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	/*
	* Copyright (c) 1999, 2012, 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 javax.crypto;

	import java.security.*;
	import java.security.spec.AlgorithmParameterSpec;
	import java.io.Serializable;
	import java.util.Enumeration;
	import java.util.Vector;

	import javax.crypto.spec.*;

	/**
	* The CryptoPermission class extends the
	* java.security.Permission class. A
	* CryptoPermission object is used to represent
	* the ability of an application/applet to use certain
	* algorithms with certain key sizes and other
	* restrictions in certain environments. <p>
	*
	* @see java.security.Permission
	*
	* @author Jan Luehe
	* @author Sharon Liu
	* @since 1.4
	*/
	class CryptoPermission extends java.security.Permission {

	private static final long serialVersionUID = 8987399626114087514L;

	private String alg;
	private int maxKeySize = Integer.MAX_VALUE; // no restriction on maxKeySize
	private String exemptionMechanism = null;
	private AlgorithmParameterSpec algParamSpec = null;
	private boolean checkParam = false; // no restriction on param

	static final String ALG_NAME_WILDCARD = "*";

	/**
	* Constructor that takes an algorithm name.
	*
	* This constructor implies that the given algorithm can be
	* used without any restrictions.
	*
	* @param alg the algorithm name.
	*/
	CryptoPermission(String alg) {
	super(null);
	this.alg = alg;
	}

	/**
	* Constructor that takes an algorithm name and a maximum
	* key size.
	*
	* This constructor implies that the given algorithm can be
	* used with a key size up to <code>maxKeySize</code>.
	*
	* @param alg the algorithm name.
	*
	* @param maxKeySize the maximum allowable key size,
	* specified in number of bits.
	*/
	CryptoPermission(String alg, int maxKeySize) {
	super(null);
	this.alg = alg;
	this.maxKeySize = maxKeySize;
	}

	/**
	* Constructor that takes an algorithm name, a maximum
	* key size, and an AlgorithmParameterSpec object.
	*
	* This constructor implies that the given algorithm can be
	* used with a key size up to <code>maxKeySize</code>, and
	* algorithm
	* parameters up to the limits set in <code>algParamSpec</code>.
	*
	* @param alg the algorithm name.
	*
	* @param maxKeySize the maximum allowable key size,
	* specified in number of bits.
	*
	* @param algParamSpec the limits for allowable algorithm
	* parameters.
	*/
	CryptoPermission(String alg,
	int maxKeySize,
	AlgorithmParameterSpec algParamSpec) {
	super(null);
	this.alg = alg;
	this.maxKeySize = maxKeySize;
	this.checkParam = true;
	this.algParamSpec = algParamSpec;
	}

	/**
	* Constructor that takes an algorithm name and the name of
	* an exemption mechanism.
	*
	* This constructor implies that the given algorithm can be
	* used without any key size or algorithm parameter restrictions
	* provided that the specified exemption mechanism is enforced.
	*
	* @param alg the algorithm name.
	*
	* @param exemptionMechanism the name of the exemption mechanism.
	*/
	CryptoPermission(String alg,
	String exemptionMechanism) {
	super(null);
	this.alg = alg;
	this.exemptionMechanism = exemptionMechanism;
	}

	/**
	* Constructor that takes an algorithm name, a maximum key
	* size, and the name of an exemption mechanism.
	*
	* This constructor implies that the given algorithm can be
	* used with a key size up to <code>maxKeySize</code>
	* provided that the
	* specified exemption mechanism is enforced.
	*
	* @param alg the algorithm name.
	* @param maxKeySize the maximum allowable key size,
	* specified in number of bits.
	* @param exemptionMechanism the name of the exemption
	* mechanism.
	*/
	CryptoPermission(String alg,
	int maxKeySize,
	String exemptionMechanism) {
	super(null);
	this.alg = alg;
	this.exemptionMechanism = exemptionMechanism;
	this.maxKeySize = maxKeySize;
	}

	/**
	* Constructor that takes an algorithm name, a maximum key
	* size, the name of an exemption mechanism, and an
	* AlgorithmParameterSpec object.
	*
	* This constructor implies that the given algorithm can be
	* used with a key size up to <code>maxKeySize</code>
	* and algorithm
	* parameters up to the limits set in <code>algParamSpec</code>
	* provided that
	* the specified exemption mechanism is enforced.
	*
	* @param alg the algorithm name.
	* @param maxKeySize the maximum allowable key size,
	* specified in number of bits.
	* @param algParamSpec the limit for allowable algorithm
	* parameter spec.
	* @param exemptionMechanism the name of the exemption
	* mechanism.
	*/
	CryptoPermission(String alg,
	int maxKeySize,
	AlgorithmParameterSpec algParamSpec,
	String exemptionMechanism) {
	super(null);
	this.alg = alg;
	this.exemptionMechanism = exemptionMechanism;
	this.maxKeySize = maxKeySize;
	this.checkParam = true;
	this.algParamSpec = algParamSpec;
	}

