1 /*
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.security.auth.kerberos;
27
28 import java.util.*;
29 import java.security.Permission;
30 import java.security.BasicPermission;
31 import java.security.PermissionCollection;
32 import java.io.ObjectStreamField;
33 import java.io.ObjectOutputStream;
34 import java.io.ObjectInputStream;
35 import java.io.IOException;
36
37 /**
38 * This class is used to restrict the usage of the Kerberos
39 * delegation model, ie: forwardable and proxiable tickets.
40 * <p>
41 * The target name of this {@code Permission} specifies a pair of
42 * kerberos service principals. The first is the subordinate service principal
43 * being entrusted to use the TGT. The second service principal designates
44 * the target service the subordinate service principal is to
45 * interact with on behalf of the initiating KerberosPrincipal. This
46 * latter service principal is specified to restrict the use of a
47 * proxiable ticket.
48 * <p>
49 * For example, to specify the "host" service use of a forwardable TGT the
50 * target permission is specified as follows:
51 *
52 * <pre>
53 * DelegationPermission("\"host/foo.example.com@EXAMPLE.COM\" \"krbtgt/EXAMPLE.COM@EXAMPLE.COM\"");
54 * </pre>
55 * <p>
56 * To give the "backup" service a proxiable nfs service ticket the target permission
57 * might be specified:
58 *
59 * <pre>
60 * DelegationPermission("\"backup/bar.example.com@EXAMPLE.COM\" \"nfs/home.EXAMPLE.COM@EXAMPLE.COM\"");
61 * </pre>
62 *
63 * @since 1.4
64 */
65
66 public final class DelegationPermission extends BasicPermission
67 implements java.io.Serializable {
68
69 private static final long serialVersionUID = 883133252142523922L;
70
71 private transient String subordinate, service;
72
73 /**
74 * Create a new {@code DelegationPermission}
75 * with the specified subordinate and target principals.
76 *
77 * <p>
78 *
79 * @param principals the name of the subordinate and target principals
80 *
81 * @throws NullPointerException if {@code principals} is {@code null}.
82 * @throws IllegalArgumentException if {@code principals} is empty.
83 */
84 public DelegationPermission(String principals) {
85 super(principals);
86 init(principals);
87 }
88
89 /**
90 * Create a new {@code DelegationPermission}
91 * with the specified subordinate and target principals.
92 * <p>
93 *
94 * @param principals the name of the subordinate and target principals
95 * <p>
96 * @param actions should be null.
97 *
98 * @throws NullPointerException if {@code principals} is {@code null}.
99 * @throws IllegalArgumentException if {@code principals} is empty.
100 */
101 public DelegationPermission(String principals, String actions) {
102 super(principals, actions);
103 init(principals);
104 }
105
106
107 /**
108 * Initialize the DelegationPermission object.
109 */
110 private void init(String target) {
111
112 StringTokenizer t = null;
113 if (!target.startsWith("\"")) {
114 throw new IllegalArgumentException
115 ("service principal [" + target +
116 "] syntax invalid: " +
117 "improperly quoted");
118 } else {
119 t = new StringTokenizer(target, "\"", false);
120 subordinate = t.nextToken();
121 if (t.countTokens() == 2) {
122 t.nextToken(); // bypass whitespace
123 service = t.nextToken();
124 } else if (t.countTokens() > 0) {
125 throw new IllegalArgumentException
126 ("service principal [" + t.nextToken() +
127 "] syntax invalid: " +
128 "improperly quoted");
129 }
130 }
131 }
132
133 /**
134 * Checks if this Kerberos delegation permission object "implies" the
135 * specified permission.
136 * <P>
137 * If none of the above are true, {@code implies} returns false.
138 * @param p the permission to check against.
139 *
140 * @return true if the specified permission is implied by this object,
141 * false if not.
142 */
143 public boolean implies(Permission p) {
144 if (!(p instanceof DelegationPermission))
145 return false;
146
147 DelegationPermission that = (DelegationPermission) p;
148 if (this.subordinate.equals(that.subordinate) &&
149 this.service.equals(that.service))
150 return true;
151
152 return false;
153 }
154
155
156 /**
157 * Checks two DelegationPermission objects for equality.
158 * <P>
159 * @param obj the object to test for equality with this object.
160 *
161 * @return true if <i>obj</i> is a DelegationPermission, and
162 * has the same subordinate and service principal as this.
163 * DelegationPermission object.
164 */
165 public boolean equals(Object obj) {
166 if (obj == this)
167 return true;
168
169 if (! (obj instanceof DelegationPermission))
170 return false;
171
172 DelegationPermission that = (DelegationPermission) obj;
173 return implies(that);
174 }
175
176 /**
177 * Returns the hash code value for this object.
178 *
179 * @return a hash code value for this object.
180 */
181 public int hashCode() {
182 return getName().hashCode();
183 }
184
185
186 /**
187 * Returns a PermissionCollection object for storing
188 * DelegationPermission objects.
189 * <br>
190 * DelegationPermission objects must be stored in a manner that
191 * allows them to be inserted into the collection in any order, but
192 * that also enables the PermissionCollection implies method to
193 * be implemented in an efficient (and consistent) manner.
194 *
195 * @return a new PermissionCollection object suitable for storing
196 * DelegationPermissions.
197 */
198
199 public PermissionCollection newPermissionCollection() {
200 return new KrbDelegationPermissionCollection();
201 }
202
203 /**
204 * WriteObject is called to save the state of the DelegationPermission
205 * to a stream. The actions are serialized, and the superclass
206 * takes care of the name.
