# systemd.system-credentials

systemd

systemd.system-credentials

7

systemd.system-credentials

System Credentials

# Description

[System and Service Credentials](https://systemd.io/CREDENTIALS) are data objects that may be passed into booted systems or system services as they are invoked. They can be acquired from various external sources, and propagated into the system and from there into system services. Credentials may optionally be encrypted with a machine-specific key and/or locked to the local TPM2 device, and are only decrypted when the consuming service is invoked.

System credentials may be used to provision and configure various aspects of the system. Depending on the consuming component credentials are only used on initial invocations or are needed for all invocations.

Credentials may be used for any kind of data, binary or text, and may carry passwords, secrets, certificates, cryptographic key material, identity information, configuration, and more.

# Well known system credentials

`firstboot.keymap`  
The console key mapping to set (e.g. `de`). Read by `systemd-firstboot(1)`, and only honoured if no console keymap has been configured before.

`firstboot.hostname`  
This credential specifies the static system hostname to set during first boot. The user will not be prompted for the hostname. Note that this controls the static hostname, not the transient hostname, and only has an effect on first boot, unlike `system.hostname` (see below). Read by `systemd-firstboot(1)` and only honoured if no static hostname has been configured before. The value may use the wildcard patterns documented in `hostname(5)` (e.g. `$-$` or `foo-????`). When the credential is applied on the running system (the usual case, by `systemd-firstboot.service` on first boot), the wildcards are resolved against the machine ID and the resulting concrete name is written to `/etc/hostname`. The name is thus *persisted* once at first boot and does not change on subsequent boots even if the word lists are later updated or the pattern is changed (for example to add more `?`/`$` tokens for additional entropy), which is the recommended way to obtain a stable, per-machine generated hostname. (When `systemd-firstboot(1)` operates on an offline image via `--root=`/`--image=`, the target's machine ID is not yet known, so the pattern is written verbatim and, like a pattern placed directly in `/etc/hostname`, re-derived on every boot rather than persisted.)

`firstboot.locale`; `firstboot.locale-messages`  
The system locale to set (e.g. `de_DE.UTF-8`). Read by `systemd-firstboot(1)`, and only honoured if no locale has been configured before. `firstboot.locale` sets `LANG`, while `firstboot.locale-message` sets `LC_MESSAGES`.

`firstboot.timezone`  
The system timezone to set (e.g. `Europe/Berlin`). Read by `systemd-firstboot(1)`, and only honoured if no system timezone has been configured before.

`firstboot.machine-tags`  
The machine tags to set, as a colon-separated list (e.g. `company.role=webserver:company.location=berlin`). Read by `systemd-firstboot(1)`, and only honoured if `/etc/machine-info` has not been configured before. Written into the `TAGS=` field of that file, see `machine-info(5)` for details.

`keyring-setup.dm-verity.NAME`; `keyring-setup.fs-verity.NAME`; `keyring-setup.bpf.NAME`  
A PEM-encoded X.509 certificate to enroll into the `.dm-verity`, `.fs-verity` or `.bpf` kernel keyring, respectively (e.g. `keyring-setup.dm-verity.vendor`). Read by `systemd-keyring-setup.service(8)`, which writes the certificate to `/run/voa/` before enrolling it, see there for details. \<NAME\> may consist of lowercase letters, digits, `.`, `_` and `-`.

`keyring-setup.os`  
A whitespace-separated list of OS identifiers (e.g. `debian:13 debian`) under which certificates are looked up in the VOA hierarchy, instead of the ones derived from `os-release(5)`. Read by `systemd-keyring-setup.service(8)`.

`login.issue`  
The data of this credential is written to `/etc/issue.d/50-provision.conf`, if the file does not exist yet. `agetty(8)` reads this file and shows its contents at the login prompt of terminal logins. See `issue(5)` for details.

Consumed by `/usr/lib/tmpfiles.d/provision.conf`, see `tmpfiles.d(5)`.

`login.motd`  
The data of this credential is written to `/etc/motd.d/50-provision.conf`, if the file does not exist yet. `pam_motd(8)` reads this file and shows its contents as "message of the day" during terminal logins. See `motd(5)` for details.

Consumed by `/usr/lib/tmpfiles.d/provision.conf`, see `tmpfiles.d(5)`.

`network.hosts`  
The data of this credential is written to `/etc/hosts`, if the file does not exist yet. See `hosts(5)` for details.

