# systemd-cryptenroll

## 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
               or EC 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. Regular passphrases
    
            5. 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.
    
           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.
    
           **systemd-cryptsetup** operates on the device backing /var/ if no
           device is specified explicitly, and no wipe operation is
           requested. (Note that in the typical case where /var/ is on the
           same file system as the root file system, this hence enrolls a key
           into the backing device of the root file system.)
    
       **TPM2 PCRs and policies**
           PCRs allow binding of the encryption of secrets to specific
           software versions and system state, so that the enrolled key is
           only accessible (may be "unsealed") if specific trusted software
           and/or configuration is used. Such bindings may be created with
           the option **--tpm2-pcrs=** described below.
    
           Secrets may also be bound indirectly: a signed policy for a state
           of some combination of PCR values is provided, and the secret is
           bound to the public part of the key used to sign this policy. This
           means that the owner of a key can generate a sequence of signed
           policies, for specific software versions and system states, and
           the secret can be decrypted as long as the machine state matches
           one of those policies. For example, a vendor may provide such a
           policy for each kernel+initrd update, allowing users to encrypt
           secrets so that they can be decrypted when running any
           kernel+initrd signed by the vendor. Such bindings may be created
           with the options **--tpm2-public-key=** , **--tpm2-public-key-pcrs=** ,
           **--tpm2-signature=** described below.
    
           See **Linux TPM PCR Registry******[1] for an authoritative list of PCRs
           and how they are updated. The table below contains a quick
           reference, describing in particular the PCRs modified by systemd.**Table 1. Well-known PCR Definitions**
           ┌─────┬─────────────────────┬───────────────────────────────┐
           │ **PCR** │ **name** │ **Explanation** │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 0   │ platform-code       │ Core system                   │
           │     │                     │ firmware                      │
           │     │                     │ executable code;              │
           │     │                     │ changes on                    │
           │     │                     │ firmware updates              │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 1   │ platform-config     │ Core system                   │
           │     │                     │ firmware data/host            │
           │     │                     │ platform                      │
           │     │                     │ configuration;                │
           │     │                     │ typically contains            │
           │     │                     │ serial and model              │
           │     │                     │ numbers, changes              │
           │     │                     │ on basic                      │
           │     │                     │ hardware/CPU/RAM              │
           │     │                     │ replacements                  │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 2   │ external-code       │ Extended or                   │
           │     │                     │ pluggable                     │
           │     │                     │ executable code;              │
           │     │                     │ includes option               │
           │     │                     │ ROMs on pluggable             │
           │     │                     │ hardware                      │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 3   │ external-config     │ Extended or                   │
           │     │                     │ pluggable firmware            │
           │     │                     │ data; includes                │
           │     │                     │ information about             │
           │     │                     │ pluggable hardware            │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 4   │ boot-loader-code    │ Boot loader and               │
           │     │                     │ additional                    │
           │     │                     │ drivers, PE                   │
           │     │                     │ binaries invoked              │
           │     │                     │ by the boot                   │
           │     │                     │ loader; changes on            │
           │     │                     │ boot loader                   │
           │     │                     │ updates.                      │
           │     │                     │ sd-stub(7)                    │
           │     │                     │ measures system               │
           │     │                     │ extension images              │
           │     │                     │ read from the ESP             │
           │     │                     │ here too (see                 │
           │     │                     │ systemd-sysext(8)).           │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 5   │ boot-loader-config  │ GPT/Partition                 │
           │     │                     │ table; changes when           │
           │     │                     │ the partitions are            │
           │     │                     │ added, modified, or           │
           │     │                     │ removed                       │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 7   │ secure-boot-policy  │ Secure Boot state;            │
           │     │                     │ changes when UEFI             │
           │     │                     │ SecureBoot mode is            │
           │     │                     │ enabled/disabled,             │
           │     │                     │ or firmware                   │
           │     │                     │ certificates (PK,             │
           │     │                     │ KEK, db, dbx, ...)            │
           │     │                     │ changes.                      │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 9   │ kernel-initrd       │ The Linux kernel              │
           │     │                     │ measures all                  │
           │     │                     │ initrds it receives           │
           │     │                     │ into this PCR.                │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 10  │ ima                 │ The IMA project               │
           │     │                     │ measures its                  │
           │     │                     │ runtime state into            │
           │     │                     │ this PCR.                     │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 11  │ kernel-boot         │ systemd-stub(7)               │
           │     │                     │ measures the ELF              │
           │     │                     │ kernel image,                 │
           │     │                     │ embedded initrd and           │
           │     │                     │ other payload of              │
           │     │                     │ the PE image it is            │
           │     │                     │ placed in into this           │
           │     │                     │ PCR.                          │
           │     │                     │ systemd-pcrphase.service(8)   │
           │     │                     │ measures boot phase           │
           │     │                     │ strings into this             │
           │     │                     │ PCR at various                │
           │     │                     │ milestones of the             │
           │     │                     │ boot process.                 │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 12  │ kernel-config       │ systemd-boot(7) measures      │
           │     │                     │ the kernel command line       │
           │     │                     │ into this PCR.                │
           │     │                     │ systemd-stub(7) measures      │
           │     │                     │ any manually specified        │
           │     │                     │ kernel command line (i.e. a   │
           │     │                     │ kernel command line that      │
           │     │                     │ overrides the one embedded    │
           │     │                     │ in the unified PE image)      │
           │     │                     │ and loaded credentials into   │
           │     │                     │ this PCR.                     │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 13  │ sysexts             │ systemd-stub(7) measures      │
           │     │                     │ any systemd-sysext(8)         │
           │     │                     │ images it passes to the       │
           │     │                     │ booted kernel into this       │
           │     │                     │ PCR.                          │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 14  │ shim-policy         │ The shim project measures     │
           │     │                     │ its "MOK" certificates and    │
           │     │                     │ hashes into this PCR.         │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 15  │ system-identity     │ systemd-cryptsetup(8)         │
           │     │                     │ optionally measures the       │
           │     │                     │ volume key of activated       │
           │     │                     │ LUKS volumes into this PCR.   │
           │     │                     │ systemd-pcrmachine.service(8) │
           │     │                     │ measures the machine-id(5)    │
           │     │                     │ into this PCR.                │
           │     │                     │ systemd-pcrfs@.service(8)     │
           │     │                     │ measures mount points, file   │
           │     │                     │ system UUIDs, labels,         │
           │     │                     │ partition UUIDs of the root   │
           │     │                     │ and /var/ filesystems into    │
           │     │                     │ this PCR.                     │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 16  │ debug               │ Debug                         │
           ├─────┼─────────────────────┼───────────────────────────────┤
           │ 23  │ application-support │ Application Support           │
           └─────┴─────────────────────┴───────────────────────────────┘
    
