Revising my lazy http/https interception setup

I’ve wrote about about creating a simple wireless (WLAN for us right-pondian) http/https interception setup before. Mostly I’m using this as a first step when testing mobile/desktop applications. Linux’ network-manager is perfectly able to create an software access-point with most modern network cards. Alas GNOME’s configuration tool only allows for the creation of ad-hoc networks (and switching to KDE for just this is a bit overkill for me) so you have to setup the access point on the command line with nmtui or nmcli. In this example I will show how to create the interception setup with the latter. ...

November 23, 2018 · 3 min · 567 words · Andreas Happe

Living with changes

This year seems to bring a lot of changes: I’ve switched employers after staying on/off at a research center or the last twelve years. When I started there, I was doing cool network coding for the SECOQC quantum key distribution network, it somehow felt as being a part of some bigger undertaking that finally let to something. My work had a tenable outcome, this compensated for the long hours and poor pay. Colleagues were (and have been until the end) good friends and oftentimes mentors. ...

November 7, 2018 · 3 min · 601 words · Andreas Happe

Fun Hacking Stuff ahead

Recently I’ve found an old post-it with guidelines I wrote myself a couple of years back, two of those stood out: make mistakes don’t buy stupid stuff Seems like I haven’t been the most consistent person back then. The post-it got discovered during a clean-up session of my flat, the same session brought up the following stupidly-bought-and-never-used gadgets: one BBC micro:bit that should be able to capture Bluetooth Low Energy transmissions one Proxmark 3 RV4 that should be able to do some nifty RFID stuff (and that I was recently able to fix) one Realtek Software-Defined Radio USB Stick (rtl-sdr).. My new year’s resolution (or rather near-future resolution) is to do /something/ hackery with that stuff. Suggestions more than welcome. ...

October 23, 2018 · 1 min · 120 words · Andreas Happe

GnuPG/PGP and Evolution/Seahorse Private Key Woes

I have a quite simple setup: Fedora 23 on my Desktop, Ubuntu 16.04 on my Notebook and a YubiKey thrown into the mix. I do have my normal GnuPG key DD436203 that I’m using. There’s also an old and revoked key 3F5D00B6 with which I was testing my YubiKey with (note to myself: don’t use an YubiKey-crested private key as you cannot backup it). My main key offers an ElGamal 2048bit subkey – which does not work with the Yubikey (as that only supports 2048bit RSA). So I ’ve added a new subkey on my laptop. ...

December 1, 2016 · 4 min · 676 words · Andreas Happe

How (NOT) to hide OpenVPN behind HTTPS/SSL

Update 2017: Sadly I found out (thanks due to the comments on this blog post) that using port-share does not encapsulates subsequent traffic in normal TLS. So using this method will not fool Deep-Package Inspection Firewalls. If you need to mask all your traffic, this is not an option – you might need to investigate stunnel, information can be found here, here or here. I assume, that the higher success rate of this method could be related to some firewalls checking the target of the initial https request. This would yield a normal website with this setup and might be enough to fool some websites. ...

December 1, 2016 · 6 min · 1175 words · Andreas Happe

Secret-sharing described by Prismacloud

One important part of the European Prismacloud project is dissemination: make ordinary people understand some of our cryptographic directives. Out of this, the following clip originated: The technique in question is called secret-sharing and was originally detailed in 1979.

February 27, 2016 · 1 min · 39 words · Andreas Happe

Firejail: Chroot on Speed

Firejail describes itself as a SUID program that reduces the risk of security breaches by restricing the running environment of running programs. We’ll just call it chroot or jail (for the BSDers out there). So, it’s SUID? First things first: it’s SUID, so if there’s an error within the firejail binary an attacker can gain root rights. This comes with the territory. How large is Firejail and how many dependencies does it have? It’s written in C and: ...

February 25, 2016 · 8 min · 1548 words · Andreas Happe

Low-hanging Security/Privacy for the Lazy 2016!

Keeping a good security and privacy is tough work. There’s always a trade-off between effort and achieved security. In this blog post I’ll mention small things that a ``normal’’ person should be able to perform — that still increase the overall security of that user’s data. Choose your Liege Bruce Schneier talks about the comeback of feudal security: you choose your liege lord and depend upon him for providing security. You pledge yourself to Google, Facebook or Apple. Your liege protects his servers (with your data) and might defend your data/emails in a legal court — for which I as a private person would not have the monies — but for that it gets access to all your data. Choose your liege carefully and only have few of them. For me Google is essential. It’s hosted mail service gets all my possible password reminder/reset emails. If it gets compromised, it’s game over for me. Similar for me is LastPass. Identify those main trust anchors and use secure and unique passwords for them. If possible enable two-factor-authentication (2FA). This forces an attacker to not just steal your password in cyberspace, but she would also need to steal a second factor (i.e. phone or RSA token) in the physical world. Few “private” hackers will escalate to this level. ...

February 25, 2016 · 5 min · 1009 words · Andreas Happe

OSCP: Check!

I have just received my OSCP exam success notification. This is a penetration-testing certification by Offensive Security with focus on hands-on-training. You get an eBook and a week’s worth of video lectures with guided exercises; access to a virtual lab with approximately 55 machines that you should gain full control over and will finish with an 24 hour exam in which you are supposed to root five target machines. All this should be documented and submitted at last 24 hours after your exam is over – my documentation had 264 pages. ...

February 7, 2016 · 2 min · 378 words · Andreas Happe

Network Concurrency Problem

A project I’m involved with has a traditional distributed client-server architecture: multiple servers are interconnected, clients connect to one more servers. In this use-case we’re expecting around four to seven servers with long-running connections between them and approx. a dozen clients with short-lived connections to the server. Initially I had used plain Java networking but during 2013 I’ve switched over to netty.io as a communication layer. Benefits were more agile networking code, better concurrency, etc. At least in theory. ...

November 13, 2015 · 3 min · 514 words · Andreas Happe