Crates.io | card-backend-scdc |
lib.rs | card-backend-scdc |
version | 0.5.0 |
source | src |
created_at | 2023-08-28 15:48:29.676628 |
updated_at | 2023-09-05 23:54:56.378197 |
description | Experimental SCDaemon Client, e.g. for use with the openpgp-card crate |
homepage | |
repository | https://gitlab.com/openpgp-card/openpgp-card |
max_upload_size | |
id | 957124 |
size | 14,398 |
This crate provides ScdBackend
/ScdTransaction
, which is an implementation
of the CardBackend
/CardTransaction
traits that uses an instance of GnuPG's
scdaemon
to access OpenPGP cards.
Note that (unlike card-backend-pcsc
), this backend doesn't implement
transaction guarantees.
Uploading RSA 4096 keys via scdaemon
doesn't work with cards that don't
support Command Chaining (e.g. the "Floss Shop OpenPGP Smart Card").
This is caused by a size limitation for client requests via the
Assuan protocol.
Assuan "Client requests" are limited to 1000 chars. Commands are sent as
ASCII encoded hex, so APDU commands are limited to around 480 bytes. This
is insufficient for importing RSA 4096 keys to the card (all other
OpenPGP card operations fit into this constraint).
When using scdaemon
via pcsc (by configuring scdaemon
with
disable-ccid
), choosing a specific card of multiple plugged-in OpenPGP
cards seems to be broken.
So you probably want to plug in only one OpenPGP card at a time when using
openpgp-card-scdc
combined with disable-ccid
.
When using scdaemon
via its default ccid
driver, choosing a
specific one of multiple plugged-in OpenPGP cards seems to only work up
to 4 plugged-in cards.
So you probably want to plug in at most four OpenPGP cards at a time when
using card-backend-scdc
with its ccid driver.
(This limit has been raised in GnuPG 2.3.x)