Command Line Tips: Checking TLS/SSL Certificate Expiration Dates.

SSL/TLS certificates are a critical part of securing websites and protecting sensitive user data. However, these certificates have an expiration date and must be renewed or replaced before they expire. In this article, we’ll explore how to check TLS/SSL Certificate expiration dates using the command line in Linux.

One of the easiest ways to check the expiration date of a certificate is to use the OpenSSL command-line tool. The command will display the expiration date of the certificate in UTC format. Replace “certificate.crt” with the path to the certificate file you want to check.

openssl x509 -enddate -noout -in certificate.crt

To automate the process of checking certificate expiration dates, you can write a script that runs the OpenSSL command periodically and sends an email notification if a certificate is nearing its expiration date. This ensures that you are alerted well in advance, allowing you to renew or replace the certificate before it expires.

It’s important to note that certificate expiration dates can vary, and it’s recommended to renew or replace certificates at least a few weeks before they expire. Failing to do so can cause your website to become inaccessible, which can lead to lost revenue and damage to your brand’s reputation.

In addition to using the command line, there are other ways to check certificate expiration dates. Most web browsers display certificate details when you click on the lock icon in the address bar. Online tools are also available that can check the expiration date of a TLS/SSL certificate.

In conclusion, checking TLS/SSL certificate expiration dates is crucial for maintaining website security. Command-line tools such as OpenSSL make this process simple and easy to automate. By following these command-line tips in Linux, you can ensure that your website remains secure and accessible to your users.