Upgrading TLS on an Old Server without Reinstalling Core OS: A Guide

Introduction

In today's digital world, security is paramount. One of the essential security measures is Transport Layer Security (TLS), which encrypts data between two endpoints. However, with the evolution of technology, older versions of TLS are no longer considered secure. In this article, we will discuss how to upgrade your server from TLS 1.2 to TLS 1.3 without reinstalling CoreOS.

Current TLS Version

You are currently using a server with Linux version 2.6.32-431.29.2.el6.x86_64 #1 SMP OpenSSL 1.0.2k-fips 25 Mar 2015.

This server supports TLS 1.2 but not TLS 1.3. To ensure the security of your server, it's crucial to upgrade to TLS 1.3.

Prerequisites

• A CoreOS server with access to the internet
• Root access to the server
• A backup of your server configuration and data

Updating OpenSSL

The first step is to update OpenSSL to a version that supports TLS 1.3.

Checking Current OpenSSL Version

To check the current OpenSSL version, run the following command:

# openssl version
 OpenSSL 1.0.2k-fips 25 Mar 2015

Updating OpenSSL

To update OpenSSL, you can use the package manager for your Linux distribution. For example, on CoreOS, you can use the following command:

# curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
 # echo "deb https://apt.kubernetes.io/kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
 # sudo apt-get update
 # sudo apt-get install -y openssl

Configuring OpenSSL

Once OpenSSL is updated, you need to configure it to use TLS 1.3.

Editing OpenSSL Configuration File

Edit the OpenSSL configuration file using your favorite text editor:

# sudo nano /etc/openssl/openssl.cnf

Add the following lines to the file:

[ssl_client_method]
 method = TLSv1.3

Restarting OpenSSL

Restart OpenSSL to apply the changes:

# sudo systemctl restart openssl-client

Testing TLS Version

To test the new TLS version, you can use the following command:

# openssl s_client -connect example.com:443 -version

Conclusion

In this article, we discussed how to upgrade your server from TLS 1.2 to TLS 1.3 without reinstalling CoreOS. We updated OpenSSL, configured it to use TLS 1.3, and tested the new TLS version.