TxMerkleProof

Overview

License: MIT

library TxMerkleProof

A library for verifying transaction inclusion in Bitcoin block. Provides functions for processing and verifying Merkle tree proofs

Errors info

InvalidMerkleNode

error InvalidMerkleNode()

Emitted when the concateneted hashes of the Merkle tree is a valid Bitcoin transaction. This error ensures that insertion attack is not possible

Functions info

verify

function verify(
    bytes32[] memory proof_,
    bytes32 root_,
    bytes32 leaf_,
    uint256 txIndex_
) internal pure returns (bool)

Returns true if leaf_ can be proven to be part of a Merkle tree defined by root_. Uses double SHA-256 hashing

Parameters:

Name	Type	Description
proof_	bytes32[]	The array of sibling hashes from the leaf to the root
root_	bytes32	Merkle root in little-endian format
leaf_	bytes32	Element that need to be proven included in a tree
txIndex_	uint256	The transaction index in the block, indicating hashing order for each pair

Return values:

Name	Type	Description
[0]	bool	Whether the leaf is the part of a Merkle tree

processProof

function processProof(
    bytes32[] memory proof_,
    bytes32 leaf_,
    uint256 txIndex_
) internal pure returns (bytes32)

Returns the rebuilt hash obtained by traversing the Merkle tree from leaf_ using proof_. A proof_ is valid if and only if the rebuilt hash matches the given tree root. The pre-images are hashed in the order calculated by the txIndex_ position. Uses double SHA-256 hashing

Parameters:

Name	Type	Description
proof_	bytes32[]	The array of sibling hashes from the leaf to the root
leaf_	bytes32	The leaf of the Merkle tree
txIndex_	uint256	The transaction index in the block, indicating hashing order for each pair

Return values:

Name	Type	Description
[0]	bytes32	The computed Merkle root