1 <?xml version='
1.0'
?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
6 <refentry id=
"systemd-creds"
7 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
10 <title>systemd-creds
</title>
11 <productname>systemd
</productname>
15 <refentrytitle>systemd-creds
</refentrytitle>
16 <manvolnum>1</manvolnum>
20 <refname>systemd-creds
</refname>
21 <refpurpose>Lists, shows, encrypts and decrypts service credentials
</refpurpose>
26 <command>systemd-creds
</command>
27 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
28 <arg choice=
"plain">COMMAND
</arg>
29 <arg choice=
"opt" rep=
"repeat">ARGS
</arg>
34 <title>Description
</title>
36 <para><command>systemd-creds
</command> is a tool for listing, showing, encrypting and decrypting unit
37 credentials. Credentials are limited-size binary or textual objects that may be passed to unit
38 processes. They are primarily used for passing cryptographic keys (both public and private) or
39 certificates, user account information or identity information from the host to services.
</para>
41 <para>Credentials are configured in unit files via the
<varname>ImportCredential=
</varname>,
42 <varname>LoadCredential=
</varname>,
<varname>SetCredential=
</varname>,
43 <varname>LoadCredentialEncrypted=
</varname>, and
<varname>SetCredentialEncrypted=
</varname> settings, see
44 <citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
47 <para>For further information see
<ulink url=
"https://systemd.io/CREDENTIALS">System and Service
48 Credentials
</ulink> documentation.
</para>
52 <title>Commands
</title>
54 <para>The following commands are understood:
</para>
58 <term><command>list
</command></term>
60 <listitem><para>Show a list of credentials passed into the current execution context. This command
61 shows the files in the directory referenced by the
<varname>$CREDENTIALS_DIRECTORY
</varname>
62 environment variable, and is intended to be executed from within service context.
</para>
64 <para>Along with each credential name, the size and security state is shown. The latter is one of
65 <literal>secure
</literal> (in case the credential is backed by unswappable memory,
66 i.e.
<literal>ramfs
</literal>),
<literal>weak
</literal> (in case it is backed by any other type of
67 memory), or
<literal>insecure
</literal> (if having any access mode that is not
0400, i.e. if readable
68 by anyone but the owner).
</para>
70 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
74 <term><command>cat
</command> <replaceable>credential...
</replaceable></term>
76 <listitem><para>Show contents of specified credentials passed into the current execution
77 context. Takes one or more credential names, whose contents shall be written to standard
80 <para>When combined with
<option>--json=
</option> or
<option>--transcode=
</option> the output is
81 transcoded in simple ways before outputting.
</para>
83 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
87 <term><command>setup
</command></term>
89 <listitem><para>Generates a host encryption key for credentials, if one has not been generated
90 already. This ensures the
<filename>/var/lib/systemd/credential.secret
</filename> file is initialized
91 with a random secret key if it doesn't exist yet. This secret key is used when encrypting/decrypting
92 credentials with
<command>encrypt
</command> or
<command>decrypt
</command>, and is only accessible to
93 the root user. Note that there's typically no need to invoke this command explicitly as it is
94 implicitly called when
<command>encrypt
</command> is invoked, and credential host key encryption
97 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
101 <term><command>encrypt
</command> <replaceable>input|-
</replaceable> <replaceable>output|-
</replaceable></term>
103 <listitem><para>Loads the specified (unencrypted plaintext) input credential file, encrypts it and
104 writes the (encrypted ciphertext) output to the specified target credential file. The resulting file
105 may be referenced in the
<varname>LoadCredentialEncrypted=
</varname> setting in unit files, or its
106 contents used literally in
<varname>SetCredentialEncrypted=
</varname> settings.
</para>
108 <para>Takes two file system paths. The file name part of the output path is embedded as name in the
109 encrypted credential, to ensure encrypted credentials cannot be renamed and reused for different
110 purposes without this being noticed. The credential name to embed may be overridden with the
111 <option>--name=
</option> setting. The input or output paths may be specified as
<literal>-
</literal>,
112 in which case the credential data is read from/written to standard input and standard output. If the
113 output path is specified as
<literal>-
</literal> the credential name cannot be derived from the file
114 system path, and thus should be specified explicitly via the
<option>--name=
</option> switch.
