3 ms·
>I would simply recalculate the CRC This is how you figure out which CRC to use in order to "simply" recalculate it. Usually you are doing this because you wa
by Isamu 7y ago
>I would simply recalculate the CRC
This is how you figure out which CRC to use in order to "simply" recalculate it.
Usually you are doing this because you want to interface with a closed-source device where only the messages are known, or if you want to check a closed-source device for vulnerabilities.
- kop316 7y agoI agree with you on that, however the article says "The CRC RevEng code can also manipulate a message to generate a desired CRC value." That is what I am confused on. Why would you need a desired CRC value?
- ifoundthetao 7y agoMaybe there are CRC values that signal hashes, and are used as such. So instead of looking at a message, it'll look at the CRC instead. This gives you the ability to not have to know the full message, but leverage this with part/none of it. Another reason might be for QA testing, or for fuzzing purposes. You don't always know the implementation details, but this type of control allows one to get more understanding of those details, by seeing how the software under test reacts. This stuff is not wildly uncommon in low-grade IoT devices, or high-end devices with a low level of security maturity.