	/**
	* Checks if the specified permission is "implied" by
	* this object.
	* <p>
	* More specifically, this method returns true if:<p>
	* <ul>
	* <li> <i>p</i> is an instance of CryptoPermission, and<p>
	* <li> <i>p</i>'s algorithm name equals or (in the case of wildcards)
	* is implied by this permission's algorithm name, and<p>
	* <li> <i>p</i>'s maximum allowable key size is less or
	* equal to this permission's maximum allowable key size, and<p>
	* <li> <i>p</i>'s algorithm parameter spec equals or is
	* implied by this permission's algorithm parameter spec, and<p>
	* <li> <i>p</i>'s exemptionMechanism equals or
	* is implied by this permission's
	* exemptionMechanism (a <code>null</code> exemption mechanism
	* implies any other exemption mechanism).
	* </ul>
	*
	* @param p the permission to check against.
	*
	* @return true if the specified permission is equal to or
	* implied by this permission, false otherwise.
	*/
	public boolean implies(Permission p) {
	if (!(p instanceof CryptoPermission))
	return false;

	CryptoPermission cp = (CryptoPermission)p;

	if ((!alg.equalsIgnoreCase(cp.alg)) &&
	(!alg.equalsIgnoreCase(ALG_NAME_WILDCARD))) {
	return false;
	}

	// alg is the same as cp's alg or
	// alg is a wildcard.
	if (cp.maxKeySize <= this.maxKeySize) {
	// check algParamSpec.
	if (!impliesParameterSpec(cp.checkParam, cp.algParamSpec)) {
	return false;
	}

	// check exemptionMechanism.
	if (impliesExemptionMechanism(cp.exemptionMechanism)) {
	return true;
	}
	}

	return false;
	}

	/**
	* Checks two CryptoPermission objects for equality. Checks that
	* <code>obj</code> is a CryptoPermission, and has the same
	* algorithm name,
	* exemption mechanism name, maximum allowable key size and
	* algorithm parameter spec
	* as this object.
	* <P>
	* @param obj the object to test for equality with this object.
	* @return true if <code>obj</code> is equal to this object.
	*/
	public boolean equals(Object obj) {
	if (obj == this)
	return true;

	if (!(obj instanceof CryptoPermission))
	return false;

	CryptoPermission that = (CryptoPermission) obj;

	if (!(alg.equalsIgnoreCase(that.alg)) \|\|
	(maxKeySize != that.maxKeySize)) {
	return false;
	}
	if (this.checkParam != that.checkParam) {
	return false;
	}
	return (equalObjects(this.exemptionMechanism,
	that.exemptionMechanism) &&
	equalObjects(this.algParamSpec,
	that.algParamSpec));
	}

	/**
	* Returns the hash code value for this object.
	*
	* @return a hash code value for this object.
	*/

	public int hashCode() {
	int retval = alg.hashCode();
	retval ^= maxKeySize;
	if (exemptionMechanism != null) {
	retval ^= exemptionMechanism.hashCode();
	}
	if (checkParam) retval ^= 100;
	if (algParamSpec != null) {
	retval ^= algParamSpec.hashCode();
	}
	return retval;
	}

	/**
	* There is no action defined for a CryptoPermission
	* onject.
	*/
	public String getActions()
	{
	return null;
	}

	/**
	* Returns a new PermissionCollection object for storing
	* CryptoPermission objects.
	*
	* @return a new PermissionCollection object suitable for storing
	* CryptoPermissions.
	*/

	public PermissionCollection newPermissionCollection() {
	return new CryptoPermissionCollection();
	}

	/**
	* Returns the algorithm name associated with
	* this CryptoPermission object.
	*/
	final String getAlgorithm() {
	return alg;
	}

	/**
	* Returns the exemption mechanism name
	* associated with this CryptoPermission
	* object.
	*/
	final String getExemptionMechanism() {
	return exemptionMechanism;
	}

	/**
	* Returns the maximum allowable key size associated
	* with this CryptoPermission object.
	*/
	final int getMaxKeySize() {
	return maxKeySize;
	}

	/**
	* Returns true if there is a limitation on the
	* AlgorithmParameterSpec associated with this
	* CryptoPermission object and false if otherwise.
	*/
	final boolean getCheckParam() {
	return checkParam;
	}

	/**
	* Returns the AlgorithmParameterSpec
	* associated with this CryptoPermission
	* object.
	*/
	final AlgorithmParameterSpec getAlgorithmParameterSpec() {
	return algParamSpec;
	}

