| /* |
| * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| |
| package sun.reflect.misc; |
| |
| import java.lang.reflect.Member; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.lang.reflect.Proxy; |
| import jdk.internal.reflect.Reflection; |
| import sun.security.util.SecurityConstants; |
| |
| public final class ReflectUtil { |
| |
| private ReflectUtil() { |
| } |
| |
| public static Class<?> forName(String name) |
| throws ClassNotFoundException { |
| checkPackageAccess(name); |
| return Class.forName(name); |
| } |
| |
| /** |
| * Ensures that access to a method or field is granted and throws |
| * IllegalAccessException if not. This method is not suitable for checking |
| * access to constructors. |
| * |
| * @param currentClass the class performing the access |
| * @param memberClass the declaring class of the member being accessed |
| * @param target the target object if accessing instance field or method; |
| * or null if accessing static field or method or if target |
| * object access rights will be checked later |
| * @param modifiers the member's access modifiers |
| * @throws IllegalAccessException if access to member is denied |
| * @implNote Delegates directly to |
| * {@link Reflection#ensureMemberAccess(Class, Class, Class, int)} |
| * which should be used instead. |
| */ |
| public static void ensureMemberAccess(Class<?> currentClass, |
| Class<?> memberClass, |
| Object target, |
| int modifiers) |
| throws IllegalAccessException |
| { |
| Reflection.ensureMemberAccess(currentClass, |
| memberClass, |
| target == null ? null : target.getClass(), |
| modifiers); |
| } |
| |
| /** |
| * Does a conservative approximation of member access check. Use this if |
| * you don't have an actual 'userland' caller Class/ClassLoader available. |
| * This might be more restrictive than a precise member access check where |
| * you have a caller, but should never allow a member access that is |
| * forbidden. |
| * |
| * @param m the {@code Member} about to be accessed |
| */ |
| public static void conservativeCheckMemberAccess(Member m) throws SecurityException{ |
| final SecurityManager sm = System.getSecurityManager(); |
| if (sm == null) |
| return; |
| |
| // Check for package access on the declaring class. |
| // |
| // In addition, unless the member and the declaring class are both |
| // public check for access declared member permissions. |
| // |
| // This is done regardless of ClassLoader relations between the {@code |
| // Member m} and any potential caller. |
| |
| final Class<?> declaringClass = m.getDeclaringClass(); |
| |
| privateCheckPackageAccess(sm, declaringClass); |
| |
| if (Modifier.isPublic(m.getModifiers()) && |
| Modifier.isPublic(declaringClass.getModifiers())) |
| return; |
| |
| // Check for declared member access. |
| sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION); |
| } |
| |
| /** |
| * Checks package access on the given class. |
| * |
| * If it is a {@link Proxy#isProxyClass(java.lang.Class)} that implements |
| * a non-public interface (i.e. may be in a non-restricted package), |
| * also check the package access on the proxy interfaces. |
| */ |
| public static void checkPackageAccess(Class<?> clazz) { |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) { |
| privateCheckPackageAccess(s, clazz); |
| } |
| } |
| |
| /** |
| * NOTE: should only be called if a SecurityManager is installed |
| */ |
| private static void privateCheckPackageAccess(SecurityManager s, Class<?> clazz) { |
| while (clazz.isArray()) { |
| clazz = clazz.getComponentType(); |
| } |
| |
| String pkg = clazz.getPackageName(); |
| if (pkg != null && !pkg.isEmpty()) { |
| s.checkPackageAccess(pkg); |
| } |
| |
| if (isNonPublicProxyClass(clazz)) { |
| privateCheckProxyPackageAccess(s, clazz); |
| } |
| } |
| |
| /** |
| * Checks package access on the given classname. |
| * This method is typically called when the Class instance is not |
| * available and the caller attempts to load a class on behalf |
| * the true caller (application). |
| */ |
| public static void checkPackageAccess(String name) { |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) { |
| String cname = name.replace('/', '.'); |
| if (cname.startsWith("[")) { |
| int b = cname.lastIndexOf('[') + 2; |
| if (b > 1 && b < cname.length()) { |
| cname = cname.substring(b); |
| } |
| } |
| int i = cname.lastIndexOf('.'); |
| if (i != -1) { |
| s.checkPackageAccess(cname.substring(0, i)); |
| } |
| } |
| } |
| |
| public static boolean isPackageAccessible(Class<?> clazz) { |
| try { |
| checkPackageAccess(clazz); |
| } catch (SecurityException e) { |
| return false; |
| } |
| return true; |
| } |
| |
| // Returns true if p is an ancestor of cl i.e. class loader 'p' can |
| // be found in the cl's delegation chain |
