1SYSTEMD-ASK-PASSWORD(1) systemd-ask-password SYSTEMD-ASK-PASSWORD(1)
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6 systemd-ask-password - Query the user for a system password
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9 systemd-ask-password [OPTIONS...] [MESSAGE]
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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.
18 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.
23 Existing agents are:
25 · A boot-time password agent asking the user for passwords using
27 plymouth(8),
28 · A boot-time password agent querying the user directly on the
30 console — systemd-ask-password-console.service(8),
31 · An agent requesting password input via a wall(1) message — systemd-
33 ask-password-wall.service(8),
34 · A TTY agent that is temporarily spawned during systemctl(1)
36 invocations,
37 · A command line agent which can be started temporarily to process
39 queued password requests — systemd-tty-ask-password-agent --query.
40 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.
45 Additional password agents may be implemented according to the systemd
47 Password Agent Specification[1].
48 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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54 The following options are understood:
55 --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].
60 --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".
67 --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"
84 --timeout=
86 Specify the query timeout in seconds. Defaults to 90s. A timeout of
87 0 waits indefinitely.
88 --echo
90 Echo the user input instead of masking it. This is useful when
91 using systemd-ask-password to query for usernames.
92 --no-tty
94 Never ask for password on current TTY even if one is available.
95 Always use agent system.
96 --accept-cached
98 If passed, accept cached passwords, i.e. passwords previously
99 entered.
100 --multiple
102 When used in conjunction with --accept-cached accept multiple
103 passwords. This will output one password per line.
104 --no-output
106 Do not print passwords to standard output. This is useful if you
107 want to store a password in kernel keyring with --keyname but do
108 not want it to show up on screen or in logs.
109 -h, --help
111 Print a short help text and exit.
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114 On success, 0 is returned, a non-zero failure code otherwise.
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117 systemd(1), systemd-ask-password-console.service(8), systemd-tty-ask-
118 password-agent(1), keyctl(1), plymouth(8), wall(1)
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121 1. systemd Password Agent Specification
122 https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents
123 2. XDG Icon Naming Specification
125 http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
126systemd 245 SYSTEMD-ASK-PASSWORD(1)