shwenzhang/AndResGuard · error · brut.androlib.AndrolibException

Invalid chunk type: expected=

Error message

Invalid chunk type: expected=%d, got=%d

What it means

In the write/encode pass, writeNextChunkCheck reads the next chunk header, writes it through with a size adjustment (diffSize), and asserts the chunk type matches what the encoder expects next. A mismatch means the source arsc structure deviates from the decode order, so the re-serialized table would be invalid and the tool aborts.

Solutions

  1. Run AndResGuard on the original aapt-built APK only, never on already-processed output
  2. Rebuild resources.arsc with the official Android build tools
  3. Upgrade AndResGuard to the latest version
  4. Diff the arsc chunk layout with aapt dump resources to identify the unexpected chunk

Example fix

// before
apply plugin: 'AndResGuard' // reprocessing a previously guarded apk
// after: feed the plugin the original unsigned release apk from the build pipeline
Defensive patterns

Strategy: try-catch

Validate before calling

if (!originalApkChecksumMatches(buildOutput)) throw new IllegalStateException("Input must be the original aapt-built APK");

Try / catch

try {
  encodeArsc(in, out);
} catch (AndrolibException e) {
  if (e.getMessage().startsWith("Invalid chunk type")) {
    logger.error("Write pass hit unexpected chunk; input arsc is non-standard");
    fallbackToNonObfuscatedBuild();
  } else throw e;
}

Prevention

When it happens

Trigger: During re-encoding, Header.readAndWriteHeader returns a header whose type != expectedType — the write-pass chunk sequence diverges from the expected table/package/typespec/config ordering, typically due to a modified or non-standard resources.arsc.

Common situations: Double-obfuscated APKs, arsc rewritten by repackers, arsc built by tools emitting chunks in a different order, or corruption in the input APK.

Related errors

AI-assisted analysis of shwenzhang/AndResGuard@e4df245d82 (2026-09-12). Data as JSON: /api/errors/9e86cafa83b7d1f9. Report an issue: GitHub.

Appendix: source

Thrown at AndResGuard-core/src/main/java/com/tencent/mm/androlib/res/decoder/ARSCDecoder.java:993

         mHeader.type
      ));
    }
  }

  private void nextChunkCheckType(int expectedType) throws IOException, AndrolibException {
    nextChunk();
    checkChunkType(expectedType);
  }

  private Header writeNextChunk(int diffSize) throws IOException, AndrolibException {
    mHeader = Header.readAndWriteHeader(mIn, mOut, diffSize);
    return mHeader;
  }

  private Header writeNextChunkCheck(int expectedType, int diffSize) throws IOException, AndrolibException {
    mHeader = Header.readAndWriteHeader(mIn, mOut, diffSize);
    if (mHeader.type != expectedType) {
      throw new AndrolibException(String.format("Invalid chunk type: expected=%d, got=%d", expectedType, mHeader.type));
    }
    return mHeader;
  }

  /**
   * 为了加速，不需要处理string,id,array，这几个是肯定不是的
   */
  private boolean isToResguardFile(String name) {
    return (!name.equals("string") && !name.equals("id") && !name.equals("array"));
  }

  public static class Header {
    public final static short TYPE_NONE = -1, TYPE_TABLE = 0x0002, TYPE_PACKAGE = 0x0200, TYPE_TYPE = 0x0201,
       TYPE_SPEC_TYPE = 0x0202, TYPE_LIBRARY = 0x0203;

    public final short type;
    public final int chunkSize;

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