mandos-keygen

Name

mandos-keygen — Generate key and password for Mandos client and server.

Synopsis

mandos-keygen { --password | -p | --passfile FILE | -F FILE }
[ --dir DIRECTORY | -d DIRECTORY ]
[ --name NAME | -n NAME ]

mandos-keygen { --help | -h }

mandos-keygen { --version | -v }

DESCRIPTION

mandos-keygen is a program to generate the OpenPGP key used by mandos-client(8mandos). The key is normally written to /etc/mandos for later installation into the initrd image, but this, and most other things, can be changed with command line options.

This program can also be used with the --password or --passfile options to generate a ready-made section for clients.conf (see mandos-clients.conf(5)).

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

--help, -h: Show a help message and exit
--dir DIRECTORY, -d DIRECTORY: Target directory for key files. Default is /etc/mandos.
--type TYPE, -t TYPE: Key type. Default is “DSA”.
--length BITS, -l BITS: Key length in bits. Default is 2048.
--subtype KEYTYPE, -s KEYTYPE: Subkey type. Default is “ELG-E” (Elgamal encryption-only).
--sublength BITS, -L BITS: Subkey length in bits. Default is 2048.
--email ADDRESS, -e ADDRESS: Email address of key. Default is empty.
--comment TEXT, -c TEXT: Comment field for key. The default value is “Mandos client key”.
--expire TIME, -x TIME: Key expire time. Default is no expiration. See gpg(1) for syntax.
--force, -f: Force overwriting old key.
--password, -p: Prompt for a password and encrypt it with the key already present in either /etc/mandos or the directory specified with the --dir option. Outputs, on standard output, a section suitable for inclusion in mandos-clients.conf(8). The host name or the name specified with the --name option is used for the section header. All other options are ignored, and no key is created.
--passfile FILE, -F FILE: The same as --password, but read from FILE, not the terminal.

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 an OpenPGP 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 the same OpenPGP key, and the password is then used to unlock the root file system, whereupon the computers can continue booting normally.

This program is a small utility to generate new OpenPGP keys for new Mandos clients, and to generate sections for inclusion in clients.conf on the server.

EXIT STATUS

The exit status will be 0 if a new key (or password, if the --password option was used) was successfully created, otherwise not.

ENVIRONMENT

TMPDIR: If set, temporary files will be created here. See mktemp(1).

FILES

Use the --dir option to change where mandos-keygen will write the key files. The default file names are shown here.

/etc/mandos/seckey.txt: OpenPGP secret key file which will be created or overwritten.
/etc/mandos/pubkey.txt: OpenPGP public key file which will be created or overwritten.
/tmp: Temporary files will be written here if TMPDIR is not set.

EXAMPLE

Normal invocation needs no options:

mandos-keygen

Create key in another directory and of another type. Force overwriting old key files:

mandos-keygen --dir ~/keydir --type RSA --force

Prompt for a password, encrypt it with the key in /etc/mandos and output a section suitable for clients.conf.

mandos-keygen --password

Prompt for a password, encrypt it with the key in the client-key directory and output a section suitable for clients.conf.

mandos-keygen --password --dir client-key

SECURITY

The --type, --length, --subtype, and --sublength options can be used to create keys of low security. If in doubt, leave them to the default values.

The key expire time is not guaranteed to be honored by mandos(8).