freebsd-nq/sbin/gbde/gbde.8
Colin Percival 6d118bffe7 Teach gbde(8) to use a key file in addition to a passphrase. This
makes it practical to use GBDE for "something you have plus something
you know" security together with a USB flash drive.

Reviewed by:	phk
MFC after:	7 days
2006-02-08 06:52:15 +00:00

257 lines
6.9 KiB
Groff

.\"
.\" Copyright (c) 2002 Poul-Henning Kamp
.\" Copyright (c) 2002 Networks Associates Technology, Inc.
.\" All rights reserved.
.\"
.\" This software was developed for the FreeBSD Project by Poul-Henning Kamp
.\" and NAI Labs, the Security Research Division of Network Associates, Inc.
.\" under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
.\" DARPA CHATS research program.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd February 12, 2005
.Dt GBDE 8
.Os
.Sh NAME
.Nm gbde
.Nd operation and management utility for Geom Based Disk Encryption
.Sh SYNOPSIS
.Nm
.Cm attach
.Ar destination
.Op Fl k Ar keyfile
.Op Fl l Ar lockfile
.Op Fl p Ar pass-phrase
.Nm
.Cm detach
.Ar destination
.Nm
.Cm init
.Ar destination
.Op Fl i
.Op Fl f Ar filename
.Op Fl K Ar new-keyfile
.Op Fl L Ar new-lockfile
.Op Fl P Ar new-pass-phrase
.Nm
.Cm setkey
.Ar destination
.Op Fl n Ar key
.Op Fl k Ar keyfile
.Op Fl l Ar lockfile
.Op Fl p Ar pass-phrase
.Op Fl K Ar new-keyfile
.Op Fl L Ar new-lockfile
.Op Fl P Ar new-pass-phrase
.Nm
.Cm nuke
.Ar destination
.Op Fl n Ar key
.Op Fl k Ar keyfile
.Op Fl l Ar lockfile
.Op Fl p Ar pass-phrase
.Nm
.Cm destroy
.Ar destination
.Op Fl k Ar keyfile
.Op Fl l Ar lockfile
.Op Fl p Ar pass-phrase
.Sh DESCRIPTION
.Bf -symbolic
NOTICE:
Please be aware that this code has not yet received much review
and analysis by qualified cryptographers and therefore should be considered
a slightly suspect experimental facility.
.Pp
We cannot at this point guarantee that the on-disk format will not change
in response to reviews or bug-fixes, so potential users are advised to
be prepared that
.Xr dump 8 Ns / Ns
.Xr restore 8
based migrations may be called for in the future.
.Ef
.Pp
The
.Nm
utility is the only official operation and management interface for the
.Xr gbde 4
.Tn GEOM
based disk encryption kernel facility.
The interaction between the
.Nm
utility and the kernel part is not a published interface.
.Pp
The operational aspect consists of two subcommands:
one to open and attach
a device to the in-kernel cryptographic
.Nm
module
.Pq Cm attach ,
and one to close and detach a device
.Pq Cm detach .
.Pp
The management part allows initialization of the master key and lock sectors
on a device
.Pq Cm init ,
initialization and replacement of pass-phrases
.Pq Cm setkey ,
and key invalidation
.Pq Cm nuke
and blackening
.Pq Cm destroy
functions.
.Pp
The
.Fl l Ar lockfile
argument is used to supply the lock selector data.
If no
.Fl l
option is specified, the first sector is used for this purpose.
.Pp
The
.Fl L Ar new-lockfile
argument
specifies the lock selector file for the key
initialized with the
.Cm init
subcommand
or modified with the
.Cm setkey
subcommand.
.Pp
The
.Fl n Ar key
argument can be used to specify to which of the four keys
the operation applies.
A value of 1 to 4 selects the specified key, a value of 0 (the default)
means
.Dq "this key"
(i.e., the key used to gain access to the device)
and a value of \-1 means
.Dq "all keys" .
.Pp
The
.Fl f Ar filename
specifies an optional parameter file for use under initialization.
.Pp
Alternatively, the
.Fl i
option toggles an interactive mode where a template file with descriptions
of the parameters can be interactively edited.
.Pp
The
.Fl p Ar pass-phrase
argument
specifies the pass-phrase used for opening the device.
If not specified, the controlling terminal will be used to prompt the user
for the pass-phrase.
Be aware that using this option may expose the pass-phrase to other
users who happen to run
.Xr ps 1
or similar while the command is running.
.Pp
The
.Fl P Ar new-pass-phrase
argument
can be used to specify the new pass-phrase to the
.Cm init
and
.Cm setkey
subcommands.
If not specified, the user is prompted for the new pass-phrase on the
controlling terminal.
Be aware that using this option may expose the pass-phrase to other
users who happen to run
.Xr ps 1
or similar while the command is running.
.Pp
The
.Fl k Ar keyfile
argument specifies a key file to be used in combination with the
pass-phrase (whether the pass-phrase is specified on the command line
or entered from the terminal) for opening the device.
The device will only be opened if the contents of the key file and the
pass-phrase are both correct.
.Pp
The
.Fl K Ar new-keyfile
argument can be used to specify a new key file to the
.Cm init
and
.Cm setkey
subcommands.
If not specified, no key file will be used (even if one was previously
used).
.Sh EXAMPLES
To initialize a device, using default parameters:
.Pp
.Dl "gbde init /dev/ad0s1f -L /etc/ad0s1f.lock"
.Pp
To attach an encrypted device:
.Pp
.Dl "gbde attach ad0s1f -l /etc/ad0s1f.lock"
.Pp
The encrypted device has the suffix
.Pa .bde
so a typical
command to create and mount a file system would be:
.Pp
.Dl "newfs /dev/ad0s1f.bde"
.Dl "mount /dev/ad0s1f.bde /secret"
.Pp
To detach an encrypted device:
.Pp
.Dl "gbde detach ad0s1f"
.Pp
Please notice that detaching an encrypted device corresponds to
physically removing it, do not forget to unmount the file system first.
.Pp
To initialize the second key using a detached lockfile and a trivial
pass-phrase:
.Pp
.Dl "gbde setkey ad0s1f -n 2 -P foo -L key2.lockfile"
.Pp
To destroy all copies of the masterkey:
.Pp
.Dl "gbde destroy ad0s1f -n -1"
.Sh SEE ALSO
.Xr gbde 4 ,
.Xr geom 4
.Sh HISTORY
This software was developed for the
.Fx
Project by
.An "Poul-Henning Kamp"
and NAI Labs, the Security Research Division of Network Associates, Inc.\&
under DARPA/SPAWAR contract N66001-01-C-8035
.Pq Dq CBOSS ,
as part of the
DARPA CHATS research program.
.Sh AUTHORS
.An "Poul-Henning Kamp" Aq phk@FreeBSD.org
.Sh BUGS
The cryptographic algorithms and the overall design have not been
attacked mercilessly for over 10 years by a gang of cryptoanalysts.