Recently I wanted to have sensors values from ArduPilot back into FrSky Taranis radio, mostly to be able to see my quadcopter's current altitude and GPS ground speed.
The goal is to have a nice real time display of telemetry sensors on Taranis LCD screen.

My quadcopter current setup is:

• Flight Controller: HobbyKing APM 2.7
• Running ArduCopter 3.2
• Radio Tx: FrSky Taranis X9D
• Running OpenTx 2.1.8
• Receiver: FrSky X8R (S-Port)

Challenge (with Big-Daddy team) :

Someone has leaked very important documents. We couldn't find any proof without one PCAP file. But this file was damaged.

The password of disclosure document is very weakness and based on Time, can be found easily.
Cryptographic algorithm is below.

Msg = "ThisIsNotARealEncryption!SeemToEncoding"
Key = 0x20120224 (if date format is 2012/02/24 00:01:01)
Cryto = C(M) = Msg * Key = 0xa92fd3a82cb4eb2ad323d795322c34f2d809f78

Answer: Decrypt(Msg)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Download : A0EBE9F0416498632193F769867744A3

Earlier December I took part in the PHD CTF Quals with two friends of mine (Alkino and Siosm). Our notes are publicly available at fs.siosm.fr.

Keywords : phdays, ctf, scapy.

About one year ago, I submitted on crackmes.de this solution to the keygenme xc2 made by Virw. Unfortunately, crackmes.de has been down for months by now, so I guess there is no harm to put both the challenge and the solution on this blog.

Keywords: keygen, windows, crc32.