Remove reset methods

pull/48/head
Graham 5 years ago
parent 446a72abc5
commit 6c3d98702c
  1. 2
      deob/src/main/java/dev/openrs2/deob/Deobfuscator.java
  2. 128
      deob/src/main/java/dev/openrs2/deob/transform/ResetTransformer.java

@ -23,6 +23,7 @@ import dev.openrs2.deob.transform.FieldOrderTransformer;
import dev.openrs2.deob.transform.OpaquePredicateTransformer;
import dev.openrs2.deob.transform.OriginalNameTransformer;
import dev.openrs2.deob.transform.RemapTransformer;
import dev.openrs2.deob.transform.ResetTransformer;
import dev.openrs2.deob.transform.UnusedArgTransformer;
import org.objectweb.asm.tree.analysis.AnalyzerException;
import org.slf4j.Logger;
@ -45,6 +46,7 @@ public final class Deobfuscator {
.add(new DummyArgTransformer())
.add(new DummyLocalTransformer())
.add(new UnusedArgTransformer())
.add(new ResetTransformer())
.add(new AccessTransformer())
.build();

@ -0,0 +1,128 @@
package dev.openrs2.deob.transform;
import java.util.HashSet;
import java.util.Set;
import dev.openrs2.asm.InsnNodeUtils;
import dev.openrs2.asm.MemberRef;
import dev.openrs2.asm.MethodNodeUtils;
import dev.openrs2.asm.classpath.ClassPath;
import dev.openrs2.asm.classpath.Library;
import dev.openrs2.asm.transform.Transformer;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;
import org.objectweb.asm.tree.analysis.AnalyzerException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class ResetTransformer extends Transformer {
private static final Logger logger = LoggerFactory.getLogger(ResetTransformer.class);
private static MemberRef findMasterReset(MethodNode method) {
AbstractInsnNode shutdownLdc = null;
for (var insn : method.instructions) {
if (insn.getOpcode() != Opcodes.LDC) {
continue;
}
var ldc = (LdcInsnNode) insn;
if (ldc.cst.equals("Shutdown complete - clean:")) {
shutdownLdc = ldc;
break;
}
}
for (var insn = shutdownLdc; insn != null; insn = insn.getPrevious()) {
if (insn.getOpcode() != Opcodes.ALOAD) {
continue;
}
var load = (VarInsnNode) insn;
if (load.var != 0) {
continue;
}
var nextInsn = InsnNodeUtils.nextReal(insn);
if (nextInsn.getOpcode() != Opcodes.INVOKEVIRTUAL) {
continue;
}
var invoke = (MethodInsnNode) nextInsn;
if (!invoke.desc.equals("()V")) {
continue;
}
return new MemberRef(invoke.owner, invoke.name, invoke.desc);
}
return null;
}
private static void findResetMethods(Set<MemberRef> resetMethods, ClassNode clazz, MethodNode method) throws AnalyzerException {
MethodNodeUtils.removeDeadCode(clazz.name, method);
for (var insn : method.instructions) {
if (insn.getOpcode() == -1 || insn.getOpcode() != Opcodes.INVOKESTATIC) {
continue;
}
var invoke = (MethodInsnNode) insn;
resetMethods.add(new MemberRef(invoke.owner, invoke.name, invoke.desc));
}
}
private final Set<MemberRef> resetMethods = new HashSet<>();
@Override
protected void preTransform(ClassPath classPath) throws AnalyzerException {
resetMethods.clear();
for (var library : classPath.getLibraries()) {
for (var clazz : library) {
for (var method : clazz.methods) {
if ((method.access & (Opcodes.ACC_NATIVE | Opcodes.ACC_ABSTRACT)) != 0) {
continue;
}
var masterReset = findMasterReset(method);
if (masterReset == null) {
continue;
}
logger.info("Identified master reset method: {}", masterReset);
var resetClass = classPath.getNode("client");
var resetMethod = resetClass.methods.stream()
.filter(m -> m.name.equals(masterReset.getName()) && m.desc.equals(masterReset.getDesc()))
.findAny()
.orElseThrow();
findResetMethods(resetMethods, resetClass, resetMethod);
resetMethod.instructions.clear();
resetMethod.tryCatchBlocks.clear();
resetMethod.instructions.add(new InsnNode(Opcodes.RETURN));
}
}
}
}
@Override
protected boolean transformClass(ClassPath classPath, Library library, ClassNode clazz) {
clazz.methods.removeIf(m -> resetMethods.contains(new MemberRef(clazz.name, m.name, m.desc)));
return false;
}
@Override
protected void postTransform(ClassPath classPath) {
logger.info("Removed {} reset methods", resetMethods.size());
}
}
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