	/**
	* Returns a string describing this CryptoPermission. The convention is to
	* specify the class name, the algorithm name, the maximum allowable
	* key size, and the name of the exemption mechanism, in the following
	* format: '("ClassName" "algorithm" "keysize" "exemption_mechanism")'.
	*
	* @return information about this CryptoPermission.
	*/
	public String toString() {
	StringBuilder buf = new StringBuilder(100);
	buf.append("(CryptoPermission " + alg + " " + maxKeySize);
	if (algParamSpec != null) {
	if (algParamSpec instanceof RC2ParameterSpec) {
	buf.append(" , effective " +
	((RC2ParameterSpec)algParamSpec).getEffectiveKeyBits());
	} else if (algParamSpec instanceof RC5ParameterSpec) {
	buf.append(" , rounds " +
	((RC5ParameterSpec)algParamSpec).getRounds());
	}
	}
	if (exemptionMechanism != null) { // OPTIONAL
	buf.append(" " + exemptionMechanism);
	}
	buf.append(")");
	return buf.toString();
	}

	private boolean impliesExemptionMechanism(String exemptionMechanism) {
	if (this.exemptionMechanism == null) {
	return true;
	}

	if (exemptionMechanism == null) {
	return false;
	}

	if (this.exemptionMechanism.equals(exemptionMechanism)) {
	return true;
	}

	return false;
	}

	private boolean impliesParameterSpec(boolean checkParam,
	AlgorithmParameterSpec algParamSpec) {
	if ((this.checkParam) && checkParam) {
	if (algParamSpec == null) {
	return true;
	} else if (this.algParamSpec == null) {
	return false;
	}

	if (this.algParamSpec.getClass() != algParamSpec.getClass()) {
	return false;
	}

	if (algParamSpec instanceof RC2ParameterSpec) {
	if (((RC2ParameterSpec)algParamSpec).getEffectiveKeyBits() <=
	((RC2ParameterSpec)
	(this.algParamSpec)).getEffectiveKeyBits()) {
	return true;
	}
	}

	if (algParamSpec instanceof RC5ParameterSpec) {
	if (((RC5ParameterSpec)algParamSpec).getRounds() <=
	((RC5ParameterSpec)this.algParamSpec).getRounds()) {
	return true;
	}
	}

	if (algParamSpec instanceof PBEParameterSpec) {
	if (((PBEParameterSpec)algParamSpec).getIterationCount() <=
	((PBEParameterSpec)this.algParamSpec).getIterationCount()) {
	return true;
	}
	}

	// For classes we don't know, the following
	// may be the best try.
	if (this.algParamSpec.equals(algParamSpec)) {
	return true;
	}
	return false;
	} else if (this.checkParam) {
	return false;
	} else {
	return true;
	}
	}

	private boolean equalObjects(Object obj1, Object obj2) {
	if (obj1 == null) {
	return (obj2 == null ? true : false);
	}

	return obj1.equals(obj2);
	}
	}

	/**
	* A CryptoPermissionCollection stores a set of CryptoPermission
	* permissions.
	*
	* @see java.security.Permission
	* @see java.security.Permissions
	* @see java.security.PermissionCollection
	*
	* @author Sharon Liu
	*/
	final class CryptoPermissionCollection extends PermissionCollection
	implements Serializable
	{
	private static final long serialVersionUID = -511215555898802763L;

	private Vector<Permission> permissions;

	/**
	* Creates an empty CryptoPermissionCollection
	* object.
	*/
	CryptoPermissionCollection() {
	permissions = new Vector<Permission>(3);
	}

	/**
	* Adds a permission to the CryptoPermissionCollection.
	*
	* @param permission the Permission object to add.
	*
	* @exception SecurityException - if this CryptoPermissionCollection
	* object has been marked <i>readOnly</i>.
	*/
	public void add(Permission permission) {
	if (isReadOnly())
	throw new SecurityException("attempt to add a Permission " +
	"to a readonly PermissionCollection");

	if (!(permission instanceof CryptoPermission))
	return;

	permissions.addElement(permission);
	}

	/**
	* Check and see if this CryptoPermission object implies
	* the given Permission object.
	*
	* @param permission the Permission object to compare
	*
	* @return true if the given permission is implied by this
	* CryptoPermissionCollection, false if not.
	*/
	public boolean implies(Permission permission) {
	if (!(permission instanceof CryptoPermission))
	return false;

	CryptoPermission cp = (CryptoPermission)permission;

	Enumeration<Permission> e = permissions.elements();

	while (e.hasMoreElements()) {
	CryptoPermission x = (CryptoPermission) e.nextElement();
	if (x.implies(cp)) {
	return true;
	}
	}
	return false;
	}

	/**
	* Returns an enumeration of all the CryptoPermission objects
	* in the container.
	*
	* @return an enumeration of all the CryptoPermission objects.
	*/

	public Enumeration<Permission> elements() {
	return permissions.elements();
	}
	}

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