Source for java.security.ProtectionDomain

   1: /* ProtectionDomain.java -- A security domain
   2:    Copyright (C) 1998, 2003, 2004  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package java.security;
  39: 
  40: import gnu.classpath.SystemProperties;
  41: 
  42: import gnu.java.lang.CPStringBuilder;
  43: 
  44: import java.util.Enumeration;
  45: 
  46: /**
  47:  * This class represents a group of classes, along with their granted
  48:  * permissions. The classes are identified by a {@link CodeSource}. Thus, any
  49:  * class loaded from the specified {@link CodeSource} is treated as part of
  50:  * this domain. The set of permissions is represented by an instance of
  51:  * {@link PermissionCollection}.
  52:  *
  53:  * <p>Every class in the system will belong to one and only one
  54:  * <code>ProtectionDomain</code>.</p>
  55:  *
  56:  * @author Aaron M. Renn (arenn@urbanophile.com)
  57:  * @version 0.0
  58:  */
  59: public class ProtectionDomain
  60: {
  61:   /** This is the <code>CodeSource</code> for this protection domain. */
  62:   private CodeSource code_source;
  63: 
  64:   /** This is the set of permissions granted to this domain. */
  65:   private PermissionCollection perms;
  66: 
  67:   /** The {@link ClassLoader} associated with this domain. */
  68:   private ClassLoader classloader;
  69: 
  70:   /** The array of Principals associated with this domain.. */
  71:   private Principal[] principals;
  72: 
  73:   /** Post 1.4 the policy may be refreshed! use false for pre 1.4. */
  74:   private boolean staticBinding;
  75: 
  76:   /** True if this protection domain has all permissions */
  77:   private boolean hasAllPermissions;
  78: 
  79:   /**
  80:    * Initializes a new instance of <code>ProtectionDomain</code> representing
  81:    * the specified {@link CodeSource} and set of permissions. No permissions
  82:    * can be added later to the {@link PermissionCollection} and this contructor
  83:    * will call the <code>setReadOnly</code> method on the specified set of
  84:    * permissions.
  85:    *
  86:    * @param codesource
  87:    *          The {@link CodeSource} for this domain.
  88:    * @param permissions
  89:    *          The set of permissions for this domain.
  90:    * @see PermissionCollection#setReadOnly()
  91:    */
  92:   public ProtectionDomain(CodeSource codesource, PermissionCollection permissions)
  93:   {
  94:     this(codesource, permissions, null, null, true);
  95:   }
  96: 
  97:   /**
  98:    * This method initializes a new instance of <code>ProtectionDomain</code>
  99:    * given its {@link CodeSource}, granted permissions, associated
 100:    * {@link ClassLoader} and {@link Principal}s.
 101:    *
 102:    * <p>Similar to the previous constructor, if the designated set of
 103:    * permissions is not <code>null</code>, the <code>setReadOnly</code> method
 104:    * is called on that set.</p>
 105:    *
 106:    * @param codesource
 107:    *          The {@link CodeSource} for this domain.
 108:    * @param permissions
 109:    *          The permission set for this domain.
 110:    * @param classloader
 111:    *          the ClassLoader associated with this domain.
 112:    * @param principals
 113:    *          the array of {@link Principal}s associated with this domain.
 114:    * @since 1.4
 115:    * @see PermissionCollection#setReadOnly()
 116:    */
 117:   public ProtectionDomain(CodeSource codesource,
 118:                           PermissionCollection permissions,
 119:                           ClassLoader classloader, Principal[] principals)
 120:   {
 121:     this(codesource, permissions, classloader, principals, false);
 122:   }
 123: 
 124:   private ProtectionDomain(CodeSource codesource,
 125:                            PermissionCollection permissions,
 126:                            ClassLoader classloader, Principal[] principals,
 127:                            boolean staticBinding)
 128:   {
 129:     super();
 130: 
 131:     code_source = codesource;
 132:     if (permissions != null)
 133:       {
 134:         perms = permissions;
 135:         perms.setReadOnly();
 136:         /* Check if this protection domain has all permissions */
 137:         Enumeration<Permission> e = permissions.elements();
 138:         while (e.hasMoreElements())
 139:           {
 140:             if (e.nextElement() instanceof AllPermission)
 141:               hasAllPermissions = true;
 142:           }
 143:       }
 144: 
 145:     this.classloader = classloader;
 146:     this.principals =
 147:         (principals != null ? (Principal[]) principals.clone() : new Principal[0]);
 148:     this.staticBinding = staticBinding;
 149:   }
 150: 
 151:   /**
 152:    * Returns the {@link CodeSource} of this domain.
