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fix: add more checks before remove or rename enum methods (#1572)

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This commit is contained in:
Skylot
2022-07-07 16:42:42 +01:00
parent e01ea7010f
commit 51555667cf
7 changed files with 173 additions and 13 deletions
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jadx-core/src/main/java/jadx/core/codegen/InsnGen.java
+3 -1
View File
@@ -823,7 +823,9 @@ public class InsnGen {
}
if (callMthNode != null) {
code.attachAnnotation(callMthNode);
code.add(callMthNode.getAlias());
}
if (insn.contains(AFlag.FORCE_RAW_NAME)) {
code.add(callMth.getName());
} else {
code.add(callMth.getAlias());
}
jadx-core/src/main/java/jadx/core/dex/attributes/AFlag.java
+2
View File
@@ -25,6 +25,8 @@ public enum AFlag {
HIDDEN, // instruction used inside other instruction but not listed in args
DONT_RENAME, // do not rename during deobfuscation
FORCE_RAW_NAME, // force use of raw name instead alias
ADDED_TO_REGION,
EXC_TOP_SPLITTER,
jadx-core/src/main/java/jadx/core/dex/visitors/EnumVisitor.java
+90 -9
View File
@@ -18,6 +18,7 @@ import jadx.core.dex.attributes.AFlag;
import jadx.core.dex.attributes.AType;
import jadx.core.dex.attributes.nodes.EnumClassAttr;
import jadx.core.dex.attributes.nodes.EnumClassAttr.EnumField;
import jadx.core.dex.attributes.nodes.RenameReasonAttr;
import jadx.core.dex.attributes.nodes.SkipMethodArgsAttr;
import jadx.core.dex.info.AccessInfo;
import jadx.core.dex.info.ClassInfo;
@@ -26,6 +27,7 @@ import jadx.core.dex.info.MethodInfo;
import jadx.core.dex.instructions.IndexInsnNode;
import jadx.core.dex.instructions.InsnType;
import jadx.core.dex.instructions.InvokeNode;
import jadx.core.dex.instructions.InvokeType;
import jadx.core.dex.instructions.args.ArgType;
import jadx.core.dex.instructions.args.InsnArg;
import jadx.core.dex.instructions.args.InsnWrapArg;
@@ -59,6 +61,7 @@ import static jadx.core.utils.InsnUtils.getWrappedInsn;
public class EnumVisitor extends AbstractVisitor {
private MethodInfo enumValueOfMth;
private MethodInfo cloneMth;
@Override
public void init(RootNode root) {
@@ -68,6 +71,12 @@ public class EnumVisitor extends AbstractVisitor {
"valueOf",
Arrays.asList(ArgType.CLASS, ArgType.STRING),
ArgType.ENUM);
cloneMth = MethodInfo.fromDetails(root,
ClassInfo.fromType(root, ArgType.OBJECT),
"clone",
Collections.emptyList(),
ArgType.OBJECT);
}
@Override
@@ -377,6 +386,7 @@ public class EnumVisitor extends AbstractVisitor {
return enumFieldNode;
}
@SuppressWarnings("StatementWithEmptyBody")
private EnumField createEnumFieldByConstructor(ClassNode cls, FieldNode enumFieldNode, ConstructorInsn co) {
// usually constructor signature is '<init>(Ljava/lang/String;I)V'.
