/*
* @(#)DelegationPermission.java 1.12 06/04/21
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.security.auth.kerberos;
import java.util.*;
import java.security.Permission;
import java.security.BasicPermission;
import java.security.PermissionCollection;
import java.io.ObjectStreamField;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
/**
* This class is used to restrict the usage of the Kerberos
* delegation model, ie: forwardable and proxiable tickets.
* <p>
* The target name of this <code>Permission</code> specifies a pair of
* kerberos service principals. The first is the subordinate service principal
* being entrusted to use the TGT. The second service principal designates
* the target service the subordinate service principal is to
* interact with on behalf of the initiating KerberosPrincipal. This
* latter service principal is specified to restrict the use of a
* proxiable ticket.
* <p>
* For example, to specify the "host" service use of a forwardable TGT the
* target permission is specified as follows:
* <p>
* <pre>
* DelegationPermission("\"host/foo.example.com@EXAMPLE.COM\" \"krbtgt/EXAMPLE.COM@EXAMPLE.COM\"");
* </pre>
* <p>
* To give the "backup" service a proxiable nfs service ticket the target permission
* might be specified:
* <p>
* <pre>
* DelegationPermission("\"backup/bar.example.com@EXAMPLE.COM\" \"nfs/home.EXAMPLE.COM@EXAMPLE.COM\"");
* </pre>
*
* @since 1.4
*/
public final class DelegationPermission extends BasicPermission
implements java.io.Serializable {
private static final long serialVersionUID = 883133252142523922L;
private transient String subordinate, service;
/**
* Create a new <code>DelegationPermission</code>
* with the specified subordinate and target principals.
*
* <p>
*
* @param principals the name of the subordinate and target principals
*
* @throws NullPointerException if <code>principals</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>principals</code> is empty.
*/
public DelegationPermission(String principals) {
super(principals);
init(principals);
}
/**
* Create a new <code>DelegationPermission</code>
* with the specified subordinate and target principals.
* <p>
*
* @param principals the name of the subordinate and target principals
* <p>
* @param actions should be null.
*
* @throws NullPointerException if <code>principals</code> is <code>null</code>.
* @throws IllegalArgumentException if <code>principals</code> is empty.
*/
public DelegationPermission(String principals, String actions) {
super(principals, actions);
init(principals);
}
/**
* Initialize the DelegationPermission object.
*/
private void init(String target) {
StringTokenizer t = null;
if (!target.startsWith("\"")) {
throw new IllegalArgumentException
("service principal [" + target +
"] syntax invalid: " +
"improperly quoted");
} else {
t = new StringTokenizer(target, "\"", false);
subordinate = t.nextToken();
if (t.countTokens() == 2) {
t.nextToken(); // bypass whitespace
service = t.nextToken();
} else if (t.countTokens() > 0) {
throw new IllegalArgumentException
("service principal [" + t.nextToken() +
"] syntax invalid: " +
"improperly quoted");
}
}
}
/**
* Checks if this Kerberos delegation permission object "implies" the
* specified permission.
* <P>
* If none of the above are true, <code>implies</code> returns false.
* @param p the permission to check against.
*
* @return true if the specified permission is implied by this object,
* false if not.
*/
public boolean implies(Permission p) {
if (!(p instanceof DelegationPermission))
return false;
DelegationPermission that = (DelegationPermission) p;
if (this.subordinate.equals(that.subordinate) &&
this.service.equals(that.service))
return true;
return false;
}
/**
* Checks two DelegationPermission objects for equality.
* <P>
* @param obj the object to test for equality with this object.
*
* @return true if <i>obj</i> is a DelegationPermission, and
* has the same subordinate and service principal as this.
* DelegationPermission object.
*/
public boolean equals(Object obj) {
if (obj == this)
return true;
if (! (obj instanceof DelegationPermission))
return false;
DelegationPermission that = (DelegationPermission) obj;
return implies(that);
}
/**
* Returns the hash code value for this object.
*
* @return a hash code value for this object.
*/
public int hashCode() {
return getName().hashCode();
}
/**
* Returns a PermissionCollection object for storing
* DelegationPermission objects.
* <br>
* DelegationPermission objects must be stored in a manner that
* allows them to be inserted into the collection in any order, but
* that also enables the PermissionCollection implies method to
* be implemented in an efficient (and consistent) manner.
*
* @return a new PermissionCollection object suitable for storing
* DelegationPermissions.
*/
public PermissionCollection newPermissionCollection() {
return new KrbDelegationPermissionCollection();
}
/**
* WriteObject is called to save the state of the DelegationPermission
* to a stream. The actions are serialized, and the superclass
* takes care of the name.
