Information

Challenge category: misc

Challenge Description

Hardware stuff can be as easy as decoding/using this protocol.

Files

We are given an bbsignal.zip file containing a .sal file. This is the file format used by Saleae Logic, a software for using logic analyzers.

Exploitation

We open up the file in Logic and are greeted with the following screen:

We add a “Serial Async” analyzer to the capture:

Now we have to select the input channel (Channel 1); all the other values can be left as they are:

Flag

After we have configured the analyzer, we can click on the little terminal icon to reveal the flag:

Conclusion

Very easy one if you’re familiar with logic analyzers, for someone who never touched Logic yet this might take a bit longer.

References

1. https://support.saleae.com/protocol-analyzers/analyzer-user-guides/using-async-serial