Merkle-Tree-Implementation-using-Python

Merkle Tree Implementation using Python

Merkle tree implementation using Python and hashlib library

The project is comprised of a MerkleTree object, containing a createMerkleTree method

class MerkleTree(object):
    def __init__(self):
        pass

Initialize constructor for MerkleTree object

    # markle tree create method taking a list and a hash function
    def createMerkleTree(self, list, hash):
        if not list:
            raise ValueError(
            'Missing List'
            )

        if(len(list) == 1):
            return list

Since this is a recursive implementation, once we have one node (root) we will return the list.

        tempList = []

Initialize temp list to store new leaves

        if( len(list) % 2 != 0):
            list.append(list[len(list)-1])

If list is odd, append tail to list

        for leaf in xrange(0, len(list), 2):
            currentHash = hash(list[leaf] + list[leaf+1])
            tempList.append(currentHash.hexdigest())

        return self.createMerkleTree(tempList, hash)

A simple test using uuid to generate random hashes and create a list:

import uuid
    hashes = []

    for x in xrange(0,10):
        hashes.append(str(uuid.uuid4().hex))

    print 'hashes {0}'.format(hashes)
    print 'finished creating hashes'
    cls = MerkleTree()
    mk = cls.createMerkleTree(hashes, hashlib.sha256)
    print 'finding merkle tree root \n'

    print 'merkle tree root is {0}'.format(mk)