merkle_tree

A small Rust library that implements a Merkle Tree using SHA-256.

This repository contains code to:

• hash data into fixed-size 32-byte hashes,
• build a Merkle tree from input data,
• compute a root hash,
• generate inclusion proofs,
• verify proofs against an expected root.

Repository contents

• src/lib.rs – crate entry point and re-exports.
• src/hash.rs – hash utilities (Hash, hash_data, hash_pair).
• src/tree.rs – MerkleTree structure and tree construction logic.
• src/proof.rs – proof types and verification (MerkleProof, ProofStep).
• tests/tree_tests.rs – tests for tree behavior and indexing helpers.
• tests/proof_tests.rs – tests for proof generation and verification.
• Cargo.toml – Rust package metadata and dependencies.
• Makefile – helper commands for common development tasks.

Quick start

with Make:

make check
make test

You can also use cargo

Notes

• Leaves are padded to the next power of two by duplicating the last leaf.
• Hashes are 32-byte arrays ([u8; 32]) because SHA-256 output size is fixed.