generate-CA.sh

#!/bin/bash

[ -n "$DEST" ] || DEST="."

mkdir -p "$DEST"

pushd "$DEST" || exit

# CA certificate (FQDN must be different from server/client)
openssl genrsa -out ca.key 2048
openssl req -new -x509 -days 365 -key ca.key -subj "/C=CN/ST=GD/L=SZ/O=Acme, Inc./CN=Acme Root CA" -out ca.crt

# server certificate (for multiple domains, change subjectAltName to: DNS:example.com,DNS:www.example.com)
openssl req -newkey rsa:2048 -nodes -keyout server.key -subj "/C=CN/ST=GD/L=SZ/O=Acme, Inc./CN=localhost" -out server.csr
openssl x509 -sha256 -req -extfile <(printf "subjectAltName=DNS:localhost") -days 365 -in server.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out server.crt

# client certificate (the p12/pem format may be useful for some clients)
openssl req -newkey rsa:2048 -nodes -keyout client.key -subj "/C=CN/ST=GD/L=SZ/O=Acme, Inc./CN=client" -out client.csr
openssl x509 -req -days 365 -in client.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out client.crt
openssl pkcs12 -export -clcerts -in client.crt -inkey client.key -out client.p12
openssl pkcs12 -in client.p12 -out client.pem -clcerts

popd || exit