Consumed by `/usr/lib/tmpfiles.d/provision.conf`, see `tmpfiles.d(5)`.

`network.dns`; `network.search_domains`  
DNS server information and search domains. Read by `systemd-resolved.service(8)`.

`network.conf.*`; `network.link.*`; `network.netdev.*`; `network.network.*`  
Configures network devices. Read by `systemd-network-generator.service(8)`. These credentials should contain valid `networkd.conf(5)`, `systemd.link(5)`, `systemd.netdev(5)`, `systemd.network(5)` configuration data. From each matching credential a separate file is created. Example: the contents of a credential `network.link.50-foobar` will be copied into a file `50-foobar.link`.

Note that the resulting files are created world-readable, it is hence recommended to not include secrets in these credentials, but supply them via separate credentials directly to `systemd-networkd.service`, e.g. `network.wireguard.*` as described below.

`network.wireguard.*`  
Configures secrets for WireGuard netdevs. Read by `systemd-networkd.service(8)`. For more information, refer to the `[WireGuard]` section of `systemd.netdev(5)`.

`passwd.hashed-password.root`; `passwd.plaintext-password.root`  
May contain the password (either in UNIX hashed format, or in plaintext) for the root users. Read by both `systemd-firstboot(1)` and `systemd-sysusers(8)`, and only honoured if no root password has been configured before.

`passwd.shell.root`  
The path to the shell program (e.g. `/bin/bash`) for the root user. Read by both `systemd-firstboot(1)` and `systemd-sysusers(8)`, and only honoured if no root shell has been configured before.

`ssh.ephemeral-authorized_keys-all`  
Provides additional public keys, given in the customary `authorized_keys` format, for all users, for incoming connections via the generated `AF_VSOCK` and `AF_UNIX` socket units.

The intended use of this is for a host system (in either VM or container configurations) to generate a keypair and inject the public key into the guest, using the private key to connect to any user account on the guest via ssh, without further authentication.

Consumed by `systemd-ssh-generator(8)`.

`ssh.authorized_keys.root`  
The data of this credential is written to `/root/.ssh/authorized_keys`, if the file does not exist yet. This allows provisioning SSH access for the system's root user.

Consumed by `/usr/lib/tmpfiles.d/provision.conf`, see `tmpfiles.d(5)`.

`ssh.listen`  
May be used to configure SSH sockets the system shall be reachable on. See `systemd-ssh-generator(8)` for details.

`sysusers.extra`  
Additional `sysusers.d(5)` lines to process during boot.

`sysctl.extra`  
Additional `sysctl.d(5)` lines to process during boot.

`tmpfiles.extra`  
Additional `tmpfiles.d(5)` lines to process during boot.

`fstab.extra`  
Additional mounts to establish at boot. For details, see `systemd-fstab-generator(8)`.

`vconsole.keymap`; `vconsole.keymap_toggle`; `vconsole.font`; `vconsole.font_map`; `vconsole.font_unimap`; `vconsole.font_scale`  
Console settings to apply, see `systemd-vconsole-setup.service(8)` for details.

`vconsole.font_scale` was added in version 262.

`getty.auto`  
Used for controlling the execution mode of `systemd-getty-generator`. See `systemd-getty-generator(8)` for details.

`getty.ttys.serial`; `getty.ttys.container`  
Used for spawning additional login prompts, see `systemd-getty-generator(8)` for details.

`journal.forward_to_socket`  
Used by `systemd-journald(8)` to determine where to forward log messages for socket forwarding, see `journald.conf(5)` for details.

`journal.storage`  
Used by `systemd-journald(8)` to determine where to store journal files, see `journald.conf(5)` for details.

`vmm.notify_socket`  
Configures an `sd_notify(3)` compatible `AF_VSOCK` socket the service manager will report status information, ready notification and exit status on. For details see `systemd(1)`.

`shell.prompt.prefix`; `shell.prompt.suffix`  
Defines strings to prefix and suffix any interactive UNIX shell prompt with. For details see `pam_systemd(8)`.

`shell.welcome`  
Define a string to print when an interactive UNIX shell initializes. For details see `pam_systemd(8)`.

`system.machine_id`  
Takes a 128bit ID to initialize the machine ID from (if it is not set yet). Interpreted by the service manager (PID 1). For details see `systemd(1)`.