           In general, encrypted volumes would be bound to some combination
           of PCRs 7, 11, and 14 (if shim/MOK is used). In order to allow
           firmware and OS version updates, it is typically not advisable to
           use PCRs such as 0 and 2, since the program code they cover should
           already be covered indirectly through the certificates measured
           into PCR 7. Validation through certificates hashes is typically
           preferable over validation through direct measurements as it is
           less brittle in context of OS/firmware updates: the measurements
           will change on every update, but signatures should remain
           unchanged. See the **Linux TPM PCR Registry******[1] for more discussion.


## 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, a recovery key, a FIDO2 token, or a TPM2 key. It's
           currently not supported to unlock a device with a PKCS#11 key in
           order to enroll a new PKCS#11 key. Thus, if in future key
           roll-over is desired it is generally recommended to ensure a
           passphrase, a recovery key, a FIDO2 token, or a TPM2 key is always
           enrolled.
    
           Also note that support for enrolling multiple FIDO2 tokens is
           currently limited. When multiple FIDO2 tokens are enrolled,
           **systemd-cryptsetup** will perform pre-flight requests to attempt to
           identify which of the enrolled tokens are currently plugged in.
           However, this is not possible for FIDO2 tokens with user
           verification (UV, usually via biometrics), in which case it will
           fall back to attempting each enrolled token one by one. This will
           result in multiple prompts for PIN and user verification. This
           limitation does not apply to PKCS#11 tokens.
    


## COMPATIBILITY



           Security technology both in systemd and in the general industry
           constantly evolves. In order to provide best security guarantees,
           the way TPM2, FIDO2, PKCS#11 devices are enrolled is regularly
           updated in newer versions of systemd. Whenever this happens the
           following compatibility guarantees are given:
    
           •   Old enrollments continue to be supported and may be unlocked
               with newer versions of systemd-cryptsetup@.service(8).
    
           •   The opposite is not guaranteed however: it might not be
               possible to unlock volumes with enrollments done with a newer
               version of **systemd-cryptenroll** with an older version of
               **systemd-cryptsetup**.
    
           That said, it is generally recommended to use matching versions of
           **systemd-cryptenroll** and **systemd-cryptsetup** , since this is best
           tested and supported.
    
           It might be advisable to re-enroll existing enrollments to take
           benefit of newer security features, as they are added to systemd.
    


