[Generate self-signed certificate] Create a self-signed certificate #linux #certificate #ssl

generate-self-cert.sh

#!/bin/bash

# Generate key and certificate
openssl genrsa -out privkey.pem 4096
openssl req -new -x509 -key privkey.pem -out cert.pem -days 1826

# Generate full self-signed certificate chain
# Create root key
openssl genrsa -des3 -out rootCA.key 4096

# Create and self sign root certificate
openssl req -x509 -new -nodes -key rootCA.key -sha256 -days 1024 -out rootCA.crt

# Create a certificate (for each server)
openssl genrsa -out mydomain.com.key 4096

# Create the CSR
openssl req -new -sha256 -key mydomain.com.key -subj "/C=US/ST=CA/O=MyOrg, Inc./CN=mydomain.com" -out mydomain.com.csr

# Verify CSR
openssl x509 -req -in mydomain.com.csr -CA rootCA.crt -CAkey rootCA.key -CAcreateserial -out mydomain.com.crt -days 500 -sha256

# Verify certificate's content
openssl x509 -in mydomain.com.crt -text -noout

generator.sh

!/usr/bin/env bash

# print usage
DOMAIN=$1
if [ -z "$1" ]; then 

    echo "USAGE: $0 domain.lan"
    echo ""
    echo "This will generate a non-secure self-signed wildcard certificate for given domain."
    echo "This should only be used in a development environment."
    exit
fi

# Add wildcard
WILDCARD="*.$DOMAIN"

# Set our CSR variables
SUBJ="
C=US
ST=NY
O=Local Developement
localityName=Local Developement
commonName=$WILDCARD
organizationalUnitName=Local Developement
emailAddress=
"

# Generate our Private Key, CSR and Certificate
openssl genrsa -out "$DOMAIN.key" 2048
openssl req -new -subj "$(echo -n "$SUBJ" | tr "\n" "/")" -key "$DOMAIN.key" -out "$DOMAIN.csr"
openssl x509 -req -days 3650 -in "$DOMAIN.csr" -signkey "$DOMAIN.key" -out "$DOMAIN.crt"
rm "$DOMAIN.csr"

echo ""
echo "Next manual steps:"
echo "- Use $DOMAIN.crt and $DOMAIN.key to configure Apache/nginx"
echo "- Import $DOMAIN.crt into Chrome settings: chrome://settings/certificates > tab 'Authorities'"