deterministic-hash

Tiny Rust library to create deterministic hashes regardless of architecture. This library is no-std compatible and uses no allocations or dependencies.

The default core::hash::Hasher implementation ensures a platform dependant hashing of datastructures that use #[derive(Hash)]. Most notably by:

• using to_ne_bytes for u{8,16,32,64,128}.
• using the native bytelength of usize.

The DeterministicHasher of this library forces the use of to_le_bytes and casts usize to u64 regardless of your platform. Hence the hasher will be less efficient, but will be deterministic when using the same library in different architecture contexts. I use a common dataprotocol library both on ARM embedded systems, wasm and x64.

You can validate the operation of this library with cross by running:

cargo install cross
cross test --target=x86_64-unknown-linux-gnu
cross test --target=aarch64-unknown-linux-gnu
cross test --target=arm-unknown-linux-gnueabihf

lib.rs:

Tiny Rust library to create deterministic hashes regardless of architecture. This library is no-std compatible and uses no allocations or dependencies.

The default core::hash::Hasher implementation ensures a platform dependant hashing of datastructures that use #[derive(Hash)]. Most notably by:

• using to_ne_bytes for u{8,16,32,64,128}.
• using the native bytelength of usize.

The DeterministicHasher of this library forces the use of to_le_bytes and casts usize to u64 regardless of your platform. Hence the hasher will be less efficient, but will be deterministic when using the same library in different architecture contexts. I use a common dataprotocol library both on ARM embedded systems, wasm and x64.

From any hasher make it deterministic by inserting DeterministicHasher in between:

let hasher = crc::crc32::Digest::new(crc::crc32::KOOPMAN);
let hasher = deterministic_hash::DeterministicHasher::new(hasher);