jdk.xml.dsig.secureValidationPolicy"));
	if (prop == null \|\| prop.isEmpty()) {
	// no policy specified, so don't enforce any restrictions
	return;
	}
	String[] entries = prop.split(",");
	for (String entry : entries) {
	String[] tokens = entry.split("\\s");
	String type = tokens[0];
	switch(type) {
	case "disallowAlg":
	if (tokens.length != 2) {
	error(entry);
	}
	disallowedAlgs.add(URI.create(tokens[1]));
	break;
	case "maxTransforms":
	if (tokens.length != 2) {
	error(entry);
	}
	maxTrans = Integer.parseUnsignedInt(tokens[1]);
	break;
	case "maxReferences":
	if (tokens.length != 2) {
	error(entry);
	}
	maxRefs = Integer.parseUnsignedInt(tokens[1]);
	break;
	case "disallowReferenceUriSchemes":
	if (tokens.length == 1) {
	error(entry);
	}
	for (int i = 1; i < tokens.length; i++) {
	String scheme = tokens[i];
	disallowedRefUriSchemes.add(
	scheme.toLowerCase(Locale.ROOT));
	}
	break;
	case "minKeySize":
	if (tokens.length != 3) {
	error(entry);
	}
	minKeyMap.put(tokens[1],
	Integer.parseUnsignedInt(tokens[2]));
	break;
	case "noDuplicateIds":
	if (tokens.length != 1) {
	error(entry);
	}
	noDuplicateIds = true;
	break;
	case "noRetrievalMethodLoops":
	if (tokens.length != 1) {
	error(entry);
	}
	noRMLoops = true;
	break;
	default:
	error(entry);
	}
	}
	}

	public static boolean restrictAlg(String alg) {
	try {
	URI uri = new URI(alg);
	return disallowedAlgs.contains(uri);
	} catch (URISyntaxException use) {
	return false;
	}
	}

	public static boolean restrictNumTransforms(int numTrans) {
	return (numTrans > maxTrans);
	}

	public static boolean restrictNumReferences(int numRefs) {
	return (numRefs > maxRefs);
	}

	public static boolean restrictReferenceUriScheme(String uri) {
	if (uri != null) {
	String scheme = java.net.URI.create(uri).getScheme();
	if (scheme != null) {
	return disallowedRefUriSchemes.contains(
	scheme.toLowerCase(Locale.ROOT));
	}
	}
	return false;
	}

	public static boolean restrictKey(String type, int size) {
	return (size < minKeyMap.getOrDefault(type, 0));
	}

	public static boolean restrictDuplicateIds() {
	return noDuplicateIds;
	}

	public static boolean restrictRetrievalMethodLoops() {
	return noRMLoops;
	}

	public static Set<URI> disabledAlgs() {
	return Collections.<URI>unmodifiableSet(disallowedAlgs);
	}

	public static int maxTransforms() {
	return maxTrans;
	}

	public static int maxReferences() {
	return maxRefs;
	}

	public static Set<String> disabledReferenceUriSchemes() {
	return Collections.<String>unmodifiableSet(disallowedRefUriSchemes);
	}

	public static int minKeySize(String type) {
	return minKeyMap.getOrDefault(type, 0);
	}

	private static void error(String entry) {
	throw new IllegalArgumentException(
	"Invalid jdk.xml.dsig.secureValidationPolicy entry: " + entry);
	}
	}

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