# crabstep
`crabstep` is a Rust library that deserializes Apple's `typedstream` data into cross-platform data structures.
## Overview
The `typedstream` format is a binary serialization protocol designed for `C` and `Objective-C` data structures. It is primarily used in Apple's `Foundation` framework, specifically within the `NSArchiver` and `NSUnarchiver` classes.
## Installation
This library is available on [crates.io](https://crates.io/crates/crabstep).
## Documentation
Documentation is available on [docs.rs](https://docs.rs/crabstep).
### Quick Start
```rust,no_run
use std::{env::current_dir, fs::File, io::Read};
use crabstep::TypedStreamDeserializer;
// Read the typedstream file into memory
let typedstream_path = current_dir()
.unwrap()
.as_path()
.join("path/to/typedstream/file");
let mut file = File::open(typedstream_path).unwrap();
let mut bytes = vec![];
file.read_to_end(&mut bytes).unwrap();
// Create a deserializer
let mut typedstream = TypedStreamDeserializer::new(&bytes);
// Iterate over the typedstream's properties
typedstream.iter_root()
.unwrap()
.for_each(|prop| println!("{:#?}", prop))
```
### Detailed examples
This crate is heavily leveraged by [`imessage-database`](https://crates.io/crates/imessage-database)'s [`body`](https://github.com/ReagentX/imessage-exporter/blob/develop/imessage-database/src/tables/messages/body.rs) module.
## Origin
The `typedstream` format is derived from the data structure used by `NeXTSTEP`'s `NXTypedStream` APIs.
## Features
- Pure Rust implementation for efficient and safe deserialization
- No dependencies on Apple frameworks
- Robust error handling for malformed or incomplete `typedstream` data
- Ergonomic `TypedStreamDeserializer` with `resolve_properties` iterator for exploring object graphs
## Reverse Engineering
A blog post describing the reverse engineering of `typedstream` is available as [an in-depth article](https://chrissardegna.com/blog/reverse-engineering-apples-typedstream-format/).
## Ferris
