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/*
* Copyright (c) 2019, 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.
*
* 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.
*/
/*
* @test
* @library /test/lib
* @modules java.base/jdk.internal.org.objectweb.asm
* @build HiddenNestmateTest
* @run testng/othervm HiddenNestmateTest
*/
import java.lang.invoke.*;
import java.lang.invoke.MethodHandles.Lookup;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.stream.Stream;
import java.util.Arrays;
import jdk.internal.org.objectweb.asm.*;
import org.testng.annotations.Test;
import static java.lang.invoke.MethodHandles.Lookup.ClassOption.*;
import static java.lang.invoke.MethodHandles.Lookup.*;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
import static org.testng.Assert.*;
public class HiddenNestmateTest {
private static final byte[] bytes = classBytes("HiddenInjected");
private static void assertNestmate(Lookup lookup) {
assertTrue((lookup.lookupModes() & PRIVATE) != 0);
assertTrue((lookup.lookupModes() & MODULE) != 0);
Class<?> hiddenClass = lookup.lookupClass();
Class<?> nestHost = hiddenClass.getNestHost();
assertTrue(hiddenClass.isHidden());
assertTrue(nestHost == MethodHandles.lookup().lookupClass());
// hidden nestmate is not listed in the return array of getNestMembers
assertTrue(Stream.of(nestHost.getNestMembers()).noneMatch(k -> k == hiddenClass));
assertTrue(hiddenClass.isNestmateOf(lookup.lookupClass()));
assertTrue(Arrays.equals(hiddenClass.getNestMembers(), nestHost.getNestMembers()));
}
/*
* Test a hidden class to have no access to private members of another class
*/
@Test
public void hiddenClass() throws Throwable {
// define a hidden class
Lookup lookup = MethodHandles.lookup().defineHiddenClass(bytes, false);
Class<?> c = lookup.lookupClass();
assertTrue(lookup.hasFullPrivilegeAccess());
assertTrue((lookup.lookupModes() & ORIGINAL) == ORIGINAL);
assertTrue(c.getNestHost() == c); // host of its own nest
assertTrue(c.isHidden());
// invoke int test(HiddenNestmateTest o) via MethodHandle
MethodHandle ctor = lookup.findConstructor(c, MethodType.methodType(void.class));
MethodHandle mh = lookup.findVirtual(c, "test", MethodType.methodType(int.class, HiddenNestmateTest.class));
try {
int x = (int) mh.bindTo(ctor.invoke()).invokeExact(this);
throw new RuntimeException("should fail when accessing HiddenNestmateTest.privMethod()");
} catch (IllegalAccessError e) {}
// invoke int test(HiddenNestmateTest o)
try {
int x1 = testInjectedClass(c);
throw new RuntimeException("should fail when accessing HiddenNestmateTest.privMethod()");
} catch (IllegalAccessError e) {}
}
/*
* Test a hidden class to have access to private members of its nestmates
*/
@Test
public void hiddenNestmate() throws Throwable {
// define a hidden nestmate class
Lookup lookup = MethodHandles.lookup().defineHiddenClass(bytes, false, NESTMATE);
Class<?> c = lookup.lookupClass();
assertNestmate(lookup);
// invoke int test(HiddenNestmateTest o) via MethodHandle
MethodHandle ctor = lookup.findConstructor(c, MethodType.methodType(void.class));
MethodHandle mh = lookup.findVirtual(c, "test", MethodType.methodType(int.class, HiddenNestmateTest.class));
int x = (int)mh.bindTo(ctor.invoke()).invokeExact( this);
assertTrue(x == privMethod());
// invoke int test(HiddenNestmateTest o)
int x1 = testInjectedClass(c);
assertTrue(x1 == privMethod());
}
/*
* Test a hidden class created with NESTMATE and STRONG option is a nestmate
*/
@Test
public void hiddenStrongClass() throws Throwable {
// define a hidden class strongly referenced by the class loader
Lookup lookup = MethodHandles.lookup().defineHiddenClass(bytes, false, NESTMATE, STRONG);
assertNestmate(lookup);
}
/*
* Fail to create a hidden class if dropping PRIVATE lookup mode
*/
@Test(expectedExceptions = IllegalAccessException.class)
public void noPrivateLookupAccess() throws Throwable {
Lookup lookup = MethodHandles.lookup().dropLookupMode(Lookup.PRIVATE);
lookup.defineHiddenClass(bytes, false, NESTMATE);
}
public void teleportToNestmate() throws Throwable {
Lookup lookup = MethodHandles.lookup().defineHiddenClass(bytes, false, NESTMATE);
assertNestmate(lookup);
// Teleport to a hidden nestmate
Lookup lc = MethodHandles.lookup().in(lookup.lookupClass());
assertTrue((lc.lookupModes() & PRIVATE) != 0);
assertTrue((lc.lookupModes() & ORIGINAL) == 0);
Lookup lc2 = lc.defineHiddenClass(bytes, false, NESTMATE);
assertNestmate(lc2);
}
/*
* Fail to create a hidden class in a different package from the lookup class' package
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void notSamePackage() throws Throwable {
MethodHandles.lookup().defineHiddenClass(classBytes("p/HiddenInjected"), false, NESTMATE);
}
/*
* invoke int test(HiddenNestmateTest o) method defined in the injected class
*/
private int testInjectedClass(Class<?> c) throws Throwable {
try {
Method m = c.getMethod("test", HiddenNestmateTest.class);
return (int) m.invoke(c.newInstance(), this);
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
private static byte[] classBytes(String classname) {
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
MethodVisitor mv;
cw.visit(V12, ACC_FINAL, classname, null, "java/lang/Object", null);
{
mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
mv.visitInsn(RETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
{
// access a private member of the nest host class
mv = cw.visitMethod(ACC_PUBLIC, "test", "(LHiddenNestmateTest;)I", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(INVOKEVIRTUAL, "HiddenNestmateTest", "privMethod", "()I");
mv.visitInsn(IRETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
cw.visitEnd();
return cw.toByteArray();
}
private int privMethod() { return 1234; }
}
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