Merkle
Author: Matter Labs
Note: security-contact: security@matterlabs.dev
Functions
calculateRoot
Calculate Merkle root by the provided Merkle proof. NOTE: When using this function, check that the _path length is equal to the tree height to prevent shorter/longer paths attack however, for chains settling on GW the proof includes the GW proof, so the path increases. See Mailbox for more details.
function calculateRoot(
bytes32[] calldata _path,
uint256 _index,
bytes32 _itemHash
) internal pure returns (bytes32);
Parameters
| Name | Type | Description |
|---|---|---|
_path | bytes32[] | Merkle path from the leaf to the root |
_index | uint256 | Leaf index in the tree |
_itemHash | bytes32 | Hash of leaf content |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bytes32 | The Merkle root |
calculateRootMemory
Calculate Merkle root by the provided Merkle proof.
NOTE: When using this function, check that the _path length is appropriate to prevent shorter/longer paths attack
NOTE the tree can be joined. In this case the second tree's leaves indexes increase by the number of leaves in the first tree.
function calculateRootMemory(
bytes32[] memory _path,
uint256 _index,
bytes32 _itemHash
) internal pure returns (bytes32);
Parameters
| Name | Type | Description |
|---|---|---|
_path | bytes32[] | Merkle path from the leaf to the root |
_index | uint256 | Leaf index in the tree. |
_itemHash | bytes32 | Hash of leaf content |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bytes32 | The Merkle root |
calculateRootPaths
Calculate Merkle root by the provided Merkle proof for a range of elements NOTE: When using this function, check that the _startPath and _endPath lengths are equal to the tree height to prevent shorter/longer paths attack
function calculateRootPaths(
bytes32[] memory _startPath,
bytes32[] memory _endPath,
uint256 _startIndex,
bytes32[] memory _itemHashes
) internal pure returns (bytes32);
Parameters
| Name | Type | Description |
|---|---|---|
_startPath | bytes32[] | Merkle path from the first element of the range to the root |
_endPath | bytes32[] | Merkle path from the last element of the range to the root |
_startIndex | uint256 | Index of the first element of the range in the tree |
_itemHashes | bytes32[] | Hashes of the elements in the range |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bytes32 | The Merkle root |
efficientHash
Keccak hash of the concatenation of two 32-byte words
function efficientHash(bytes32 _lhs, bytes32 _rhs)
internal
pure
returns (bytes32 result);
_validatePathLengthForSingleProof
function _validatePathLengthForSingleProof(uint256 _index, uint256 _pathLength)
private
pure;