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@ -6,33 +6,33 @@ pragma solidity ^0.4.11; |
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* @note Based on https://github.com/ameensol/merkle-tree-solidity/blob/master/src/MerkleProof.sol |
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*/ |
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library MerkleProof { |
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/* |
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* @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves |
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* and each pair of pre-images is sorted. |
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* @param _proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree |
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* @param _root Merkle root |
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* @param _leaf Leaf of Merkle tree |
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*/ |
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function verifyProof(bytes _proof, bytes32 _root, bytes32 _leaf) constant returns (bool) { |
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bytes32 proofElement; |
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bytes32 computedHash = _leaf; |
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/* |
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* @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves |
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* and each pair of pre-images is sorted. |
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* @param _proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree |
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* @param _root Merkle root |
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* @param _leaf Leaf of Merkle tree |
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*/ |
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function verifyProof(bytes _proof, bytes32 _root, bytes32 _leaf) constant returns (bool) { |
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bytes32 proofElement; |
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bytes32 computedHash = _leaf; |
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for (uint256 i = 32; i <= _proof.length; i += 32) { |
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assembly { |
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// Load the current element of the proof |
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proofElement := mload(add(_proof, i)) |
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} |
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for (uint256 i = 32; i <= _proof.length; i += 32) { |
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assembly { |
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// Load the current element of the proof |
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proofElement := mload(add(_proof, i)) |
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} |
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if (computedHash < proofElement) { |
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// Hash(current computed hash + current element of the proof) |
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computedHash = sha3(computedHash, proofElement); |
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} else { |
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// Hash(current element of the proof + current computed hash) |
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computedHash = sha3(proofElement, computedHash); |
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} |
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} |
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// Check if the computed hash (root) is equal to the provided root |
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return computedHash == _root; |
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if (computedHash < proofElement) { |
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// Hash(current computed hash + current element of the proof) |
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computedHash = sha3(computedHash, proofElement); |
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} else { |
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// Hash(current element of the proof + current computed hash) |
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computedHash = sha3(proofElement, computedHash); |
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} |
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} |
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// Check if the computed hash (root) is equal to the provided root |
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return computedHash == _root; |
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} |
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} |
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