resources: improve string pool decoding and errors reporting

jadx-core/src/main/java/jadx/api/ResourcesLoader.java

@@ -2,6 +2,7 @@ package jadx.api;
 
 import jadx.api.ResourceFile.ZipRef;
 import jadx.core.codegen.CodeWriter;
+import jadx.core.utils.Utils;
 import jadx.core.utils.exceptions.JadxException;
 import jadx.core.utils.files.InputFile;
 import jadx.core.xmlgen.ResTableParser;
@@ -61,7 +62,7 @@ public final class ResourcesLoader {
 			inputStream = new BufferedInputStream(zipFile.getInputStream(entry));
 			return decoder.decode(entry.getSize(), inputStream);
 		} catch (Exception e) {
-			throw new JadxException("Error load: " + zipRef, e);
+			throw new JadxException("Error decode: " + zipRef.getEntryName(), e);
 		} finally {
 			try {
 				if (zipFile != null) {
@@ -90,8 +91,11 @@ public final class ResourcesLoader {
 			});
 		} catch (JadxException e) {
 			LOG.error("Decode error", e);
+			CodeWriter cw = new CodeWriter();
+			cw.add("Error decode ").add(rf.getType().toString().toLowerCase());
+			cw.startLine(Utils.getStackTrace(e.getCause()));
+			return cw;
 		}
-		return null;
 	}
 
 	private static CodeWriter loadContent(JadxDecompiler jadxRef, ResourceType type,

jadx-core/src/main/java/jadx/core/xmlgen/BinaryXMLParser.java

@@ -5,7 +5,6 @@ import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.nodes.DexNode;
 import jadx.core.dex.nodes.FieldNode;
 import jadx.core.dex.nodes.RootNode;
-import jadx.core.utils.Utils;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 import jadx.core.xmlgen.entry.ValuesParser;
 
@@ -75,20 +74,12 @@ public class BinaryXMLParser extends CommonBinaryParser {
 		}
 	}
 
-	public synchronized CodeWriter parse(InputStream inputStream) {
+	public synchronized CodeWriter parse(InputStream inputStream) throws IOException {
 		writer = new CodeWriter();
 		writer.add("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
 		is = new ParserStream(inputStream);
 		firstElement = true;
-		try {
 		decode();
-		} catch (IOException e) {
-			LOG.debug("Binary xml decode failed", e);
-			CodeWriter cw = new CodeWriter();
-			cw.add("Error decode binary xml");
-			cw.startLine(Utils.getStackTrace(e));
-			return cw;
-		}
 		writer.finish();
 		return writer;
 	}

jadx-core/src/main/java/jadx/core/xmlgen/CommonBinaryParser.java

 package jadx.core.xmlgen;
 
 import java.io.IOException;
+import java.util.Arrays;
 
 public class CommonBinaryParser extends ParserConstants {
-
 	protected ParserStream is;
 
 	protected String[] parseStringPool() throws IOException {
@@ -29,16 +29,14 @@ public class CommonBinaryParser extends ParserConstants {
 		is.checkPos(start + stringsStart, "Expected strings start");
 		long stringsEnd = stylesStart == 0 ? chunkEnd : start + stylesStart;
 		String[] strings = new String[stringCount];
+		byte[] strArray = is.readInt8Array((int) (stringsEnd - is.getPos()));
 		if ((flags & UTF8_FLAG) != 0) {
 			// UTF-8
 			for (int i = 0; i < stringCount; i++) {
-				// is.checkPos(start + stringsStart + stringsOffset[i], "Expected string start");
-				strings[i] = is.readString8();
+				strings[i] = extractString8(strArray, stringsOffset[i]);
 			}
-			is.skipToPos(stringsEnd, "Skip string8 padding");
 		} else {
 			// UTF-16
-			byte[] strArray = is.readInt8Array((int) (stringsEnd - is.getPos()));
 			for (int i = 0; i < stringCount; i++) {
 				// don't trust specified string length, read until \0
 				// stringsOffset can be same for different indexes
@@ -56,9 +54,22 @@ public class CommonBinaryParser extends ParserConstants {
 		return strings;
 	}
 