| private static boolean isAncestor(ClassLoader p, ClassLoader cl) { |
| ClassLoader acl = cl; |
| do { |
| acl = acl.getParent(); |
| if (p == acl) { |
| return true; |
| } |
| } while (acl != null); |
| return false; |
| } |
| |
| /** |
| * Returns true if package access check is needed for reflective |
| * access from a class loader 'from' to classes or members in |
| * a class defined by class loader 'to'. This method returns true |
| * if 'from' is not the same as or an ancestor of 'to'. All code |
| * in a system domain are granted with all permission and so this |
| * method returns false if 'from' class loader is a class loader |
| * loading system classes. On the other hand, if a class loader |
| * attempts to access system domain classes, it requires package |
| * access check and this method will return true. |
| */ |
| public static boolean needsPackageAccessCheck(ClassLoader from, ClassLoader to) { |
| if (from == null || from == to) |
| return false; |
| |
| if (to == null) |
| return true; |
| |
| return !isAncestor(from, to); |
| } |
| |
| /** |
| * Check package access on the proxy interfaces that the given proxy class |
| * implements. |
| * |
| * @param clazz Proxy class object |
| */ |
| public static void checkProxyPackageAccess(Class<?> clazz) { |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) { |
| privateCheckProxyPackageAccess(s, clazz); |
| } |
| } |
| |
| /** |
| * NOTE: should only be called if a SecurityManager is installed |
| */ |
| private static void privateCheckProxyPackageAccess(SecurityManager s, Class<?> clazz) { |
| // check proxy interfaces if the given class is a proxy class |
| if (Proxy.isProxyClass(clazz)) { |
| for (Class<?> intf : clazz.getInterfaces()) { |
| privateCheckPackageAccess(s, intf); |
| } |
| } |
| } |
| /** |
| * Access check on the interfaces that a proxy class implements and throw |
| * {@code SecurityException} if it accesses a restricted package from |
| * the caller's class loader. |
| * |
| * @param ccl the caller's class loader |
| * @param interfaces the list of interfaces that a proxy class implements |
| */ |
| public static void checkProxyPackageAccess(ClassLoader ccl, |
| Class<?>... interfaces) |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) { |
| for (Class<?> intf : interfaces) { |
| ClassLoader cl = intf.getClassLoader(); |
| if (needsPackageAccessCheck(ccl, cl)) { |
| privateCheckPackageAccess(sm, intf); |
| } |
| } |
| } |
| } |
| |
| // Note that bytecode instrumentation tools may exclude 'sun.*' |
| // classes but not generated proxy classes and so keep it in com.sun.* |
| public static final String PROXY_PACKAGE = "com.sun.proxy"; |
| |
| /** |
| * Test if the given class is a proxy class that implements |
| * non-public interface. Such proxy class may be in a non-restricted |
| * package that bypasses checkPackageAccess. |
| */ |
| public static boolean isNonPublicProxyClass(Class<?> cls) { |
| if (!Proxy.isProxyClass(cls)) { |
| return false; |
| } |
| String pkg = cls.getPackageName(); |
| return pkg == null || !pkg.startsWith(PROXY_PACKAGE); |
| } |
| |
| /** |
| * Check if the given method is a method declared in the proxy interface |
| * implemented by the given proxy instance. |
| * |
| * @param proxy a proxy instance |
| * @param method an interface method dispatched to a InvocationHandler |
| * |
| * @throws IllegalArgumentException if the given proxy or method is invalid. |
| */ |
| public static void checkProxyMethod(Object proxy, Method method) { |
| // check if it is a valid proxy instance |
| if (proxy == null || !Proxy.isProxyClass(proxy.getClass())) { |
| throw new IllegalArgumentException("Not a Proxy instance"); |
| } |
| if (Modifier.isStatic(method.getModifiers())) { |
| throw new IllegalArgumentException("Can't handle static method"); |
| } |
| |
| Class<?> c = method.getDeclaringClass(); |
| if (c == Object.class) { |
| String name = method.getName(); |
| if (name.equals("hashCode") || name.equals("equals") || name.equals("toString")) { |
| return; |
| } |
| } |
| |
| if (isSuperInterface(proxy.getClass(), c)) { |
| return; |
| } |
| |
| // disallow any method not declared in one of the proxy interfaces |
| throw new IllegalArgumentException("Can't handle: " + method); |
| } |
| |
| private static boolean isSuperInterface(Class<?> c, Class<?> intf) { |
| for (Class<?> i : c.getInterfaces()) { |
| if (i == intf) { |
| return true; |
| } |
| if (isSuperInterface(i, intf)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Checks if {@code Class cls} is a VM-anonymous class |
| * as defined by {@link jdk.internal.misc.Unsafe#defineAnonymousClass} |
| * (not to be confused with a Java Language anonymous inner class). |
| */ |
| public static boolean isVMAnonymousClass(Class<?> cls) { |
| return cls.getName().indexOf('/') > -1; |
| } |
| } |