Inform Protocol

UniFi devices communicate to their controller via HTTP POST as application/x-binary containing it's current status every ~10 seconds to the inform URL. The inform URL defaults to http://unifi:8080/inform but may be set to the controller's IP address. A controller will respond with either a no-op and an interval for the next inform or command for the device to execute. A UniFi device will execute commands and send another inform packet. Requests and responses share the same format encoded in big endian byte order. When reading, inform packets are decrypted before decompression, inverse is true for writing. There is currently only one payload version. Payload version 1 is JSON content and is the current version.

Encryption/Decryption

There are two possible ciphers used to encrypt the inform payload. Although you can send the controller plain-text, it will not respond to non-encrypted payloads. AES-CBC is used, and is the default, if the 1st-bit is set on the flag, or AES-GCM if the 1st-bit and 4th-bit are set. The Initialization Vector is 16 bytes in length and is sent in the header. The default encryption authkey is the MD5 hash of ubnt (ba86f2bbe107c7c57eb5f2690775c712). When decrypting AES-GCM the first 40 bytes of the packet is used as the additional authenticated data (AAD) and the last 16 bytes of the payload is the tag.

Compression/Decompression

There are two possible compression modes used at the moment. The default method is ZLib and uses the 2nd-bit of the flag. Snappy is another possible compression method and uses the 3rd-bit.

Packet Structure

Flags