#!/usr/bin/perl -w

# luksformat - wrapper around LUKS-capable cryptsetup and mkfs for easy
# creation of an encrypted device.
#
# (C) 2005 Canonical Ltd.
# Author: Martin Pitt <martin.pitt@ubuntu.com>
# License: GNU General Public License, v2 or any later
# (https://www.gnu.org/copyleft/gpl.html)

use Getopt::Long qw(:config pass_through);

BEGIN {
    eval 'use Locale::gettext';
    if ($@) {
        *gettext = sub { shift };
        *textdomain = sub { "" };
        *LC_MESSAGES = sub { 5 };
    }
    eval {
        require POSIX;
        import POSIX qw(setlocale);
    };
    if ($@) {
        *setlocale = sub { return 1 };
    }
}

setlocale(LC_MESSAGES, "");
textdomain("luksformat");

if ($> != 0) {
    print STDERR gettext("This program needs to be started as root\n");
    exit 1;
}

sub usage() {
    print gettext("luksformat - Create and format an encrypted LUKS device
Usage: luksformat [-t <file system>] <device> [ mkfs options ]\n\n");
    exit 1;
}

# default file system
$fs = 'vfat';
exit 1 unless GetOptions ('t|type=s' => \$fs);

GetOptions ('help', \$help);
if (($#ARGV < 0) || ($help)) {
    usage();
}

$device = shift(@ARGV);

open(MOUNTS, "/proc/mounts");
while (<MOUNTS>) {
    die sprintf(gettext("Error: device mounted: %s\n"), $device) if (/\Q$device\E/)
}

if (-x "/usr/sbin/mkfs.$fs") {
    $mkfs = "/usr/sbin/mkfs.$fs";
}
elsif (-x "/usr/bin/mkfs.$fs") {
    $mkfs = "/usr/bin/mkfs.$fs";
}
elsif (-x "/sbin/mkfs.$fs") {
    $mkfs = "/sbin/mkfs.$fs";
}
elsif (-x "/bin/mkfs.$fs") {
    $mkfs = "/bin/mkfs.$fs";
}
else {
    printf STDERR (gettext("Error: invalid file system: %s\n"), $fs);
    exit 1;
}

# generate temporary mapped device name which is not yet used
$name = "";
for ($i = 1; $i < 100; $i++) {
    if (! -e "/dev/mapper/luksformat$i") {
	$name = "luksformat$i";
	last;
    }
}

$name or die sprintf(gettext("Error: could not generate temporary mapped device name"));

# we do not need to be overly concerned with race conditions here, cryptsetup
# will just fail if the name already exists now.
printf (gettext("Creating encrypted device on %s...\n"), $device);
if ((system 'cryptsetup', 'luksFormat', $device)) {
    die sprintf(gettext("Could not create LUKS device %s"), $device);
}

print gettext("Please enter your passphrase again to verify it\n");
if ((system 'cryptsetup', 'open', '--type', 'luks', $device, $name) != 0) {
    print STDERR gettext("The passphrases you entered were not identical\n");
    exit 1;
}

$result = system $mkfs, "/dev/mapper/$name", @ARGV;
print "\n";
system 'udevadm', 'settle', '--timeout=30';
system 'cryptsetup', 'luksClose', $name;

die sprintf(gettext("Could not format device with file system %s"), $fs) if $result;

__END__

=head1 NAME

luksformat - Create and format an encrypted LUKS device

=head1 SYNOPSIS

B<luksformat> [B<-t> I<fstype>] I<device> [ mkfs options ]

=head1 DESCRIPTION

B<luksformat> is a wrapper around B<cryptsetup> and B<mkfs> which provides an
easy interface for creating an encrypted device that follows the LUKS standard
and for putting a file system onto the encrypted device.

The default file system is B<vfat> since that is most commonly used on
removable devices. However, you can specify any available file system with the
B<-t> option.

=head1 SEE ALSO

L<cryptsetup(8)>, L<mkfs(8)>

=head1 AUTHOR

This program was written by Martin Pitt <martin.pitt@ubuntu.com>.