      1 /*
      2  * Copyright (c) 2000, 2019, 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.io.IOException;
     29 import java.io.ObjectInputStream;
     30 import java.io.ObjectOutputStream;
     31 import java.io.ObjectStreamField;
     32 import java.security.Permission;
     33 import java.security.PermissionCollection;
     34 import java.util.*;
     35 import java.util.concurrent.ConcurrentHashMap;
     36
     37 /**
     38  * This class is used to protect Kerberos services and the
     39  * credentials necessary to access those services. There is a one to
     40  * one mapping of a service principal and the credentials necessary
     41  * to access the service. Therefore granting access to a service
     42  * principal implicitly grants access to the credential necessary to
     43  * establish a security context with the service principal. This
     44  * applies regardless of whether the credentials are in a cache
     45  * or acquired via an exchange with the KDC. The credential can
     46  * be either a ticket granting ticket, a service ticket or a secret
     47  * key from a key table.
     48  * <p>
     49  * A ServicePermission contains a service principal name and
     50  * a list of actions which specify the context the credential can be
     51  * used within.
     52  * <p>
     53  * The service principal name is the canonical name of the
     54  * {@code KerberosPrincipal} supplying the service, that is
     55  * the KerberosPrincipal represents a Kerberos service
     56  * principal. This name is treated in a case sensitive manner.
     57  * An asterisk may appear by itself, to signify any service principal.
     58  * <p>
     59  * Granting this permission implies that the caller can use a cached
     60  * credential (TGT, service ticket or secret key) within the context
     61  * designated by the action. In the case of the TGT, granting this
     62  * permission also implies that the TGT can be obtained by an
     63  * Authentication Service exchange.
     64  * <p>
     65  * Granting this permission also implies creating {@link KerberosPrincipal}
     66  * or {@link org.ietf.jgss.GSSName GSSName} without providing a Kerberos
     67  * realm, as long as the permission's service principal is in this realm.
     68  * <p>
     69  * The possible actions are:
     70  *
     71  * <pre>
     72  *    initiate -              allow the caller to use the credential to
     73  *                            initiate a security context with a service
     74  *                            principal.
     75  *
     76  *    accept -                allow the caller to use the credential to
     77  *                            accept security context as a particular
     78  *                            principal.
     79  * </pre>
     80  *
     81  * For example, to specify the permission to access to the TGT to
     82  * initiate a security context the permission is constructed as follows:
     83  *
     84  * <pre>
     85  *     ServicePermission("krbtgt/EXAMPLE.COM@EXAMPLE.COM", "initiate");
     86  * </pre>
     87  * <p>
     88  * To obtain a service ticket to initiate a context with the "host"
     89  * service the permission is constructed as follows:
     90  * <pre>
     91  *     ServicePermission("host/foo.example.com@EXAMPLE.COM", "initiate");
     92  * </pre>
     93  * <p>
     94  * For a Kerberized server the action is "accept". For example, the permission
     95  * necessary to access and use the secret key of the  Kerberized "host"
     96  * service (telnet and the likes)  would be constructed as follows:
     97  *
     98  * <pre>
     99  *     ServicePermission("host/foo.example.com@EXAMPLE.COM", "accept");
    100  * </pre>
    101  *
    102  * @since 1.4
    103  */
    104
    105 public final class ServicePermission extends Permission
    106     implements java.io.Serializable {
    107
    108     private static final long serialVersionUID = -1227585031618624935L;
    109
    110     /**
    111      * Initiate a security context to the specified service
    112      */
    113     private final static int INITIATE   = 0x1;
    114
    115     /**
    116      * Accept a security context
    117      */
    118     private final static int ACCEPT     = 0x2;
    119
    120     /**
    121      * All actions
    122      */
    123     private final static int ALL        = INITIATE|ACCEPT;
    124
    125     /**
    126      * No actions.
    127      */
    128     private final static int NONE    = 0x0;
    129
    130     // the actions mask
    131     private transient int mask;
    132
    133     /**
    134      * the actions string.
    135      *
    136      * @serial
    137      */
    138
    139     private String actions; // Left null as long as possible, then
    140                             // created and re-used in the getAction function.
