phpman > man > systemd-cryptenroll(1)

SYSTEMD-CRYPTENROLL(1)                   systemd-cryptenroll                  SYSTEMD-CRYPTENROLL(1)



NAME
       systemd-cryptenroll - Enroll PKCS#11, FIDO2, TPM2 token/devices to LUKS2 encrypted volumes

SYNOPSIS
       systemd-cryptenroll [OPTIONS...] [DEVICE]

DESCRIPTION
       systemd-cryptenroll is a tool for enrolling hardware security tokens and devices into a LUKS2
       encrypted volume, which may then be used to unlock the volume during boot. Specifically, it
       supports tokens and credentials of the following kind to be enrolled:

        1. PKCS#11 security tokens and smartcards that may carry an RSA key pair (e.g. various
           YubiKeys)

        2. FIDO2 security tokens that implement the "hmac-secret" extension (most FIDO2 keys,
           including YubiKeys)

        3. TPM2 security devices

        4. Recovery keys. These are similar to regular passphrases, however are randomly generated
           on the computer and thus generally have higher entropy than user chosen passphrases.
           Their character set has been designed to ensure they are easy to type in, while having
           high entropy. They may also be scanned off screen using QR codes. Recovery keys may be
           used for unlocking LUKS2 volumes wherever passphrases are accepted. They are intended to
           be used in combination with an enrolled hardware security token, as a recovery option
           when the token is lost.

        5. Regular passphrases

       In addition, the tool may be used to enumerate currently enrolled security tokens and wipe a
       subset of them. The latter may be combined with the enrollment operation of a new security
       token, in order to update or replace enrollments.

       The tool supports only LUKS2 volumes, as it stores token meta-information in the LUKS2 JSON
       token area, which is not available in other encryption formats.

LIMITATIONS
       Note that currently when enrolling a new key of one of the five supported types listed above,
       it is required to first provide a passphrase or recovery key (i.e. one of the latter two key
       types). For example, it's currently not possible to unlock a device with a FIDO2 key in order
       to enroll a new FIDO2 key. Instead, in order to enroll a new FIDO2 key, it is necessary to
       provide an already enrolled regular passphrase or recovery key. Thus, if in future key
       roll-over is desired it's generally recommended to combine TPM2, FIDO2, PKCS#11 key
       enrollment with enrolling a regular passphrase or recovery key.

       Also note that support for enrolling multiple FIDO2 tokens is currently not too useful, as
       while unlocking systemd-cryptsetup cannot identify which token is currently plugged in and
       thus does not know which authentication request to send to the device. This limitation does
       not apply to tokens enrolled via PKCS#11 — because tokens of this type may be identified
       immediately, before authentication.

OPTIONS
       The following options are understood:

       --password
           Enroll a regular password/passphrase. This command is mostly equivalent to cryptsetup
           luksAddKey, however may be combined with --wipe-slot= in one call, see below.

       --recovery-key
           Enroll a recovery key. Recovery keys are most identical to passphrases, but are computer
           generated instead of human chosen, and thus have a guaranteed high entropy. The key uses
           a character set that is easy to type in, and may be scanned off screen via a QR code.

       --pkcs11-token-uri=URI
           Enroll a PKCS#11 security token or smartcard (e.g. a YubiKey). Expects a PKCS#11
           smartcard URI referring to the token. Alternatively the special value "auto" may be
           specified, in order to automatically determine the URI of a currently plugged in security
           token (of which there must be exactly one). The special value "list" may be used to
           enumerate all suitable PKCS#11 tokens currently plugged in. The security token must
           contain an RSA key pair which is used to encrypt the randomly generated key that is used
           to unlock the LUKS2 volume. The encrypted key is then stored in the LUKS2 JSON token
           header area.

           In order to unlock a LUKS2 volume with an enrolled PKCS#11 security token, specify the
           pkcs11-uri= option in the respective /etc/crypttab line:

               myvolume /dev/sda1 - pkcs11-uri=auto

           See crypttab(5) for a more comprehensive example of a systemd-cryptenroll invocation and
           its matching /etc/crypttab line.

       --fido2-device=PATH
           Enroll a FIDO2 security token that implements the "hmac-secret" extension (e.g. a
           YubiKey). Expects a hidraw device referring to the FIDO2 device (e.g.  /dev/hidraw1).
           Alternatively the special value "auto" may be specified, in order to automatically
           determine the device node of a currently plugged in security token (of which there must
           be exactly one). The special value "list" may be used to enumerate all suitable FIDO2
           tokens currently plugged in. Note that many hardware security tokens that implement FIDO2
           also implement the older PKCS#11 standard. Typically FIDO2 is preferable, given it's
           simpler to use and more modern.

           In order to unlock a LUKS2 volume with an enrolled FIDO2 security token, specify the
           fido2-device= option in the respective /etc/crypttab line:

               myvolume /dev/sda1 - fido2-device=auto

           See crypttab(5) for a more comprehensive example of a systemd-cryptenroll invocation and
           its matching /etc/crypttab line.

       --fido2-with-client-pin=BOOL
           When enrolling a FIDO2 security token, controls whether to require the user to enter a
           PIN when unlocking the volume (the FIDO2 "clientPin" feature). Defaults to "yes". (Note:
           this setting is without effect if the security token does not support the "clientPin"
           feature at all, or does not allow enabling or disabling it.)

       --fido2-with-user-presence=BOOL
           When enrolling a FIDO2 security token, controls whether to require the user to verify
           presence (tap the token, the FIDO2 "up" feature) when unlocking the volume. Defaults to
           "yes". (Note: this setting is without effect if the security token does not support the
           "up" feature at all, or does not allow enabling or disabling it.)

