Thursday, October 24, 2019 [Tweets] [Favorites]

AirDrop and Quarantine Flags

Howard Oakley:

AirDrop has a bigger problem, though: because it’s a semi-public way of pushing files of unknown pedigree onto an unsuspecting Mac (or iOS device), macOS attaches a quarantine flag to everything transferred by AirDrop. For documents that’s only a minor irritant, now that macOS so promiscuously sets quarantine flags on every document opened by a sandboxed app. It can still catch you out when you try to open that document with an app other than the default for that type.

But for apps, command tools and other forms of executable code, this is more serious. If you’ve just copied one of those across, on the receiving Mac that software is now going to trigger a full Gatekeeper first run check. If that destination system happens to be Catalina and the software should be notarized but isn’t, you could find yourself wasting time slipping it past that. For command tools in particular that can come as a complete surprise.

[…]

In Catalina, if the app isn’t notarized, double-clicking it will elicit the usual failure dialog, and opening it using the Finder’s Open command gives you the option to open it regardless.

I get why this happens, but it’s annoying when you just want to send yourself a file. I used to do this frequently during development to test the in-progress app on other systems. In that situation, you really don’t want to have to go through the full notarization process. The contextual menu bypass seems unreliable. Sometimes it doesn’t work the first time, sometimes it launches the app but shows an error message, anyway, and I’ve received one report of it not working at all. I’ve taken to transferring using rsync or scp, as those don’t add quarantine flags.

Previously:

2 Comments

It's time someone writes a background app that uses fsevents to learn about new files and automatically removes the quarantine flags :)

Sören Nils Kuklau

It’s time someone writes a background app that uses fsevents to learn about new files and automatically removes the quarantine flags :)

You can probably achieve that with a Folder Action. Seems someone else had the same thought.

Not sure how reliably Folder Actions are triggered, but presumably enough for downloading stuff in Safari?

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