Script to generate an OpenVPN client configuration file in the unified format

ovpn-writer.sh

#!/bin/bash
#

if [ "$#" -lt 6 ]; then
    echo "./ovpn-writer.sh  <server address> <protocol> "
    echo "                  <port> <ca certificate> "
    echo "                  <client certificate> <client key>"
    echo "                  [tls key] "
    exit 1
fi

server=${1?"The server address is required"}
protocol=${2?"The protocol is required (e.g. udp)"}
port=${3?"Port number is required (e.g. 1194)"}
cacert=${4?"The path to the ca certificate file is required"}
client_cert=${5?"The path to the client certificate file is required"}
client_key=${6?"The path to the client private key file is required"}
tls_key=${7}

cat << EOF
setenv FORWARD_COMPATIBLE 1
client
dev tun
remote ${server} ${port}
resolv-retry infinite
nobind
persist-key
persist-tun
verb 3
keepalive 10 600
proto ${protocol}
cipher BF-CBC
<ca>
EOF
cat ${cacert}
cat << EOF
</ca>
<cert>
EOF
cat ${client_cert} | sed -n '/.*BEGIN.*/, /.*END.*/p'
cat << EOF
</cert>
<key>
EOF
cat ${client_key}
cat << EOF
</key>
EOF
if [[ -z $tls_key ]]; then
    exit 0
fi
cat << EOF
remote-cert-tls server
key-direction 1
<tls-auth>
EOF
cat ${tls_key} | sed -n '/.*BEGIN.*/, /.*END.*/p'
cat << EOF
</tls-auth>
EOF