Provided by: mandos-client_1.8.8-1_amd64 bug

NAME

       password-agent - Run Mandos client as a systemd password agent.

SYNOPSIS

       password-agent [--agent-directory=DIRECTORY]
                      [--helper-directory=DIRECTORY]
                      [--user=USERID]
                      [--group=GROUPID]
                      [--] [MANDOS_CLIENT [OPTIONS...]]

       password-agent --test

       password-agent {--help | -?}

       password-agent --usage

       password-agent {--version | -V}

DESCRIPTION

       password-agent is a program which is meant to be a systemd(1) “Password Agent” (See
       Password Agents[1]). The aim of this program is therefore to acquire and then send a
       password to some other program which will use the password to unlock the encrypted root
       disk.

       This program is not meant to be invoked directly, but can be in order to test it.

PURPOSE

       The purpose of this is to enable remote and unattended rebooting of client host computer
       with an encrypted root file system. See the section called “OVERVIEW” for details.

OPTIONS

       --agent-directory DIRECTORY
           Specify a different agent directory. The default is “/run/systemd/ask-password” as per
           the Password Agents[1] specification.

       --helper-directory DIRECTORY
           Specify a different helper directory. The default is “/lib/mandos/plugin-helpers”,
           which will exist in the initial RAM disk environment. (This will simply be passed to
           the MANDOS_CLIENT program via the MANDOSPLUGINHELPERDIR environment variable. See
           mandos-client(8mandos).)

       --user USERID
           Change real user ID to USERID when running MANDOS_CLIENT. The default is 65534.  Note:
           This must be a number, not a name.

       --group GROUPID
           Change real group ID to GROUPID when running MANDOS_CLIENT. The default is 65534.
           Note: This must be a number, not a name.

       MANDOS_CLIENT
           This specifies the file name for mandos-client(8mandos). If the “--” option is given,
           any following options are passed to the MANDOS_CLIENT program. The default is
           “/lib/mandos/plugins.d/mandos-client” (which is the correct location for the initial
           RAM disk environment) without any options.

       --help, -?
           Gives a help message about options and their meanings.

       --test
           Ignore normal operation; instead only run self-tests. Adding the --help option may
           show more options possible in combination with --test.

       --usage
           Gives a short usage message.

       --version, -V
           Prints the program version.

OVERVIEW

       This is part of the Mandos system for allowing computers to have encrypted root file
       systems and at the same time be capable of remote and/or unattended reboots. The computers
       run a small client program in the initial RAM disk environment which will communicate with
       a server over a network. All network communication is encrypted using TLS. The clients are
       identified by the server using a TLS key; each client has one unique to it. The server
       sends the clients an encrypted password. The encrypted password is decrypted by the
       clients using a separate OpenPGP key, and the password is then used to unlock the root
       file system, whereupon the computers can continue booting normally.

       This program, password-agent, will run on the client side in the initial RAM disk
       environment, and is responsible for getting a password from the Mandos client program
       itself, and to send that password to whatever is currently asking for a password using the
       systemd Password Agents[1] mechanism.

       To accomplish this, password-agent runs the mandos-client program (which is the actual
       client program communicating with the Mandos server) or, alternatively, any executable
       file specified as MANDOS_CLIENT, and, as soon as a password is acquired from the
       MANDOS_CLIENT program, sends that password (as per the Password Agents[1] specification)
       to all currently unanswered password questions.

       This program should be started (normally as a systemd service, which in turn is normally
       started by a systemd.path(5) file) as a reaction to files named “ask.xxxx” appearing in
       the agent directory “/run/systemd/ask-password” (or the directory specified by
       --agent-directory).

EXIT STATUS

       Exit status of this program is zero if no errors were encountered, and otherwise not.

ENVIRONMENT

       This program does not use any environment variables itself, it only passes on its
       environment to MANDOS_CLIENT. Also, the --helper-directory option will affect the
       environment variable MANDOSPLUGINHELPERDIR for MANDOS_CLIENT.

FILES

       /run/systemd/ask-password
           The default directory to watch for password questions as per the Password Agents[1]
           specification; can be changed by the --agent-directory option.

       /lib/mandos/plugin-helpers
           The helper directory as supplied to MANDOS_CLIENT via the MANDOSPLUGINHELPERDIR
           environment variable; can be changed by the --helper-directory option.

BUGS

       Please report bugs to the Mandos development mailing list: <mandos-dev@recompile.se>
       (subscription required). Note that this list is public. The developers can be reached
       privately at <mandos@recompile.se> (OpenPGP key fingerprint 153A 37F1 0BBA 0435 987F 2C4A
       7223 2973 CA34 C2C4 for encrypted mail).

EXAMPLE

       Normal invocation needs no options:

       password-agent

       Run an alternative MANDOS_CLIENT program::

       password-agent /usr/local/sbin/alternate

       Use alternative locations for the helper directory and the Mandos client, and add extra
       options suitable for running in the normal file system:

       password-agent --helper-directory=/usr/lib/x86_64-linux-gnu/mandos/plugin-helpers --
       /usr/lib/x86_64-linux-gnu/mandos/plugins.d/mandos-client
       --pubkey=/etc/keys/mandos/pubkey.txt --seckey=/etc/keys/mandos/seckey.txt
       --tls-pubkey=/etc/keys/mandos/tls-pubkey.pem
       --tls-privkey=/etc/keys/mandos/tls-privkey.pem

       Use the default location for mandos-client(8mandos), but add many options to it:

       password-agent -- /lib/mandos/mandos-client --pubkey=/etc/mandos/keys/pubkey.txt
       --seckey=/etc/mandos/keys/seckey.txt --tls-pubkey=/etc/mandos/keys/tls-pubkey.pem
       --tls-privkey=/etc/mandos/keys/tls-privkey.pem

       Only run the self-tests:

       password-agent --test

SECURITY

       This program will need to run as the root user in order to read the agent directory and
       the “ask.xxxx” files there, and will, when starting the Mandos client program, require the
       ability to set the “real” user and group ids to another user, by default user and group
       65534, which are assumed to be non-privileged. This is done in order to match the
       expectations of mandos-client(8mandos), which assumes that its executable file is owned by
       the root user and also has the set-user-ID bit set (see execve(2)).

SEE ALSO

       intro(8mandos), mandos-client(8mandos), systemd(1),

       Password Agents[1]
           The specification for systemd “Password Agent” programs, which password-agent follows.

COPYRIGHT

       Copyright © 2019 Teddy Hogeborn, Björn Påhlsson

       This manual page is part of Mandos.

       Mandos is free software: you can redistribute it and/or modify it under the terms of the
       GNU General Public License as published by the Free Software Foundation, either version 3
       of the License, or (at your option) any later version.

       Mandos is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with Mandos. If
       not, see http://www.gnu.org/licenses/.

NOTES

        1. Password Agents
           https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/