/* * Copyright (c) 2000, 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 javax.security.auth.kerberos; import java.util.*; import java.security.Permission; 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 protect Kerberos services and the * credentials necessary to access those services. There is a one to * one mapping of a service principal and the credentials necessary * to access the service. Therefore granting access to a service * principal implicitly grants access to the credential necessary to * establish a security context with the service principal. This * applies regardless of whether the credentials are in a cache * or acquired via an exchange with the KDC. The credential can * be either a ticket granting ticket, a service ticket or a secret * key from a key table. *

* A ServicePermission contains a service principal name and * a list of actions which specify the context the credential can be * used within. *

* The service principal name is the canonical name of the * KereberosPrincipal supplying the service, that is * the KerberosPrincipal represents a Kerberos service * principal. This name is treated in a case sensitive manner. * An asterisk may appear by itself, to signify any service principal. *

* Granting this permission implies that the caller can use a cached * credential (TGT, service ticket or secret key) within the context * designated by the action. In the case of the TGT, granting this * permission also implies that the TGT can be obtained by an * Authentication Service exchange. *

* The possible actions are: *

*

 *    initiate -              allow the caller to use the credential to
 *                            initiate a security context with a service
 *                            principal.
 *
 *    accept -                allow the caller to use the credential to
 *                            accept security context as a particular
 *                            principal.
 * 
* * For example, to specify the permission to access to the TGT to * initiate a security context the permission is constructed as follows: *

*

 *     ServicePermission("krbtgt/EXAMPLE.COM@EXAMPLE.COM", "initiate");
 * 
*

* To obtain a service ticket to initiate a context with the "host" * service the permission is constructed as follows: *

 *     ServicePermission("host/foo.example.com@EXAMPLE.COM", "initiate");
 * 
*

* For a Kerberized server the action is "accept". For example, the permission * necessary to access and use the secret key of the Kerberized "host" * service (telnet and the likes) would be constructed as follows: *

*

 *     ServicePermission("host/foo.example.com@EXAMPLE.COM", "accept");
 * 
* * @since 1.4 */ public final class ServicePermission extends Permission implements java.io.Serializable { private static final long serialVersionUID = -1227585031618624935L; /** * Initiate a security context to the specified service */ private final static int INITIATE = 0x1; /** * Accept a security context */ private final static int ACCEPT = 0x2; /** * All actions */ private final static int ALL = INITIATE|ACCEPT; /** * No actions. */ private final static int NONE = 0x0; // the actions mask private transient int mask; /** * the actions string. * * @serial */ private String actions; // Left null as long as possible, then // created and re-used in the getAction function. /** * Create a new ServicePermission * with the specified servicePrincipal * and action. * * @param servicePrincipal the name of the service principal. * An asterisk may appear by itself, to signify any service principal. *

* @param action the action string */ public ServicePermission(String servicePrincipal, String action) { super(servicePrincipal); init(servicePrincipal, getMask(action)); } /** * Initialize the ServicePermission object. */ private void init(String servicePrincipal, int mask) { if (servicePrincipal == null) throw new NullPointerException("service principal can't be null"); if ((mask & ALL) != mask) throw new IllegalArgumentException("invalid actions mask"); this.mask = mask; } /** * Checks if this Kerberos service permission object "implies" the * specified permission. *

* If none of the above are true, implies 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 ServicePermission)) return false; ServicePermission that = (ServicePermission) p; return ((this.mask & that.mask) == that.mask) && impliesIgnoreMask(that); } boolean impliesIgnoreMask(ServicePermission p) { return ((this.getName().equals("*")) || this.getName().equals(p.getName())); } /** * Checks two ServicePermission objects for equality. *

