Add initial DummyTransformer

master
Graham 5 years ago
parent 55646c8384
commit 3c1ec9f210
  1. 4
      deob/src/main/java/dev/openrs2/deob/Deobfuscator.java
  2. 258
      deob/src/main/java/dev/openrs2/deob/transform/DummyTransformer.java

@ -15,6 +15,7 @@ import dev.openrs2.deob.transform.BitShiftTransformer;
import dev.openrs2.deob.transform.CanvasTransformer; import dev.openrs2.deob.transform.CanvasTransformer;
import dev.openrs2.deob.transform.ClassForNameTransformer; import dev.openrs2.deob.transform.ClassForNameTransformer;
import dev.openrs2.deob.transform.CounterTransformer; import dev.openrs2.deob.transform.CounterTransformer;
import dev.openrs2.deob.transform.DummyTransformer;
import dev.openrs2.deob.transform.ExceptionTracingTransformer; import dev.openrs2.deob.transform.ExceptionTracingTransformer;
import dev.openrs2.deob.transform.FieldOrderTransformer; import dev.openrs2.deob.transform.FieldOrderTransformer;
import dev.openrs2.deob.transform.OpaquePredicateTransformer; import dev.openrs2.deob.transform.OpaquePredicateTransformer;
@ -32,7 +33,8 @@ public final class Deobfuscator {
new BitShiftTransformer(), new BitShiftTransformer(),
new CounterTransformer(), new CounterTransformer(),
new CanvasTransformer(), new CanvasTransformer(),
new FieldOrderTransformer() new FieldOrderTransformer(),
new DummyTransformer()
); );
public static void main(String[] args) throws IOException, AnalyzerException { public static void main(String[] args) throws IOException, AnalyzerException {