    141
    142     /**
    143      * Create a new {@code ServicePermission}
    144      * with the specified {@code servicePrincipal}
    145      * and {@code action}.
    146      *
    147      * @param servicePrincipal the name of the service principal.
    148      * An asterisk may appear by itself, to signify any service principal.
    149      *
    150      * @param action the action string
    151      */
    152     public ServicePermission(String servicePrincipal, String action) {
    153         // Note: servicePrincipal can be "@REALM" which means any principal in
    154         // this realm implies it. action can be "-" which means any
    155         // action implies it.
    156         super(servicePrincipal);
    157         init(servicePrincipal, getMask(action));
    158     }
    159
    160     /**
    161      * Creates a ServicePermission object with the specified servicePrincipal
    162      * and a pre-calculated mask. Avoids the overhead of re-computing the mask.
    163      * Called by ServicePermissionCollection.
    164      */
    165     ServicePermission(String servicePrincipal, int mask) {
    166         super(servicePrincipal);
    167         init(servicePrincipal, mask);
    168     }
    169
    170     /**
    171      * Initialize the ServicePermission object.
    172      */
    173     private void init(String servicePrincipal, int mask) {
    174
    175         if (servicePrincipal == null)
    176                 throw new NullPointerException("service principal can't be null");
    177
    178         if ((mask & ALL) != mask)
    179             throw new IllegalArgumentException("invalid actions mask");
    180
    181         this.mask = mask;
    182     }
    183
    184
    185     /**
    186      * Checks if this Kerberos service permission object "implies" the
    187      * specified permission.
    188      * <P>
    189      * More specifically, this method returns true if all of the following
    190      * are true (and returns false if any of them are not):
    191      * <ul>
    192      * <li> <i>p</i> is an instanceof {@code ServicePermission},
    193      * <li> <i>p</i>'s actions are a proper subset of this
    194      * {@code ServicePermission}'s actions,
    195      * <li> <i>p</i>'s name is equal to this {@code ServicePermission}'s name
    196      * or this {@code ServicePermission}'s name is "*".
    197      * </ul>
    198      *
    199      * @param p the permission to check against.
    200      *
    201      * @return true if the specified permission is implied by this object,
    202      * false if not.
    203      */
    204     @Override
    205     public boolean implies(Permission p) {
    206         if (!(p instanceof ServicePermission))
    207             return false;
    208
    209         ServicePermission that = (ServicePermission) p;
    210
    211         return ((this.mask & that.mask) == that.mask) &&
    212             impliesIgnoreMask(that);
    213     }
    214
    215
    216     boolean impliesIgnoreMask(ServicePermission p) {
    217         return ((this.getName().equals("*")) ||
    218                 this.getName().equals(p.getName()) ||
    219                 (p.getName().startsWith("@") &&
    220                         this.getName().endsWith(p.getName())));
    221     }
    222
    223     /**
    224      * Checks two ServicePermission objects for equality.
    225      *
    226      * @param obj the object to test for equality with this object.
    227      *
    228      * @return true if {@code obj} is a ServicePermission, and has the
    229      *  same service principal, and actions as this
    230      * ServicePermission object.
    231      */
    232     @Override
    233     public boolean equals(Object obj) {
    234         if (obj == this)
    235             return true;
    236
    237         if (! (obj instanceof ServicePermission))
    238             return false;
    239
    240         ServicePermission that = (ServicePermission) obj;
    241         return (this.mask == that.mask) &&
    242             this.getName().equals(that.getName());
    243
    244
    245     }
    246
    247     /**
    248      * Returns the hash code value for this object.
    249      *
    250      * @return a hash code value for this object.
    251      */
    252     @Override
    253     public int hashCode() {
    254         return (getName().hashCode() ^ mask);
    255     }
    256
    257
    258     /**
    259      * Returns the "canonical string representation" of the actions in the
    260      * specified mask.
    261      * Always returns present actions in the following order:
    262      * initiate, accept.
