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1: /* SecureClassLoader.java --- A Secure Class Loader 2: Copyright (C) 1999, 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: /** 41: * A Secure Class Loader for loading classes with additional 42: * support for specifying code source and permissions when 43: * they are retrieved by the system policy handler. 44: * 45: * @since 1.2 46: * 47: * @author Mark Benvenuto 48: */ 49: public class SecureClassLoader extends ClassLoader 50: { 51: java.util.WeakHashMap protectionDomainCache = new java.util.WeakHashMap(); 52: 53: protected SecureClassLoader(ClassLoader parent) 54: { 55: super(parent); 56: SecurityManager sm = System.getSecurityManager(); 57: if(sm != null) 58: sm.checkCreateClassLoader(); 59: } 60: 61: protected SecureClassLoader() 62: { 63: SecurityManager sm = System.getSecurityManager(); 64: if(sm != null) 65: sm.checkCreateClassLoader(); 66: } 67: 68: /** 69: * Creates a class using an array of bytes and a 70: * CodeSource. 71: * 72: * @param name the name to give the class. null if unknown. 73: * @param b the data representing the classfile, in classfile format. 74: * @param off the offset into the data where the classfile starts. 75: * @param len the length of the classfile data in the array. 76: * @param cs the CodeSource for the class or null when unknown. 77: * 78: * @return the class that was defined and optional CodeSource. 79: * 80: * @exception ClassFormatError if the byte array is not in proper classfile format. 81: */ 82: protected final Class defineClass(String name, byte[] b, int off, int len, 83: CodeSource cs) 84: { 85: if (cs != null) 86: { 87: ProtectionDomain protectionDomain; 88: 89: synchronized (protectionDomainCache) 90: { 91: protectionDomain = (ProtectionDomain)protectionDomainCache.get(cs); 92: } 93: 94: if (protectionDomain == null) 95: { 96: protectionDomain 97: = new ProtectionDomain(cs, getPermissions(cs), this, null); 98: synchronized (protectionDomainCache) 99: { 100: ProtectionDomain domain 101: = (ProtectionDomain)protectionDomainCache.get(cs); 102: if (domain == null) 103: protectionDomainCache.put(cs, protectionDomain); 104: else 105: protectionDomain = domain; 106: } 107: } 108: return super.defineClass(name, b, off, len, protectionDomain); 109: } 110: else 111: return super.defineClass(name, b, off, len); 112: } 113: 114: /** 115: * Returns a PermissionCollection for the specified CodeSource. 116: * The default implementation invokes 117: * java.security.Policy.getPermissions. 118: * 119: * This method is called by defineClass that takes a CodeSource 120: * arguement to build a proper ProtectionDomain for the class 121: * being defined. 122: */ 123: protected PermissionCollection getPermissions(CodeSource cs) 124: { 125: Policy policy = Policy.getCurrentPolicy(); 126: return policy.getPermissions(cs); 127: } 128: }
GNU Classpath (0.20) |