Files
openzeppelin-contracts/contracts/MerkleProof.sol
Francisco Giordano a7e91856f3 Update to Truffle 4.1.5 and Ganache 6.1.0 (#876)
* Update to ganache-cli v6.1.0 and truffle v4.1.0

* Update to stable version of ganache-cli

* fix: update event emission warning

- Fix event emission warnings for solidity 4.21 after truffle has been
updated to use this version

* fix pr review comments

* update to truffle v4.1.5

* update package-lock

* add additional emit keywords

* update solidity-coverage to 0.4.15

* update to solium 1.1.6

* fix MerkleProof coverage analysis by testing through wrapper

* change version pragma to ^0.4.21

* fix solium linting errors
2018-04-09 20:48:32 -03:00

36 lines
1.2 KiB
Solidity

pragma solidity ^0.4.21;
/*
* @title MerkleProof
* @dev Merkle proof verification
* @note Based on https://github.com/ameensol/merkle-tree-solidity/blob/master/src/MerkleProof.sol
*/
library MerkleProof {
/*
* @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves
* and each pair of pre-images is sorted.
* @param _proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree
* @param _root Merkle root
* @param _leaf Leaf of Merkle tree
*/
function verifyProof(bytes32[] _proof, bytes32 _root, bytes32 _leaf) internal pure returns (bool) {
bytes32 computedHash = _leaf;
for (uint256 i = 0; i < _proof.length; i++) {
bytes32 proofElement = _proof[i];
if (computedHash < proofElement) {
// Hash(current computed hash + current element of the proof)
computedHash = keccak256(computedHash, proofElement);
} else {
// Hash(current element of the proof + current computed hash)
computedHash = keccak256(proofElement, computedHash);
}
}
// Check if the computed hash (root) is equal to the provided root
return computedHash == _root;
}
}