SSL vs TLS Protocol Differences and Comparisons

As we move the communication and various aspects of life online, ensuring the secure communication through the internet has only grown in importance. It is essential, as for example, that the financial transactions executed on the web and apps are secure and untampered. Security of the networked communication and the Internet in general ensures the confidentiality, integrity, and availability of data.

To achieve such security, security protocols for the Internet have been developed and evolved as internet becomes more pervasive and connects more people, applications, and systems. One of the security protocols is Secure Socket Layer (SSL), which is often used to refer to Transport Layer Security (TLS). The SSL/TLS protocol specifies a set of rules for establishing secure communication between two endpoints, a client and a server, over non secure network.
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How to Install and Configure Nginx on Ubuntu 20.04

If you dabble in website/backend development, devops, or system administration, Nginx may not be a foreign name. This piece of open source software was first released in 2004 as an alternative to Apache web server. The main focus of Nginx was on performance and stability, primarily achieving a web server that could handle a lot of concurrent connections and hence addressing the C10K problem. The popularity of Nginx has been growing steadily since its initial public release. It has evolved to become a top choice in web server category. According to W3Techs, there are more than 43% of global top 10,000 websites and 44% of global top 1,000 websites running on Nginx in February 2022. Continue reading

Check Time Machine When MacOS Does Not Show the Actual Free Disk Space

In this post, we will explore a small quirk of MacOS. The title should be self-explanatory but might not be so obvious to heavy GUI users. Let’s take a closer look into this seemingly-feature-not-bug behavior on MacOS.

Time Machine is a built-in tool on MacOS for performing partial or full system backup. Time Machine works by taking snapshots of the system and storing those snapshots at external storage devices connected to the machine. To restore the backup, another built-in tool named Migration Assistant is used. Both Time Machine and Migration Assistant are GUI tools. These built-in tools enable users to conveniently transfer or migrate the content of an old Mac, be it documents, user accounts and settings, to a new Mac.

A full backup created with Time Machine can be restored by Migration Assistant through simple GUI-based flow. The process of copying all files from old Mac to the new Mac handled by Migration Assistant is performed with minimum user intervention. This really saves the time compared to performing the data transfer or copying manually. Continue reading

How To Update Node.js on MacOS: Hindsight on Old Mac

Updating packages and apps on MacOS is usually a trivial task. There are several avenues available, depending on the personal preference and degree of familiarity with various tools available on Mac. Now consider a case for updating Node.js (and subsequently npm) on MacOS. What are the options?

tl;dr Updating Node.js with lightweight package manager such as n is less error prone especially for older MacOS version

Let’s start by listing the options on our perusal.

Option 1: Download the installer from and install the binary

This option is ideal for the first installation. It is less ideal for update / version upgrade or if we want to maintain several nodejs versions on the machine. Continue reading

How to Configure and Use Passwordless SSH for Infrastructure Automation on Ubuntu

In the previous post, we revisited SSH public key authentication protocol that brought passwordless SSH to life. We perused and summarized the RFCs. To visualize the authentication process, we drew the arrows that highlight the sequences of messages exchanged between the client and the server.

Not to get overwhelmed with theories, we set up a mini lab to demonstrate how a client should authenticate itself against a remote server with passwordless SSH. We ran the experiment in a cloud environment provided by Digital Ocean.

And probably you may ask this question, “Why running the experiment in the cloud?”

The very simple answer to this is “to emulate the situations when passwordless SSH shines”.

Let’s go into more details by reviewing the use cases.
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