логика полного дешифрования диска (Full disk decryption logic)
Имя (Name)
systemd-cryptsetup@.service, systemd-cryptsetup - Full disk
decryption logic
Синопсис (Synopsis)
systemd-cryptsetup@.service
system-systemd\x2dcryptsetup.slice
/usr/lib/systemd/systemd-cryptsetup
Описание (Description)
systemd-cryptsetup@.service is a service responsible for setting
up encrypted block devices. It is instantiated for each device
that requires decryption for access.
systemd-cryptsetup@.service instances are part of the
system-systemd\x2dcryptsetup.slice slice, which is destroyed only
very late in the shutdown procedure. This allows the encrypted
devices to remain up until filesystems have been unmounted.
systemd-cryptsetup@.service will ask for hard disk passwords via
the password agent logic
At early boot and when the system manager configuration is
reloaded, /etc/crypttab is translated into
systemd-cryptsetup@.service units by
systemd-cryptsetup-generator(8).
In order to unlock a volume a password or binary key is required.
systemd-cryptsetup@.service tries to acquire a suitable password
or binary key via the following mechanisms, tried in order:
1. If a key file is explicitly configured (via the third column
in /etc/crypttab), a key read from it is used. If a PKCS#11
token, FIDO2 token or TPM2 device is configured (using the
pkcs11-uri=, fido2-device=, tpm2-device= options) the key is
decrypted before use.
2. If no key file is configured explicitly this way, a key file
is automatically loaded from
/etc/cryptsetup-keys.d/volume.key and
/run/cryptsetup-keys.d/volume.key, if present. Here too, if a
PKCS#11/FIDO2/TPM2 token/device is configured, any key found
this way is decrypted before use.
3. If the try-empty-password option is specified it is then
attempted to unlock the volume with an empty password.
4. The kernel keyring is then checked for a suitable cached
password from previous attempts.
5. Finally, the user is queried for a password, possibly
multiple times, unless the headless option is set.
If no suitable key may be acquired via any of the mechanisms
describes above, volume activation fails.
Смотри также (See also)
systemd(1), systemd-cryptsetup-generator(8), crypttab(5),
systemd-cryptenroll(1), cryptsetup(8)
Примечание (Note)
1. password agent logic
https://systemd.io/PASSWORD_AGENTS/
