Step 1: Download certbot from git

You need to fetch the source code of Let’s Encrypt on your server which your domain address is pointing to. This step may take a couple minutes.

$ git clone https://github.com/certbot/certbot

$ cd certbot

$ ./certbot-auto –help

Remark: Python 2.7.8 (or above) should be installed beforehand.

Step2: generates certificates and a private key

By executing following command in your terminal, Let’s Encrypt generates certificates and a private key for you.

$ ./certbot-auto certonly -a standalone \

-d example.com -d example.com

Remark:Keys are generated in /etc/letsencrypt/live/example.com directory

Step3: Generate PKCS12 Files From PEM Files

To convert the PEM files to PKCS12 version:
Go to /etc/letsencrypt/live/example.com
convert the keys to PKCS12 using OpenSSL in the terminal as follows.

$ openssl pkcs12 -export -in fullchain.pem \

       -inkey privkey.pem \

           -out keystore.p12 \

       -name tomcat \

       -CAfile chain.pem \

       -caname root

Enter Export Password:

Verifying – Enter Export Password:

(Note:- Write single line at a time and press enter)

Step4: Configuration of Spring Boot Application

Open your ‘application.properties’
Put this configuration there.

server.port=8443 security.require-ssl=true

server.ssl.key-store=/etc/letsencrypt/live/example.com/keystore.p12

server.ssl.key-store-password= password

server.ssl.keyStoreType= PKCS12

server.ssl.keyAlias= tomcat