* @param obj the object to test for equality with this object. * * @return true if obj is a ServicePermission, and has the * same service principal, and actions as this * ServicePermission object. */ public boolean equals(Object obj) { if (obj == this) return true; if (! (obj instanceof ServicePermission)) return false; ServicePermission that = (ServicePermission) obj; return ((this.mask & that.mask) == that.mask) && this.getName().equals(that.getName()); } /** * Returns the hash code value for this object. * * @return a hash code value for this object. */ public int hashCode() { return (getName().hashCode() ^ mask); } /** * Returns the "canonical string representation" of the actions in the * specified mask. * Always returns present actions in the following order: * initiate, accept. * * @param mask a specific integer action mask to translate into a string * @return the canonical string representation of the actions */ private static String getActions(int mask) { StringBuilder sb = new StringBuilder(); boolean comma = false; if ((mask & INITIATE) == INITIATE) { if (comma) sb.append(','); else comma = true; sb.append("initiate"); } if ((mask & ACCEPT) == ACCEPT) { if (comma) sb.append(','); else comma = true; sb.append("accept"); } return sb.toString(); } /** * Returns the canonical string representation of the actions. * Always returns present actions in the following order: * initiate, accept. */ public String getActions() { if (actions == null) actions = getActions(this.mask); return actions; } /** * Returns a PermissionCollection object for storing * ServicePermission objects. *
* ServicePermission 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 * ServicePermissions. */ public PermissionCollection newPermissionCollection() { return new KrbServicePermissionCollection(); } /** * Return the current action mask. * * @return the actions mask. */ int getMask() { return mask; } /** * Convert an action string to an integer actions mask. * * @param action the action string * @return the action mask */ private static int getMask(String action) { if (action == null) { throw new NullPointerException("action can't be null"); } if (action.equals("")) { throw new IllegalArgumentException("action can't be empty"); } int mask = NONE; char[] a = action.toCharArray(); int i = a.length - 1; if (i < 0) return mask; while (i != -1) { char c; // skip whitespace while ((i!=-1) && ((c = a[i]) == ' ' || c == '\r' || c == '\n' || c == '\f' || c == '\t')) i--; // check for the known strings int matchlen; if (i >= 7 && (a[i-7] == 'i' || a[i-7] == 'I') && (a[i-6] == 'n' || a[i-6] == 'N') && (a[i-5] == 'i' || a[i-5] == 'I') && (a[i-4] == 't' || a[i-4] == 'T') && (a[i-3] == 'i' || a[i-3] == 'I') && (a[i-2] == 'a' || a[i-2] == 'A') && (a[i-1] == 't' || a[i-1] == 'T') && (a[i] == 'e' || a[i] == 'E')) { matchlen = 8; mask |= INITIATE; } else if (i >= 5 && (a[i-5] == 'a' || a[i-5] == 'A') && (a[i-4] == 'c' || a[i-4] == 'C') && (a[i-3] == 'c' || a[i-3] == 'C') && (a[i-2] == 'e' || a[i-2] == 'E') && (a[i-1] == 'p' || a[i-1] == 'P') && (a[i] == 't' || a[i] == 'T')) { matchlen = 6; mask |= ACCEPT; } else { // parse error throw new IllegalArgumentException( "invalid permission: " + action); } // make sure we didn't just match the tail of a word // like "ackbarfaccept". Also, skip to the comma. boolean seencomma = false; while (i >= matchlen && !seencomma) { switch(a[i-matchlen]) { case ',': seencomma = true; /*FALLTHROUGH*/ case ' ': case '\r': case '\n': case '\f': case '\t': break; default: throw new IllegalArgumentException( "invalid permission: " + action); } i--; } // point i at the location of the comma minus one (or -1). i -= matchlen; } return mask; } /** * WriteObject is called to save the state of the ServicePermission * to a stream. The actions are serialized, and the superclass * takes care of the name. */ private void writeObject(java.io.ObjectOutputStream s) throws IOException { // Write out the actions. The superclass takes care of the name // call getActions to make sure actions field is initialized if (actions == null) getActions(); s.defaultWriteObject(); } /** * readObject is called to restore the state of the * ServicePermission from a stream. */ private void readObject(java.io.ObjectInputStream s) throws IOException, ClassNotFoundException { // Read in the action, then initialize the rest s.defaultReadObject(); init(getName(),getMask(actions)); } /* public static void main(String args[]) throws Exception { ServicePermission this_ = new ServicePermission(args[0], "accept"); ServicePermission that_ = new ServicePermission(args[1], "accept,initiate"); 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"); KrbServicePermissionCollection nps = new KrbServicePermissionCollection(); nps.add(this_); nps.add(new ServicePermission("nfs/example.com@EXAMPLE.COM", "accept")); nps.add(new ServicePermission("host/example.com@EXAMPLE.COM", "initiate")); System.out.println("nps.implies(that) = " + nps.implies(that_)); System.out.println("-----\n"); Enumeration e = nps.elements(); while (e.hasMoreElements()) { ServicePermission x = (ServicePermission) e.nextElement(); System.out.println("nps.e = " + x); } } */ } final class KrbServicePermissionCollection extends PermissionCollection implements java.io.Serializable { // Not serialized; see serialization section at end of class private transient List perms; public KrbServicePermissionCollection() { 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 ServicePermission)) return false; ServicePermission np = (ServicePermission) permission; int desired = np.getMask(); int effective = 0; int needed = desired; synchronized (this) { int len = perms.size(); // need to deal with the case where the needed permission has // more than one action and the collection has individual permissions // that sum up to the needed. for (int i = 0; i < len; i++) { ServicePermission x = (ServicePermission) perms.get(i); //System.out.println(" trying "+x); if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(np)) { effective |= x.getMask(); if ((effective & desired) == desired) return true; needed = (desired ^ effective); } } } return false; } /** * Adds a permission to the ServicePermissions. The key for * the hash is the name. * * @param permission the Permission object to add. * * @exception IllegalArgumentException - if the permission is not a * ServicePermission * * @exception SecurityException - if this PermissionCollection object * has been marked readonly */ public void add(Permission permission) { if (! (permission instanceof ServicePermission)) 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 ServicePermission objects * in the container. * * @return an enumeration of all the ServicePermission objects. */ public Enumeration elements() { // Convert Iterator into Enumeration synchronized (this) { return Collections.enumeration(perms); } } private static final long serialVersionUID = -4118834211490102011L; // Need to maintain serialization interoperability with earlier releases, // which had the serializable field: // private Vector permissions; /** * @serialField permissions java.util.Vector * A list of ServicePermission objects. */ private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("permissions", Vector.class), }; /** * @serialData "permissions" field (a Vector containing the ServicePermissions). */ /* * 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 ServicePermissions 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); } }