Comment by hnburnsy

5 years ago

'AWDL is an Apple-proprietary mesh networking protocol designed to allow Apple devices like iPhones, iPads, Macs and Apple Watches to form ad-hoc peer-to-peer mesh networks. ... And even if you haven't been using those features, if people nearby have been then it's quite possible your device joined the AWDL mesh network they were using anyway.'

Wow, so Apple was ahead of Amazon's Sidewalk with AWDL. Can you disable this?

4 comments

hnburnsy

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neilalexander  5 years ago

> Wow, so Apple was ahead of Amazon's Sidewalk with AWDL.

Not exactly. The wording in the article implies that AWDL forms some kind of multi-hop network topology, but it doesn’t - it just enables nearby devices to communicate with each other directly at Wi-Fi speeds without the burden of pairing (like Wi-Fi Direct) or being associated with the same Wi-Fi network.

This is used not just in AirDrop but also in the Multipeer Connectivity Framework, AirPlay 2 and the Continuity framework. The standard discovery mechanism for these services is mDNS over AWDL, so for a device to browse for or advertise these services, it needs to be aware of other nearby AWDL neighbours first. (For example, you can browse for and discover other nearby AirDrop devices even if you don’t allow incoming AirDrop enabled yourself.)

It’s also worth noting that Apple devices very strictly do not send or receive AWDL traffic when they are locked/asleep, and will often even stop listening on the AWDL social channels when there are no services being advertised or in use.

philsnow  5 years ago

It looks like disabling airdrop doesn't do anything:

> All iOS devices are constantly receiving and processing BLE advertisement frames like this. In the case of these AirDrop advertisements, when the device is in the default "Contacts Only" mode, sharingd (which parses BLE advertisements) checks whether this unsalted, truncated hash matches the truncated hashes of any emails or phone numbers in the device's address book.

Then follows the section on brute-forcing 2 bytes (only) of a SHA256 hash.

Spray noise on channels 6 and 44?

  • richardwhiuk  5 years ago

    I don't think that proves what you think it does - that's with AirDrop on, but in a limited mode.

    If you turn AirDrop/Bluetooth off, you may well disable this.

    On my phone:

    - If you disable Bluetooth in the notification tray, then it goes to Bluetooth "Not Connected", but not Off. - If you disable Bluetooth in settings, AirDrop automatically goes into "Receiving Off". - If you then enable AirDrop, it'll automatically turn Bluetooth on.

    So I don't think it's true that you can't disable it - unless the UI is misleading about Off.