Libreswan Opportunistic IPsec using LetsEncrypt

Introduction

Libreswan Opportunistic IPsec using LetsEncrypt is a project created during Google Summer of Code 2019. It adds a utility letsencrypt to the ipsec. letsencrypt invokes any of several utilities involved in controlling the Opportunistic Encryption system, running the specified {command} with the specified [argument] as if it had been invoked directly.

e.g. ipsec letsencrypt -h lists the available commands.

It is a program in libreswan, which integrates libreswan with Opportunistic Encryption utilities. The script provides various OE functionality e.g. initial OE setup, testing configuration/connection, generating and updating Let's Encrypt certificates. The details about the utilities and using them can be found in the Documentation: Libreswan Opportunistic IPsec using LetsEncrypt . Also, the documentation includes the sample output for each {command} and [argument].

Implementation

Various functionalities of the project are listed below:

• Can establish the secure OE (Opportunistic Encryption) connections between two hosts (client and server).
• Checks for the success in establishing the OE connection.
• Easy to install on the hosts (client and server).
• Can test OE connections between two hosts.
• Checks if certbot is installed (on the server).
• Can generate Let's Encrypt certificates for the server using certbot.
• Generates the certbot configuration for reusing the private key.
• Enables automatic update of the generated certificates using cron tabs, keeping the private key same.
• Manual updating of keys also implemented.
• Generates the #pkcs12 file.
• Imports the generated certificates into NSS Database to be used for OE.
• Downloads the LetsEncrypt CA and intermediate certificates.
• Saves the default client/server configuration.
• Displays OE connection status to the user.
• Displays the certificates installed in NSS database.
• Provides details about various available utilities, {commands} and [arguments].

Source code

The source code of Libreswan Opportunistic IPsec using LetsEncrypt is available at Github:Libreswan-Opportunistic-IPsec. The original developer of the program is Rishabh. The project was developed under the expert guidance/mentorship of Paul Wouters & Tuomo Soini. This project was sponsored by Google as a part of Google Summer of Code 2019 Program.

Future Scope

Following are the future Scopes of the project:

• NSS certificates reload needs to restart IPSec.
• Option for testing connection for any custom server.
• Enabling server to server communication.
• Fixing the issue when 2 tunnels are up for the same connection, whenever the server/client restarts or crashes.
• Adding functionality to choose from multiple configurations for clients and servers.
• Auto detecting whether the other host is server or client and choose from the available configurations accordingly.
• Add functionality to fix the commonly found issues automatically. E.g. when the user has more than one configuration files in /etc/ipsec.d directory OR when there is no host ip in policies/private-*.

License

This project is Licensed under GNU General Public License v2.0.