vpngen/vpngen/default/easy-rsa/inherit-inter

#!/bin/bash

# Build a new PKI which is rooted on an intermediate certificate generated
# by ./build-inter or ./pkitool --inter from a parent PKI.  The new PKI should
# have independent vars settings, and must use a different KEY_DIR directory
# from the parent.  This tool can be used to generate arbitrary depth
# certificate chains.
#
# To build an intermediate CA, follow the same steps for a regular PKI but
# replace ./build-key or ./pkitool --initca with this script.

# The EXPORT_CA file will contain the CA certificate chain and should be
# referenced by the OpenVPN "ca" directive in config files.  The ca.crt file
# will only contain the local intermediate CA -- it's needed by the easy-rsa
# scripts but not by OpenVPN directly.
EXPORT_CA="export-ca.crt"

if [ $# -ne 2 ]; then
    echo "usage: $0 <parent-key-dir> <common-name>"
    echo "parent-key-dir: the KEY_DIR directory of the parent PKI"
    echo "common-name: the common name of the intermediate certificate in the parent PKI"
    exit 1;
fi

if [ "$KEY_DIR" ]; then
    cp "$1/$2.crt" "$KEY_DIR/ca.crt"
    cp "$1/$2.key" "$KEY_DIR/ca.key"

    if [ -e "$1/$EXPORT_CA" ]; then
	PARENT_CA="$1/$EXPORT_CA"
    else
	PARENT_CA="$1/ca.crt"
    fi
    cp "$PARENT_CA" "$KEY_DIR/$EXPORT_CA"
    cat "$KEY_DIR/ca.crt" >> "$KEY_DIR/$EXPORT_CA"
else
    echo 'Please source the vars script first (i.e. "source ./vars")'
    echo 'Make sure you have edited it to reflect your configuration.'
fi