fix: resolved regression in Kotlin metadata parser

jadx-core/src/main/java/jadx/core/deobf/Deobfuscator.java

@@ -28,6 +28,7 @@ import jadx.core.dex.nodes.ClassNode;
 import jadx.core.dex.nodes.FieldNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.nodes.RootNode;
+import jadx.core.utils.kotlin.KotlinMetadataUtils;
 
 public class Deobfuscator {
 	private static final Logger LOG = LoggerFactory.getLogger(Deobfuscator.class);
@@ -36,9 +37,6 @@ public class Deobfuscator {
 
 	public static final String CLASS_NAME_SEPARATOR = ".";
 	public static final String INNER_CLASS_SEPARATOR = "$";
-	public static final String KOTLIN_METADATA_ANNOTATION = "kotlin.Metadata";
-	public static final String KOTLIN_METADATA_D2_PARAMETER = "d2";
-	public static final String KOTLIN_METADATA_CLASSNAME_REGEX = "(L.*;)";
 
 	private final JadxArgs args;
 	private final RootNode root;
@@ -351,9 +349,8 @@ public class Deobfuscator {
 		} else {
 			if (!clsMap.containsKey(classInfo)) {
 				String clsShortName = classInfo.getShortName();
-				if (shouldRename(clsShortName) || reservedClsNames.contains(clsShortName)) {
-					makeClsAlias(cls);
-				}
+				boolean badName = shouldRename(clsShortName) || reservedClsNames.contains(clsShortName);
+				makeClsAlias(cls, badName);
 			}
 		}
 		for (ClassNode innerCls : cls.getInnerClasses()) {
@@ -366,7 +363,7 @@ public class Deobfuscator {
 		if (deobfClsInfo != null) {
 			return deobfClsInfo.getAlias();
 		}
-		return makeClsAlias(cls);
+		return makeClsAlias(cls, true);
 	}
 
 	public String getPkgAlias(ClassNode cls) {
@@ -387,41 +384,35 @@ public class Deobfuscator {
 		}
 	}
 
-	private String makeClsAlias(ClassNode cls) {
-		ClassInfo classInfo = cls.getClassInfo();
-
-		String metadataClassName = "";
-		String metadataPackageName = "";
+	private String makeClsAlias(ClassNode cls, boolean badName) {
+		String alias = null;
+		String pkgName = null;
 		if (this.parseKotlinMetadata) {
-			String rawClassName = getRawClassNameFromMetadata(cls);
-			if (rawClassName != null) {
-				metadataClassName = rawClassName.substring(rawClassName.lastIndexOf(".") + 1, rawClassName.length() - 1);
-				if (rawClassName.lastIndexOf(".") != -1) {
-					metadataPackageName = rawClassName.substring(1, rawClassName.lastIndexOf("."));
+			ClassInfo kotlinCls = KotlinMetadataUtils.getClassName(cls);
+			if (kotlinCls != null) {
+				alias = prepareNameFull(kotlinCls.getShortName(), "C");
+				pkgName = kotlinCls.getPackage();
 			}
 		}
-		}
-		String alias = null;
-
-		if (this.useSourceNameAsAlias) {
+		if (alias == null && this.useSourceNameAsAlias) {
 			alias = getAliasFromSourceFile(cls);
 		}
 
+		ClassInfo classInfo = cls.getClassInfo();
 		if (alias == null) {
-			if (metadataClassName.isEmpty()) {
+			if (badName) {
 				String clsName = classInfo.getShortName();
 				String prefix = makeClsPrefix(cls);
 				alias = String.format("%sC%04d%s", prefix, clsIndex++, prepareNamePart(clsName));
 			} else {
-				alias = metadataClassName;
+				// rename not needed
+				return classInfo.getShortName();
 			}
 		}
-		PackageNode pkg;
-		if (metadataPackageName.isEmpty()) {
-			pkg = getPackageNode(classInfo.getPackage(), true);
-		} else {
-			pkg = getPackageNode(metadataPackageName, true);
+		if (pkgName == null) {
+			pkgName = classInfo.getPackage();
 		}
+		PackageNode pkg = getPackageNode(pkgName, true);
 		clsMap.put(classInfo, new DeobfClsInfo(this, cls, pkg, alias));
 		return alias;
 	}
@@ -484,29 +475,6 @@ public class Deobfuscator {
 		return result;
 	}
 