</para>
116 <para>The credential data is encrypted and authenticated symmetrically with one of the following
117 encryption keys:
</para>
120 <listitem><para>A secret key automatically derived from the system's TPM2 chip. This encryption key
121 is not stored on the host system and thus decryption is only possible with access to the original
122 TPM2 chip. Or in other words, the credential secured in this way can only be decrypted again by the
123 local machine.
</para></listitem>
125 <listitem><para>A secret key stored in the
<filename>/var/lib/systemd/credential.secret
</filename>
126 file which is only accessible to the root user. This
"host" encryption key is stored on the host
127 file system, and thus decryption is possible with access to the host file system and sufficient
128 privileges. The key is automatically generated when needed, but can also be created explicitly with
129 the
<command>setup
</command> command, see above.
</para></listitem>
131 <listitem><para>A combination of the above: an encryption key derived from both the TPM2 chip and
132 the host file system. This means decryption requires both access to the original TPM2 chip and the
133 OS installation. This is the default mode of operation if a TPM2 chip is available and
134 <filename>/var/lib/systemd/
</filename> resides on persistent media.
</para></listitem>
137 <para>Which of the three keys shall be used for encryption may be configured with the
138 <option>--with-key=
</option> switch. Depending on the use-case for the encrypted credential the key
139 to use may differ. For example, for credentials that shall be accessible from the initrd, encryption
140 with the host key is not appropriate, since access to the host key is typically not available from
141 the initrd. Thus, for such credentials only the TPM2 key should be used.
</para>
143 <para>Encrypted credentials are always encoded in Base64.
</para>
145 <para>Use
<command>decrypt
</command> (see below) to undo the encryption operation, and acquire the
146 decrypted plaintext credential from the encrypted ciphertext credential.
</para>
148 <para>The credential data is encrypted using AES256-GCM, i.e. providing both confidentiality and
149 integrity, keyed by a SHA256 hash of one or both of the secret keys described above.
</para>
151 <xi:include href=
"version-info.xml" xpointer=
"v250"/>
156 <term><command>decrypt
</command> <replaceable>input|-
</replaceable>
157 <optional><replaceable>output|-
</replaceable></optional></term>
159 <listitem><para>Undoes the effect of the
<command>encrypt
</command> operation: loads the specified
160 (encrypted ciphertext) input credential file, decrypts and authenticates it and writes the (decrypted
161 plaintext) output to the specified target credential file.
</para>
163 <para>Takes one or two file system paths. The file name part of the input path is compared with the
164 credential name embedded in the encrypted file. If it does not match decryption fails. This is done
165 in order to ensure that encrypted credentials are not re-purposed without this being detected. The
166 credential name to compare with the embedded credential name may also be overridden with the
167 <option>--name=
</option> switch. If the input path is specified as
<literal>-
</literal>, the
168 encrypted credential is read from standard input. If only one path is specified or the output path
169 specified as
<literal>-
</literal>, the decrypted credential is written to standard output. In this
170 mode, the expected name embedded in the credential cannot be derived from the path and should be
171 specified explicitly with
<option>--name=
</option>.
</para>
173 <para>Decrypting credentials requires access to the original TPM2 chip and/or credentials host key,
174 see above. Information about which keys are required is embedded in the encrypted credential data,
175 and thus decryption is entirely automatic.
</para>
177 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
181 <term><command>has-tpm2
</command></term>
183 <listitem><para>Reports whether the system is equipped with a TPM2 device usable for protecting
184 credentials. If a TPM2 device has been discovered, is supported, and is being used by firmware,
185 by the OS kernel drivers and by userspace (i.e. systemd) this prints
<literal>yes
</literal> and exits
186 with exit status zero. If no such device is discovered/supported/used, prints
187 <literal>no
</literal>. Otherwise prints
<literal>partial
</literal>. In either of these two cases
188 exits with non-zero exit status. It also shows four lines indicating separately whether firmware,
189 drivers, the system and the kernel discovered/support/use TPM2.
