/*
* Copyright (c) 1999, 2007, 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.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import java.util.NoSuchElementException;
import java.io.Serializable;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
/**
* This class contains CryptoPermission objects, organized into
* PermissionCollections according to algorithm names.
*
* <p>When the <code>add</code> method is called to add a
* CryptoPermission, the CryptoPermission is stored in the
* appropriate PermissionCollection. If no such
* collection exists yet, the algorithm name associated with
* the CryptoPermission object is
* determined and the <code>newPermissionCollection</code> method
* is called on the CryptoPermission or CryptoAllPermission class to
* create the PermissionCollection and add it to the Permissions object.
*
* @see javax.crypto.CryptoPermission
* @see java.security.PermissionCollection
* @see java.security.Permissions
*
* @author Sharon Liu
* @since 1.4
*/
final class CryptoPermissions extends PermissionCollection
implements Serializable {
private static final long serialVersionUID = 4946547168093391015L;
// This class is similar to java.security.Permissions
private Hashtable perms;
/**
* Creates a new CryptoPermissions object containing
* no CryptoPermissionCollections.
*/
CryptoPermissions() {
perms = new Hashtable(7);
}
/**
* Populates the crypto policy from the specified
* InputStream into this CryptoPermissions object.
*
* @param in the InputStream to load from.
*
* @exception SecurityException if cannot load
* successfully.
*/
void load(InputStream in)
throws IOException, CryptoPolicyParser.ParsingException {
CryptoPolicyParser parser = new CryptoPolicyParser();
parser.read(new BufferedReader(new InputStreamReader(in, "UTF-8")));
CryptoPermission[] parsingResult = parser.getPermissions();
for (int i = 0; i < parsingResult.length; i++) {
this.add(parsingResult[i]);
}
}
/**
* Returns true if this CryptoPermissions object doesn't
* contain any CryptoPermission objects; otherwise, returns
* false.
*/
boolean isEmpty() {
return perms.isEmpty();
}
/**
* Adds a permission object to the PermissionCollection for the
* algorithm returned by
* <code>(CryptoPermission)permission.getAlgorithm()</code>.
*
* This method creates
* a new PermissionCollection object (and adds the permission to it)
* if an appropriate collection does not yet exist. <p>
*
* @param permission the Permission object to add.
*
* @exception SecurityException if this CryptoPermissions object is
* marked as readonly.
*
* @see isReadOnly
*/
public void add(Permission permission) {
if (isReadOnly())
throw new SecurityException("Attempt to add a Permission " +
"to a readonly CryptoPermissions " +
"object");
if (!(permission instanceof CryptoPermission))
return;
CryptoPermission cryptoPerm = (CryptoPermission)permission;
PermissionCollection pc =
getPermissionCollection(cryptoPerm);
pc.add(cryptoPerm);
String alg = cryptoPerm.getAlgorithm();
if (!perms.containsKey(alg)) {
perms.put(alg, pc);
}
}
/**
* Checks if this object's PermissionCollection for permissons
* of the specified permission's algorithm implies the specified
* permission. Returns true if the checking succeeded.
*
* @param permission the Permission object to check.
*
* @return true if "permission" is implied by the permissions
* in the PermissionCollection it belongs to, false if not.
*
*/
public boolean implies(Permission permission) {
if (!(permission instanceof CryptoPermission)) {
return false;
}
CryptoPermission cryptoPerm = (CryptoPermission)permission;
PermissionCollection pc =
getPermissionCollection(cryptoPerm.getAlgorithm());
return pc.implies(cryptoPerm);
}
/**
* Returns an enumeration of all the Permission objects in all the
* PermissionCollections in this CryptoPermissions object.
*
* @return an enumeration of all the Permissions.
*/
public Enumeration elements() {
// go through each Permissions in the hash table
// and call their elements() function.
return new PermissionsEnumerator(perms.elements());
}
/**
* Returns a CryptoPermissions object which
* represents the minimum of the specified
* CryptoPermissions object and this
* CryptoPermissions object.
