fix: ignore incorrect dex files in apk (#700)

jadx-core/src/main/java/jadx/core/utils/files/InputFile.java

@@ -20,6 +20,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.android.dex.Dex;
+import com.android.dex.DexException;
 
 import jadx.core.utils.AsmUtils;
 import jadx.core.utils.exceptions.DecodeException;
@@ -52,7 +53,7 @@ public class InputFile {
 		String fileName = file.getName();
 
 		if (fileName.endsWith(".dex")) {
-			addDexFile(fileName, new Dex(file), file.toPath());
+			addDexFile(fileName, file.toPath());
 			return;
 		}
 		if (fileName.endsWith(".smali")) {
@@ -60,12 +61,12 @@ public class InputFile {
 			SmaliOptions options = new SmaliOptions();
 			options.outputDexFile = output.toAbsolutePath().toString();
 			Smali.assemble(options, file.getAbsolutePath());
-			addDexFile("", new Dex(output.toFile()), output);
+			addDexFile(fileName, output);
 			return;
 		}
 		if (fileName.endsWith(".class")) {
 			for (Path path : loadFromClassFile(file)) {
-				addDexFile(path);
+				addDexFile(fileName, path);
 			}
 			return;
 		}
@@ -80,7 +81,7 @@ public class InputFile {
 			}
 			if (fileName.endsWith(".jar")) {
 				for (Path path : loadFromJar(file.toPath())) {
-					addDexFile(path);
+					addDexFile(fileName, path);
 				}
 				return;
 			}
@@ -96,18 +97,6 @@ public class InputFile {
 		LOG.warn("No dex files found in {}", file);
 	}
 
-	private void addDexFile(Path path) throws IOException {
-		addDexFile(path.getFileName().toString(), path);
-	}
-
-	private void addDexFile(String fileName, Path path) throws IOException {
-		addDexFile(fileName, new Dex(Files.readAllBytes(path)), path);
-	}
-
-	private void addDexFile(String fileName, Dex dexBuf, Path path) {
-		dexFiles.add(new DexFile(this, fileName, dexBuf, path));
-	}
-
 	private boolean loadFromZip(String ext) throws IOException, DecodeException {
 		int index = 0;
 		try (ZipFile zf = new ZipFile(file)) {
@@ -127,9 +116,8 @@ public class InputFile {
 							|| entryName.endsWith(instantRunDexSuffix)) {
 						switch (ext) {
 							case ".dex":
-								Path path = makeDexBuf(entryName, inputStream);
-								if (path != null) {
-									addDexFile(entryName, path);
+								Path path = copyToTmpDex(entryName, inputStream);
+								if (addDexFile(entryName, path)) {
 									index++;
 								}
 								break;
@@ -163,8 +151,32 @@ public class InputFile {
 		return index > 0;
 	}
 
+	private boolean addDexFile(String entryName, @Nullable Path filePath) {
+		if (filePath == null) {
+			return false;
+		}
+		Dex dexBuf = loadDexBufFromPath(filePath, entryName);
+		if (dexBuf == null) {
+			return false;
+		}
+		dexFiles.add(new DexFile(this, entryName, dexBuf, filePath));
+		return true;
+	}
+
 	@Nullable
-	private Path makeDexBuf(String entryName, InputStream inputStream) {
+	private Dex loadDexBufFromPath(Path path, String entryName) {
+		try {
+			return new Dex(Files.readAllBytes(path));
+		} catch (DexException e) {
+			LOG.error("Failed to load dex file: {}, error: {}", entryName, e.getMessage());
+		} catch (Exception e) {
+			LOG.error("Failed to load dex file: {}, error: {}", entryName, e.getMessage(), e);
+		}
+		return null;
+	}
+
+	@Nullable
+	private Path copyToTmpDex(String entryName, InputStream inputStream) {
 		try {
 			Path path = FileUtils.createTempFile(".dex");
 			Files.copy(inputStream, path, StandardCopyOption.REPLACE_EXISTING);

jadx-core/src/test/java/jadx/core/utils/files/InputFileTest.java

@@ -0,0 +1,37 @@
+package jadx.core.utils.files;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.utils.exceptions.DecodeException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.notNullValue;
+
+class InputFileTest {
+	private static final String TEST_SAMPLES_DIR = "test-samples/";
+
+	@Test
+	public void testApkWithFakeDex() throws IOException, DecodeException {
+		File sample = getFileFromSampleDir("app-with-fake-dex.apk");
+
+		List<InputFile> list = new ArrayList<>();
+		InputFile.addFilesFrom(sample, list, false);
+		assertThat(list, hasSize(1));
+		InputFile inputFile = list.get(0);
+		assertThat(inputFile.getDexFiles(), hasSize(1));
+	}
+
+	private static File getFileFromSampleDir(String fileName) {
+		URL resource = InputFileTest.class.getClassLoader().getResource(TEST_SAMPLES_DIR + fileName);
+		assertThat(resource, notNullValue());
+		String pathStr = resource.getFile();
+		return new File(pathStr);
+	}
+}