</para>
191 <para>Combine with
<option>--quiet
</option> to suppress the output.
</para>
193 <xi:include href=
"version-info.xml" xpointer=
"v251"/></listitem>
196 <xi:include href=
"standard-options.xml" xpointer=
"help" />
197 <xi:include href=
"standard-options.xml" xpointer=
"version" />
202 <title>Options
</title>
207 <term><option>--system
</option></term>
209 <listitem><para>When specified with the
<command>list
</command> and
<command>cat
</command> commands
210 operates on the credentials passed to system as a whole instead of on those passed to the current
211 execution context. This is useful in container environments where credentials may be passed in from
212 the container manager.
</para>
214 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
218 <term><option>--user
</option></term>
220 <listitem><para>When specified with the
<command>encrypt
</command> and
<command>decrypt
</command>
221 commands encrypts a user-scoped (rather than a system-scoped) credential. Use
<option>--uid=
</option>
222 to select which user the credential is from. Such credentials may only be decrypted from the
223 specified user's context, except if privileges can be acquired. Generally, when an encrypted
224 credential shall be used in the per-user service manager it should be encrypted with this option set,
225 when it shall be used in the system service manager it should be encrypted without.
</para>
227 <para>Internally, this ensures that the selected user's numeric UID and username, as well as the
229 <citerefentry><refentrytitle>machine-id
</refentrytitle><manvolnum>5</manvolnum></citerefentry> are
230 incorporated into the encryption key.
</para>
232 <xi:include href=
"version-info.xml" xpointer=
"v256"/></listitem>
236 <term><option>--uid=
</option></term>
238 <listitem><para>Specifies the user to encrypt the credential for. Takes a user name or numeric
239 UID. If set, implies
<option>--user
</option>. If set to the special string
<literal>self
</literal>
240 sets the user to the user of the calling process. If
<option>--user
</option> is used without
241 <option>--uid=
</option> then
<option>--uid=self
</option> is implied, i.e. the credential is encrypted
242 for the calling user.
</para>
244 <xi:include href=
"version-info.xml" xpointer=
"v256"/></listitem>
248 <term><option>--transcode=
</option></term>
250 <listitem><para>When specified with the
<command>cat
</command> or
<command>decrypt
</command>
251 commands, transcodes the output before showing it. Takes one of
<literal>base64
</literal>,
252 <literal>unbase64
</literal>,
<literal>hex
</literal> or
<literal>unhex
</literal> as argument, in order
253 to encode/decode the credential data with Base64 or as series of hexadecimal values.
</para>
255 <para>Note that this has no effect on the
<command>encrypt
</command> command, as encrypted
256 credentials are unconditionally encoded in Base64.
</para>
258 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
262 <term><option>--newline=
</option></term>
264 <listitem><para>When specified with
<command>cat
</command> or
<command>decrypt
</command> controls
265 whether to add a trailing newline character to the end of the output if it doesn't end in one,
266 anyway. Takes one of
<literal>auto
</literal>,
<literal>yes
</literal> or
<literal>no
</literal>. The
267 default mode of
<literal>auto
</literal> will suffix the output with a single newline character only
268 when writing credential data to a TTY.
</para>
270 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
274 <term><option>--pretty
</option></term>
275 <term><option>-p
</option></term>
277 <listitem><para>When specified with
<command>encrypt
</command> controls whether to show the encrypted
278 credential as
<varname>SetCredentialEncrypted=
</varname> setting that may be pasted directly into a
279 unit file. Has effect only when used together with
<option>--name=
</option> and
<literal>-
</literal>
280 as the output file.
</para>
282 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
286 <term><option>--name=
<replaceable>name
</replaceable></option></term>
288 <listitem><para>When specified with the
<command>encrypt
</command> command controls the credential
289 name to embed in the encrypted credential data. If not specified the name is chosen automatically
290 from the filename component of the specified output path. If specified as empty string no
291 credential name is embedded in the encrypted credential, and no verification of credential name is
292 done when the credential is decrypted.
