This part of the programming section covers serialized data. Serialized data is stored in binary, meaning it is not readily human-readable. Since many characters stored will not be in ASCII, reading the file does nothing for us.
Each challenge will instruct us on how the data is formatted. We will typically be provided with a data structure to store the serialized elements. Each part of the data structure will have a specific size (either fixed or variable). We will use this to read the data into the structure.
We must process the data once we read the structure to get the flag. This will be different for each challenge, but we will walk through each. This is typically not challenging, especially if you're confident in the other half of the programming section.
When we read data, we will use the binary flag on fopen to indicate we are reading binary data. We will use fread to read all the data because this lets us specify the number of bytes we want to read. This way, we can control how much data is read into the variable we store.
We will almost always build a struct containing a data structure representing the serialized data. When we read the data, we can read it right into the struct without any trouble. Then, we can process the data stored in the struct.
We will use two primary methods for storing the struct. There are some advantages and disadvantages to both:
Nearly all the challenges are formatted the same, so we can use the same template. This is also almost true for the non-serialized section.
Let's get solving!