`system.hostname`  
Accepts a (transient) hostname to configure during early boot. The static hostname specified in `/etc/hostname`, if configured, takes precedence over this setting. Interpreted by the service manager (PID 1). For details see `systemd(1)`. Also see `firstboot.hostname` above. The value may use the wildcard patterns documented in `hostname(5)` (`?` and `$`), which are expanded deterministically from the machine ID when the credential is applied. As this is a transient hostname that is re-applied on every boot, a wildcard value is re-derived each boot (and may change if the word lists change) and is never persisted; pass an already-resolved name if a stable hostname is required. Note also that the word-list tokens require the word lists to be present, which is generally not the case in the initrd so during initrd the default hostname is used and in late boot the resolved one becomes available.

`home.add-signing-key.*`  
Adds a new signing key for user records to the system. The credential contents should contain a user signing key, for example as reported by `homectl get-signing-key`. Multiple keys may be specified, and they will be put in place under the name of the credential name suffix (which must itself carry the `.public` suffix). For details see `homectl(1)`.

`home.create.*`  
Creates a new home area for the specified user with the user record data passed in. For details see `homectl(1)`.

`home.register.*`  
Registers an existing home area for the specified user with the user record data passed in. For details see `homectl(1)`.

`cryptsetup.passphrase`; `cryptsetup.tpm2-pin`; `cryptsetup.fido2-pin`; `cryptsetup.pkcs11-pin`; `cryptsetup.luks2-pin`  
Specifies the passphrase/PINs to use for unlock encrypted storage volumes. For details see `systemd-cryptsetup(8)`.

`systemd.extra-unit.*`; `systemd.unit-dropin.*`  
These credentials specify extra units and drop-ins to add to the system. For details see `systemd-debug-generator(8)`.

`udev.conf.*`; `udev.rules.*`  
Configures udev configuration file and udev rules. Read by `systemd-udev-load-credentials.service`, which invokes `udevadm control --load-credentials`. These credentials directly translate to a matching `udev.conf(5)` or `udev(7)` rules file. Example: the contents of a credential `udev.conf.50-foobar` will be copied into a file `/run/udev/udev.conf.d/50-foobar.conf`, and `udev.rules.50-foobar` will be copied into a file `/run/udev/rules.d/50-foobar.rules`. See `udev(7)`, `udev.conf(5)`, and `udevadm(8)` for details.

`import.pull`  
Specified disk images (tarballs and DDIs) to automatically download and install at boot. For details see `systemd-import-generator(8)`.

`userdb.user.*`; `userdb.group.*`; `userdb.transient.user.*`; `userdb.transient.group.*`  
Configure JSON user and group records. Read by `systemd-userdb-load-credentials.service`, which invokes `userdbctl load-credentials`. These credentials directly translate to matching [JSON User](https://systemd.io/USER_RECORD) and [JSON Group](https://systemd.io/GROUP_RECORD) records. Example: the contents of a credential `userdb.user.foobar` will be copied into a file `/etc/userdb/foobar.user`, and `userdb.group.foobar` will be copied into a file `/etc/userdb/foobar.group`. Symlinks for the uid/gid will also be created in `/etc/userdb/`, as well as the corresponding`.membership` files. See `systemd-userdbd.service(8)`, `nss-systemd(8)`, and `userdbctl(1)` for details.

Any passed user records must contain uid and gid fields. Any passed group records must contain a gid field. For both user and group records, the credential suffix (for `userdb.user.foobar` the suffix is `foobar`) must match the user or group name field from the user or group record.

Note that the records created for `userdb.user.*` and `userdb.group.*` credentials are created in `/etc/userdb/` and the records created for `userdb.transient.user.*` and `userdb.transient.group.*` are created in `/run/userdb/` (`/etc/passwd` and `/etc/group` are not modified).

`fsck.*`  
Read by `systemd-fsck@.service`, `systemd-fsck-root.service`, and `systemd-fsck-usr.service`. See `systemd-fsck@.service(8)` for more details.

`quotacheck.*`  
Read by `systemd-quotacheck@.service` and `systemd-quotacheck-root.service`. See `systemd-quotacheck(8)` for more details.

`imds.*`  
Read by `systemd-imdsd@.service(8)`.

# See Also

`systemd(1)`, `kernel-command-line(7)`, `smbios-type-11(7)`