-	/**
-	 * Try to get class name form Kotlin meta data
-	 *
-	 * @param cls
-	 * @return
-	 */
-	@Nullable
-	private String getRawClassNameFromMetadata(ClassNode cls) {
-		if (cls.getAnnotation(KOTLIN_METADATA_ANNOTATION) != null
-				&& cls.getAnnotation(KOTLIN_METADATA_ANNOTATION).getValues().get(KOTLIN_METADATA_D2_PARAMETER) != null
-				&& cls.getAnnotation(KOTLIN_METADATA_ANNOTATION).getValues().get(KOTLIN_METADATA_D2_PARAMETER) instanceof List) {
-			Object rawClassNameObject =
-					((List) cls.getAnnotation(KOTLIN_METADATA_ANNOTATION).getValues().get(KOTLIN_METADATA_D2_PARAMETER)).get(0);
-			if (rawClassNameObject instanceof String) {
-				String rawClassName = ((String) rawClassNameObject).trim().replace("/", ".");
-				if (rawClassName.length() > 1 && rawClassName.matches(KOTLIN_METADATA_CLASSNAME_REGEX)) {
-					return rawClassName;
-				}
-			}
-		}
-		return null;
-	}
-
 	@Nullable
 	private String getAliasFromSourceFile(ClassNode cls) {
 		SourceFileAttr sourceFileAttr = cls.get(AType.SOURCE_FILE);
@@ -628,6 +596,24 @@ public class Deobfuscator {
 		return NameMapper.removeInvalidCharsMiddle(name);
 	}
 
+	private String prepareNameFull(String name, String prefix) {
+		if (name.length() > maxLength) {
+			return makeHashName(name, prefix);
+		}
+		String result = NameMapper.removeInvalidChars(name, prefix);
+		if (result.isEmpty()) {
+			return makeHashName(name, prefix);
+		}
+		if (NameMapper.isReserved(result)) {
+			return prefix + result;
+		}
+		return result;
+	}
+
+	private static String makeHashName(String name, String invalidPrefix) {
+		return invalidPrefix + 'x' + Integer.toHexString(name.hashCode());
+	}
+
 	private void dumpClassAlias(ClassNode cls) {
 		PackageNode pkg = getPackageNode(cls.getPackage(), false);
 

jadx-core/src/main/java/jadx/core/utils/kotlin/KotlinMetadataUtils.java

+package jadx.core.utils.kotlin;
+
+import java.util.List;
+
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import jadx.api.plugins.input.data.annotations.EncodedType;
+import jadx.api.plugins.input.data.annotations.EncodedValue;
+import jadx.api.plugins.input.data.annotations.IAnnotation;
+import jadx.core.dex.info.ClassInfo;
+import jadx.core.dex.nodes.ClassNode;
+
+// TODO: parse data from d1 (protobuf encoded) to get original method names and other useful info
+public class KotlinMetadataUtils {
+	private static final Logger LOG = LoggerFactory.getLogger(KotlinMetadataUtils.class);
+
+	private static final String KOTLIN_METADATA_ANNOTATION = "Lkotlin/Metadata;";
+	private static final String KOTLIN_METADATA_D2_PARAMETER = "d2";
+	private static final String KOTLIN_METADATA_CLASSNAME_REGEX = "(L.*;)";
+
+	/**
+	 * Try to get class info from Kotlin Metadata annotation
+	 */
+	@Nullable
+	public static ClassInfo getClassName(ClassNode cls) {
+		IAnnotation metadataAnnotation = cls.getAnnotation(KOTLIN_METADATA_ANNOTATION);
+		List<EncodedValue> d2Param = getParamAsList(metadataAnnotation, KOTLIN_METADATA_D2_PARAMETER);
+		if (d2Param == null || d2Param.isEmpty()) {
+			return null;
+		}
+		EncodedValue firstValue = d2Param.get(0);
+		if (firstValue == null || firstValue.getType() != EncodedType.ENCODED_STRING) {
+			return null;
+		}
+		try {
+			String rawClassName = ((String) firstValue.getValue()).trim();
+			if (rawClassName.matches(KOTLIN_METADATA_CLASSNAME_REGEX)) {
+				return ClassInfo.fromName(cls.root(), rawClassName);
+			}
+		} catch (Exception e) {
+			LOG.error("Failed to parse kotlin metadata", e);
+		}
+		return null;
+	}
+
+	@SuppressWarnings("unchecked")
+	private static List<EncodedValue> getParamAsList(IAnnotation annotation, String paramName) {
+		if (annotation == null) {
+			return null;
+		}
+		EncodedValue encodedValue = annotation.getValues().get(paramName);
+		if (encodedValue == null || encodedValue.getType() != EncodedType.ENCODED_ARRAY) {
+			return null;
+		}
+		return (List<EncodedValue>) encodedValue.getValue();
+	}
+}

