1 /* 2 * Copyright (c) 2015, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.security.AccessController; 25 import java.security.Permission; 26 import java.security.Policy; 27 import java.security.PrivilegedAction; 28 import java.security.ProtectionDomain; 29 30 public class CustomPolicy extends Policy { 31 32 // the ProtectionDomain of CustomPolicy 33 private final ProtectionDomain policyPd; 34 35 public CustomPolicy() { 36 policyPd = AccessController.doPrivileged( 37 (PrivilegedAction<ProtectionDomain>) 38 () -> this.getClass().getProtectionDomain()); 39 } 40 41 @Override 42 public boolean implies(ProtectionDomain pd, Permission perm) { 43 System.out.println("CustomPolicy.implies"); 44 45 // If the protection domain is the same as CustomPolicy, then 46 // we return true. This is to prevent recursive permission checks 47 // that lead to StackOverflow errors when the policy implementation 48 // performs a sensitive operation that triggers a permission check, 49 // for example, as below. 50 if (pd == policyPd) { 51 return true; 52 } 53 54 // Do something that triggers a permission check to make sure that 55 // we don't cause a StackOverflow error. 56 String home = AccessController.doPrivileged( 57 (PrivilegedAction<String>) () -> System.getProperty("user.home")); 58 59 return true; 60 } 61 }