## UNLOCKING



           The following options are understood that may be used to unlock
           the device in preparation of the enrollment operations:
    
           **--unlock-key-file=**_PATH_
               Use a file instead of a password/passphrase read from stdin to
               unlock the volume. Expects the PATH to the file containing
               your key to unlock the volume. Currently there is nothing like
               **--key-file-offset=** or **--key-file-size=** so this file has to
               only contain the full key.
    
               Added in version 252.
    
           **--unlock-fido2-device=**_PATH_
               Use a FIDO2 device instead of a password/passphrase read from
               stdin to unlock the volume. 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). This
               automatic discovery is unsupported if **--fido2-device=** option
               is also specified. Note that currently FIDO2 devices enrolled
               without an accompanying LUKS2 token (i.e.
               **--fido2-parameters-in-header=no**) cannot be used for unlocking.
    
               Added in version 253.
    
           **--unlock-tpm2-device=**_PATH_
               Use a TPM2 device instead of a password/passphrase read from
               stdin to unlock the volume. 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).
    
               Added in version 256.
    


## SIMPLE ENROLLMENT



           The following options are understood that may be used to enroll
           simple user input based unlocking:
    
           **--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.
    
               Added in version 248.
    
           **--recovery-key**
               Enroll a recovery key. Recovery keys are mostly identical to
               passphrases, but are computer-generated instead of being
               chosen by a human, 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.
    
               Added in version 248.
    


## PKCS#11 ENROLLMENT



           The following option is understood that may be used to enroll
           PKCS#11 tokens:
    
           **--pkcs11-token-uri=**_URI_
               Enroll a PKCS#11 security token or smartcard (e.g. a YubiKey).
               Expects a PKCS#11 URI that allows finding an X.509 certificate
               or a public key on the token. The URI must also be suitable to
               find a related private key after changing the type of object
               in it. Alternatively the special value "auto" may be
               specified, in order to automatically determine the suitable
               URI if a single security token containing a single key pair is
               plugged in. The special value "list" may be used to enumerate
               all suitable PKCS#11 tokens currently plugged in.
    
               The PKCS#11 token must contain an RSA or EC key pair which
               will be used to unlock a LUKS2 volume. For RSA, a randomly
               generated volume key is encrypted with a public key in the
               token, and stored in the LUKS2 JSON token header area. To
               unlock a volume, the stored encrypted volume key will be
               decrypted with a private key in the token. For ECC, ECDH
               algorithm is used: we generate a pair of EC keys in the same
               EC group, then derive a shared secret using the generated
               private key and the public key in the token. The derived
               shared secret is used as a volume key. The generated public
               key is stored in the LUKS2 JSON token header area. The
               generated private key is erased. To unlock a volume, we derive
               the shared secret with the stored public key and a private key
               in the token.
    
               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 none pkcs11-uri=auto
    
               See crypttab(5) for a more comprehensive example of a
               **systemd-cryptenroll** invocation and its matching /etc/crypttab
               line.
    
               Added in version 248.
    


## FIDO2 ENROLLMENT



           The following options are understood that may be used to enroll
           FIDO2 tokens:
    
           **--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). This automatic discovery is unsupported if
               **--unlock-fido2-device=** option is also specified. 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 is 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 none fido2-device=auto
    
               See crypttab(5) for a more comprehensive example of a
               **systemd-cryptenroll** invocation and its matching /etc/crypttab
               line.
    
               Added in version 248.
    
           **--fido2-credential-algorithm=**_STRING_
               Specify COSE algorithm used in credential generation. The
               default value is "es256". Supported values are "es256",
               "rs256" and "eddsa".
    
               "es256" denotes ECDSA over NIST P-256 with SHA-256.  "rs256"
               denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256.
               "eddsa" denotes EDDSA over Curve25519 with SHA-512.
    
               Note that your authenticator may choose not to support some
               algorithms.
    
               Added in version 251.
    
           **--fido2-salt-file=**_PATH_
               When enrolling a FIDO2 security token, specifies the path to a
               file or an **AF_UNIX** socket from which we should read the salt
               value to be used in the HMAC operation performed by the FIDO2
               security token. If this option is not specified, the salt will
               be randomly generated.
    
               Added in version 257.
    
           **--fido2-parameters-in-header=**_BOOL_
               When enrolling a FIDO2 security token, controls whether to
               store FIDO2 parameters in a token in the LUKS2 superblock.
               Defaults to "yes". If set to "no", the **fido2-cid=** option has
               to be specified manually in the respective /etc/crypttab line
               along with a key file. See crypttab(5) for details.
    
