merkle

merkle is a lightweight Rust implementation of a Merkle tree.

Features

• external dependency agnostic
• std::hash::Hasher compatibility
• standard types hasher implementations
• #[derive(Hashable)] support for simple struct
• customizable merkle leaf/node hashing algorithm
• support for custom hash types (e.g. [u8; 16], [u64; 4], [u128; 2], struct)
• customizable hashing algorithm
• linear memory layout, no nodes on heap
• buildable from iterator, objects or hashes
• certificate transparency style merkle hashing support
• SPV included

Documentation

Documentation is available.

Examples

• test_sip.rs: algorithm implementation example for std sip hasher, u64 hash items
• test_xor128.rs: custom hash example xor128
• test_cmh.rs: custom merkle hasher implementation example
• crypto_bitcoin_mt.rs: bitcoin merkle tree using crypto lib
• crypto_chaincore_mt.rs: chain core merkle tree using crypto lib
• ring_bitcoin_mt.rs: bitcoin merkle tree using ring lib

Quick start

``` extern crate crypto; extern crate merkle_light;

use std::fmt; use std::hash::Hasher; use std::iter::FromIterator; use crypto::sha3::{Sha3, Sha3Mode}; use crypto::digest::Digest; use merklelight::hash::{Algorithm, Hashable}; use merklelight::merkle::MerkleTree;

pub struct ExampleAlgorithm(Sha3);

impl ExampleAlgorithm { pub fn new() -> ExampleAlgorithm { ExampleAlgorithm(Sha3::new(Sha3Mode::Sha3_256)) } }

impl Default for ExampleAlgorithm { fn default() -> ExampleAlgorithm { ExampleAlgorithm::new() } }

impl Hasher for ExampleAlgorithm { #[inline] fn write(&mut self, msg: &[u8]) { self.0.input(msg) }

#[inline]
fn finish(&self) -> u64 {
    unimplemented!()
}

}

impl Hashable for [u8; 32] { fn hash(&self, state: &mut ExampleAlgorithm) { Hasher::write(state, self.as_ref()) } }

impl Algorithm<[u8; 32]> for ExampleAlgorithm { #[inline] fn hash(&mut self) -> [u8; 32] { let mut h = [0u8; 32]; self.0.result(&mut h); h }

#[inline]
fn reset(&mut self) {
    self.0.reset();
}

}

fn main() { let mut h1 = [0u8; 32]; let mut h2 = [0u8; 32]; let mut h3 = [0u8; 32]; h1[0] = 0x11; h2[0] = 0x22; h3[0] = 0x33;

let t: MerkleTree<[u8; 32], ExampleAlgorithm> = MerkleTree::from_iter(vec![h1, h2, h3]);
println!("{:?}", t.root());

} ```

Bug Reporting

Please report bugs either as pull requests or as issues in the issue tracker. merkle has a full disclosure vulnerability policy. Please do NOT attempt to report any security vulnerability in this code privately to anybody.

License

See LICENSE.