trusty (8) password-prompt.8mandos.gz

NAME

       password-prompt - Prompt for a password and output it.

SYNOPSIS

       password-prompt [--prefix PREFIX | -p PREFIX]
                       [--debug]

       password-prompt {--help | -?}

       password-prompt --usage

       password-prompt {--version | -V}

DESCRIPTION

       All password-prompt does is prompt for a password and output any given password to standard output.

       This program is not very useful on its own. This program is really meant to run as a plugin in the Mandos
       client-side system, where it is used as a fallback and alternative to retrieving passwords from a Mandos
       server.

       This program is little more than a getpass(3) wrapper, although actual use of that function is not
       guaranteed or implied.

OPTIONS

       This program is commonly not invoked from the command line; it is normally started by the Mandos plugin
       runner, see plugin-runner(8mandos). Any command line options this program accepts are therefore normally
       provided by the plugin runner, and not directly.

       --prefix=PREFIX, -p PREFIX
           Prefix string shown before the password prompt.

       --debug
           Enable debug mode. This will enable a lot of output to standard error about what the program is
           doing. The program will still perform all other functions normally.

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

       --usage
           Gives a short usage message.

       --version, -V
           Prints the program version.

EXIT STATUS

       If exit status is 0, the output from the program is the password as it was read. Otherwise, if exit
       status is other than 0, the program has encountered an error, and any output so far could be corrupt
       and/or truncated, and should therefore be ignored.

ENVIRONMENT

       CRYPTTAB_SOURCE, CRYPTTAB_NAME
           If set, these environment variables will be assumed to contain the source device name and the target
           device mapper name, respectively, and will be shown as part of the prompt.

           These variables will normally be inherited from plugin-runner(8mandos), which will normally have
           inherited them from /scripts/local-top/cryptroot in the initial RAM disk environment, which will have
           set them from parsing kernel arguments and /conf/conf.d/cryptroot (also in the initial RAM disk
           environment), which in turn will have been created when the initial RAM disk image was created by
           /usr/share/initramfs-tools/hooks/cryptroot, by extracting the information of the root file system
           from /etc/crypttab.

           This behavior is meant to exactly mirror the behavior of askpass, the default password prompter.

BUGS

       None are known at this time.

EXAMPLE

       Note that normally, command line options will not be given directly, but via options for the Mandos
       plugin-runner(8mandos).

       Normal invocation needs no options:

       password-prompt

       Show a prefix before the prompt; in this case, a host name. It might be useful to be reminded of which
       host needs a password, in case of KVM switches, etc.

       password-prompt --prefix=host.example.org:

       Run in debug mode.

       password-prompt --debug

SECURITY

       On its own, this program is very simple, and does not exactly present any security risks. The one thing
       that could be considered worthy of note is this: This program is meant to be run by plugin-
       runner(8mandos), and will, when run standalone, outside, in a normal environment, immediately output on
       its standard output any presumably secret password it just received. Therefore, when running this program
       standalone (which should never normally be done), take care not to type in any real secret password by
       force of habit, since it would then immediately be shown as output.

       To further alleviate any risk of being locked out of a system, the plugin-runner(8mandos) has a fallback
       mode which does the same thing as this program, only with less features.

SEE ALSO

       intro(8mandos) crypttab(5) mandos-client(8mandos) plugin-runner(8mandos),

COPYRIGHT

       Copyright © 2008-2009, 2011-2012 Teddy Hogeborn, Björn Påhlsson

       This manual page 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.

       This manual page 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 this program. If not, see
       http://www.gnu.org/licenses/.