207 */
208 private synchronized void writeObject(java.io.ObjectOutputStream s)
209 throws IOException
210 {
211 s.defaultWriteObject();
212 }
213
214 /**
215 * readObject is called to restore the state of the
216 * DelegationPermission from a stream.
217 */
218 private synchronized void readObject(java.io.ObjectInputStream s)
219 throws IOException, ClassNotFoundException
220 {
221 // Read in the action, then initialize the rest
222 s.defaultReadObject();
223 init(getName());
224 }
225
226 /*
227 public static void main(String args[]) throws Exception {
228 DelegationPermission this_ =
229 new DelegationPermission(args[0]);
230 DelegationPermission that_ =
231 new DelegationPermission(args[1]);
232 System.out.println("-----\n");
233 System.out.println("this.implies(that) = " + this_.implies(that_));
234 System.out.println("-----\n");
235 System.out.println("this = "+this_);
236 System.out.println("-----\n");
237 System.out.println("that = "+that_);
238 System.out.println("-----\n");
239
240 KrbDelegationPermissionCollection nps =
241 new KrbDelegationPermissionCollection();
242 nps.add(this_);
243 nps.add(new DelegationPermission("\"host/foo.example.com@EXAMPLE.COM\" \"CN=Gary Ellison/OU=JSN/O=SUNW/L=Palo Alto/ST=CA/C=US\""));
244 try {
245 nps.add(new DelegationPermission("host/foo.example.com@EXAMPLE.COM \"CN=Gary Ellison/OU=JSN/O=SUNW/L=Palo Alto/ST=CA/C=US\""));
246 } catch (Exception e) {
247 System.err.println(e);
248 }
249
250 System.out.println("nps.implies(that) = " + nps.implies(that_));
251 System.out.println("-----\n");
252
253 Enumeration e = nps.elements();
254
255 while (e.hasMoreElements()) {
256 DelegationPermission x =
257 (DelegationPermission) e.nextElement();
258 System.out.println("nps.e = " + x);
259 }
260 }
261 */
262 }
263
264
265 final class KrbDelegationPermissionCollection extends PermissionCollection
266 implements java.io.Serializable {
267
268 // Not serialized; see serialization section at end of class.
269 private transient List<Permission> perms;
270
271 public KrbDelegationPermissionCollection() {
272 perms = new ArrayList<Permission>();
273 }
274
275
276 /**
277 * Check and see if this collection of permissions implies the permissions
278 * expressed in "permission".
279 *
280 * @param permission the Permission object to compare
281 *
282 * @return true if "permission" is a proper subset of a permission in
283 * the collection, false if not.
284 */
285 public boolean implies(Permission permission) {
286 if (! (permission instanceof DelegationPermission))
287 return false;
288
289 synchronized (this) {
290 for (Permission x : perms) {
291 if (x.implies(permission))
292 return true;
293 }
294 }
295 return false;
296
297 }
298
299 /**
300 * Adds a permission to the DelegationPermissions. The key for
301 * the hash is the name.
302 *
303 * @param permission the Permission object to add.
304 *
305 * @exception IllegalArgumentException - if the permission is not a
306 * DelegationPermission
307 *
308 * @exception SecurityException - if this PermissionCollection object
309 * has been marked readonly
310 */
311 public void add(Permission permission) {
312 if (! (permission instanceof DelegationPermission))
313 throw new IllegalArgumentException("invalid permission: "+
314 permission);
315 if (isReadOnly())
316 throw new SecurityException("attempt to add a Permission to a readonly PermissionCollection");
317
318 synchronized (this) {
319 perms.add(0, permission);
320 }
321 }
322
323 /**
324 * Returns an enumeration of all the DelegationPermission objects
325 * in the container.
326 *
327 * @return an enumeration of all the DelegationPermission objects.
328 */
329 public Enumeration<Permission> elements() {
330 // Convert Iterator into Enumeration
331 synchronized (this) {
332 return Collections.enumeration(perms);
333 }
334 }
335
336 private static final long serialVersionUID = -3383936936589966948L;
337
338 // Need to maintain serialization interoperability with earlier releases,
339 // which had the serializable field:
340 // private Vector permissions;
341 /**
342 * @serialField permissions java.util.Vector
343 * A list of DelegationPermission objects.
344 */
345 private static final ObjectStreamField[] serialPersistentFields = {
346 new ObjectStreamField("permissions", Vector.class),
347 };
348
349 /**
350 * @serialData "permissions" field (a Vector containing the DelegationPermissions).
351 */
352 /*
353 * Writes the contents of the perms field out as a Vector for
354 * serialization compatibility with earlier releases.
355 */
356 private void writeObject(ObjectOutputStream out) throws IOException {
357 // Don't call out.defaultWriteObject()
358
359 // Write out Vector
360 Vector<Permission> permissions = new Vector<>(perms.size());
361
362 synchronized (this) {
363 permissions.addAll(perms);
364 }
365
366 ObjectOutputStream.PutField pfields = out.putFields();
367 pfields.put("permissions", permissions);
368 out.writeFields();
369 }
370
371 /*
372 * Reads in a Vector of DelegationPermissions and saves them in the perms field.
373 */
374 @SuppressWarnings("unchecked")
375 private void readObject(ObjectInputStream in)
376 throws IOException, ClassNotFoundException
377 {
378 // Don't call defaultReadObject()
379
380 // Read in serialized fields
381 ObjectInputStream.GetField gfields = in.readFields();
382
383 // Get the one we want
384 Vector<Permission> permissions =
385 (Vector<Permission>)gfields.get("permissions", null);
386 perms = new ArrayList<Permission>(permissions.size());
387 perms.addAll(permissions);
388 }
389 }