               Added in version 257.
    
           **--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.)
    
               Added in version 249.
    
           **--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.)
    
               Added in version 249.
    
           **--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.)
    
               Added in version 249.
    


## TPM2 ENROLLMENT



           The following options are understood that may be used to enroll
           TPM2 devices:
    
           **--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 none 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.
    
               Added in version 248.
    
           **--tpm2-device-key=**_PATH_
               Enroll a TPM2 security chip using its public key. Expects a
               path referring to the TPM2 public key in TPM2B_PUBLIC format.
               This cannot be used with **--tpm2-device=** , as it performs the
               same operation, but without connecting to the TPM2 security
               chip; instead the enrollment is calculated using the provided
               TPM2 key. This is useful in situations where the TPM2 security
               chip is not available at the time of enrollment.
    
               The key, in most cases, should be the Storage Root Key (SRK)
               from a local TPM2 security chip. If a key from a different
               handle (not the SRK) is used, you must specify its handle
               index using **--tpm2-seal-key-handle=**.
    
               The systemd-tpm2-setup.service(8) service writes the SRK to
               /run/systemd/tpm2-srk-public-key.tpm2b_public automatically
               during boot, in the correct format.
    
               Alternatively, you may use **systemd-analyze srk** to retrieve the
               SRK from the TPM2 security chip explicitly. See
               systemd-analyze(1) for details. Example:
    
                   systemd-analyze srk > srk.tpm2b_public
    
               Added in version 255.
    
           **--tpm2-seal-key-handle=**_HANDLE_
               Configures which parent key to use for sealing, using the TPM
               handle (index) of the key. This is used to "seal" (encrypt) a
               secret and must be used later to "unseal" (decrypt) the
               secret. Expects a hexadecimal 32bit integer, optionally
               prefixed with "0x". Allowable values are any handle index in
               the persistent ("0x81000000"-"0x81ffffff") or transient
               ("0x80000000"-"0x80ffffff") ranges. Since transient handles
               are lost after a TPM reset, and may be flushed during TPM
               context switching, they should not be used except for very
               specific use cases, e.g. testing.
    
               The default is the Storage Root Key (SRK) handle index
               "0x81000001". A value of 0 will use the default. For the SRK
               handle, a new key will be created and stored in the TPM if one
               does not already exist; for any other handle, the key must
               already exist in the TPM at the specified handle index.
    
               This should not be changed unless you know what you are doing.
    
               Added in version 255.
    
           **--tpm2-pcrs=**_PCR[+PCR...]_
               Configures the TPM2 PCRs (Platform Configuration Registers) to
               bind to when enrollment is requested via **--tpm2-device=**. Takes
               a list of PCR entries, where each entry starts with a name or
               numeric index in the range 0...23, optionally followed by ":"
               and a hash algorithm name (specifying the PCR bank),
               optionally followed by "=" and a hash digest value. Multiple
               PCR entries are separated by "+". If an empty string is
               specified, binds the enrollment to no PCRs at all (this is
               also the default, if this option is not used). See the table
               above for a list of available PCRs.
    
               Example:
               **--tpm2-pcrs=boot-loader-code+platform-config+boot-loader-config**
               specifies that PCR registers 4, 1, and 5 should be used.
    
               Example: **--tpm2-pcrs=7:sha256** specifies that PCR register 7
               from the SHA256 bank should be used.
    
               Example:
               **--tpm2-pcrs=4:sha1=3a3f780f11a4b49969fcaa80cd6e3957c33b2275**
               specifies that PCR register 4 from the SHA1 bank should be
               used, and a hash digest value of
               3a3f780f11a4b49969fcaa80cd6e3957c33b2275 will be used instead
               of reading the current PCR value.
    
               Added in version 248.
    
           **--tpm2-with-pin=**_BOOL_
               When enrolling a TPM2 device, controls whether to require the
               user to enter a PIN when unlocking the volume in addition to
               PCR binding, based on TPM2 policy authentication. Defaults to
               "no". Despite being called PIN, any character can be used, not
               just numbers.
    
               Note that incorrect PIN entry when unlocking increments the
               TPM dictionary attack lockout mechanism, and may lock out
               users for a prolonged time, depending on its configuration.
               The lockout mechanism is a global property of the TPM,
               **systemd-cryptenroll** does not control or configure the lockout
               mechanism. You may use tpm2-tss tools to inspect or configure
               the dictionary attack lockout, with **tpm2_getcap**(1) and
               **tpm2_dictionarylockout**(1) commands, respectively.
    
               Added in version 251.
    
