udigest 0.1.0 - Docs.rs

Unambiguously digest structured data

udigest provides utilities for unambiguous hashing the structured data. Structured data can be anything that implements Digestable trait:

str, String, CStr, CString
Integers: i8, i16, i32, i64, i128, u8, u16, u32, u64, u128, char
Containers: Box, Arc, Rc, Cow, Option, Result
Collections: arrays, slices, Vec, LinkedList, VecDeque, BTreeSet, BTreeMap

The trait is intentionally not implemented for certain types:

HashMap, HashSet as they can not be traversed in determenistic order
usize, isize as their byte size varies on differnet platforms

The Digestable trait can be implemented for the struct using a macro:

use udigest::{Tag, udigest};
use sha2::Sha256;

#[derive(udigest::Digestable)]
struct Person {
    name: String,
    job_title: String,
}
let alice = &Person {
    name: "Alice".into(),
    job_title: "cryptographer".into(),
};

let tag = Tag::<Sha256>::new("udigest.example");
let hash = udigest(tag, &alice);

The crate intentionally does not try to follow any existing standards for unambiguous encoding. The format for encoding was desingned specifically for udigest to provide a better usage experience in Rust. The details of encoding format can be found in encoding module.

Features

std implements Digestable trait for types in standard library
alloc implements Digestable trait for type in alloc crate
derive enables Digestable proc macro