Handoff Messages enable users to start tasks on one iOS or macOS device and finish them on another. Handoff is supported with the Apple Calendar, Contacts, Mail, Maps, Messages, Notes, Reminders, Safari, Pages, Numbers, Keynote applications, as well as certain third-party applications that are designed to support Handoff by their developers.
This message type was first described by Guillaume Celosia and Mathieu Cunche in Discontinued Privacy: Personal Data Leaks in Apple Bluetooth-Low-Energy Continuity Protocols.
| Field Name | Info | Example | Length | Type | Notes |
|---|---|---|---|---|---|
| btcommon.apple.handoff.copy | Copy/Cut Performed | No (0x0) | 1 | BOOL | |
| btcommon.apple.handoff.seqnum | IV (Sequence Number) | 23113 | 2 | UINT16 | |
| btcommon.apple.handoff.authtag | AES-GCM Auth Tag | 48 | 1 | Bytes | |
| btcommon.apple.handoff.encdata | Encrypted Handoff Data | f28a1927bd62fd895b5a | 10 | Bytes |
The message fields, observed values and their meaning:
- Type: 1 byte, 0x0C -- indicates a Handoff message
- Length: 1 byte -- number of bytes in the message
- Version: 1 byte
- Initialization Vector: 2 bytes
- AES-GCM Auth Tag: 1 byte
- Encrypted Payload: 10 bytes