TLS stands for Transport Layer Security. It is a protocol that is designed to ensure secure communication over a network.
It is considered as a standard best practice to implement this protocol while designing secure websites and applications.
Here at LinuxAPT, as part of our Server Management Services, we regularly help our Customers to perform related TLS queries.
In this context, we shall look into different methods of verifying if a web server supports TLS or not on Ubuntu 20.04.
To verify if a web server supports TLS or not, you can make use of any of the following two methods on a Ubuntu 20.04 system.
"Nmap" is a very commonly used utility for discovering hosts and services on a network.
To use this utility for verifying if a server supports TLS or not on Ubuntu 20.04, you will have to perform the following steps:
i. Install the "Nmap" Utility on your Ubuntu 20.04 System
First, you need to install "Nmap" on your Ubuntu 20.04 system with the command shown below:
$ sudo apt install nmap
ii. Use the "Nmap" Utility for Verifying if a Server Supports TLS or not on Ubuntu 20.04
Now you can use this utility for verifying if a server supports TLS or not on Ubuntu 20.04 in the manner shown below:
$ nmap --script ssl-enum-ciphers –p 443 DomainNameOfServerHere, you need to replace the DomainNameOfServer with the actual domain name of the server whose TLS support you want to verify.
For example, we have replaced it with "google.com" in our case to get:
$ nmap --script ssl-enum-ciphers –p 443 google.comFrom the output, you will see that TLS is supported by our specified web server.
"OpenSSL" is a feature-filled tool for transport layer security. For using this tool to verify if a server supports TLS or not on Ubuntu 20.04, you will have to perform the steps listed below:
i. Install the "OpenSSL" tool on your Ubuntu 20.04 System
First, you need to install the OpenSSL tool on your Ubuntu 20.04 system with the following command:
$ sudo apt install openssl
ii. Use the "OpenSSL" Tool for Verifying if a Server Supports TLS or not on Ubuntu 20.04
Now you can use this tool for verifying if a server supports TLS or not on Ubuntu 20.04 in the following manner:
$ sudo openssl s_client –connect DomainNameOfServer:443 –tls1_3Here, you need to replace the DomainNameOfServer with the actual domain name of the server whose TLS support you want to verify.
For example, we have replaced it with "google.com" in our case.
Also, you can replace –tls1_3 with –tls1, -tls1_1, -tls1_2 for TLS version 1.0, 1.1, and 1.2 respectively to get:
$ sudo openssl s_client –connect google.com:443 –tls1_3The output will show that TLS is supported by our specified web server.
This article covers different methods to enable you find out if your specified web server is supporting TLS or not.
By so doing, you will be able to ensure whether your information is going to stay secure while using that web server or not.
TLS is an acronym for Transport Layer Security. TLS facilitates secure communication between computers on the Internet.
In this guide, we used both openssl and nmap.
To Verify TLS Support with Openssl:
Openssl is an open source tool for implementing secure communications on the Internet. The openssl tool is available on all major Linux distributions.
If the openssl tool is not already installed on your Linux machine, you may install it as follows.
On Ubuntu/Debian based distributions:
$ sudo apt install opensslOn CentOS/Red Hat based distributions:
$ sudo yum install opensslNow, to verify TLSv1.3 support on your server or website, run the following command.
$ sudo openssl s_client -connect domain.com:443 -tls1_3
