raphw
not able to intercept java.lang package
not able to intercept java.lang.Runtime
package com.security.aspect_example;
import net.bytebuddy.dynamic.loading.ClassInjector;
import net.bytebuddy.utility.JavaModule;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import java.io.File;
import java.lang.instrument.Instrumentation;
import java.nio.file.Files;
import net.bytebuddy.agent.ByteBuddyAgent;
import net.bytebuddy.agent.builder.AgentBuilder;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.ClassFileLocator;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.dynamic.loading.ClassInjector;
import net.bytebuddy.implementation.MethodDelegation;
import net.bytebuddy.implementation.bind.annotation.SuperCall;
import net.bytebuddy.matcher.ElementMatchers;
import java.io.File;
import java.lang.instrument.Instrumentation;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.security.ProtectionDomain;
import java.util.Collections;
import java.util.concurrent.Callable;
public class AspectExampleApplication {
public static void main(String[] args) throws Exception {
premain(null, ByteBuddyAgent.install());
Runtime.getRuntime().exec("ls");
}
public static void premain(String arg, Instrumentation inst) throws Exception {
File temp = Files.createTempDirectory("tmp").toFile();
ClassInjector.UsingInstrumentation.of(temp, ClassInjector.UsingInstrumentation.Target.BOOTSTRAP, inst).inject(Collections.singletonMap(
new TypeDescription.ForLoadedType(MyInterceptor.class),
ClassFileLocator.ForClassLoader.read(MyInterceptor.class)));
new AgentBuilder.Default()
.ignore(ElementMatchers.nameStartsWith("net.bytebuddy."))
.type(ElementMatchers.nameEndsWith("java.lang.Runtime"))
.transform(new AgentBuilder.Transformer() {
@Override
public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassLoader classLoader,JavaModule javaModule, ProtectionDomain protectionDomain) {
return builder.method(ElementMatchers.named("getRuntime")).intercept(MethodDelegation.to(MyInterceptor.class));
}
}).installOn(inst);
}
public static class MyInterceptor {
public static String intercept(@SuperCall Callable<String> zuper) throws Exception {
System.out.println("Intercepted!");
return zuper.call();
}
}
}
You would need to enable retransformation using RetransformationStrategy.RETRANSFORM, and likely set disableClassFormatChanges(). Runtime will already be loaded when the JVM dispatches the agent.
update to this, still not working
public static void premain(String arg, Instrumentation inst) throws Exception {
File temp = Files.createTempDirectory("tmp").toFile();
ClassInjector.UsingInstrumentation.of(temp, ClassInjector.UsingInstrumentation.Target.BOOTSTRAP, inst).inject(Collections.singletonMap(
new TypeDescription.ForLoadedType(MyInterceptor.class),
ClassFileLocator.ForClassLoader.read(MyInterceptor.class)));
new AgentBuilder.Default()
.with(AgentBuilder.RedefinitionStrategy.RETRANSFORMATION)
.disableClassFormatChanges()
.ignore(ElementMatchers.nameStartsWith("net.bytebuddy."))
.type(ElementMatchers.nameEndsWith("java.lang.Runtime"))
.transform(new AgentBuilder.Transformer() {
@Override
public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassLoader classLoader,JavaModule javaModule, ProtectionDomain protectionDomain) {
return builder.method(ElementMatchers.named("getRuntime")).intercept(MethodDelegation.to(MyInterceptor.class));
}
}).installOn(inst);
}
public static class MyInterceptor {
public static String intercept(@SuperCall Callable<String> zuper) throws Exception {
System.out.println("Intercepted!");
return zuper.call();
}
}
If you add a listener, you will see an error message. With retransofation, you cannot apply all forms of transformations. You will likely need to switch over to Advice.
would the advice be able to intercept core java packages like Runtime.exec() ?
I have tried LTW using aspectJ weaver as a java agent, still couldn’t intercept. Is there some resource you could help with?
If you look up YouTube and Vimeo, I have given a row of introductions to the topic. Looking at Byte Buddy's tests is also a good option.