    263      *
    264      * @param mask a specific integer action mask to translate into a string
    265      * @return the canonical string representation of the actions
    266      */
    267     static String getActions(int mask)
    268     {
    269         StringBuilder sb = new StringBuilder();
    270         boolean comma = false;
    271
    272         if ((mask & INITIATE) == INITIATE) {
    273             if (comma) sb.append(',');
    274             else comma = true;
    275             sb.append("initiate");
    276         }
    277
    278         if ((mask & ACCEPT) == ACCEPT) {
    279             if (comma) sb.append(',');
    280             else comma = true;
    281             sb.append("accept");
    282         }
    283
    284         return sb.toString();
    285     }
    286
    287     /**
    288      * Returns the canonical string representation of the actions.
    289      * Always returns present actions in the following order:
    290      * initiate, accept.
    291      */
    292     @Override
    293     public String getActions() {
    294         if (actions == null)
    295             actions = getActions(this.mask);
    296
    297         return actions;
    298     }
    299
    300
    301     /**
    302      * Returns a PermissionCollection object for storing
    303      * ServicePermission objects.
    304      * <br>
    305      * ServicePermission objects must be stored in a manner that
    306      * allows them to be inserted into the collection in any order, but
    307      * that also enables the PermissionCollection implies method to
    308      * be implemented in an efficient (and consistent) manner.
    309      *
    310      * @return a new PermissionCollection object suitable for storing
    311      * ServicePermissions.
    312      */
    313     @Override
    314     public PermissionCollection newPermissionCollection() {
    315         return new KrbServicePermissionCollection();
    316     }
    317
    318     /**
    319      * Return the current action mask.
    320      *
    321      * @return the actions mask.
    322      */
    323     int getMask() {
    324         return mask;
    325     }
    326
    327     /**
    328      * Convert an action string to an integer actions mask.
    329      *
    330      * Note: if action is "-", action will be NONE, which means any
    331      * action implies it.
    332      *
    333      * @param action the action string.
    334      * @return the action mask
    335      */
    336     private static int getMask(String action) {
    337
    338         if (action == null) {
    339             throw new NullPointerException("action can't be null");
    340         }
    341
    342         if (action.equals("")) {
    343             throw new IllegalArgumentException("action can't be empty");
    344         }
    345
    346         int mask = NONE;
    347
    348         char[] a = action.toCharArray();
    349
    350         if (a.length == 1 && a[0] == '-') {
    351             return mask;
    352         }
    353
    354         int i = a.length - 1;
    355
    356         while (i != -1) {
    357             char c;
    358
    359             // skip whitespace
    360             while ((i!=-1) && ((c = a[i]) == ' ' ||
    361                                c == '\r' ||
    362                                c == '\n' ||
    363                                c == '\f' ||
    364                                c == '\t'))
    365                 i--;
    366
    367             // check for the known strings
    368             int matchlen;
    369
    370             if (i >= 7 && (a[i-7] == 'i' || a[i-7] == 'I') &&
    371                           (a[i-6] == 'n' || a[i-6] == 'N') &&
    372                           (a[i-5] == 'i' || a[i-5] == 'I') &&
    373                           (a[i-4] == 't' || a[i-4] == 'T') &&
    374                           (a[i-3] == 'i' || a[i-3] == 'I') &&
    375                           (a[i-2] == 'a' || a[i-2] == 'A') &&
    376                           (a[i-1] == 't' || a[i-1] == 'T') &&
    377                           (a[i] == 'e' || a[i] == 'E'))
    378             {
    379                 matchlen = 8;
    380                 mask |= INITIATE;
    381
    382             } else if (i >= 5 && (a[i-5] == 'a' || a[i-5] == 'A') &&
    383                                  (a[i-4] == 'c' || a[i-4] == 'C') &&
    384                                  (a[i-3] == 'c' || a[i-3] == 'C') &&
    385                                  (a[i-2] == 'e' || a[i-2] == 'E') &&
    386                                  (a[i-1] == 'p' || a[i-1] == 'P') &&
    387                                  (a[i] == 't' || a[i] == 'T'))
    388             {
    389                 matchlen = 6;
    390                 mask |= ACCEPT;
    391
    392             } else {
    393                 // parse error
    394                 throw new IllegalArgumentException(
    395                         "invalid permission: " + action);
    396             }
    397
    398             // make sure we didn't just match the tail of a word
    399             // like "ackbarfaccept".  Also, skip to the comma.
