ctf-writeups

Roman Wire

A Roman device speaks with a flash memory over SPI, but something feels off. Somewhere in that uneasy exchange an important data is being passed.

A saleae logic .sal file is provided in the attachment. Download Saleae Logic 2 from , open the waveform, we can find a SPI waveform:

Data is transferred on both MOSI and MISO. Deinterleave and print as ascii:

>>> print(bytes.fromhex("646576656c6f7065720063616e006d616e616765005265616420666c616720617320616e206f6c6420726f6d616e206d6573736167652100544c424c7b46304c315f46314c305f413445797d"))
b'developer\x00can\x00manage\x00Read flag as an old roman message!\x00TLBL{F0L1_F1L0_A4Ey}'

Flag is ASIS{M0S1_M1S0_H4Lf} after rot13.