solidity/test/libsolidity/smtCheckerTests/complex/MerkleProof.sol
2019-11-18 13:15:10 +01:00

43 lines
1.8 KiB
Solidity

pragma experimental SMTChecker;
/**
* @title MerkleProof
* @dev Merkle proof verification 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 are 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 verify(bytes32[] memory 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(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;
}
}
// ----
// Warning: (755-767): Assertion checker does not yet support this expression.
// Warning: (988-991): Assertion checker does not yet implement type abi
// Warning: (988-1032): Assertion checker does not yet implement this type of function call.
// Warning: (1175-1178): Assertion checker does not yet implement type abi
// Warning: (1175-1219): Assertion checker does not yet implement this type of function call.
// Warning: (755-767): Assertion checker does not yet support this expression.