I'm trying to recreate the behavior described in Will's blog post but getting the following exception on an attempt to run it via:
$ java -javaagent:agent/target/securityfixer-agent-1.0-SNAPSHOT.jar=bootstrap/target/securityfixer-bootstrap-1.0-SNAPSHOT.jar -jar example/target/securi
tyfixer-example-1.0-SNAPSHOT.jar
Exception in thread "main" java.lang.NoClassDefFoundError: net/bytebuddy/implementation/Implementation$Context$Factory
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getDeclaredMethod(Unknown Source)
at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown Source)
at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: net.bytebuddy.implementation.Implementation$Context$Factory
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 5 more
FATAL ERROR in native method: processing of -javaagent failed
The structure is as described in Will's blog - 3 separate jars, one with the agent, one with the interceptor and one with Main class.
I also tried to run it as an executable jar by adding the mainClass stanza into the securityfixer-example's manifest, but that seems to be bypassing instrumentation altogether:
$ java -jar example/target/securityfixer-example-1.0-SNAPSHOT.jar -javaagent:agent/target/securityfixer-agent-1.0-SNAPSHOT.jar=bootstrap/target/securityfixer-bootstrap-1.0-SNAPSHOT.jar
Security manager is set!
ATTACK SUCCEEDED: Security manager was reset!
What could I be missing here? Thanks in advance.
The following setup seems to be working:
byte-buddy-1.0.0.jar must be inside java-agents-experiments\securityfixer\agent\target along with the genarated securityfixer-agent-1.0-SNAPSHOT.jar as the latter depends on the former. This is achieved by including the following plugin, which performs the copying, in securityfixer-agent/pom.xml:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.8</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}</outputDirectory>
<includeScope>runtime</includeScope>
</configuration>
</execution>
</executions>
</plugin>
as well as the following reference in the <Boot-Class-Path> to the artifact produced by above stanza:
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifestEntries>
<Can-Redefine-Classes>true</Can-Redefine-Classes>
<Can-Retransform-Classes>true</Can-Retransform-Classes>
<Agent-Class>com.excelsiorsoft.securityfixer.agent.SecurityFixerAgent</Agent-Class>
<Premain-Class>com.excelsiorsoft.securityfixer.agent.SecurityFixerAgent</Premain-Class>
<Boot-Class-Path>byte-buddy-1.0.0.jar</Boot-Class-Path>
</manifestEntries>
</archive>
</configuration>
</plugin>
So that unnecessary dependencies (such as securityfixer-bootstrap) are not being copied by the above plugin along with the byte-buddy-1.0.0.jar I needed to change their scope to provided. maven-dependency-plugin seems to skip copying dependencies with that scope to its destination folder.
To be able to run it as executable jar we need to add the <mainClass> stanza to securityfixer-example/pom.xml:
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<mainClass>securityfixer.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
.
$ java -javaagent:agent/target/securityfixer-agent-1.0-SNAPSHOT.jar=bootstrap/target/securityfixer-bootstrap-1.0-SNAPSHOT.jar -jar example/target/securit yfixer-example-1.0-SNAPSHOT.jar
Security manager is set!
ATTACK FAILED: SecurityManager cannot be reset!
Feel free to comment - perhaps there's a more elegant solution. Thanks!