/mandos/trunk

#!/bin/sh -e

# 

# Mandos key generator - create a new OpenPGP key for a Mandos client

# 

# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson

# 

# This program 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 program 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/>.

# 

# Contact the authors at <mandos@fukt.bsnet.se>.

# 

VERSION="1.0"

KEYDIR="/etc/mandos"

KEYTYPE=DSA

KEYLENGTH=1024

SUBKEYTYPE=ELG-E

SUBKEYLENGTH=2048

KEYNAME="`hostname --fqdn`"

KEYEMAIL=""

KEYCOMMENT="Mandos client key"

KEYEXPIRE=0

FORCE=no

KEYCOMMENT_ORIG="$KEYCOMMENT"

# Parse options

TEMP=`getopt --options vhd:t:l:n:e:c:x:f \

    --longoptions version,help,dir:,type:,length:,name:,email:,comment:,expire:,force \

    --name "$0" -- "$@"`

help(){

cat <<EOF

Usage: `basename $0` [options]

Options:

  -v, --version         Show program's version number and exit

  -h, --help            Show this help message and exit

  -d DIR, --dir DIR     Target directory for key files

  -t TYPE, --type TYPE  Key type.  Default is DSA.

  -l BITS, --length BITS

                        Key length in bits.  Default is 1024.

  -s TYPE, --subtype TYPE

                        Subkey type.  Default is ELG-E.

  -L BITS, --sublength BITS

                        Subkey length in bits.  Default is 2048.

  -n NAME, --name NAME  Name of key.  Default is the FQDN.

  -e EMAIL, --email EMAIL

                        Email address of key.  Default is empty.

  -c COMMENT, --comment COMMENT

                        Comment field for key.  The default value is

                        "Mandos client key".

  -x TIME, --expire TIME

                        Key expire time.  Default is no expiration.

                        See gpg(1) for syntax.

  -f, --force           Force overwriting old keys.

EOF

}

eval set -- "$TEMP"

while :; do

    case "$1" in

	-d|--dir) KEYDIR="$2"; shift 2;;

	-t|--type) KEYTYPE="$2"; shift 2;;

	-s|--subtype) SUBKEYTYPE="$2"; shift 2;;

	-l|--length) KEYLENGTH="$2"; shift 2;;

	-L|--sublength) SUBKEYLENGTH="$2"; shift 2;;

	-n|--name) KEYNAME="$2"; shift 2;;

	-e|--email) KEYEMAIL="$2"; shift 2;;

	-c|--comment) KEYCOMMENT="$2"; shift 2;;

	-x|--expire) KEYEXPIRE="$2"; shift 2;;

	-f|--force) FORCE=yes; shift;;

	-v|--version) echo "$0 $VERSION"; exit;;

	-h|--help) help; exit;;

	--) shift; break;;

	*) echo "Internal error" >&2; exit 1;;

    esac

done

if [ "$#" -gt 0 ]; then

    echo "Unknown arguments: '$@'" >&2

    exit 1

fi

SECKEYFILE="$KEYDIR/seckey.txt"

PUBKEYFILE="$KEYDIR/pubkey.txt"

# Check for some invalid values

if [ -d "$KEYDIR" ]; then :; else

    echo "$KEYDIR not a directory" >&2

    exit 1

fi

if [ -w "$KEYDIR" ]; then :; else

    echo "Directory $KEYDIR not writeable" >&2

    exit 1

fi

if [ -z "$KEYTYPE" ]; then

    echo "Empty key type" >&2

    exit 1

fi

if [ -z "$KEYNAME" ]; then

    echo "Empty key name" >&2

    exit 1

fi

if [ -z "$KEYLENGTH" ] || [ "$KEYLENGTH" -lt 512 ]; then

    echo "Invalid key length" >&2

    exit 1

fi

if [ -z "$KEYEXPIRE" ]; then

    echo "Empty key expiration" >&2

    exit 1

fi

# Make FORCE be 0 or 1

case "$FORCE" in

    [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]) FORCE=1;;

    [Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|*) FORCE=0;;

esac

if { [ -e "$SECKEYFILE" ] || [ -e "$PUBKEYFILE" ]; } \

    && [ "$FORCE" -eq 0 ]; then

    echo "Refusing to overwrite old key files; use --force" >&2

    exit 1

fi

# Set lines for GnuPG batch file

if [ -n "$KEYCOMMENT" ]; then

    KEYCOMMENTLINE="Name-Comment: $KEYCOMMENT"

fi

if [ -n "$KEYEMAIL" ]; then

    KEYEMAILLINE="Name-Email: $KEYEMAIL"

fi

# Create temp files

BATCHFILE="`mktemp -t mandos-gpg-batch.XXXXXXXXXX`"

SECRING="`mktemp -t mandos-gpg-secring.XXXXXXXXXX`"

PUBRING="`mktemp -t mandos-gpg-pubring.XXXXXXXXXX`"

# Remove temporary files on exit

trap "

set +e; \

rm --force $PUBRING $BATCHFILE; \

shred --remove $SECRING; \

stty echo; \

" EXIT

# Create batch file for GnuPG

cat >"$BATCHFILE" <<EOF

Key-Type: $KEYTYPE

Key-Length: $KEYLENGTH

#Key-Usage: encrypt,sign,auth

Subkey-Type: $SUBKEYTYPE

Subkey-Length: $SUBKEYLENGTH

#Subkey-Usage: encrypt,sign,auth

Name-Real: $KEYNAME

$KEYCOMMENTLINE

$KEYEMAILLINE

Expire-Date: $KEYEXPIRE

#Preferences: <string>

#Handle: <no-spaces>

%pubring $PUBRING

%secring $SECRING

%commit

EOF

umask 027

# Generate a new key in the key rings

gpg --no-random-seed-file --quiet --batch --no-tty \

    --no-default-keyring --no-options --enable-dsa2 \

    --secret-keyring "$SECRING" --keyring "$PUBRING" \

    --gen-key "$BATCHFILE"

rm --force "$BATCHFILE"

# Backup any old key files

if cp --backup=numbered --force "$SECKEYFILE" "$SECKEYFILE" \

    2>/dev/null; then

    shred --remove "$SECKEYFILE"

fi

if cp --backup=numbered --force "$PUBKEYFILE" "$PUBKEYFILE" \

    2>/dev/null; then

    rm --force "$PUBKEYFILE"

fi

FILECOMMENT="Mandos client key for $KEYNAME"

if [ "$KEYCOMMENT" != "$KEYCOMMENT_ORIG" ]; then

    FILECOMMENT="$FILECOMMENT ($KEYCOMMENT)"

fi

if [ -n "$KEYEMAIL" ]; then

    FILECOMMENT="$FILECOMMENT <$KEYEMAIL>"

fi

# Export keys from key rings to key files

gpg --no-random-seed-file --quiet --batch --no-tty --armor \

    --no-default-keyring --no-options --enable-dsa2 \

    --secret-keyring "$SECRING" --keyring "$PUBRING" \

    --export-options export-minimal --comment "$FILECOMMENT" \

    --output "$SECKEYFILE" --export-secret-keys

gpg --no-random-seed-file --quiet --batch --no-tty --armor \

    --no-default-keyring --no-options --enable-dsa2 \

    --secret-keyring "$SECRING" --keyring "$PUBRING" \

    --export-options export-minimal --comment "$FILECOMMENT" \

    --output "$PUBKEYFILE" --export

trap - EXIT

# Remove the key rings

shred --remove "$SECRING"

rm --force "$PUBRING"