generate-SSL-key-cert-csr.sh

#!/bin/bash 

## references:
## 1.) https://www.digitalocean.com/community/tutorials/openssl-essentials-working-with-ssl-certificates-private-keys-and-csrs

function usage() {
    if [ $# -lt 1 ]; then
        echo "----------------------------------------------------------------------"
        echo "---------------------------- USAGE -----------------------------------"
        echo "----------------------------------------------------------------------"
        echo "$0 [<CERT_BASENAME>:-domain] [<CERT_DAYS>:-999]"
        echo "CERT_BASENAME: default=domain, change to some name - no space allowed!"
        echo "CERT_DAYS: default=1095 (3 years)"
    fi
}
usage $*

CERT_BASENAME="${1:-domain}"
CERT_DAYS=${2:-999}

SUBJ="/C=US/ST=State/L=Local/O=Company/CN=domain"

echo -e "\n----------------------------------------------------------------------"
echo "#### ---- Configurations: -----"
echo "----------------------------------------------------------------------"
echo "CERT_BASENAME=${CERT_BASENAME} (for *.key, csr, crt files)"
echo "CERT_DAYS=${CERT_DAYS}"
echo "SUBJ=${SUBJ}"

echo -e "\n----------------------------------------------------------------------"
echo "#### ---- OpenSSL version information: -----"
echo "----------------------------------------------------------------------"
openssl version -a

echo -e "\n----------------------------------------------------------------------"
echo "#### ---- Generate Private Key & Self-signing Certificat: -----"
echo "----------------------------------------------------------------------"
openssl req \
       -newkey rsa:2048 -nodes -keyout ${CERT_BASENAME}.key \
       -x509 -days ${CERT_DAYS} -out ${CERT_BASENAME}.crt \
       -subj ${SUBJ}

echo -e "\n----------------------------------------------------------------------"
echo "#### ---- Generate CSR (Certificate Signing Request): -----"
echo "----------------------------------------------------------------------"
openssl req \
       -key ${CERT_BASENAME}.key \
       -new -out ${CERT_BASENAME}.csr \
       -subj ${SUBJ}

ls -al ${CERT_BASENAME}*

echo -e "\n----------------------------------------------------------------------"
echo "#### ---- Validate Key, CSR, Self-Signing Certificate: ----"
echo "----------------------------------------------------------------------"
openssl rsa -noout -modulus -in ${CERT_BASENAME}.key | openssl md5
openssl x509 -noout -modulus -in ${CERT_BASENAME}.crt | openssl md5
openssl req -noout -modulus -in ${CERT_BASENAME}.csr | openssl md5
echo ">>> All three MD5 output above should be the same to be validate!"