For my current project we have Ansible deploy scripts for our handful of services to a set of development servers. This has generally worked well, but occasionally we need to SSH directly to the server to debug an issue. Ideally I'd like to SSH to a server via it's Ansible hostname rather than having to look up its IP or machine name.
You may have heard that the NSA can decrypt SSH at least some of the time. If you have not, then read the latest batch of Snowden documents now. All of it. This post will still be here when you finish. My goal with this post here is to make NSA analysts sad. TL;DR: Scan this post for fixed width fonts, these will be the config file snippets and commands you have to use. || Déjà shaarlié il me semble mais là c'est la bavouille de guigui qu'on rajoute: https://shaarli.guiguishow.info/?qQJoJQhttps://pad.lqdn.fr/p/ssh-hardening
Back in December when I revamped the SSH banner and started collecting the fingerprint I noticed an odd behavior. It turns out that a few SSH keys are used a lot more than once. For example, the following SSH fingerprint can be found on more than 250,000 devices!
Voici la suite des « études » des leaks (fuites) de Snowden menées pour NSA-Observer. Dans cet article, nous allons revenir sur les révélations du Spiegel datant de fin décembre lors du 31c3 (Chaos Computer Congress) et du 17 janvier 2015 portant sur les moyens offensifs de la NSA ainsi que d'autres agences concernant la cryptographie.
BULLRUN est un « programme » de la NSA exploitant différents moyens pour accéder à du contenu chiffré. Le New York Times avait abordé le sujet fin 2013 dans son article « Secret Documents Reveal N.S.A. Campaign Against Encryption » mais sans aucun détail (comme The Guardian ou encore propublica).
The “TL;DR” summary of what follows below is: If you configure your IPsec based VPN properly, you are not affected. Always use Perfect Forward Secrecy (“pfs=yes” wich is the default in libreswan IPsec) and avoid PreSharedKeys (authby=secret which is not the default in libreswan IPsec). If you really need to use PSK, use a strong shared secret that cannot be brute forced. The NSA has their own version of IKEcrack running on millions of dollars worth of CPU’s. Also, the NSA sneaks into your router to steal your PSK’s so they can decrypt all your traffic.
f you work a lot on linux and use ssh often, you quickly realize that typing your password every time you connect to a remote host gets annoying.
Not only that, it is not the best solution in terms of security either:
Every time you type a password, a snooper has an extra chance to see it.
Every host you ssh to with which you use your password, well, has to know your password. Or a hash of your password. In any case, you probably have typed your password on that host once or twice in your life (even if just for passwd, for example).
If you are victim of a Man In The Middle attack, your password may get stolen. Sure, you can verify the fingerprint of every host you connect to, and disable authentication without challenge and response in your ssh config. But what if there was a way you didn't have to do that?
If you've ever used SSH keys to manage multiple machines, then chances are you've used SSH-agent. This tool is designed to keep a SSH key in memory so that the user doesn't have to type their passphrase in every time. However, this can create some security risk. A user running as root may have the ability to pull the decrypted SSH key from memory and reconstruct it. Due to needing root access, this attack may seem useless. For example, an attacker may be able to install a keylogger and use that to obtain the passphrase for the SSH key. However, this causes the attacker to have to wait for the target to type in their passphrase. This might be hours, days, or weeks, depending on how often the target logs out. This is why obtaining the SSH key from memory is vital to pivoting to other machines in a speedy fashion.
zssh (Zmodem SSH) is a program for interactively transferring files to a remote machine while using the secure shell (ssh). It is intended to be a convenient alternative to scp , allowing to transfer files without having to open another session and re-authenticate oneself.
Did you know that when you’re using OpenSSH from the command line you have a variety of escape sequences available to you? SSH somewhere, then type “~” and “?” (tilde, then question mark) to see all the options.
Underwear is a library for easily deploying any Python-powered web application to one or more Linux servers. Underwear is configurable by a YAML template and takes care of installing packages, configuring web/WSGI servers, and securing the server.
What Problem Does Underwear Solve?
Despite the advent of configuration management tools such as Puppet, Chef, Ansible, and Salt, it remains difficult to deploy a web application because you have to first learn one of those tools and then write scripts in the tool’s domain-specific language.
Underwear makes deploying to a traditional Linux server stack as easy as deploying to Heroku by providing a pre-packaged, easily configurable library. Deployments can be executed simply by installing Underwear with pip, specifying the IP addresses of the server(s) to deploy to, then running a couple of commands.
SSH is one of the most widely used protocols for connecting to remote shells. While there are numerous SSH clients the most-used still remains OpenSSH's ssh. OpenSSH has been the default ssh client for every major Linux operation, and is trusted by cloud computing providers such as Amazon's EC2 services and web hosting companies like MediaTemple. There is a plethora of tips and tricks that can be used to make your experience even better than it already is. Read on to discover some of the best tweaks to your favorite SSH client.
Imagine you’re developing a web application using a framework like Rails. You’ve got your development server fired up and are regularly reloading http://localhost:3000 to see your changes. All is going well until you want to integrate with some 3rd party service that needs to talk to your application. You’re not really going to deploy to staging on every change, are you?
If you have control over the router, then you can simply forward an external port to your local machine. Bu you’re obviously a cool startup hacker, so of course you’re working in a coffee shop or co-work space. You’ve got no time for outdated ideas like “offices”. What are you to do?
Mosh(mobile shell) is Remote terminal application that allows roaming, supports intermittent connectivity, and provides intelligent local echo and line editing of user keystrokes.
Mosh is a replacement for SSH. It's more robust and responsive, especially over Wi-Fi, cellular, and long-distance links.
Mosh is free software, available for GNU/Linux, FreeBSD, Solaris, Mac OS X, and Android.
Change IP. Stay connected
Mosh automatically roams as you move between Internet connections. Use Wi-Fi on the train, Ethernet in a hotel, and LTE on a beach: you'll stay logged in. Most network programs lose their connections after roaming, including SSH and Web apps like Gmail. Mosh is different.