// sometimes for one field enum second arg can be omitted
@@ -417,13 +427,12 @@ public class EnumVisitor extends AbstractVisitor {
}
private void removeEnumMethods(ClassNode cls, ArgType clsType, FieldNode valuesField) {
String valuesMethod = "values()" + TypeGen.signature(ArgType.array(clsType));
FieldInfo valuesFieldInfo = valuesField.getFieldInfo();
String valuesMethodShortId = "values()" + TypeGen.signature(ArgType.array(clsType));
MethodNode valuesMethod = null;
// remove compiler generated methods
for (MethodNode mth : cls.getMethods()) {
MethodInfo mi = mth.getMethodInfo();
if (mi.isClassInit()) {
if (mi.isClassInit() || mth.isNoCode()) {
continue;
}
String shortId = mi.getShortId();
@@ -432,12 +441,33 @@ public class EnumVisitor extends AbstractVisitor {
mth.add(AFlag.DONT_GENERATE);
}
markArgsForSkip(mth);
} else if (shortId.equals(valuesMethod)
|| usesValuesField(mth, valuesFieldInfo)
|| simpleValueOfMth(mth, clsType)) {
} else if (mi.getShortId().equals(valuesMethodShortId)) {
if (isValuesMethod(mth, clsType)) {
valuesMethod = mth;
mth.add(AFlag.DONT_GENERATE);
} else {
// custom values method => rename to resolve conflict with enum method
mth.getMethodInfo().setAlias("valuesCustom");
mth.addAttr(new RenameReasonAttr(mth).append("to resolve conflict with enum method"));
}
} else if (isValuesMethod(mth, clsType)) {
if (!mth.getMethodInfo().getAlias().equals("values") && !mth.getUseIn().isEmpty()) {
// rename to use default values method
mth.getMethodInfo().setAlias("values");
mth.addAttr(new RenameReasonAttr(mth).append("to match enum method name"));
mth.add(AFlag.DONT_RENAME);
}
valuesMethod = mth;
mth.add(AFlag.DONT_GENERATE);
} else if (simpleValueOfMth(mth, clsType)) {
mth.add(AFlag.DONT_GENERATE);
}
}
FieldInfo valuesFieldInfo = valuesField.getFieldInfo();
for (MethodNode mth : cls.getMethods()) {
// fix access to 'values' field and 'values()' method
fixValuesAccess(mth, valuesFieldInfo, clsType, valuesMethod);
}
}
private void markArgsForSkip(MethodNode mth) {
@@ -458,6 +488,25 @@ public class EnumVisitor extends AbstractVisitor {
return false;
}
// TODO: support other method patterns ???
private boolean isValuesMethod(MethodNode mth, ArgType clsType) {
ArgType retType = mth.getReturnType();
if (!retType.isArray() || !retType.getArrayElement().equals(clsType)) {
return false;
}
InsnNode returnInsn = BlockUtils.getOnlyOneInsnFromMth(mth);
if (returnInsn == null || returnInsn.getType() != InsnType.RETURN || returnInsn.getArgsCount() != 1) {
return false;
}
InsnNode wrappedInsn = getWrappedInsn(getSingleArg(returnInsn));
IndexInsnNode castInsn = (IndexInsnNode) checkInsnType(wrappedInsn, InsnType.CHECK_CAST);
if (castInsn != null && Objects.equals(castInsn.getIndex(), ArgType.array(clsType))) {
InvokeNode invokeInsn = (InvokeNode) checkInsnType(getWrappedInsn(getSingleArg(castInsn)), InsnType.INVOKE);
return invokeInsn != null && invokeInsn.getCallMth().equals(cloneMth);
}
return false;
}
private boolean simpleValueOfMth(MethodNode mth, ArgType clsType) {
InsnNode returnInsn = InsnUtils.searchSingleReturnInsn(mth, insn -> insn.getArgsCount() == 1);
if (returnInsn == null) {
@@ -472,9 +521,41 @@ public class EnumVisitor extends AbstractVisitor {
return false;
}
private boolean usesValuesField(MethodNode mth, FieldInfo valuesFieldInfo) {
private void fixValuesAccess(MethodNode mth, FieldInfo valuesFieldInfo, ArgType clsType, @Nullable MethodNode valuesMethod) {
MethodInfo mi = mth.getMethodInfo();
if (mi.isConstructor() || mi.isClassInit() || mth.isNoCode() || mth == valuesMethod) {
return;
}
// search value field usage
Predicate<InsnNode> insnTest = insn -> Objects.equals(((IndexInsnNode) insn).getIndex(), valuesFieldInfo);
return InsnUtils.searchInsn(mth, InsnType.SGET, insnTest) != null;
InsnNode useInsn = InsnUtils.searchInsn(mth, InsnType.SGET, insnTest);
if (useInsn == null) {
return;
}
// replace 'values' field with 'values()' method
InsnUtils.replaceInsns(mth, insn -> {
if (insn.getType() == InsnType.SGET && insnTest.test(insn)) {
MethodInfo valueMth = valuesMethod == null
? getValueMthInfo(mth.root(), clsType)
: valuesMethod.getMethodInfo();
InvokeNode invokeNode = new InvokeNode(valueMth, InvokeType.STATIC, 0);
invokeNode.setResult(insn.getResult());
