Reverse-engineering Codemasters' BIGF archive format in Ruby
4 days ago
- #reverse engineering
- #binary file parsing
- #Ruby programming
- Ruby's strings can be used as byte buffers, making it suitable for reverse-engineering binary file formats, particularly with `File.binread` and slicing operations.
- The `String#unpack` method is a key tool in Ruby for decoding binary data, supporting directives for integers and floats with specified endianness, and it is fast due to being C-implemented.
- Ruby allows reading binary files without external dependencies, using standard library features to handle tasks like parsing headers, directories, and data sections, and providing REPL support for interactive exploration.
- The article details parsing Codemasters' BIGF archive format, including handling different directory layouts, classifying records by bit patterns, and addressing issues like NaN values and endianness.
- Ruby's ergonomic features, such as string slicing, NUL-terminated string handling, and clear code that mirrors specifications, make it effective for reverse-engineering tasks.