feat: handle java.lang.invoke.BoundMethodHandle correctly (#78)

terminator-commons/src/main/java/io/github/algomaster99/terminator/commons/fingerprint/classfile/RuntimeClass.java

@@ -37,4 +37,16 @@ public static boolean isGeneratedClassExtendingMagicAccessor(byte[] classfileByt
             return false;
         }
     }
+
+    /**
+     * During the runtime the jvm binds methodhandles to the class {@link java.lang.invoke.BoundMethodHandle}.
+     * These classes are generated at runtime and should be ignored. We can identify them by checking if the super class is {@link java.lang.invoke.BoundMethodHandle}.
+     * @param classfileBytes  the class file bytes
+     * @return  true if the class is a bound method handle, false otherwise.
+     */
+    public static boolean isBoundMethodHandle(byte[] classfileBytes) {
+        ClassReader reader = new ClassReader(classfileBytes);
+        System.err.println(reader.getSuperName());
+        return reader.getSuperName().equals("java/lang/invoke/BoundMethodHandle");
+    }
 }

watchdog-agent/src/main/java/io/github/algomaster99/Terminator.java

@@ -33,12 +33,8 @@ public byte[] transform(
     private static byte[] isLoadedClassWhitelisted(String className, byte[] classfileBuffer) {
         Map<String, List<Provenance>> fingerprints = options.getFingerprints();
         if (RuntimeClass.isProxyClass(classfileBuffer)
-                || RuntimeClass.isGeneratedClassExtendingMagicAccessor(classfileBuffer)) {
-            return classfileBuffer;
-        }
-        if (className.contains("$")) {
-            // FIXME: we need to check inner classes without loading them. Maybe add the hashes for inner classes in the
-            // fingerprints?
+                || RuntimeClass.isGeneratedClassExtendingMagicAccessor(classfileBuffer)
+                || RuntimeClass.isBoundMethodHandle(classfileBuffer)) {
             return classfileBuffer;
         }
         for (String expectedClassName : fingerprints.keySet()) {

watchdog-agent/src/test/java/OptionsTest.java

@@ -66,4 +66,11 @@ void verifyJdkIndexerFindsOrgXmlSax() throws Exception {
         var var = options.getJdkFingerprints().keySet().stream().collect(Collectors.toSet());
         assertThat(var).contains("org/xml/sax/helpers/NamespaceSupport");
     }
+
+    @Test
+    void verifyJdkIndexerFindsMethodHandle() throws Exception {
+        Options options = new Options("skipShutdown=true");
+        boolean containsKey = options.getJdkFingerprints().containsKey("java/lang/invoke/BoundMethodHandle");
+        assertThat(containsKey).isTrue();
+    }
 }