1SYSTEMD-ASK-PASSWORD(1)      systemd-ask-password      SYSTEMD-ASK-PASSWORD(1)
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NAME

6       systemd-ask-password - Query the user for a system password
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SYNOPSIS

9       systemd-ask-password [OPTIONS...] [MESSAGE]
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DESCRIPTION

12       systemd-ask-password may be used to query a system password or
13       passphrase from the user, using a question message specified on the
14       command line. When run from a TTY it will query a password on the TTY
15       and print it to standard output. When run with no TTY or with --no-tty
16       it will use the system-wide query mechanism, which allows active users
17       to respond via several agents, listed below.
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19       The purpose of this tool is to query system-wide passwords — that is
20       passwords not attached to a specific user account. Examples include:
21       unlocking encrypted hard disks when they are plugged in or at boot,
22       entering an SSL certificate passphrase for web and VPN servers.
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24       Existing agents are:
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26       •   A boot-time password agent asking the user for passwords using
27           plymouth(8),
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29       •   A boot-time password agent querying the user directly on the
30           console — systemd-ask-password-console.service(8),
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32       •   An agent requesting password input via a wall(1) message — systemd-
33           ask-password-wall.service(8),
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35       •   A TTY agent that is temporarily spawned during systemctl(1)
36           invocations,
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38       •   A command line agent which can be started temporarily to process
39           queued password requests — systemd-tty-ask-password-agent --query.
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41       Answering system-wide password queries is a privileged operation, hence
42       all the agents listed above (except for the last one), run as
43       privileged system services. The last one also needs elevated
44       privileges, so should be run through sudo(8) or similar.
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46       Additional password agents may be implemented according to the systemd
47       Password Agent Specification[1].
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49       If a password is queried on a TTY, the user may press TAB to hide the
50       asterisks normally shown for each character typed. Pressing Backspace
51       as first key achieves the same effect.
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OPTIONS

54       The following options are understood:
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56       --icon=
57           Specify an icon name alongside the password query, which may be
58           used in all agents supporting graphical display. The icon name
59           should follow the XDG Icon Naming Specification[2].
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61       --id=
62           Specify an identifier for this password query. This identifier is
63           freely choosable and allows recognition of queries by involved
64           agents. It should include the subsystem doing the query and the
65           specific object the query is done for. Example:
66           "--id=cryptsetup:/dev/sda5".
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68       --keyname=
69           Configure a kernel keyring key name to use as cache for the
70           password. If set, then the tool will try to push any collected
71           passwords into the kernel keyring of the root user, as a key of the
72           specified name. If combined with --accept-cached, it will also try
73           to retrieve such cached passwords from the key in the kernel
74           keyring instead of querying the user right away. By using this
75           option, the kernel keyring may be used as effective cache to avoid
76           repeatedly asking users for passwords, if there are multiple
77           objects that may be unlocked with the same password. The cached key
78           will have a timeout of 2.5min set, after which it will be purged
79           from the kernel keyring. Note that it is possible to cache multiple
80           passwords under the same keyname, in which case they will be stored
81           as NUL-separated list of passwords. Use keyctl(1) to access the
82           cached key via the kernel keyring directly. Example:
83           "--keyname=cryptsetup"
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85       --credential=
86           Configure a credential to read the password from – if it exists.
87           This may be used in conjunction with the LoadCredential= and
88           SetCredential= settings in unit files. See systemd.exec(5) for
89           details. If not specified, defaults to "password". This option has
90           no effect if no credentials directory is passed to the program
91           (i.e.  $CREDENTIALS_DIRECTORY is not set) or if the no credential
92           of the specified name exists.
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94       --timeout=
95           Specify the query timeout in seconds. Defaults to 90s. A timeout of
96           0 waits indefinitely.
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98       --echo=yes|no|masked
99           Controls whether to echo user input. Takes a boolean or the special
100           string "masked", the default being the latter. If enabled the typed
101           characters are echoed literally, which is useful for prompting for
102           usernames and other non-protected data. If disabled the typed
103           characters are not echoed in any form, the user will not get
104           feedback on their input. If set to "masked", an asterisk ("*") is
105           echoed for each character typed. In this mode, if the user hits the
106           tabulator key ("↹"), echo is turned off. (Alternatively, if the
107           user hits the backspace key ("⌫") while no data has been entered
108           otherwise, echo is turned off, too).
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110       --echo, -e
111           Equivalent to --echo=yes, see above.
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113       --emoji=yes|no|auto
114           Controls whether or not to prefix the query with a lock and key
115           emoji (🔐), if the TTY settings permit this. The default is "auto",
116           which defaults to "yes", unless --echo=yes is given.
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118       --no-tty
119           Never ask for password on current TTY even if one is available.
120           Always use agent system.
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122       --accept-cached
123           If passed, accept cached passwords, i.e. passwords previously
124           entered.
125
126       --multiple
127           When used in conjunction with --accept-cached accept multiple
128           passwords. This will output one password per line.
129
130       --no-output
131           Do not print passwords to standard output. This is useful if you
132           want to store a password in kernel keyring with --keyname= but do
133           not want it to show up on screen or in logs.
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135       -n
136           By default, when writing the acquired password to standard output
137           it is suffixed by a newline character. This may be turned off with
138           the -n switch, similar to the switch of the same name of the
139           echo(1) command.
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141       -h, --help
142           Print a short help text and exit.
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EXIT STATUS

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

148       systemd(1), systemd-ask-password-console.service(8), systemd-tty-ask-
149       password-agent(1), keyctl(1), plymouth(8), wall(1)
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NOTES

152        1. systemd Password Agent Specification
153           https://systemd.io/PASSWORD_AGENTS/
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155        2. XDG Icon Naming Specification
156           http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
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160systemd 251                                            SYSTEMD-ASK-PASSWORD(1)
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