// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/MerkleProof.sol)pragmasolidity ^0.8.20;/**
* @dev These functions deal with verification of Merkle Tree proofs.
*
* The tree and the proofs can be generated using our
* https://github.com/OpenZeppelin/merkle-tree[JavaScript library].
* You will find a quickstart guide in the readme.
*
* WARNING: You should avoid using leaf values that are 64 bytes long prior to
* hashing, or use a hash function other than keccak256 for hashing leaves.
* This is because the concatenation of a sorted pair of internal nodes in
* the Merkle tree could be reinterpreted as a leaf value.
* OpenZeppelin's JavaScript library generates Merkle trees that are safe
* against this attack out of the box.
*/libraryMerkleProof{
/**
*@dev The multiproof provided is not valid.
*/errorMerkleProofInvalidMultiproof();
/**
* @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
* defined by `root`. For this, a `proof` must be provided, containing
* sibling hashes on the branch from the leaf to the root of the tree. Each
* pair of leaves and each pair of pre-images are assumed to be sorted.
*/functionverify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internalpurereturns (bool) {
return processProof(proof, leaf) == root;
}
/**
* @dev Calldata version of {verify}
*/functionverifyCalldata(bytes32[] calldata proof, bytes32 root, bytes32 leaf) internalpurereturns (bool) {
return processProofCalldata(proof, leaf) == root;
}
/**
* @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
* from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
* hash matches the root of the tree. When processing the proof, the pairs
* of leafs & pre-images are assumed to be sorted.
*/functionprocessProof(bytes32[] memory proof, bytes32 leaf) internalpurereturns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i =0; i < proof.length; i++) {
computedHash = _hashPair(computedHash, proof[i]);
}
return computedHash;
}
/**
* @dev Calldata version of {processProof}
*/functionprocessProofCalldata(bytes32[] calldata proof, bytes32 leaf) internalpurereturns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i =0; i < proof.length; i++) {
computedHash = _hashPair(computedHash, proof[i]);
}
return computedHash;
}
/**
* @dev Returns true if the `leaves` can be simultaneously proven to be a part of a Merkle tree defined by
* `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/functionmultiProofVerify(bytes32[] memory proof,
bool[] memory proofFlags,
bytes32 root,
bytes32[] memory leaves
) internalpurereturns (bool) {
return processMultiProof(proof, proofFlags, leaves) == root;
}
/**
* @dev Calldata version of {multiProofVerify}
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/functionmultiProofVerifyCalldata(bytes32[] calldata proof,
bool[] calldata proofFlags,
bytes32 root,
bytes32[] memory leaves
) internalpurereturns (bool) {
return processMultiProofCalldata(proof, proofFlags, leaves) == root;
}
/**
* @dev Returns the root of a tree reconstructed from `leaves` and sibling nodes in `proof`. The reconstruction
* proceeds by incrementally reconstructing all inner nodes by combining a leaf/inner node with either another
* leaf/inner node or a proof sibling node, depending on whether each `proofFlags` item is true or false
* respectively.
*
* CAUTION: Not all Merkle trees admit multiproofs. To use multiproofs, it is sufficient to ensure that: 1) the tree
* is complete (but not necessarily perfect), 2) the leaves to be proven are in the opposite order they are in the
* tree (i.e., as seen from right to left starting at the deepest layer and continuing at the next layer).
*/functionprocessMultiProof(bytes32[] memory proof,
bool[] memory proofFlags,
bytes32[] memory leaves
) internalpurereturns (bytes32 merkleRoot) {
// This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by// consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the// `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of// the Merkle tree.uint256 leavesLen = leaves.length;
uint256 proofLen = proof.length;
uint256 totalHashes = proofFlags.length;
// Check proof validity.if (leavesLen + proofLen != totalHashes +1) {
revert MerkleProofInvalidMultiproof();
}
// The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using// `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".bytes32[] memory hashes =newbytes32[](totalHashes);
uint256 leafPos =0;
uint256 hashPos =0;
uint256 proofPos =0;
// At each step, we compute the next hash using two values:// - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we// get the next hash.// - depending on the flag, either another value from the "main queue" (merging branches) or an element from the// `proof` array.for (uint256 i =0; i < totalHashes; i++) {
bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
bytes32 b = proofFlags[i]
? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
: proof[proofPos++];
hashes[i] = _hashPair(a, b);
}
if (totalHashes >0) {
if (proofPos != proofLen) {
revert MerkleProofInvalidMultiproof();
}
unchecked {
return hashes[totalHashes -1];
}
} elseif (leavesLen >0) {
return leaves[0];
} else {
return proof[0];
}
}
/**
* @dev Calldata version of {processMultiProof}.
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/functionprocessMultiProofCalldata(bytes32[] calldata proof,
bool[] calldata proofFlags,
bytes32[] memory leaves
) internalpurereturns (bytes32 merkleRoot) {
// This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by// consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the// `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of// the Merkle tree.uint256 leavesLen = leaves.length;
uint256 proofLen = proof.length;
uint256 totalHashes = proofFlags.length;
// Check proof validity.if (leavesLen + proofLen != totalHashes +1) {
revert MerkleProofInvalidMultiproof();
}
// The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using// `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".bytes32[] memory hashes =newbytes32[](totalHashes);
uint256 leafPos =0;
uint256 hashPos =0;
uint256 proofPos =0;
// At each step, we compute the next hash using two values:// - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we// get the next hash.// - depending on the flag, either another value from the "main queue" (merging branches) or an element from the// `proof` array.for (uint256 i =0; i < totalHashes; i++) {
bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
bytes32 b = proofFlags[i]
? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
: proof[proofPos++];
hashes[i] = _hashPair(a, b);
}
if (totalHashes >0) {
if (proofPos != proofLen) {
revert MerkleProofInvalidMultiproof();
}
unchecked {
return hashes[totalHashes -1];
}
} elseif (leavesLen >0) {
return leaves[0];
} else {
return proof[0];
}
}
/**
* @dev Sorts the pair (a, b) and hashes the result.
*/function_hashPair(bytes32 a, bytes32 b) privatepurereturns (bytes32) {
return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
}
/**
* @dev Implementation of keccak256(abi.encode(a, b)) that doesn't allocate or expand memory.
*/function_efficientHash(bytes32 a, bytes32 b) privatepurereturns (bytes32 value) {
/// @solidity memory-safe-assemblyassembly {
mstore(0x00, a)
mstore(0x20, b)
value :=keccak256(0x00, 0x40)
}
}
}