# See the License for the specific language governing permissions and
# limitations under the License.
-# usage: $0 SERVER_HOST [DEST_HOST]
-# ssh to SERVER_HOST, create a cert & client config, put it on
-# DEST_HOST, or localhost by default. Assumes server was setup
-# by the other script in this dir.
-
set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
[[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
+readonly this_file="$(readlink -f -- "${BASH_SOURCE[0]}")"; cd "${this_file%/*}"
+
+
usage() {
- cat <<EOF
-usage: ${0##*/} VPN_SERVER_HOST [CLIENT_HOST]
+ cat <<'EOF'
+usage: ${0##*/} VPN_SERVER_HOST
+
+-b COMMON_NAME By default, use $CLIENT_HOST or if it is not given,
+ $HOSTNAME. If the cert already exists on the server,
+ with the CLIENT_NAME name, we use the existing one. See
+ comment below if we ever want to check existing common
+ names. They must be unique per server, so you can use
+ $(uuidgen) if needed. You used to be able to create
+ multiple with the same name, but not connect at the
+ same time, but now, the generator keeps track, so you
+ can't generate.
+
+-c CLIENT_HOST Default is localhost. Else we ssh to root@CLIENT_HOST.
+-n CONFIG_NAME default is client
+-o SERVER_CONFIG_NAME Default is CONFIG_NAME
+-s SCRIPT_PATH Use custom up/down script at SCRIPT_PATH. copied to same path
+ on client, if client is not localhost.
Generate a client cert and config and install it on locally or on
CLIENT_HOST if given. Uses default config options, and expects be able
-to ssh to VPN_SERVER_HOST and CLIENT_HOST.
+to ssh to VPN_SERVER_HOST and CLIENT_HOST as root, or if CLIENT_HOST is
+localhost, just to sudo this script as root.
+
+
+
+
+Note: Uses GNU getopt options parsing style
EOF
- exit ${1:-0}
+ exit ${1:-0}
}
-case $1 in
- -h|--help) usage 0 ;;
-esac
+# to get the common name
+# cn=$(s openssl x509 -noout -nameopt multiline -subject \
+ # -in /etc/openvpn/client/mail.crt | \
+ # sed -rn 's/^\s*commonName\s*=\s*(.*)/\1/p')
-(($# <= 1)) || usage 1
-host=$1
+####### begin command line parsing and checking ##############
+
shell="bash -c"
-if [[ $2 ]]; then
- shell="ssh $2"
+name=client
+custom_script=false
+script=/etc/openvpn/update-resolv-conf
+client_host=$CLIENT_HOST
+
+temp=$(getopt -l help hb:c:n:o:s: "$@") || usage 1
+eval set -- "$temp"
+while true; do
+ case $1 in
+ -b) common_name="$2"; shift 2 ;;
+ -c) client_host=$2; shell="ssh root@$client_host"; shift 2 ;;
+ -n) name="$2"; shift 2 ;;
+ -o) server_name="$2"; shift 2 ;;
+ -s) custom_script=true; script="$2"; shift 2 ;;
+ -h|--help) usage ;;
+ --) shift; break ;;
+ *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
+ esac
+done
+
+if [[ ! $server_name ]]; then
+ server_name="$name"
+fi
+
+if [[ ! $common_name ]]; then
+ if [[ $client_host ]]; then
+ common_name=$client_host
+ else
+ common_name=$HOSTNAME
+ fi
fi
+host=$1
+[[ $host ]] || usage 1
+
+####### end command line parsing and checking ##############
+
# bash or else we get motd spam. note sleep 2, sleep 1 failed.
-ssh $host bash <<EOF | $shell 'id -u | grep -xF 0 || s=sudo; $s tar xzv -C /etc/openvpn'
-set -eE -o pipefail
-cd /etc/openvpn/easy-rsa
-source vars >/dev/null
+$shell '[[ -e /etc/openvpn ]] || apt install openvpn'
+if ! ssh root@$host bash -s -- $server_name $common_name < client-cert-helper \
+ | $shell 'id -u | grep -xF 0 || s=sudo; $s tar xzv -C /etc/openvpn/client'; then
+ echo ssh root@$host cat /tmp/vpn-mk-client-cert.log:
+ ssh root@$host cat /tmp/vpn-mk-client-cert.log
+ echo EOF for root@$host:/tmp/vpn-mk-client-cert.log
+ exit 1
+fi
-# uuidgen because common name must be unique
-{ echo -e '\n\n\n\n\n'\$(uuidgen)'\n\n\n\n\n'; sleep 2; echo -e 'y\ny\n'; } | ./build-key client &>/dev/null
+port=$(echo '/^port/ {print $2}' | ssh root@$host awk -f - /etc/openvpn/server/$name.conf | tail -n1)
-d=\$(mktemp -d)
-cp /etc/openvpn/easy-rsa/keys/ca.crt \
- /etc/openvpn/update-resolv-conf \
- /usr/share/doc/openvpn/examples/sample-config-files/client.conf \$d
-mv /etc/openvpn/easy-rsa/keys/client.{crt,key} \$d
-sed -i --follow-symlinks "s/^remote .*/remote $host 1194/" \$d/client.conf
+f=/etc/openvpn/client/$name.crt
+if ! $shell "test -s $f"; then
+ # if common name is not unique, you get empty file. and if we didn't silence
+ # build-key, you'd see an error "TXT_DB error number 2"
+ echo "$0: error: $f is empty or otherwise bad. is this common name unique?"
+ exit 1
+fi
-tar cz -C \$d .
-rm -rf \$d
+$shell "dd of=/etc/openvpn/client/$name.conf" <<EOF
+# From example config, from debian stretch to buster
+client
+dev tun
+proto udp
+remote $host $port
+resolv-retry infinite
+nobind
+persist-key
+persist-tun
+ca ca-$name.crt
+cert $name.crt
+key $name.key
+# disabled for better performance
+#comp-lzo
+verb 3
+
+# matching server config
+cipher AES-256-CBC
+
+# example config has the commented line, but this other thing looks stronger,
+# and I've seen it in a vpn provider I trust
+# ns-cert-type server
+remote-cert-tls server
+
+# more resilient when running as nonroot
+persist-key
+
+# See comments in server side configuration.
+# The minimum of the client & server config is what is used by openvpn.
+reneg-sec 432000
+
+tls-auth ta-$name.key 1
EOF
+
+if [[ $script ]]; then
+ $shell "tee -a /etc/openvpn/client/$name.conf" <<EOF
+# This script will update local dns
+# to what the server sends, if it sends dns.
+script-security 2
+up "$script"
+down "$script"
+EOF
+
+ if [[ $client_host ]] && $custom_script; then
+ $shell "dd of=$script" <$script
+ $shell "chmod +x $script"
+ fi
+fi
+
+$shell 'cd /etc/openvpn; for f in client/*; do ln -sf $f .; done'