OpenSSL Installation Guide

Overview

This guide explains how to build and install the latest stable version of OpenSSL (3.5.x LTS or higher) in the system’s default locations.

Required Dependencies

Install the build dependencies:

sudo apt update
sudo apt install -y build-essential checkinstall zlib1g-dev libssl-dev
sudo apt install -y perl-modules-5.* perl-doc

Step 1: Download and Verify OpenSSL 3.5.x

OpenSSL 3.5.x can be downloaded from the official GitHub releases page

# Create a working directory
mkdir -p ~/openssl-build && cd ~/openssl-build

# Download OpenSSL 3.5.3 (replace with latest version if available)
wget https://github.com/openssl/openssl/releases/download/openssl-3.5.3/openssl-3.5.3.tar.gz
wget https://github.com/openssl/openssl/releases/download/openssl-3.5.3/openssl-3.5.3.tar.gz.sha256

# Verify the checksum
sha256sum -c openssl-3.5.3.tar.gz.sha256

# Extract source code
tar -xzf openssl-3.5.3.tar.gz
cd openssl-3.5.3

Step 2: Configure OpenSSL 3.5.x

Configure OpenSSL for installation into /usr/local/:

./config --prefix=/usr/local --openssldir=/usr/local/ssl

Step 3: Compile OpenSSL

# Compile OpenSSL (parallel build using all available cores)
make -j$(nproc)

# Run test suite (recommended but optional)
make test

Step 4: Install OpenSSL

# Install OpenSSL (requires root privileges)
sudo make install

Step 5: Update User Environment

Open ~/.bashrc and add at the bottom:

# Use custom OpenSSL 3.5.3
export PATH=/usr/local/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/lib64:$LD_LIBRARY_PATH

Apply the changes:

source ~/.bashrc

Step 6: Verify Installation

Check which OpenSSL is being used by default:

which openssl
openssl version -a