           **--tpm2-public-key=**_PATH_ , **--tpm2-public-key-pcrs=**_PCR[+PCR...]_ ,
           **--tpm2-signature=**_PATH_
               Configures a TPM2 signed PCR policy to bind encryption to. The
               **--tpm2-public-key=** option accepts a path to a PEM encoded RSA
               public key, to bind the encryption to. If this is not
               specified explicitly, but a file tpm2-pcr-public-key.pem
               exists in one of the directories /etc/systemd/, /run/systemd/,
               /usr/lib/systemd/ (searched in this order), it is
               automatically used. The **--tpm2-public-key-pcrs=** option takes a
               list of TPM2 PCR indexes to bind to (same syntax as
               **--tpm2-pcrs=** described above). If not specified, defaults to
               11 (i.e. this binds the policy to any unified kernel image for
               which a PCR signature can be provided).
    
               Note the difference between **--tpm2-pcrs=** and
               **--tpm2-public-key-pcrs=** : the former binds decryption to the
               current, specific PCR values; the latter binds decryption to
               any set of PCR values for which a signature by the specified
               public key can be provided. The latter is hence more useful in
               scenarios where software updates shall be possible without
               losing access to all previously encrypted LUKS2 volumes. Like
               with **--tpm2-pcrs=** , names defined in the table above can also
               be used to specify the registers, for instance
               **--tpm2-public-key-pcrs=boot-loader-code+system-identity**.
    
               The **--tpm2-signature=** option takes a path to a TPM2 PCR
               signature file as generated by the systemd-measure(1) tool. If
               this is not specified explicitly, a suitable signature file
               tpm2-pcr-signature.json is searched for in /etc/systemd/,
               /run/systemd/, /usr/lib/systemd/ (in this order) and used. If
               a signature file is specified or found it is used to verify if
               the volume can be unlocked with it given the current PCR
               state, before the new slot is written to disk. This is
               intended as safety net to ensure that access to a volume is
               not lost if a public key is enrolled for which no valid
               signature for the current PCR state is available. If the
               supplied signature does not unlock the current PCR state and
               public key combination, no slot is enrolled and the operation
               will fail. If no signature file is specified or found no such
               safety verification is done.
    
               Added in version 252.
    
           **--tpm2-pcrlock=**_PATH_
               Configures a TPM2 pcrlock policy to bind encryption to.
               Expects a path to a pcrlock policy file as generated by the
               systemd-pcrlock(8) tool. If a TPM2 device is enrolled and this
               option is not used but a file pcrlock.json is found in
               /run/systemd/ or /var/lib/systemd/ it is automatically used.
               Assign an empty string to turn this behaviour off.
    
               Added in version 255.
    


## OTHER OPTIONS



           The following additional options are understood:
    
           **--wipe-slot=**_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 --unlock-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
    
               Added in version 248.
    
           **--list-devices**
               Show a list of candidate block devices this command may
               operate on. Specifically, this enumerates block devices
               currently present that contain a LUKS superblock, and shows
               their device node paths along with any of their symlinks. The
               devices must implement the **hmac-secret** extension to be
               useable.
    
               Added in version 257.
    
           **-h** , **--help**
               Print a short help text and exit.
    
           **--version**
               Print a short version string and exit.
    
           **--no-pager**
               Do not pipe output into a pager.
    


## CREDENTIALS



           **systemd-cryptenroll** supports the service credentials logic as
           implemented by _ImportCredential=_ /_LoadCredential=_ /_SetCredential=_
           (see systemd.exec(5) for details). The following credentials are
           used when passed in:
    
           _cryptenroll.passphrase_ , _cryptenroll.new-passphrase_
               May contain the passphrase to unlock the volume with/to newly
               enroll.
    
               Added in version 256.
    
           _cryptenroll.tpm2-pin_ , _cryptenroll.new-tpm2-pin_
               May contain the TPM2 PIN to unlock the volume with/to newly
               enroll.
    
               Added in version 256.
    
           _cryptenroll.fido2-pin_
               If a FIDO2 token is enrolled this may contain the PIN of the
               token.
    
               Added in version 256.
    
           _cryptenroll.pkcs11-pin_
               If a PKCS#11 token is enrolled this may contain the PIN of the
               token.
    
               Added in version 256.
    


## EXIT STATUS



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


## EXAMPLES



           crypttab(5) and systemd-measure(1) contain various examples
           employing **systemd-cryptenroll**.
    


## NOTES



            1. Linux TPM PCR Registry
               https://uapi-group.org/specifications/specs/linux_tpm_pcr_registry/
    


* * *