 153:    *
 154:    * @return the {@link CodeSource} of this domain.
 155:    * @since 1.2
 156:    */
 157:   public final CodeSource getCodeSource()
 158:   {
 159:     return code_source;
 160:   }
 161: 
 162:   /**
 163:    * Returns the {@link ClassLoader} of this domain.
 164:    *
 165:    * @return the {@link ClassLoader} of this domain.
 166:    * @since 1.4
 167:    */
 168:   public final ClassLoader getClassLoader()
 169:   {
 170:     return this.classloader;
 171:   }
 172: 
 173:   /**
 174:    * Returns a clone of the {@link Principal}s of this domain.
 175:    *
 176:    * @return a clone of the {@link Principal}s of this domain.
 177:    * @since 1.4
 178:    */
 179:   public final Principal[] getPrincipals()
 180:   {
 181:     return (Principal[]) principals.clone();
 182:   }
 183: 
 184:   /**
 185:    * Returns the {@link PermissionCollection} of this domain.
 186:    *
 187:    * @return The {@link PermissionCollection} of this domain.
 188:    */
 189:   public final PermissionCollection getPermissions()
 190:   {
 191:     return perms;
 192:   }
 193: 
 194:   /**
 195:    * Tests whether or not the specified {@link Permission} is implied by the
 196:    * set of permissions granted to this domain.
 197:    *
 198:    * @param permission
 199:    *          the {@link Permission} to test.
 200:    * @return <code>true</code> if the specified {@link Permission} is implied
 201:    *         for this domain, <code>false</code> otherwise.
 202:    */
 203:   public boolean implies(Permission permission)
 204:   {
 205:     if (hasAllPermissions)
 206:       return true;
 207:     if (staticBinding)
 208:       return (perms == null ? false : perms.implies(permission));
 209:     // Else dynamically bound.  Do we have it?
 210:     // NOTE: this will force loading of Policy.currentPolicy
 211:     return Policy.getCurrentPolicy().implies(this, permission);
 212:   }
 213: 
 214:   /**
 215:    * Returns a string representation of this object. It will include the
 216:    * {@link CodeSource} and set of permissions associated with this domain.
 217:    *
 218:    * @return A string representation of this object.
 219:    */
 220:   public String toString()
 221:   {
 222:     String linesep = SystemProperties.getProperty("line.separator");
 223:     CPStringBuilder sb = new CPStringBuilder("ProtectionDomain (").append(linesep);
 224: 
 225:     if (code_source == null)
 226:       sb.append("CodeSource:null");
 227:     else
 228:       sb.append(code_source);
 229: 
 230:     sb.append(linesep);
 231:     if (classloader == null)
 232:       sb.append("ClassLoader:null");
 233:     else
 234:       sb.append(classloader);
 235: 
 236:     sb.append(linesep);
 237:     sb.append("Principals:");
 238:     if (principals != null && principals.length > 0)
 239:       {
 240:         sb.append("[");
 241:         Principal pal;
 242:         for (int i = 0; i < principals.length; i++)
 243:           {
 244:             pal = principals[i];
 245:             sb.append("'").append(pal.getName())
 246:                 .append("' of type ").append(pal.getClass().getName());
 247:             if (i < principals.length-1)
 248:               sb.append(", ");
 249:           }
 250:         sb.append("]");
 251:       }
 252:     else
 253:       sb.append("none");
 254: 
 255:     sb.append(linesep);
 256:     if (!staticBinding) // include all but dont force loading Policy.currentPolicy
 257:       if (Policy.isLoaded())
 258:         try
 259:           {
 260:             sb.append(Policy.getPolicy().getPermissions(this));
 261:           }
 262:         catch (SecurityException e)
 263:           {
 264:             // We are not allowed access to the policy.
 265:             sb.append(perms);
 266:           }
 267:       else // fallback on this one's permissions
 268:         sb.append(perms);
 269:     else
 270:       sb.append(perms);
 271: 
 272:     return sb.append(linesep).append(")").append(linesep).toString();
 273:   }
 274: }