FIX: Messages with IDs starting with 66 and 67

[vphelipe]

🇧🇷 🇧🇷 🇧🇷 🇧🇷 🇧🇷

Pull Request: Fixing encodeBinaryNode in Whiskeysockets

Problem Description

The encodeBinaryNode method in the Whiskeysockets library had a bug in the writeString function. The issue stemmed from an incorrect order of type checks, causing strings that should be encoded as text to be misinterpreted as hexadecimal.

Problematic Behavior

The isHex(str) check in writeString occurred before decoding as a JID or falling back to writeStringRaw(str). As a result, strings with hexadecimal-like characters were treated as hex values, producing malformed nodes.

This affected the sendMessageAck function, which generates and sends acknowledgment nodes. Malformed nodes were not recognized by recipients, resulting in infinite resends and message flow blockages.

Example received message triggering the bug:

{
  "key": {
    "remoteJid": "[email protected]",
    "fromMe": false,
    "id": "679d1b73e54738f418353c1f"
  },
  "messageTimestamp": 1738349428,
  "pushName": "Adcol  Contabilidade",
  "message": {
    "conversation": "Prezado(a)\n...",
    "messageContextInfo": {
      "deviceListMetadataVersion": 2
    }
  }
}

Malformed ACK node sent:

{
  "tag": "ack",
  "attrs": {
    "id": "679d1b73e54738f418353c1f",
    "to": "556182615929:[email protected]",
    "class": "receipt"
  }
}

---

Solution Implemented

The writeString function was updated to ensure:

1. Tokens from TOKEN_MAP are prioritized.
2. Nibble-encoded strings are processed appropriately.
3. Strings are decoded as JIDs if possible.
4. Non-JIDs default to raw text encoding with writeStringRaw.
5. Hexadecimal packing is the final fallback.

Updated writeString implementation:

const writeString = (str) => {
    const tokenIndex = TOKEN_MAP[str];
    if (tokenIndex) {
        if (typeof tokenIndex.dict === 'number') {
            pushByte(TAGS.DICTIONARY_0 + tokenIndex.dict);
        }
        pushByte(tokenIndex.index);
    }
    else if (isNibble(str)) {
        writePackedBytes(str, 'nibble');
    }
    else {
        const decodedJid = (0, jid_utils_1.jidDecode)(str);
        if (decodedJid) {
            writeJid(decodedJid);
        }
        else {
            writeStringRaw(str);
        }
    }
};

Benefits

• Correctly encodes strings resembling hexadecimal values but acting as identifiers.
• Resolves malformed nodes in sendMessageAck.
• Eliminates infinite ACK resend loops.

Tests Performed

Tests included:

1. IDs starting with 66 and 67.

All tests confirmed correct ACK formatting and server acceptance without retries.

Conclusion

This PR resolves a critical encoding issue in encodeBinaryNode, ensuring reliable and efficient message handling. It eliminates malformed ACK nodes and improves library stability and communication performance.

THANKS to Renato (https://github.com/renatoiub) for providing me with numbers that send this type of message for testing.

[whiskeysockets-bot]

Thanks for your contribution.

The next step is to wait for review and approval to merge it to main repository

The community can help reacting with a thumb up (:thumbsup:) for approval and rocket (:rocket:) for who has tested it.

To test this PR you can run the following command below:

# NPM
npm install @whiskeysockets/baileys@vphelipe/Baileysbsb#master
# YARN v2
yarn add @whiskeysockets/baileys@vphelipe/Baileysbsb#master

[T3uZ]

functional

[purpshell]

This PR shouldn't be merged as the hex encoding is now totally useless ( if (str) creates dead code). Thanks anyways