       --fido2-with-user-verification=BOOL
           When enrolling a FIDO2 security token, controls whether to require user verification when
           unlocking the volume (the FIDO2 "uv" feature). Defaults to "no". (Note: this setting is
           without effect if the security token does not support the "uv" feature at all, or does
           not allow enabling or disabling it.)

       --tpm2-device=PATH
           Enroll a TPM2 security chip. Expects a device node path referring to the TPM2 chip (e.g.
           /dev/tpmrm0). Alternatively the special value "auto" may be specified, in order to
           automatically determine the device node of a currently discovered TPM2 device (of which
           there must be exactly one). The special value "list" may be used to enumerate all
           suitable TPM2 devices currently discovered.

           In order to unlock a LUKS2 volume with an enrolled TPM2 security chip, specify the
           tpm2-device= option in the respective /etc/crypttab line:

               myvolume /dev/sda1 - tpm2-device=auto

           See crypttab(5) for a more comprehensive example of a systemd-cryptenroll invocation and
           its matching /etc/crypttab line.

           Use --tpm2-pcrs= (see below) to configure which TPM2 PCR indexes to bind the enrollment
           to.

       --tpm2-pcrs= [PCR...]
           Configures the TPM2 PCRs (Platform Configuration Registers) to bind the enrollment
           requested via --tpm2-device= to. Takes a "+" separated list of numeric PCR indexes in the
           range 0...23. If not used, defaults to PCR 7 only. If an empty string is specified, binds
           the enrollment to no PCRs at all. PCRs allow binding the enrollment to specific software
           versions and system state, so that the enrolled unlocking key is only accessible (may be
           "unsealed") if specific trusted software and/or configuration is used.

           Table 1. Well-known PCR Definitions
           ┌────┬───────────────────────────────────┐
           │PCR │ Explanation                       │
           ├────┼───────────────────────────────────┤
           │0   │ Core system firmware executable   │
           │    │ code; changes on firmware updates │
           ├────┼───────────────────────────────────┤
           │1   │ Core system firmware data/host    │
           │    │ platform configuration; typically │
           │    │ contains serial and model         │
           │    │ numbers, changes on basic         │
           │    │ hardware/CPU/RAM replacements     │
           ├────┼───────────────────────────────────┤
           │2   │ Extended or pluggable executable  │
           │    │ code; includes option ROMs on     │
           │    │ pluggable hardware                │
           ├────┼───────────────────────────────────┤
           │3   │ Extended or pluggable firmware    │
           │    │ data; includes information about  │
           │    │ pluggable hardware                │
           ├────┼───────────────────────────────────┤
           │4   │ Boot loader; changes on boot      │
           │    │ loader updates                    │
           ├────┼───────────────────────────────────┤
           │5   │ GPT/Partition table; changes when │
           │    │ the partitions are added,         │
           │    │ modified or removed               │
           ├────┼───────────────────────────────────┤
           │6   │ Power state events; changes on    │
           │    │ system suspend/sleep              │
           ├────┼───────────────────────────────────┤
           │7   │ Secure boot state; changes when   │
           │    │ UEFI SecureBoot mode is           │
           │    │ enabled/disabled                  │
           ├────┼───────────────────────────────────┤
           │8   │ sd-boot(7) measures the kernel    │
           │    │ command line in this PCR.         │
           └────┴───────────────────────────────────┘

       --wipe-slot= [SLOT...]
           Wipes one or more LUKS2 key slots. Takes a comma separated list of numeric slot indexes,
           or the special strings "all" (for wiping all key slots), "empty" (for wiping all key
           slots that are unlocked by an empty passphrase), "password" (for wiping all key slots
           that are unlocked by a traditional passphrase), "recovery" (for wiping all key slots that
           are unlocked by a recovery key), "pkcs11" (for wiping all key slots that are unlocked by
           a PKCS#11 token), "fido2" (for wiping all key slots that are unlocked by a FIDO2 token),
           "tpm2" (for wiping all key slots that are unlocked by a TPM2 chip), or any combination of
           these strings or numeric indexes, in which case all slots matching either are wiped. As
           safety precaution an operation that wipes all slots without exception (so that the volume
           cannot be unlocked at all anymore, unless the volume key is known) is refused.

           This switch may be used alone, in which case only the requested wipe operation is
           executed. It may also be used in combination with any of the enrollment options listed
           above, in which case the enrollment is completed first, and only when successful the wipe
           operation executed — and the newly added slot is always excluded from the wiping.
           Combining enrollment and slot wiping may thus be used to update existing enrollments:

               systemd-cryptenroll /dev/sda1 --wipe-slot=tpm2 --tpm2-device=auto

           The above command will enroll the TPM2 chip, and then wipe all previously created TPM2
           enrollments on the LUKS2 volume, leaving only the newly created one. Combining wiping and
           enrollment may also be used to replace enrollments of different types, for example for
           changing from a PKCS#11 enrollment to a FIDO2 one:

               systemd-cryptenroll /dev/sda1 --wipe-slot=pkcs11 --fido2-device=auto

           Or for replacing an enrolled empty password by TPM2:

               systemd-cryptenroll /dev/sda1 --wipe-slot=empty --tpm2-device=auto

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

EXIT STATUS
       On success, 0 is returned, a non-zero failure code otherwise.

SEE ALSO
       systemd(1), systemd-cryptsetup@.service(8), crypttab(5), cryptsetup(8)



systemd 249                                                                   SYSTEMD-CRYPTENROLL(1)