@ -0,0 +1,258 @@
package dev.openrs2.deob.transform;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import dev.openrs2.asm.InsnNodeUtils;
import dev.openrs2.asm.MemberRef;
import dev.openrs2.asm.classpath.ClassPath;
import dev.openrs2.asm.transform.Transformer;
import dev.openrs2.deob.analysis.IntInterpreter;
import dev.openrs2.deob.analysis.IntValue;
import dev.openrs2.util.collect.DisjointSet;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;
import org.objectweb.asm.tree.analysis.Analyzer;
import org.objectweb.asm.tree.analysis.AnalyzerException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class DummyTransformer extends Transformer {
private static final Logger logger = LoggerFactory.getLogger(DummyTransformer.class);
private static final class ArgRef {
private final DisjointSet.Partition<MemberRef> method;
private final int arg;
public ArgRef(DisjointSet.Partition<MemberRef> method, int arg) {
this.method = method;
this.arg = arg;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
ArgRef argRef = (ArgRef) o;
return arg == argRef.arg &&
method.equals(argRef.method);
}
@Override
public int hashCode() {
return Objects.hash(method, arg);
}
}
private static boolean evaluateUnaryBranch(int opcode, int value) {
switch (opcode) {
case Opcodes.IFEQ:
return value == 0;
case Opcodes.IFNE:
return value != 0;
default:
throw new IllegalArgumentException();
}
}
private static boolean evaluateBinaryBranch(int opcode, int value1, int value2) {
switch (opcode) {
case Opcodes.IF_ICMPEQ:
return value1 == value2;
case Opcodes.IF_ICMPNE:
return value1 != value2;
case Opcodes.IF_ICMPLT:
return value1 < value2;
case Opcodes.IF_ICMPGE:
return value1 >= value2;
case Opcodes.IF_ICMPGT:
return value1 > value2;
case Opcodes.IF_ICMPLE:
return value1 <= value2;
default:
throw new IllegalArgumentException();
}
}
private final Multimap<ArgRef, IntValue> argValues = HashMultimap.create();
private final Map<DisjointSet.Partition<MemberRef>, Integer[]> constArgs = new HashMap<>();
private DisjointSet<MemberRef> inheritedMethodSets;
private int loadsInlined, branchesSimplified;
@Override
protected void preTransform(ClassPath classPath) {
inheritedMethodSets = classPath.createInheritedMethodSets();
loadsInlined = 0;
branchesSimplified = 0;
}
@Override
protected void prePass(ClassPath classPath) {
argValues.clear();
}
@Override
protected boolean transformCode(ClassNode clazz, MethodNode method) throws AnalyzerException {
var parentMethod = inheritedMethodSets.get(new MemberRef(clazz.name, method.name, method.desc));
var parameters = constArgs.get(parentMethod);
var analyzer = new Analyzer<>(new IntInterpreter(parameters));
analyzer.analyze(clazz.name, method);
var frames = analyzer.getFrames();
var changed = false;
var alwaysTakenUnaryBranches = new ArrayList<JumpInsnNode>();
var neverTakenUnaryBranches = new ArrayList<JumpInsnNode>();
var alwaysTakenBinaryBranches = new ArrayList<JumpInsnNode>();
var neverTakenBinaryBranches = new ArrayList<JumpInsnNode>();
for (var i = 0; i < frames.length; i++) {
var frame = frames[i];
if (frame == null) {
continue;
}
var stackSize = frame.getStackSize();
var insn = method.instructions.get(i);
switch (insn.getOpcode()) {
case Opcodes.INVOKEVIRTUAL:
case Opcodes.INVOKESPECIAL:
case Opcodes.INVOKESTATIC:
case Opcodes.INVOKEINTERFACE:
var invoke = (MethodInsnNode) insn;
var invokedMethod = inheritedMethodSets.get(new MemberRef(invoke.owner, invoke.name, invoke.desc));
if (invokedMethod == null) {
continue;
}
var args = Type.getArgumentTypes(invoke.desc).length;
for (int j = 0, k = 0; j < args; j++) {
var arg = frame.getStack(stackSize - args + j);
argValues.put(new ArgRef(invokedMethod, k), arg);
k += arg.getSize();
}
break;
case Opcodes.ILOAD:
var iload = (VarInsnNode) insn;
var value = frame.getLocal(iload.var);
if (value.isConstant()) {
method.instructions.set(insn, InsnNodeUtils.createIntConstant(value.getIntValue()));
loadsInlined++;
changed = true;
}
break;
case Opcodes.IFEQ:
case Opcodes.IFNE:
value = frame.getStack(stackSize - 1);
if (!value.isConstant()) {
continue;
}
var taken = evaluateUnaryBranch(insn.getOpcode(), value.getIntValue());
if (taken) {
alwaysTakenUnaryBranches.add((JumpInsnNode) insn);
} else {
neverTakenUnaryBranches.add((JumpInsnNode) insn);
}
break;
case Opcodes.IF_ICMPEQ:
case Opcodes.IF_ICMPNE:
case Opcodes.IF_ICMPLT:
case Opcodes.IF_ICMPGE:
case Opcodes.IF_ICMPGT:
case Opcodes.IF_ICMPLE:
var value1 = frame.getStack(stackSize - 2);
if (!value1.isConstant()) {
continue;
}
var value2 = frame.getStack(stackSize - 1);
if (!value2.isConstant()) {
continue;
}
taken = evaluateBinaryBranch(insn.getOpcode(), value1.getIntValue(), value2.getIntValue());
if (taken) {
alwaysTakenBinaryBranches.add((JumpInsnNode) insn);
} else {
neverTakenBinaryBranches.add((JumpInsnNode) insn);
}
break;
}
}
for (var insn : alwaysTakenUnaryBranches) {
method.instructions.insertBefore(insn, new InsnNode(Opcodes.POP));
method.instructions.set(insn, new JumpInsnNode(Opcodes.GOTO, insn.label));
branchesSimplified++;
changed = true;
}
for (var insn : neverTakenUnaryBranches) {
method.instructions.set(insn, new InsnNode(Opcodes.POP));
branchesSimplified++;
changed = true;
}
for (var insn : alwaysTakenBinaryBranches) {
method.instructions.insertBefore(insn, new InsnNode(Opcodes.POP));
method.instructions.insertBefore(insn, new InsnNode(Opcodes.POP));
method.instructions.set(insn, new JumpInsnNode(Opcodes.GOTO, insn.label));
branchesSimplified++;
changed = true;
}
for (var insn : neverTakenBinaryBranches) {
method.instructions.insertBefore(insn, new InsnNode(Opcodes.POP));
method.instructions.set(insn, new InsnNode(Opcodes.POP));
branchesSimplified++;
changed = true;
}
return changed;
}
@Override
protected void postPass(ClassPath classPath) {
for (var method : inheritedMethodSets) {
var args = (Type.getArgumentsAndReturnSizes(method.iterator().next().getDesc()) >> 2) - 1;
var parameters = new Integer[args];
for (int i = 0; i < args; i++) {
var values = argValues.get(new ArgRef(method, i));
if (values.size() != 1) {
continue;
}
var value = values.iterator().next();
if (value.isConstant()) {
parameters[i] = value.getIntValue();
}
}
constArgs.put(method, parameters);
}
}
@Override
protected void postTransform(ClassPath classPath) {
logger.info("Inlined {} dummy loads and simplified {} dummy branches", loadsInlined, branchesSimplified);
}
}
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