More censorship trickery

I updated some of my git repos. crash can now be used with Disguise Filters to serve an innocent redirect webpage when certain secrets are not passed beforehand so nobody except you will ever see that there is a shell server inside, even if they observe the SNIs that are in use. I also updated the docu on how you setup WA proxies with it since this changed in newer versions of the app.

Then there is an entirely new PoC repo to tunnel traffic through passkey servers. Thx to the ppl that tested it with me. Check it out, its fancy new Perl code!

Easterbug trickery

 Happy Easteregg searching.

rustup client sides trickery

I tried to understand some things about the rust build/eco system and were surprised how easy it is to pwn. Wonder whether its the same for golang.

crash + psc 37c3 release

crash and psc now build and run on Windoze systems. psc contains a new feature that lets you bounce binary data back and forth through your local pty to a e.g. remote netcat, dd or other utilities so you can fwd SSH connections directly through your terminal or up/download binary data without any remote agent.

Roaming trickery

I added support for roaming and suspend/resume to crash. Now you can change your IP, VPN, physlayer, NAT, VM-routing etc. at runtime and stay connected to your remote shell. You may also suspend the session to a ticket and resume it from a different laptop from the other side of the globe while keeping your shell.

Privacy side note: As always, this implies that you know what you are doing when using VPNs. Disrupted VPN routing may leak your IP address regardless of roaming but with roaming enabled you wouldn't immediately notice as the session just continues. However, to reveal the IP a single leaked packet suffices.

It is now also possible to build and run crash and psc on Windows, including all the nice features.

More crash + psc trickery

I reworked the local address binding and connecting part of my anti censorship tools crash and psc, so it is now possible to use SOCKS5 client side connects by using -x (similar to curl) and to let the SOCKS5 proxy resolve DNS names (-N) in order to allow browsing with chrome (but check README).

You can also check out @fullspectrumdev's blog writeups on pentest use-cases and cross-compilation.

Interestingly, OpenSSH now also supports traffic blinding, which is included in crash since years.

New 7350 0day trickery (cybah cybah)

 

Manjaro seems to be quite popular distro, according to distrowatch. LPE can be found here.

More tunneling trickery

In order to properly proxy messenger apps from censored networks to outside, I added the -X switch to crash and documented on how you would configure your setup within the contrib folder.

It is already field-tested in certain countries. Nevertheless, if you have deeper knowledge on censorship equipement or extra tips for better connectivity and can battle test the setups, just let me know.

Tunneling trickery

 

I re-polished a 10y old project that is one of the most complete tunneling solutions available for ICMP, ICMPv6, DNS over IP and DNS over IPv6 when it comes to setting up connectivity in restrictive environments. I added some fixes so it now properly also works behind NAT.

DTLS trickery

Probably the last post in 2022.

I fixed SOCKS5 handling in psc and crash so that it is now possible to use it with curl and IPv6. Also added DTLS (read: TLS over UDP) support for crash in order to make it possible to use anti censorship SOCKS proxies in countries that block outgoing TCP connections such as in Iran (see previous post).

When I read about LibreSSL having QUIC support, I tried to use this, but their bold announcement was a spoiler. They only "support" the QUIC handshake to obtain keying materials by means of TLS integration. I wouldn't really call this "QUIC support", although I love LibreSSL much more than OpenSSL (due to their permanent API changes). As DTLS has only reliability for its handshake, I had to add my own TCP-style data flow mechanisms to handle packet loss and re-orders. OpenSSL also wants to add QUIC support, so lets see in a couple of years how far this goes (hopefully with full proto and API support and not just the handshake) to finally have a usable QUIC lib.

Crash also switched from TLS v1.2 to v1.3 being mandatory, i.e. it is not proto compatible to the 2.x versions anymore. As soon as DTLS v1.3 will be widely deployed, it will also switch to DTLS v1.3. Due to all these new features and compat things the crash-3 versions are dubbed experimental (although working stable).

Wish you a nice rest of 2022 and a Guten Rutsch for 2023!