Table of Contents
GnuPG introduction tutorial
Introduction
This document describes how to use gnupg (gpg) tool to make a basic (everyday) operations, described in this page. Also, it's highly recommended to read mentioned document first.
GnuPG is a standard tool to use. It's a text-based console application, but it's a way more ease to use comparing with a graphical application.
Getting GnuPG
Mac OS X
Install brew tool
Brew tool is a tool of Homebrew_(package_management_software), so, in order to install it, please do the following:
- Open a terminal found on /Applications/Utilities/
- Run
xcode-select –install
- Click install button on the dialog
- Wait until complete
The full article might be found at http://osxdaily.com/2014/02/12/install-command-line-tools-mac-os-x/
- Run in terminal the following
/usr/bin/ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”
Brew
It's an easy to do in MacOS using brew. Just run in the terminal (mentioned early): brew install gpg
Debian-based OSes (ubuntu, debian, devuan)
You need a sudo access in order to install a package.
Open your favourite terminal and type sudo apt-get install gpg.
Please note, in most cases gpg is already installed.
SuSe/OpenSuse
The same requirements.
Open your favourite terminal and type sudo zypper install gpg.
Please note, in most cases gpg is already installed.
Other linuxes/BSDs
Use your own package manager, or compile GnuPG from source.
Windows
Under windows it's possible to get it running via cygwin.
Using GnuPG
Key creation
In order to create a key pair type in terminal the following: gpg –full-generate-key
Choose first method e.g. RSA and RSA.
Choose 4096 bits key long (it's more technically secure).
We'd recommend to choose 2 year lifespan.
Finally type your name, email and comment for the key pair (this is optional, you can leave it blank). You will be asked to type a passphrase to encrypt your private key with.
NOTE: Don't forget your passphrase, you can loss your private key without passphrase.
After this please be patient, some time is required to generate a key pair.
Import public key
To import someone's else public key all you need is type in terminal gpg –import <filename of the public key>
Commit your own public key
To publish your public key you need to provide it first. To get a file with your own public key, just type the following in terminal: gpg –export –armor 'yourname@example.com' > yourname.asc
Sign the data
Data encryption
Encrypt
To encrypt some data (e.g. file in the example below) you need to know a recipient and his/her public key. On the example below we're encrypting data in file secret.pdf for alice@askele.com: gpg -r 'alice@askele.com' -e secret.pdf
Result file will be secret.pdf.gpg
Decrypt
In order to decrypt some data (e.g. file) you need to type the following (assuming you receive secret.pdf.gpg): gpg -d secret.pdf.gpg > secret.pdf
Result will be stored in secret.pdf which is a plain (decrypted) data.