jadx-core/src/test/java/jadx/tests/integration/deobf/TestKotlinMetadata.java

+package jadx.tests.integration.deobf;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestKotlinMetadata extends SmaliTest {
+	// @formatter:off
+	/*
+		@file:JvmName("TestKotlinMetadata")
+		class TestMetaData {
+
+			@JvmField
+			val id = 1
+
+			@JvmName("makeTwo")
+			fun double(x: Int): Int {
+				return 2 * x
+			}
+		}
+	*/
+	// @formatter:on
+
+	@Test
+	public void test() {
+		prepareArgs(true);
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.containsOne("class TestMetaData {");
+	}
+
+	@Test
+	public void testIgnoreMetadata() {
+		prepareArgs(false);
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.containsOne("class C0000TestKotlinMetadata {");
+	}
+
+	private void prepareArgs(boolean parseKotlinMetadata) {
+		enableDeobfuscation();
+		args.setDeobfuscationMinLength(100); // rename everything
+		getArgs().setParseKotlinMetadata(parseKotlinMetadata);
+		disableCompilation();
+	}
+}

jadx-core/src/test/smali/deobf/TestKotlinMetadata.smali

+.class public final Ldeobf/TestKotlinMetadata;
+.super Ljava/lang/Object;
+.source "TestMetaData.kt"
+
+
+# annotations
+.annotation runtime Lkotlin/Metadata;
+    bv = {
+        0x1,
+        0x0,
+        0x3
+    }
+    d1 = {
+        "\u0000\u0014\n\u0002\u0018\u0002\n\u0002\u0010\u0000\n\u0002\u0008\u0002\n\u0002\u0010\u0008\n\u0002\u0008\u0004\u0018\u00002\u00020\u0001B\u0005\u00a2\u0006\u0002\u0010\u0002J\u0015\u0010\u0005\u001a\u00020\u00042\u0006\u0010\u0006\u001a\u00020\u0004H\u0007\u00a2\u0006\u0002\u0008\u0007R\u0010\u0010\u0003\u001a\u00020\u00048\u0006X\u0087D\u00a2\u0006\u0002\n\u0000\u00a8\u0006\u0008"
+    }
+    d2 = {
+        "LTestMetaData;",
+        "",
+        "()V",
+        "id",
+        "",
+        "double",
+        "x",
+        "makeTwo",
+        "test"
+    }
+    k = 0x1
+    mv = {
+        0x1,
+        0x4,
+        0x0
+    }
+.end annotation
+
+
+# instance fields
+.field public final id:I
+    .annotation build Lkotlin/jvm/JvmField;
+    .end annotation
+.end field
+
+
+# direct methods
+.method public constructor <init>()V
+    .registers 2
+
+    .prologue
+    .line 4
+    invoke-direct {p0}, Ljava/lang/Object;-><init>()V
+
+    .line 7
+    const/4 v0, 0x1
+
+    iput v0, p0, Ldeobf/TestKotlinMetadata;->id:I
+
+    return-void
+.end method
+
+
+# virtual methods
+.method public final makeTwo(I)I
+    .registers 3
+    .param p1, "x"    # I
+    .annotation build Lkotlin/jvm/JvmName;
+        name = "makeTwo"
+    .end annotation
+
+    .prologue
+    .line 11
+    mul-int/lit8 v0, p1, 0x2
+
+    return v0
+.end method