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// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023.
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0;
contract Ownable
{
// Variable that maintains
// owner address
address private _owner;
// Sets the original owner of
// contract when it is deployed
constructor()
{
_owner = msg.sender;
}
// Publicly exposes who is the
// owner of this contract
function owner() public view returns(address)
{
return _owner;
}
// onlyOwner modifier that validates only
// if caller of function is contract owner,
// otherwise not
modifier onlyOwner()
{
require(isOwner(),
"Function accessible only by the owner !!");
_;
}
// function for owners to verify their ownership.
// Returns true for owners otherwise false
function isOwner() public view returns(bool)
{
return msg.sender == _owner;
}
}
contract Notarizer is Ownable
{
uint256 public prevBlock;
event RootHash(bytes32 rootHash, uint256 indexed prevBlock);
//Store proof AKA hash
function storeNewRootHash(bytes32 _rootHash) onlyOwner external {
emit RootHash(_rootHash, prevBlock);
prevBlock = block.number;
}
function verify(bytes32 root, bytes32 leaf, bytes32[] memory proof) external 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(
abi.encodePacked(computedHash, proofElement)
);
} else {
// Hash(current element of the proof + current computed hash)
computedHash = keccak256(
abi.encodePacked(proofElement, computedHash)
);
}
}
// Check if the computed hash (root) is equal to the provided root
return computedHash == root;
}
} |