if (valuesMethod == null) {
// forcing enum method (can overlap and get renamed by custom method)
invokeNode.add(AFlag.FORCE_RAW_NAME);
}
mth.addDebugComment("Replace access to removed values field (" + valuesFieldInfo.getName() + ") with 'values()' method");
return invokeNode;
}
return null;
});
}
private MethodInfo getValueMthInfo(RootNode root, ArgType clsType) {
return MethodInfo.fromDetails(root,
ClassInfo.fromType(root, clsType),
"values",
Collections.emptyList(), ArgType.array(clsType));
}
private static void processEnumCls(ClassNode cls, EnumField field, ClassNode innerCls) {
jadx-core/src/main/java/jadx/core/utils/BlockUtils.java
+3
View File
@@ -1013,6 +1013,9 @@ public class BlockUtils {
*/
@Nullable
public static InsnNode getOnlyOneInsnFromMth(MethodNode mth) {
if (mth.isNoCode()) {
return null;
}
InsnNode insn = null;
for (BlockNode block : mth.getBasicBlocks()) {
List<InsnNode> blockInsns = block.getInstructions();
jadx-core/src/main/java/jadx/core/utils/InsnUtils.java
+32
View File
@@ -1,6 +1,7 @@
package jadx.core.utils;
import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;
import org.jetbrains.annotations.Nullable;
@@ -140,6 +141,37 @@ public class InsnUtils {
return null;
}
public static void replaceInsns(MethodNode mth, Function<InsnNode, InsnNode> replaceFunction) {
for (BlockNode block : mth.getBasicBlocks()) {
List<InsnNode> insns = block.getInstructions();
int insnsCount = insns.size();
for (int i = 0; i < insnsCount; i++) {
InsnNode insn = insns.get(i);
replaceInsnsInInsn(mth, insn, replaceFunction);
InsnNode replace = replaceFunction.apply(insn);
if (replace != null) {
BlockUtils.replaceInsn(mth, block, i, replace);
}
}
}
}
public static void replaceInsnsInInsn(MethodNode mth, InsnNode insn, Function<InsnNode, InsnNode> replaceFunction) {
int argsCount = insn.getArgsCount();
for (int i = 0; i < argsCount; i++) {
InsnArg arg = insn.getArg(i);
if (arg.isInsnWrap()) {
InsnNode wrapInsn = ((InsnWrapArg) arg).getWrapInsn();
replaceInsnsInInsn(mth, wrapInsn, replaceFunction);
InsnNode replace = replaceFunction.apply(wrapInsn);
if (replace != null) {
InsnRemover.unbindArgUsage(mth, arg);
insn.setArg(i, InsnArg.wrapInsnIntoArg(replace));
}
}
}
}
@Nullable
public static RegisterArg getRegFromInsn(List<RegisterArg> regs, InsnType insnType) {
for (RegisterArg reg : regs) {
jadx-core/src/test/java/jadx/tests/integration/enums/TestEnumObfuscated.java
+22 -3
View File
@@ -1,8 +1,10 @@
package jadx.tests.integration.enums;
import java.util.Collections;
import org.junit.jupiter.api.Test;
import jadx.core.dex.nodes.ClassNode;
import jadx.api.CommentsLevel;
import jadx.tests.api.SmaliTest;
import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
@@ -32,14 +34,31 @@ public class TestEnumObfuscated extends SmaliTest {
public synthetic int getNum() {
return this.num;
}
// custom values method
// should be kept and renamed to avoid collision to enum 'values()' method
public static int values() {
return new TestEnumObfuscated[0];
}
// usage of renamed 'values()' method, should be renamed back to 'values'
public static int valuesCount() {
return vs().length;
}
// usage of renamed '$VALUES' field, should be replaced with 'values()' method call
public static int valuesFieldUse() {
return $VLS.length;
}
}
*/
// @formatter:on
@Test
public void test() {
ClassNode cls = getClassNodeFromSmali();
assertThat(cls)
getArgs().setCommentsLevel(CommentsLevel.WARN);
getArgs().setRenameFlags(Collections.emptySet());
assertThat(getClassNodeFromSmali())
.code()
.doesNotContain("$VLS")
.doesNotContain("vo(")
jadx-core/src/test/smali/enums/TestEnumObfuscated.smali
+21
View File
@@ -72,6 +72,27 @@
return-object v0
.end method
.method public static values()[Lenums/TestEnumObfuscated;
.registers 1
sget-object v0, Lenums/TestEnumObfuscated;->$VLS:[Lenums/TestEnumObfuscated;
return v0
.end method
.method public static valuesCount()I
.registers 2
invoke-static {v0, p0}, Lenums/TestEnumObfuscated;->vs()[Lenums/TestEnumObfuscated;
move-result-object v0
array-length v1, v0
return v1
.end method
.method public static valuesFieldUse()I
.registers 2
sget-object v0, Lenums/TestEnumObfuscated;->$VLS:[Lenums/TestEnumObfuscated;
array-length v1, v0
return v1
.end method
.method public synthetic getNum()I
.registers 2