    400             boolean seencomma = false;
    401             while (i >= matchlen && !seencomma) {
    402                 switch(a[i-matchlen]) {
    403                 case ',':
    404                     seencomma = true;
    405                     break;
    406                 case ' ': case '\r': case '\n':
    407                 case '\f': case '\t':
    408                     break;
    409                 default:
    410                     throw new IllegalArgumentException(
    411                             "invalid permission: " + action);
    412                 }
    413                 i--;
    414             }
    415
    416             // point i at the location of the comma minus one (or -1).
    417             i -= matchlen;
    418         }
    419
    420         return mask;
    421     }
    422
    423
    424     /**
    425      * WriteObject is called to save the state of the ServicePermission
    426      * to a stream. The actions are serialized, and the superclass
    427      * takes care of the name.
    428      */
    429     private void writeObject(java.io.ObjectOutputStream s)
    430         throws IOException
    431     {
    432         // Write out the actions. The superclass takes care of the name
    433         // call getActions to make sure actions field is initialized
    434         if (actions == null)
    435             getActions();
    436         s.defaultWriteObject();
    437     }
    438
    439     /**
    440      * readObject is called to restore the state of the
    441      * ServicePermission from a stream.
    442      */
    443     private void readObject(java.io.ObjectInputStream s)
    444          throws IOException, ClassNotFoundException
    445     {
    446         // Read in the action, then initialize the rest
    447         s.defaultReadObject();
    448         init(getName(),getMask(actions));
    449     }
    450
    451
    452     /*
    453       public static void main(String[] args) throws Exception {
    454       ServicePermission this_ =
    455       new ServicePermission(args[0], "accept");
    456       ServicePermission that_ =
    457       new ServicePermission(args[1], "accept,initiate");
    458       System.out.println("-----\n");
    459       System.out.println("this.implies(that) = " + this_.implies(that_));
    460       System.out.println("-----\n");
    461       System.out.println("this = "+this_);
    462       System.out.println("-----\n");
    463       System.out.println("that = "+that_);
    464       System.out.println("-----\n");
    465
    466       KrbServicePermissionCollection nps =
    467       new KrbServicePermissionCollection();
    468       nps.add(this_);
    469       nps.add(new ServicePermission("nfs/example.com@EXAMPLE.COM",
    470       "accept"));
    471       nps.add(new ServicePermission("host/example.com@EXAMPLE.COM",
    472       "initiate"));
    473       System.out.println("nps.implies(that) = " + nps.implies(that_));
    474       System.out.println("-----\n");
    475
    476       Enumeration e = nps.elements();
    477
    478       while (e.hasMoreElements()) {
    479       ServicePermission x =
    480       (ServicePermission) e.nextElement();
    481       System.out.println("nps.e = " + x);
    482       }
    483
    484       }
    485     */
    486
    487 }
    488
    489
    490 final class KrbServicePermissionCollection extends PermissionCollection
    491     implements java.io.Serializable {
    492
    493     // Key is the service principal, value is the ServicePermission.
    494     // Not serialized; see serialization section at end of class
    495     private transient ConcurrentHashMap<String, Permission> perms;
    496
    497     public KrbServicePermissionCollection() {
    498         perms = new ConcurrentHashMap<>();
    499     }
    500
    501     /**
    502      * Check and see if this collection of permissions implies the permissions
    503      * expressed in "permission".
    504      *
    505      * @param permission the Permission object to compare
    506      *
    507      * @return true if "permission" is a proper subset of a permission in
    508      * the collection, false if not.
    509      */
    510     @Override
    511     public boolean implies(Permission permission) {
    512         if (! (permission instanceof ServicePermission))
    513             return false;
    514
    515         ServicePermission np = (ServicePermission) permission;
    516         int desired = np.getMask();
    517
    518         if (desired == 0) {
    519             for (Permission p: perms.values()) {
    520                 ServicePermission sp = (ServicePermission)p;
    521                 if (sp.impliesIgnoreMask(np)) {
    522                     return true;
    523                 }
    524             }
    525             return false;
    526         }
    527
    528
    529         // first, check for wildcard principal
    530         ServicePermission x = (ServicePermission)perms.get("*");
    531         if (x != null) {
    532             if ((x.getMask() & desired) == desired) {
    533                 return true;
    534             }
    535         }
    536
    537         // otherwise, check for match on principal
    538         x = (ServicePermission)perms.get(np.getName());
    539         if (x != null) {
    540             //System.out.println("  trying "+x);
    541             if ((x.getMask() & desired) == desired) {
    542                 return true;
    543             }
    544         }
    545         return false;
    546     }
    547
    548     /**
    549      * Adds a permission to the ServicePermissions. The key for
    550      * the hash is the name.
