How to hash files in Node.JS

The process is quite simple actually. Unfortunately ,as much things in Node.js, it works asynchronously, for some applications this will be perfect, but for some others it will be a mess to wait for the freaking hash to do something else, anyway I am not going to discuss that here I actually like Node.js. Please note that in the following …

How to generate RSA key pair in Node.JS?

Very straight forward process. Not complicated at all, I would say that the most difficult part would be to actually tweak the options, however the code below actually works and provides you the time it took to generate the key pair as well, just for informational purposes. Run the following code in Node.js. const crypto = require(‘crypto’); const RSA = …

vManage API to GUI mapping

I’ve been working with vManage APIs for a while now, and if there is something clear to me is that is quite difficult sometimes to find information on the internet about a specific URL, meaning to find the accurate description of requests and responses. I’ve decided that I will add to this post all each URL and where to find …

How to hash files in Linux?

How many times have you needed to get the hash of any file in Linux? For whatever purpose you have needed to do that, rest assured that there is a set of commands that will make your life easier. These commands are part of Linux core utils. MD5 md5sum <file_name> SHA-1 sha1sum <file_name> SHA-256 sha256sum <file_name> SHA-384 sha384sum <file_name> SHA-512 …

How to create a Node.JS application with Express Generator

I am assuming that you already have Node.JS installed. If you don’t, worry not! you can get your own copy today from the Node.JS download section! Using ExpressJS is very quick and easy. It generates all the file structure needed for a web application. You can select  any of the different views they have available, in this case I am …

How to Encrypt / Decrypt with AES (CCM & GCM) in Node.JS

First of all we have to understand what is CCM mode and GCM mode. Roughly: CCM CCM mode (Counter with CBC-MAC) is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits. GCM Galois/Counter …

How to add sudo users in Linux

First of all you have to be logged in as root. Just type command below followed by your password: terminator@skynet:~$ sudo su – [sudo] password for terminator: Now that you are root you can use the following command to create the user: adduser <username> You will be prompted for password, information and confirmation. Once done you can use the following …

How to see running processes in Linux

One essential command to know when you are experimenting in Linux is the command to see which processes are running in your machine, just in case you need to kill one of them for any reason. This command is top and you use it like this: Type top in a Linux Terminal and press Enter: pi@raspberrypi:~ $ top You should …

Check property of JSON response in Postman

In the Tests section of any request you can check if the JSON response contains or doesn’t contain a specific property like this: // Verify that header object is NOT returned pm.test(“Verify that header:{…} object is NOT returned”, function () {  pm.expect(pm.response.json()).to.not.have.property(‘header’); }); // Verify that data object is returned pm.test(“Verify that data:{…} object is returned”, function () {  pm.expect(pm.response.json()).to.have.property(‘data’); …

How to see available disk space in Linux

Playing around with a Raspberry PI I came to need this info. Here is the command: df -h You should see something similar to this: pi@raspberrypi:~ $ df -h Filesystem Size Used Avail Use% Mounted on /dev/root 26G 6.5G 18G 27% / devtmpfs 334M 0 334M 0% /dev tmpfs 463M 0 463M 0% /dev/shm tmpfs 463M 6.4M 456M 2% /run …