*
* @param other the CryptoPermission
* object to compare with this object.
*/
CryptoPermissions getMinimum(CryptoPermissions other) {
if (other == null) {
return null;
}
if (this.perms.containsKey(CryptoAllPermission.ALG_NAME)) {
return other;
}
if (other.perms.containsKey(CryptoAllPermission.ALG_NAME)) {
return this;
}
CryptoPermissions ret = new CryptoPermissions();
PermissionCollection thatWildcard =
(PermissionCollection)other.perms.get(
CryptoPermission.ALG_NAME_WILDCARD);
int maxKeySize = 0;
if (thatWildcard != null) {
maxKeySize = ((CryptoPermission)
thatWildcard.elements().nextElement()).getMaxKeySize();
}
// For each algorithm in this CryptoPermissions,
// find out if there is anything we should add into
// ret.
Enumeration thisKeys = this.perms.keys();
while (thisKeys.hasMoreElements()) {
String alg = (String)thisKeys.nextElement();
PermissionCollection thisPc =
(PermissionCollection)this.perms.get(alg);
PermissionCollection thatPc =
(PermissionCollection)other.perms.get(alg);
CryptoPermission[] partialResult;
if (thatPc == null) {
if (thatWildcard == null) {
// The other CryptoPermissions
// doesn't allow this given
// algorithm at all. Just skip this
// algorithm.
continue;
}
partialResult = getMinimum(maxKeySize, thisPc);
} else {
partialResult = getMinimum(thisPc, thatPc);
}
for (int i = 0; i < partialResult.length; i++) {
ret.add(partialResult[i]);
}
}
PermissionCollection thisWildcard =
(PermissionCollection)this.perms.get(
CryptoPermission.ALG_NAME_WILDCARD);
// If this CryptoPermissions doesn't
// have a wildcard, we are done.
if (thisWildcard == null) {
return ret;
}
// Deal with the algorithms only appear
// in the other CryptoPermissions.
maxKeySize =
((CryptoPermission)
thisWildcard.elements().nextElement()).getMaxKeySize();
Enumeration thatKeys = other.perms.keys();
while (thatKeys.hasMoreElements()) {
String alg = (String)thatKeys.nextElement();
if (this.perms.containsKey(alg)) {
continue;
}
PermissionCollection thatPc =
(PermissionCollection)other.perms.get(alg);
CryptoPermission[] partialResult;
partialResult = getMinimum(maxKeySize, thatPc);
for (int i = 0; i < partialResult.length; i++) {
ret.add(partialResult[i]);
}
}
return ret;
}
/**
* Get the minimum of the two given PermissionCollection
* <code>thisPc</code> and <code>thatPc</code>.
*
* @param thisPc the first given PermissionColloection
* object.
*
* @param thatPc the second given PermissionCollection
* object.
*/
private CryptoPermission[] getMinimum(PermissionCollection thisPc,
PermissionCollection thatPc) {
Vector permVector = new Vector(2);
Enumeration thisPcPermissions = thisPc.elements();
// For each CryptoPermission in
// thisPc object, do the following:
// 1) if this CryptoPermission is implied
// by thatPc, this CryptoPermission
// should be returned, and we can
// move on to check the next
// CryptoPermission in thisPc.
// 2) otherwise, we should return
// all CryptoPermissions in thatPc
// which
// are implied by this CryptoPermission.
// Then we can move on to the
// next CryptoPermission in thisPc.
while (thisPcPermissions.hasMoreElements()) {
CryptoPermission thisCp =
(CryptoPermission)thisPcPermissions.nextElement();
Enumeration thatPcPermissions = thatPc.elements();
while (thatPcPermissions.hasMoreElements()) {
CryptoPermission thatCp =
(CryptoPermission)thatPcPermissions.nextElement();
if (thatCp.implies(thisCp)) {
permVector.addElement(thisCp);
break;
}
if (thisCp.implies(thatCp)) {
permVector.addElement(thatCp);
}
}
}
CryptoPermission[] ret = new CryptoPermission[permVector.size()];
permVector.copyInto(ret);
return ret;
}
/**
* Returns all the CryptoPermission objects in the given
* PermissionCollection object
* whose maximum keysize no greater than <code>maxKeySize</code>.
