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If you have experience with contact cards, then it's all the same as far as end applications are concerned, it's abstracted away. > is gnupg aware of contactle

by xaduha 6y ago

If you have experience with contact cards, then it's all the same as far as end applications are concerned, it's abstracted away. > is gnupg aware of contactless readers and will it e.g. ask for your PIN without the card being present and then prompt you to tap the card? No, it will behave as if there's no card/ring if you don't have it around the reader. Software polish is a weak point, e.g things like `ssh-add -s /usr/lib/opensc-pkcs11.so` can be used to 'cache' the PIN for a session as far as `ssh -A` connection is concerned, but that's not exactly the height of usability.

ryukafalz 6y ago
Ahh, interesting. I suppose then testing when it’s possible to insert/remove a contact card without disruption would give me a good idea of what to expect from a contactless card. Thanks for the info! EDIT: It seems like requesting a decryption, removing/inserting a Yubikey while the pinentry screen is up, then entering the PIN does not work. I suppose I've broken the session then. So I'm guessing to use a ring form-factor card, I'd have to keep the ring above the reader during the whole operation, which means I'd have to remove it to place on the reader and can't just keep it on/tap when needed. Hm. That's a bit unfortunate. (Also possible the Yubikey behaves differently as it's both reader and card in one... I don't have a dedicated reader set up to test with at the moment.) EDIT 2: For anyone who comes across this later: no, a dedicated reader behaves the same way; once the pinentry prompt is open, you can't remove the card and reinsert without invalidating that request.
- xaduha 6y ago
  BTW if you decide to buy a contactless reader steer clear of acr122u, they pop up first in the search results and either fake or bad or both. Research before you buy, don't look for NFC, looks for contactless PC/SC https://ccid.apdu.fr/#readers https://ccid.apdu.fr/#readers http://nfc-tools.org/index.php/Devices_compatibility_matrix http://nfc-tools.org/index.php/Devices_compatibility_matrix https://webshop.d-logic.net/nfc-rfid-device-comparison https://webshop.d-logic.net/nfc-rfid-device-comparison

by xaduha 6y ago

ryukafalz 6y ago

Ahh, interesting. I suppose then testing when it’s possible to insert/remove a contact card without disruption would give me a good idea of what to expect from a contactless card. Thanks for the info! EDIT: It seems like requesting a decryption, removing/inserting a Yubikey while the pinentry screen is up, then entering the PIN does not work. I suppose I've broken the session then. So I'm guessing to use a ring form-factor card, I'd have to keep the ring above the reader during the whole operation, which means I'd have to remove it to place on the reader and can't just keep it on/tap when needed. Hm. That's a bit unfortunate. (Also possible the Yubikey behaves differently as it's both reader and card in one... I don't have a dedicated reader set up to test with at the moment.) EDIT 2: For anyone who comes across this later: no, a dedicated reader behaves the same way; once the pinentry prompt is open, you can't remove the card and reinsert without invalidating that request.

xaduha 6y ago
BTW if you decide to buy a contactless reader steer clear of acr122u, they pop up first in the search results and either fake or bad or both. Research before you buy, don't look for NFC, looks for contactless PC/SC https://ccid.apdu.fr/#readers https://ccid.apdu.fr/#readers http://nfc-tools.org/index.php/Devices_compatibility_matrix http://nfc-tools.org/index.php/Devices_compatibility_matrix https://webshop.d-logic.net/nfc-rfid-device-comparison https://webshop.d-logic.net/nfc-rfid-device-comparison