@jstark/tplink-smarthome-crypto

Encryption/decryption for TP-Link Smart Home device communication — a maintained, dependency-free fork of plasticrake/tplink-smarthome-crypto. Requires Node.js 22+.

TP-Link devices use a simple XOR "autokey" cipher. TCP messages are prefixed with a 4-byte big-endian length header; UDP messages are not.

Install

npm install @jstark/tplink-smarthome-crypto

Usage

const {
  encrypt,
  decrypt,
  encryptWithHeader,
  decryptWithHeader,
} = require('@jstark/tplink-smarthome-crypto');

const payload = '{"system":{"get_sysinfo":{}}}';

// UDP (no length header)
const udp = encrypt(payload);
decrypt(udp).toString(); // -> original payload

// TCP (4-byte length header)
const tcp = encryptWithHeader(payload);
decryptWithHeader(tcp).toString(); // -> original payload

API

All functions accept a Buffer or string and return a Buffer.

• encrypt(input, firstKey = 0xab) — encrypt without a length header (UDP).
• decrypt(input, firstKey = 0xab) — decrypt data without a length header (UDP).
• encryptWithHeader(input, firstKey = 0xab) — encrypt and prepend a 4-byte length header (TCP).
• decryptWithHeader(input, firstKey = 0xab) — strip the 4-byte header and decrypt (TCP).

Supported Devices

Smart plugs/switches (HS100, HS200, HSxxx, KPxxx) and smart bulbs (LB100, LB200, LBxxx, KLxxx). Note that Tapo devices are not supported.

Related Projects

• @jstark/tplink-smarthome-api — the smart home API that uses this library (same monorepo)
• TP-Link Smarthome Device Simulator — useful for automated testing
• TP-Link Smarthome Homebridge Plugin

Credits

Forked from plasticrake/tplink-smarthome-crypto (MIT). Thanks to George Georgovassilis and Thomas Baust for figuring out the HS1XX encryption.