    551      *
    552      * @param permission the Permission object to add.
    553      *
    554      * @exception IllegalArgumentException - if the permission is not a
    555      *                                       ServicePermission
    556      *
    557      * @exception SecurityException - if this PermissionCollection object
    558      *                                has been marked readonly
    559      */
    560     @Override
    561     public void add(Permission permission) {
    562         if (! (permission instanceof ServicePermission))
    563             throw new IllegalArgumentException("invalid permission: "+
    564                                                permission);
    565         if (isReadOnly())
    566             throw new SecurityException("attempt to add a Permission to a readonly PermissionCollection");
    567
    568         ServicePermission sp = (ServicePermission)permission;
    569         String princName = sp.getName();
    570
    571         // Add permission to map if it is absent, or replace with new
    572         // permission if applicable. NOTE: cannot use lambda for
    573         // remappingFunction parameter until JDK-8076596 is fixed.
    574         perms.merge(princName, sp,
    575             new java.util.function.BiFunction<>() {
    576                 @Override
    577                 public Permission apply(Permission existingVal,
    578                                         Permission newVal) {
    579                     int oldMask = ((ServicePermission)existingVal).getMask();
    580                     int newMask = ((ServicePermission)newVal).getMask();
    581                     if (oldMask != newMask) {
    582                         int effective = oldMask | newMask;
    583                         if (effective == newMask) {
    584                             return newVal;
    585                         }
    586                         if (effective != oldMask) {
    587                             return new ServicePermission(princName, effective);
    588                         }
    589                     }
    590                     return existingVal;
    591                 }
    592             }
    593         );
    594     }
    595
    596     /**
    597      * Returns an enumeration of all the ServicePermission objects
    598      * in the container.
    599      *
    600      * @return an enumeration of all the ServicePermission objects.
    601      */
    602     @Override
    603     public Enumeration<Permission> elements() {
    604         return perms.elements();
    605     }
    606
    607     private static final long serialVersionUID = -4118834211490102011L;
    608
    609     // Need to maintain serialization interoperability with earlier releases,
    610     // which had the serializable field:
    611     // private Vector permissions;
    612
    613     /**
    614      * @serialField permissions java.util.Vector
    615      *     A list of ServicePermission objects.
    616      */
    617     private static final ObjectStreamField[] serialPersistentFields = {
    618         new ObjectStreamField("permissions", Vector.class),
    619     };
    620
    621     /**
    622      * @serialData "permissions" field (a Vector containing the ServicePermissions).
    623      */
    624     /*
    625      * Writes the contents of the perms field out as a Vector for
    626      * serialization compatibility with earlier releases.
    627      */
    628     private void writeObject(ObjectOutputStream out) throws IOException {
    629         // Don't call out.defaultWriteObject()
    630
    631         // Write out Vector
    632         Vector<Permission> permissions = new Vector<>(perms.values());
    633
    634         ObjectOutputStream.PutField pfields = out.putFields();
    635         pfields.put("permissions", permissions);
    636         out.writeFields();
    637     }
    638
    639     /*
    640      * Reads in a Vector of ServicePermissions and saves them in the perms field.
    641      */
    642     @SuppressWarnings("unchecked")
    643     private void readObject(ObjectInputStream in)
    644         throws IOException, ClassNotFoundException
    645     {
    646         // Don't call defaultReadObject()
    647
    648         // Read in serialized fields
    649         ObjectInputStream.GetField gfields = in.readFields();
    650
    651         // Get the one we want
    652         Vector<Permission> permissions =
    653                 (Vector<Permission>)gfields.get("permissions", null);
    654         perms = new ConcurrentHashMap<>(permissions.size());
    655         for (Permission perm : permissions) {
    656             perms.put(perm.getName(), perm);
    657         }
    658     }
    659 }