Si proche et pourtant si loin

Description

Your neighbor Charlie likes to stay at the cutting edge of technology. She recently installed a strange stone in her refrigerator that regularly measures and transmits temperature, humidity, and atmospheric pressure to her phone. This way, her vegetables are always kept under perfect conditions.

Your neighbor Charlie values her privacy. She refuses to transmit the climate data from her refrigerator in plain text to the entire neighborhood. To achieve this, a highly secure system has been implemented to encrypt the measurements.

Your neighbor Charlie enjoys playing CTFs. She has hidden a flag in the data transmitted by the pebble. She challenges you to recover this flag (usual format FCSC{).

During a poker night at Charlie’s place, you capture Bluetooth traffic (capture btmon.pcap). While grabbing a drink from her refrigerator, you accidentally notice that the pebble vibrates when it comes into contact with your phone. You quickly dump your phone logs to investigate later (file adb-logcat.txt.gz).