openvpn-embed-certificates.sh

Simple script for embedding OpenVPN certificates

#!/bin/bash

set +e

backup() {
  if [[ -e "$1.backup" ]]; then
    echo "Backup file already exists! Remove if necessary."
    exit 10
  fi
  echo "Creating backup of $1 in $1.backup" >&2
  cp "$1"{,.backup}
}

embed_credential() {
  config_path="$1"
  file_type="$2"
  file_path="$3"
  { echo "###############" ;
    echo "<$file_type>" ;
    grep -zoP '(-----BEGIN)(?s).*(-----END).*(-----)' "$file_path" | tr -d '\0';
    #tr -d '\0' < "$file_path" ;
    echo ;
    echo "</$file_type>" ;} >> "$config_path"
}

embed() {
  config_path="$1"
  if ! grep -E "^(tls-auth|ca|cert|key) " "$config_path" >/dev/null; then
    echo "No certificates to embed!" 
    exit 2
  fi
 
  key_direction="$(grep -E "^tls-auth " "$config_path" | awk '{ print $3;}')"
  echo "key-direction $key_direction" >> "$config_path"
 
  for ftype in tls-auth ca cert key; do
    file_path="$(grep -E "^$ftype " "$config_path" | awk '{ print $2;}')"
    embed_credential "$config_path" "$ftype" "$file_path"
    sed -i -e "/^$ftype .*$/d" "$config_path"
  done
  echo "Certificates successfully embedded!"
}

remove_default_route() {
  config_path="$1"
  { echo "pull-filter ignore \"redirect-gateway\""; 
    echo "pull-filter ignore \"route 0.0.0.0 0.0.0.0\""; } >> "$config_path"
}

main() {
  if [[ ! -f "$1" ]]; then
    echo "ERROR! No such file $1"
    exit 1
  fi
  backup "$1"
  remove_default_route "$1"
  embed "$1"
}

main "$1"