MerkleProof.sol

pragma solidity ^0.4.16;

library MerkleProof
{
    uint256 constant ONE_SHL_255 = 57896044618658097711785492504343953926634992332820282019728792003956564819968;
    
    function Hash( bytes data )
        public pure
        returns (uint256)
    {
        uint256 x = uint256(keccak256(data));
        // Clears highest bit from result
        if( x & ONE_SHL_255 > 0 )
            return x ^ ONE_SHL_255;
        return x;
    }
    
    
    function Hash2( uint256 a, uint256 b )
        public pure
        returns (uint256)
    {
        uint256 x = uint256(keccak256(abi.encodePacked(a, b)));
        // Clears highest bit from result
        if( x & ONE_SHL_255 > 0 )
            return x ^ ONE_SHL_255;
        return x;
    }

    /*
    * Test case:
    * "0x1a792cf089bfa56eae57ffe87e9b22f9c9bfe52c1ac300ea1f43f4ab53b4b794","0x2584db4a68aa8b172f70bc04e2e74541617c003374de6eb4b295e823e5beab01",["0x1ab0c6948a275349ae45a06aad66a8bd65ac18074615d53676c09b67809099e0","0x093fd25755220b8f497d65d2538c01ed279c131f63e42b2942867f2bd6622486","0xb1d101d9a9d27c3a8ed9d1b6548626eacf3d19546306117eb8af547d1e97189e","0xcb431dd627bc8dcfd858eae9304dc71a8d3f34a8de783c093188bb598eeafd04"]
    */
    function Verify( uint256 root, uint256 leaf_hash, uint256[] path )
        public pure returns (bool)
    {
        if( path.length == 0 )
            return leaf_hash == root;

        uint256 node = leaf_hash;
        uint256 item;
        for( uint256 i = 0; i < path.length; i++ )
        {
            item = path[i];
            if( (item & ONE_SHL_255) > 0 ) {
                node = Hash2(node, item ^ ONE_SHL_255);
            }
            else {
                node = Hash2(item, node);
            }
        }
        
        return node == root;
    }
}