*/
private synchronized void writeObject(java.io.ObjectOutputStream s)
throws IOException
{
s.defaultWriteObject();
}
/**
* readObject is called to restore the state of the
* DelegationPermission from a stream.
*/
private synchronized void readObject(java.io.ObjectInputStream s)
throws IOException, ClassNotFoundException
{
// Read in the action, then initialize the rest
s.defaultReadObject();
init(getName());
}
/*
public static void main(String args[]) throws Exception {
DelegationPermission this_ =
new DelegationPermission(args[0]);
DelegationPermission that_ =
new DelegationPermission(args[1]);
System.out.println("-----\n");
System.out.println("this.implies(that) = " + this_.implies(that_));
System.out.println("-----\n");
System.out.println("this = "+this_);
System.out.println("-----\n");
System.out.println("that = "+that_);
System.out.println("-----\n");
KrbDelegationPermissionCollection nps =
new KrbDelegationPermissionCollection();
nps.add(this_);
nps.add(new DelegationPermission("\"host/foo.example.com@EXAMPLE.COM\" \"CN=Gary Ellison/OU=JSN/O=SUNW/L=Palo Alto/ST=CA/C=US\""));
try {
nps.add(new DelegationPermission("host/foo.example.com@EXAMPLE.COM \"CN=Gary Ellison/OU=JSN/O=SUNW/L=Palo Alto/ST=CA/C=US\""));
} catch (Exception e) {
System.err.println(e);
}
System.out.println("nps.implies(that) = " + nps.implies(that_));
System.out.println("-----\n");
Enumeration e = nps.elements();
while (e.hasMoreElements()) {
DelegationPermission x =
(DelegationPermission) e.nextElement();
System.out.println("nps.e = " + x);
}
}
*/
}
final class KrbDelegationPermissionCollection extends PermissionCollection
implements java.io.Serializable {
// Not serialized; see serialization section at end of class.
private transient List perms;
public KrbDelegationPermissionCollection() {
perms = new ArrayList();
}
/**
* Check and see if this collection of permissions implies the permissions
* expressed in "permission".
*
* @param p the Permission object to compare
*
* @return true if "permission" is a proper subset of a permission in
* the collection, false if not.
*/
public boolean implies(Permission permission) {
if (! (permission instanceof DelegationPermission))
return false;
DelegationPermission np = (DelegationPermission) permission;
synchronized (this) {
int len = perms.size();
for (int i = 0; i < len; i++) {
DelegationPermission x = (DelegationPermission) perms.get(i);
if (x.implies(np))
return true;
}
}
return false;
}
/**
* Adds a permission to the DelegationPermissions. The key for
* the hash is the name.
*
* @param permission the Permission object to add.
*
* @exception IllegalArgumentException - if the permission is not a
* DelegationPermission
*
* @exception SecurityException - if this PermissionCollection object
* has been marked readonly
*/
public void add(Permission permission) {
if (! (permission instanceof DelegationPermission))
throw new IllegalArgumentException("invalid permission: "+
permission);
if (isReadOnly())
throw new SecurityException("attempt to add a Permission to a readonly PermissionCollection");
synchronized (this) {
perms.add(0, permission);
}
}
/**
* Returns an enumeration of all the DelegationPermission objects
* in the container.
*
* @return an enumeration of all the DelegationPermission objects.
*/
public Enumeration elements() {
// Convert Iterator into Enumeration
synchronized (this) {
return Collections.enumeration(perms);
}
}
private static final long serialVersionUID = -3383936936589966948L;
// Need to maintain serialization interoperability with earlier releases,
// which had the serializable field:
// private Vector permissions;
/**
* @serialField permissions java.util.Vector
* A list of DelegationPermission objects.
*/
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("permissions", Vector.class),
};
/**
* @serialData "permissions" field (a Vector containing the DelegationPermissions).
*/
/*
* Writes the contents of the perms field out as a Vector for
* serialization compatibility with earlier releases.
*/
private void writeObject(ObjectOutputStream out) throws IOException {
// Don't call out.defaultWriteObject()
// Write out Vector
Vector permissions = new Vector(perms.size());
synchronized (this) {
permissions.addAll(perms);
}
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("permissions", permissions);
out.writeFields();
}
/*
* Reads in a Vector of DelegationPermissions and saves them in the perms field.
*/
private void readObject(ObjectInputStream in) throws IOException,
ClassNotFoundException {
// Don't call defaultReadObject()
// Read in serialized fields
ObjectInputStream.GetField gfields = in.readFields();
// Get the one we want
Vector permissions = (Vector)gfields.get("permissions", null);
perms = new ArrayList(permissions.size());
perms.addAll(permissions);
}
}
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