# Merkle Proof

Allows users to verify Merkle Tree proofs. It is based on the OZ implementation. The tree and the proofs can be generated using <https://github.com/merkletreejs/merkletreejs>.

{% hint style="danger" %}

```
You should avoid using leaf values that are 64 bytes long prior to hashing.
```

{% endhint %}

## Interface

### <mark style="color:blue;">verify</mark>

**Returns true if a `leaf` can be proved to be a part of a Merkle tree defined by `root`.**

```rust
public fun verify(
    proof: &vector<vector<u8>>,
    root: vector<u8>,
    leaf: vector<u8>
  ): bool
```

* **@param proof:** The Merkle proof.
* **@param root:** The root of Merkle Tree.
* **@param leaf:** The `leaf` we wish to prove if it is part of the tree.
* **@return bool.** If it is part of the Merkle tree.

### <mark style="color:blue;">verify\_with\_index</mark>

**Returns true if a `leaf` can be proved to be a part of a Merkle tree defined by `root`. For this, a `proof` must be provided, containing sibling hashes on the branch from the leaf to the root of the tree. Each pair of leaves and each pair of pre-images are assumed to be sorted.**

{% hint style="success" %}
The index logic is from ENS token: <https://etherscan.io/token/0xC18360217D8F7Ab5e7c516566761Ea12Ce7F9D72#code>
{% endhint %}

```rust
public fun verify_with_index(
    proof: &vector<vector<u8>>,
    root: vector<u8>,
    leaf: vector<u8>
): (bool, u256)
```

* **@param proof:** The Merkle proof.
* **@param root:** The root of Merkle Tree.
* **@param leaf:** The `leaf` we wish to prove if it is part of the tree.
* **@return bool.** If it is part of the Merkle tree.
* **@return u256.** The index of the `leaf.`