Split OpenVPN configuration files

12/12/2018 Categories: Réseau, Système Tags: , , Aucun commentaire

Source: npm

Splits OpenVPN (.ovpn) files into separate files for private key, user+ca certificates and tls-auth key, for use with network-manager in debian/ubuntu.

openvpn-config-splitter can be installed using npm:

# NPM:
npm install -g openvpn-config-splitter
# Install globally
$ npm install -g openvpn-config-splitter
# Run it, specifying your unsplit OpenVPN configuration file
$ ovpnsplit path/to/some/config.ovpn
# Config is now split into separate files, new configuration
# linking to the split files has been generated
$ ls path/to/some
ca.crt  client.key  client.ovpn  client.split.ovpn  ta.key  user.crt
var fs = require('fs'),
 configPath = '/some/path/to',
 splitter = require('openvpn-config-splitter');
 
var paths = {
 'caCert': configPath + '/openvpn-ca.crt',
 'userCert': configPath + '/openvpn-user.crt',
 'privateKey': configPath + '/openvpn-private.key',
 'tlsAuth': configPath + '/openvpn-tls.key'
};
 
fs.readFile(configPath + '/config.ovpn', function(err, originalConfig) {
 if (err) {
 console.error('Could not read file (' + err.path + ')');
 process.exit(1);
 }
 
 splitter.split(originalConfig, paths, function(err, parts, missing) {
 if (err) {
 console.error(err);
 process.exit(1);
 }
 
 /**
 * `parts` now contain the matched parts of the config + new config
 * (caCert, userCert, privateKey, tlsAuth, config)
 *
 * `missing` is an array containing the parts that were NOT found -
 * use this if you want to warn the user or fall back if you require
 * a specific part to be present
 */
 // Want to write the split files? 
 splitter.writeToFiles(parts, paths, function(err) {
 if (err) {
 console.log(err);
 process.exit(1);
 }
 
 console.log('Hooray, we split the files and wrote them to disk!');
 });
 
 });
});
Categories: Réseau, Système Tags: , ,

Typical iptables

# Modify this file accordingly for your specific requirement.
# http://www.thegeekstuff.com
# 1. Delete all existing rules
iptables -F

# 2. Set default chain policies
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP

# 3. Block a specific ip-address
#BLOCK_THIS_IP="x.x.x.x"
#iptables -A INPUT -s "$BLOCK_THIS_IP" -j DROP
 Lire la suite...

(D)DoS Deflate

11/12/2018 Categories: Réseau, Système Tags: , Aucun commentaire

About

(D)DoS Deflate is a lightweight bash shell script designed to assist in the process of blocking a denial of service attack. It utilizes the command below to create a list of IP addresses connected to the server, along with their total number of connections. It is one of the simplest and easiest to install solutions at the software level.

netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

IP addresses with over a pre-configured number of connections are automatically blocked in the server’s firewall, which can be direct iptables or Advanced Policy Firewall (APF). (We highly recommend that you use APF on your server in general, but deflate will work without it.)

Notable Features

  • It is possible to whitelist IP addresses, via /usr/local/ddos/ignore.ip.list.
  • Simple configuration file: /usr/local/ddos/ddos.conf
  • IP addresses are automatically unblocked after a preconfigured time limit (default: 600 seconds)
  • The script can run at a chosen frequency via the configuration file (default: 1 minute)
  • You can receive email alerts when IP addresses are blocked.

Installation

wget http://www.inetbase.com/scripts/ddos/install.sh
chmod 0700 install.sh
./install.sh

Uninstallation

wget http://www.inetbase.com/scripts/ddos/uninstall.ddos
chmod 0700 uninstall.ddos
./uninstall.ddos

Questions?

Although most things are explained on this page, if you have any further questions, you may contact the original developer of the script, Zaf.

Categories: Réseau, Système Tags: ,

How To Use Port Knocking to Hide your SSH Daemon from Attackers on Ubuntu

Introduction

Servers, by definition, are implemented as a means of providing services and making applications and resources accessible to users. However, any computer connected to the internet is inevitably targeted by malicious users and scripts hoping to take advantage of security vulnerabilities.

Firewalls exist and should be used to block access on ports not being utilized by a service, but there is still the question of what to do about services that you want access to, but do not want to expose to everybody. You want access when you need it, but want it blocked off otherwise.

Port knocking is one method of obscuring the services that you have running on your machine. It allows your firewall to protect your services until you ask for a port to be opened through a specific sequence of network traffic.

In this guide, we will discuss how to implement port knocking as a method of obscuring your SSH daemon on an Ubuntu 12.04 VPS using the knockd package.

Note: This tutorial covers IPv4 security. In Linux, IPv6 security is maintained separately from IPv4. For example, « iptables » only maintains firewall rules for IPv4 addresses but it has an IPv6 counterpart called « ip6tables », which can be used to maintain firewall rules for IPv6 network addresses.

If your VPS is configured for IPv6, please remember to secure both your IPv4 and IPv6 network interfaces with the appropriate tools. For more information about IPv6 tools, refer to this guide: How To Configure Tools to Use IPv6 on a Linux VPS

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How To Configure Port Knocking Using Only IPTables on an Ubuntu VPS

Source: digitalocean.com

Introduction

Servers that are connected to the internet are subjected to all manners of attacks and probes by malicious users, scripts, and automated bots. It is sometimes a balancing act to secure your server from attacks without affecting legitimate access to your services and resources.

Certain types of services are meant to be visible and consumable to the public internet. An example of this is a web server. Other types of services are typically used by only the system administrator or a select number of individuals and are not meant to be a public resource.

A concept known as port knocking is a way of shielding processes that fit into the latter description. Port knocking works by covering the ports associated with a process behind a firewall until a specific, predetermined sequence of network activity occurs. At this point, the port knocking service reconfigures the firewall to allow access to the protected application.

In a previous article, we discussed how to enable port knocking through a specially designed port knocking service. In this article, we will discuss an alternative method of configuring port knocking.

This method does not rely on an external application to alter the firewall rules. Instead, the iptables firewall can take advantage of a state-tracking module called « recent » to do all of this within the firewall rules themselves.

We will be configuring this on an Ubuntu 12.04 droplet, but any kind of Linux server should operate in a similar manner.

Note: This tutorial covers IPv4 security. In Linux, IPv6 security is maintained separately from IPv4. For example, « iptables » only maintains firewall rules for IPv4 addresses but it has an IPv6 counterpart called « ip6tables », which can be used to maintain firewall rules for IPv6 network addresses.

If your VPS is configured for IPv6, please remember to secure both your IPv4 and IPv6 network interfaces with the appropriate tools. For more information about IPv6 tools, refer to this guide: How To Configure Tools to Use IPv6 on a Linux VPS

Lire la suite…