</para>
294 <para>When specified with the
<command>decrypt
</command> command control the credential name to
295 validate the credential name embedded in the encrypted credential with. If not specified the name is
296 chosen automatically from the filename component of the specified input path. If no credential name
297 is embedded in the encrypted credential file (i.e. the
<option>--name=
</option> with an empty string
298 was used when encrypted) the specified name has no effect as no credential name validation is
301 <para>Embedding the credential name in the encrypted credential is done in order to protect against
302 reuse of credentials for purposes they weren't originally intended for, under the assumption the
303 credential name is chosen carefully to encode its intended purpose.
</para>
305 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
309 <term><option>--timestamp=
<replaceable>timestamp
</replaceable></option></term>
311 <listitem><para>When specified with the
<command>encrypt
</command> command controls the timestamp to
312 embed into the encrypted credential. Defaults to the current time. Takes a timestamp specification in
313 the format described in
314 <citerefentry><refentrytitle>systemd.time
</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
</para>
316 <para>When specified with the
<command>decrypt
</command> command controls the timestamp to use to
317 validate the
"not-after" timestamp that was configured with
<option>--not-after=
</option> during
318 encryption. If not specified defaults to the current system time.
</para>
320 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
324 <term><option>--not-after=
<replaceable>timestamp
</replaceable></option></term>
326 <listitem><para>When specified with the
<command>encrypt
</command> command controls the time when the
327 credential shall not be used anymore. This embeds the specified timestamp in the encrypted
328 credential. During decryption the timestamp is checked against the current system clock, and if the
329 timestamp is in the past the decryption will fail. By default no such timestamp is set. Takes a
330 timestamp specification in the format described in
331 <citerefentry><refentrytitle>systemd.time
</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
</para>
333 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
337 <term><option>--with-key=
</option></term>
338 <term><option>-H
</option></term>
339 <term><option>-T
</option></term>
341 <listitem><para>When specified with the
<command>encrypt
</command> command controls the
342 encryption/signature key to use. Takes one of
<literal>host
</literal>,
<literal>tpm2
</literal>,
343 <literal>host+tpm2
</literal>,
<literal>null
</literal>,
<literal>auto
</literal>,
344 <literal>auto-initrd
</literal>. See above for details on the three key types. If set to
345 <literal>auto
</literal> (which is the default) the TPM2 key is used if a TPM2 device is found and not
346 running in a container. The host key is used if
<filename>/var/lib/systemd/
</filename> is on
347 persistent media. This means on typical systems the encryption is by default bound to both the TPM2
348 chip and the OS installation, and both need to be available to decrypt the credential again. If
349 <literal>auto
</literal> is selected but neither TPM2 is available (or running in container) nor
350 <filename>/var/lib/systemd/
</filename> is on persistent media, encryption will fail. If set to
351 <literal>null
</literal> a fixed zero length key is used (thus, in this mode no confidentiality
352 nor authenticity are provided!). This logic is useful to cover for systems that lack a TPM2 chip but
353 where credentials shall be generated. Note that decryption of such credentials is refused on systems
354 that have a TPM2 chip and where UEFI SecureBoot is enabled (this is done so that such a locked down
355 system cannot be tricked into loading a credential generated this way that lacks authentication
356 information). If set to
<literal>auto-initrd
</literal> a TPM2 key is used if a TPM2 is found. If not
357 a fixed zero length key is used, equivalent to
<literal>null
</literal> mode. This option is
358 particularly useful to generate credentials files that are encrypted/authenticated against TPM2 where
359 available but still work on systems lacking support for this.
</para>
361 <para>The
<option>-H
</option> switch is a shortcut for
<option>--with-key=host
</option>. Similar,
362 <option>-T
</option> is a shortcut for
<option>--with-key=tpm2
</option>.
</para>
364 <para>When encrypting credentials that shall be used in the initrd (where
365 <filename>/var/lib/systemd/
</filename> is typically not available) make sure to use
366 <option>--with-key=auto-initrd
</option> mode, to disable binding against the host secret.
</para>
368 <para>This switch has no effect on the
<command>decrypt
</command> command, as information on which
369 key to use for decryption is included in the encrypted credential already.
