, systemd-cryptsetup - Full disk decryption logic
is a service responsible for setting up encrypted block devices. It is instantiated for each device that requires decryption for access.
will ask for hard disk passwords via the
m[blue]password agent logicm, in order to query the user for the password using the right mechanism at boot and during runtime.
At early boot and when the system manager configuration is reloaded,
is translated into
In order to unlock a volume a password or binary key is required.
tries to acquire a suitable password or binary key via the following mechanisms, tried in order:
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
options) the key is decrypted before use.
If no key file is configured explicitly this way, a key file is automatically loaded from
/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.
option is specified it is then attempted to unlock the volume with an empty password.
The kernel keyring is then checked for a suitable cached password from previous attempts.
Finally, the user is queried for a password, possibly multiple times.
If no suitable key may be acquired via any of the mechanisms describes above, volume activation fails.
password agent logic