Name

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

Synopsis

mandos-keygen [ --dir DIRECTORY | -d DIRECTORY ]
[ --type KEYTYPE | -t KEYTYPE ]
[ --length BITS | -l BITS ]
[ --subtype KEYTYPE | -s KEYTYPE ]
[ --sublength BITS | -L BITS ]
[ --name NAME | -n NAME ]
[ --email ADDRESS | -e ADDRESS ]
[ --comment TEXT | -c TEXT ]
[ --expire TIME | -x TIME ]
[ --tls-keytype KEYTYPE | -T KEYTYPE ]
[ --force | -f ]

mandos-keygen { --password | -p | --passfile FILE | -F FILE }
[ --dir DIRECTORY | -d DIRECTORY ]
[ --name NAME | -n NAME ] [ --no-ssh | -S ]

mandos-keygen { --help | -h }

mandos-keygen { --version | -v }

DESCRIPTION

mandos-keygen is a program to generate the TLS and OpenPGP keys used by mandos-client(8mandos). The keys are normally written to /etc/keys/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/keys/mandos.

--type TYPE, -t TYPE

OpenPGP key type. Default is “RSA”.

--length BITS, -l BITS

OpenPGP key length in bits. Default is 4096.

--subtype KEYTYPE, -s KEYTYPE

OpenPGP subkey type. Default is “RSA”

--sublength BITS, -L BITS

OpenPGP subkey length in bits. Default is 4096.

--email ADDRESS, -e ADDRESS

Email address of key. Default is empty.

--comment TEXT, -c TEXT

Comment field for key. Default is empty.

--expire TIME, -x TIME

Key expire time. Default is no expiration. See gpg(1) for syntax.

--tls-keytype KEYTYPE, -T KEYTYPE

TLS key type. Default is “ed25519”

--force, -f

Force overwriting old key.

--password, -p

Prompt for a password and encrypt it with the key already present in either /etc/keys/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. Note: white space is stripped from the beginning and from the end of the password; See the section called “BUGS”.

--passfile FILE, -F FILE

The same as --password, but read from FILE, not the terminal, and white space is not stripped from the password in any way.

--no-ssh, -S

When --password or --passfile is given, this option will prevent mandos-keygen from calling ssh-keyscan to get an SSH fingerprint for this host and, if successful, output suitable config options to use this fingerprint as a checker option in the output. This is otherwise the default behavior.

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 is a small utility to generate new TLS and 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/keys/mandos/seckey.txt

OpenPGP secret key file which will be created or overwritten.

/etc/keys/mandos/pubkey.txt

OpenPGP public key file which will be created or overwritten.

/etc/keys/mandos/tls-privkey.pem

Private key file which will be created or overwritten.

/etc/keys/mandos/tls-pubkey.pem

Public key file which will be created or overwritten.

/tmp

Temporary files will be written here if TMPDIR is not set.

BUGS

The --password/-p option strips white space from the start and from the end of the password before using it. If this is a problem, use the --passfile option instead, which does not do this.

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

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 keys in /etc/keys/mandos and output a section suitable for clients.conf.

mandos-keygen --password

Prompt for a password, encrypt it with the keys 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).

SEE ALSO

intro(8mandos), gpg(1), mandos-clients.conf(5), mandos(8), mandos-client(8mandos), ssh-keyscan(1)