</para>
371 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
375 <term><option>--tpm2-device=
<replaceable>PATH
</replaceable></option></term>
377 <listitem><para>Controls the TPM2 device to use. Expects a device node path referring to the TPM2
378 chip (e.g.
<filename>/dev/tpmrm0
</filename>). Alternatively the special value
<literal>auto
</literal>
379 may be specified, in order to automatically determine the device node of a suitable TPM2 device (of
380 which there must be exactly one). The special value
<literal>list
</literal> may be used to enumerate
381 all suitable TPM2 devices currently discovered.
</para>
383 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
387 <term><option>--tpm2-pcrs=
<replaceable>PCR
<optional>+PCR...
</optional></replaceable></option></term>
389 <listitem><para>Configures the TPM2 PCRs (Platform Configuration Registers) to bind the encryption
390 key to. Takes a
<literal>+
</literal> separated list of numeric PCR indexes in the range
0…
23. If not
391 used, defaults to PCR
7 only. If an empty string is specified, binds the encryption key to no PCRs at
392 all. For details about the PCRs available, see the documentation of the switch of the same name for
393 <citerefentry><refentrytitle>systemd-cryptenroll
</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
</para>
395 <xi:include href=
"version-info.xml" xpointer=
"v250"/></listitem>
399 <term><option>--tpm2-public-key=
<replaceable>PATH
</replaceable></option></term>
400 <term><option>--tpm2-public-key-pcrs=
<replaceable>PCR
<optional>+PCR...
</optional></replaceable></option></term>
402 <listitem><para>Configures a TPM2 signed PCR policy to bind encryption to, for use with the
403 <command>encrypt
</command> command. The
<option>--tpm2-public-key=
</option> option accepts a path to
404 a PEM encoded RSA public key, to bind the encryption to. If this is not specified explicitly, but a
405 file
<filename>tpm2-pcr-public-key.pem
</filename> exists in one of the directories
406 <filename>/etc/systemd/
</filename>,
<filename>/run/systemd/
</filename>,
407 <filename>/usr/lib/systemd/
</filename> (searched in this order), it is automatically used. The
408 <option>--tpm2-public-key-pcrs=
</option> option takes a list of TPM2 PCR indexes to bind to (same
409 syntax as
<option>--tpm2-pcrs=
</option> described above). If not specified defaults to
11 (i.e. this
410 binds the policy to any unified kernel image for which a PCR signature can be provided).
</para>
412 <para>Note the difference between
<option>--tpm2-pcrs=
</option> and
413 <option>--tpm2-public-key-pcrs=
</option>: the former binds decryption to the current, specific PCR
414 values; the latter binds decryption to any set of PCR values for which a signature by the specified
415 public key can be provided. The latter is hence more useful in scenarios where software updates shall
416 be possible without losing access to all previously encrypted secrets.
</para>
418 <xi:include href=
"version-info.xml" xpointer=
"v252"/></listitem>
422 <term><option>--tpm2-signature=
<replaceable>PATH
</replaceable></option></term>
424 <listitem><para>Takes a path to a TPM2 PCR signature file as generated by the
425 <citerefentry><refentrytitle>systemd-measure
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
426 tool and that may be used to allow the
<command>decrypt
</command> command to decrypt credentials that
427 are bound to specific signed PCR values. If this is not specified explicitly, and a credential
428 with a signed PCR policy is attempted to be decrypted, a suitable signature file
429 <filename>tpm2-pcr-signature.json
</filename> is searched for in
<filename>/etc/systemd/
</filename>,
430 <filename>/run/systemd/
</filename>,
<filename>/usr/lib/systemd/
</filename> (in this order) and
433 <xi:include href=
"version-info.xml" xpointer=
"v252"/></listitem>
437 <term><option>--allow-null
</option></term>
439 <listitem><para>Allow decrypting credentials that use an empty key.
</para>
441 <xi:include href=
"version-info.xml" xpointer=
"v256"/></listitem>
445 <term><option>--quiet
</option></term>
446 <term><option>-q
</option></term>
448 <listitem><para>When used with
<command>has-tpm2
</command> suppresses the output, and only returns an
449 exit status indicating support for TPM2.