* For all CryptoPermission objects with a maximum keysize greater
* than <code>maxKeySize</code>, this method constructs a
* corresponding CryptoPermission object whose maximum keysize is
* set to <code>maxKeySize</code>, and includes that in the result.
*
* @param maxKeySize the given maximum key size.
*
* @param pc the given PermissionCollection object.
*/
private CryptoPermission[] getMinimum(int maxKeySize,
PermissionCollection pc) {
Vector permVector = new Vector(1);
Enumeration enum_ = pc.elements();
while (enum_.hasMoreElements()) {
CryptoPermission cp =
(CryptoPermission)enum_.nextElement();
if (cp.getMaxKeySize() <= maxKeySize) {
permVector.addElement(cp);
} else {
if (cp.getCheckParam()) {
permVector.addElement(
new CryptoPermission(cp.getAlgorithm(),
maxKeySize,
cp.getAlgorithmParameterSpec(),
cp.getExemptionMechanism()));
} else {
permVector.addElement(
new CryptoPermission(cp.getAlgorithm(),
maxKeySize,
cp.getExemptionMechanism()));
}
}
}
CryptoPermission[] ret = new CryptoPermission[permVector.size()];
permVector.copyInto(ret);
return ret;
}
/**
* Returns the PermissionCollection for the
* specified algorithm. Returns null if there
* isn't such a PermissionCollection.
*
* @param alg the algorithm name.
*/
PermissionCollection getPermissionCollection(String alg) {
// If this CryptoPermissions includes CryptoAllPermission,
// we should return CryptoAllPermission.
if (perms.containsKey(CryptoAllPermission.ALG_NAME)) {
return
(PermissionCollection)(perms.get(CryptoAllPermission.ALG_NAME));
}
PermissionCollection pc = (PermissionCollection)perms.get(alg);
// If there isn't a PermissionCollection for
// the given algorithm,we should return the
// PermissionCollection for the wildcard
// if there is one.
if (pc == null) {
pc = (PermissionCollection)perms.get(
CryptoPermission.ALG_NAME_WILDCARD);
}
return pc;
}
/**
* Returns the PermissionCollection for the algorithm
* associated with the specified CryptoPermission
* object. Creates such a PermissionCollection
* if such a PermissionCollection does not
* exist yet.
*
* @param cryptoPerm the CryptoPermission object.
*/
private PermissionCollection getPermissionCollection(
CryptoPermission cryptoPerm) {
String alg = cryptoPerm.getAlgorithm();
PermissionCollection pc = (PermissionCollection)perms.get(alg);
if (pc == null) {
pc = cryptoPerm.newPermissionCollection();
}
return pc;
}
}
final class PermissionsEnumerator implements Enumeration {
// all the perms
private Enumeration perms;
// the current set
private Enumeration permset;
PermissionsEnumerator(Enumeration e) {
perms = e;
permset = getNextEnumWithMore();
}
public synchronized boolean hasMoreElements() {
// if we enter with permissionimpl null, we know
// there are no more left.
if (permset == null)
return false;
// try to see if there are any left in the current one
if (permset.hasMoreElements())
return true;
// get the next one that has something in it...
permset = getNextEnumWithMore();
// if it is null, we are done!
return (permset != null);
}
public synchronized Object nextElement() {
// hasMoreElements will update permset to the next permset
// with something in it...
if (hasMoreElements()) {
return permset.nextElement();
} else {
throw new NoSuchElementException("PermissionsEnumerator");
}
}
private Enumeration getNextEnumWithMore() {
while (perms.hasMoreElements()) {
PermissionCollection pc =
(PermissionCollection) perms.nextElement();
Enumeration next = pc.elements();
if (next.hasMoreElements())
return next;
}
return null;
}
}