DOKK / manpages / debian 10 / systemd / systemd-cryptsetup.8.en
SYSTEMD-CRYPTSETUP@.SERVICE(8) systemd-cryptsetup@.service SYSTEMD-CRYPTSETUP@.SERVICE(8)

systemd-cryptsetup@.service, systemd-cryptsetup - Full disk decryption logic

systemd-cryptsetup@.service

/lib/systemd/systemd-cryptsetup

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 will ask for hard disk passwords via the password agent logic[1], 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, /etc/crypttab is translated into systemd-cryptsetup@.service units by systemd-cryptsetup-generator(8).

systemd(1), systemd-cryptsetup-generator(8), crypttab(5), cryptsetup(8)

1.
password agent logic
https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents
systemd 241