+	private static String extractString8(byte[] strArray, int offset) {
+		int start = offset + skipStrLen8(strArray, offset);
+		int len = strArray[start++];
+		if (len == 0) {
+			return "";
+		}
+		if ((len & 0x80) != 0) {
+			len = ((len & 0x7F) << 8) | (strArray[start++] & 0xFF);
+		}
+		byte[] arr = Arrays.copyOfRange(strArray, start, start + len);
+		return new String(arr, ParserStream.STRING_CHARSET_UTF8);
+	}
+
 	private static String extractString16(byte[] strArray, int offset) {
 		int len = strArray.length;
-		int start = offset + 2;
+		int start = offset + skipStrLen16(strArray, offset);
 		int end = start;
 		while (true) {
 			if (end + 1 >= len) {
@@ -69,7 +80,16 @@ public class CommonBinaryParser extends ParserConstants {
 			}
 			end += 2;
 		}
-		return new String(strArray, start, end - start, ParserStream.STRING_CHARSET_UTF16);
+		byte[] arr = Arrays.copyOfRange(strArray, start, end);
+		return new String(arr, ParserStream.STRING_CHARSET_UTF16);
+	}
+
+	private static int skipStrLen8(byte[] strArray, int offset) {
+		return (strArray[offset] & 0x80) == 0 ? 1 : 2;
+	}
+
+	private static int skipStrLen16(byte[] strArray, int offset) {
+		return (strArray[offset + 1] & 0x80) == 0 ? 2 : 4;
 	}
 
 	protected void die(String message) throws IOException {

jadx-core/src/main/java/jadx/core/xmlgen/ParserStream.java

@@ -9,6 +9,9 @@ public class ParserStream {
 	protected static final Charset STRING_CHARSET_UTF16 = Charset.forName("UTF-16LE");
 	protected static final Charset STRING_CHARSET_UTF8 = Charset.forName("UTF-8");
 
+	private static final int[] EMPTY_INT_ARRAY = new int[0];
+	private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
+
 	private final InputStream input;
 	private long readPos = 0;
 
@@ -46,34 +49,14 @@ public class ParserStream {
 		return readInt32() & 0xFFFFFFFFL;
 	}
 
-	public String readString8Fixed(int len) throws IOException {
-		String str = new String(readInt8Array(len), STRING_CHARSET_UTF8);
-		return str.trim();
-	}
-
 	public String readString16Fixed(int len) throws IOException {
 		String str = new String(readInt8Array(len * 2), STRING_CHARSET_UTF16);
 		return str.trim();
 	}
 
-	public String readString8() throws IOException {
-		decodeLength8();
-		int len = decodeLength8();
-		String str = new String(readInt8Array(len), STRING_CHARSET_UTF8);
-		checkInt8(0, "Not a trailing zero at string8 end");
-		return str;
-	}
-
-	public String readString16() throws IOException {
-		int len = decodeLength16();
-		String str = new String(readInt8Array(len), STRING_CHARSET_UTF16);
-		checkInt16(0, "Not a trailing zero at string16 end");
-		return str;
-	}
-
 	public int[] readInt32Array(int count) throws IOException {
 		if (count == 0) {
-			return new int[0];
+			return EMPTY_INT_ARRAY;
 		}
 		int[] arr = new int[count];
 		for (int i = 0; i < count; i++) {
@@ -84,7 +67,7 @@ public class ParserStream {
 
 	public byte[] readInt8Array(int count) throws IOException {
 		if (count == 0) {
-			return new byte[0];
+			return EMPTY_BYTE_ARRAY;
 		}
 		readPos += count;
 		byte[] arr = new byte[count];
@@ -147,22 +130,6 @@ public class ParserStream {
 		checkPos(expectedOffset, error);
 	}
 
-	public int decodeLength8() throws IOException {
-		int len = readInt8();
-		if ((len & 0x80) != 0) {
-			len = ((len & 0x7F) << 8) | readInt8();
-		}
-		return len;
-	}
-
-	public int decodeLength16() throws IOException {
-		int len = readInt16();
-		if ((len & 0x8000) != 0) {
-			len = ((len & 0x7FFF) << 16) | readInt16();
-		}
-		return len;
-	}
-
 	@Override
 	public String toString() {
 		return "pos: 0x" + Long.toHexString(readPos);

jadx-core/src/main/java/jadx/core/xmlgen/ResTableParser.java

 package jadx.core.xmlgen;
 
 import jadx.core.codegen.CodeWriter;
-import jadx.core.utils.Utils;
 import jadx.core.xmlgen.entry.EntryConfig;
 import jadx.core.xmlgen.entry.RawNamedValue;
 import jadx.core.xmlgen.entry.RawValue;
@@ -59,16 +58,8 @@ public class ResTableParser extends CommonBinaryParser {
 		resStorage.finish();
 	}
 
-	public CodeWriter decodeToCodeWriter(InputStream inputStream) {
-		try {
+	public CodeWriter decodeToCodeWriter(InputStream inputStream) throws IOException {
 		decode(inputStream);
-		} catch (IOException e) {
-			LOG.debug("arsc decode failed", e);
-			CodeWriter cw = new CodeWriter();
-			cw.add("Error decode arsc");
-			cw.startLine(Utils.getStackTrace(e));
-			return cw;
-		}
 
 		CodeWriter writer = new CodeWriter();
 		writer.add("app package: ").add(resStorage.getAppPackage());