</para>
451 <xi:include href=
"version-info.xml" xpointer=
"v251"/></listitem>
454 <xi:include href=
"standard-options.xml" xpointer=
"no-pager" />
455 <xi:include href=
"standard-options.xml" xpointer=
"no-legend" />
456 <xi:include href=
"standard-options.xml" xpointer=
"json" />
461 <title>Exit status
</title>
463 <para>On success,
0 is returned.
</para>
465 <para>In case of the
<command>has-tpm2
</command> command returns
0 if a TPM2 device is discovered,
466 supported and used by firmware, driver, and userspace (i.e. systemd). Otherwise returns the OR
467 combination of the value
1 (in case firmware support is missing),
2 (in case driver support is missing)
468 and
4 (in case userspace support is missing). If no TPM2 support is available at all, value
7 is hence
473 <title>Examples
</title>
476 <title>Encrypt a password for use as credential
</title>
478 <para>The following command line encrypts the specified password
<literal>hunter2
</literal>, writing the result
479 to a file
<filename>password.cred
</filename>.
</para>
481 <programlisting># echo -n hunter2 | systemd-creds encrypt - password.cred
</programlisting>
483 <para>This decrypts the file
<filename>password.cred
</filename> again, revealing the literal password:
</para>
485 <programlisting># systemd-creds decrypt password.cred
486 hunter2
</programlisting>
490 <title>Encrypt a password and include it in a unit file
</title>
492 <para>The following command line prompts the user for a password and generates a
493 <varname>SetCredentialEncrypted=
</varname> line from it for a credential named
494 <literal>mysql-password
</literal>, suitable for inclusion in a unit file.
</para>
496 <programlisting># systemd-ask-password -n | systemd-creds encrypt --name=mysql-password -p - -
498 SetCredentialEncrypted=mysql-password: \
499 k6iUCUh0RJCQyvL8k8q1UyAAAAABAAAADAAAABAAAAASfFsBoPLIm/dlDoGAAAAAAAAAA \
500 NAAAAAgAAAAAH4AILIOZ3w6rTzYsBy9G7liaCAd4i+Kpvs8mAgArzwuKxd0ABDjgSeO5k \
501 mKQc58zM94ZffyRmuNeX1lVHE+
9e2YD87KfRFNoDLS7F3YmCb347gCiSk2an9egZ7Y0Xs \
502 700Kr6heqQswQEemNEc62k9RJnEl2q7SbcEYguegnPQUATgAIAAsAAAASACA/B90W7E+6 \
503 yAR9NgiIJvxr9bpElztwzB5lUJAxtMBHIgAQACCaSV9DradOZz4EvO/LSaRyRSq2Hj0ym \
504 gVJk/dVzE8Uxj8H3RbsT7rIBH02CIgm/Gv1ukSXO3DMHmVQkDG0wEciyageTfrVEer8z5 \
505 9cUQfM5ynSaV2UjeUWEHuz4fwDsXGLB9eELXLztzUU9nsAyLvs3ZRR+eEK/A==
</programlisting>
507 <para>The generated line can be pasted
1:
1 into a unit file, and will ensure the acquired password will
508 be made available in the
<varname>$CREDENTIALS_DIRECTORY
</varname><filename>/mysql-password
</filename>
509 credential file for the started service.
</para>
511 <para>Utilizing the unit file drop-in logic this can be used to securely pass a password credential to
512 a unit. A similar, more comprehensive set of commands to insert a password into a service
513 <filename>xyz.service
</filename>:
</para>
515 <programlisting># mkdir -p /etc/systemd/system/xyz.service.d
516 # systemd-ask-password -n | ( echo
"[Service]" && systemd-creds encrypt --name=mysql-password -p - - )
>/etc/systemd/system/xyz.service.d/
50-password.conf
517 # systemctl daemon-reload
518 # systemctl restart xyz.service
</programlisting>
523 <title>See Also
</title>
524 <para><simplelist type=
"inline">
525 <member><citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
526 <member><citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
527 <member><citerefentry><refentrytitle>systemd-measure
</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>