class MerkleTreeGenerator(object):
def __init__(self):
self.tree = MerkleTools(hash_type='sha256')
def populate(self, node_generator):
"""
Populate Merkle Tree with data from node_generator. This requires that node_generator yield byte[] elements.
Hashes, computes hex digest, and adds it to the Merkle Tree
:param node_generator:
:return:
"""
for data in node_generator:
hashed = hash_byte_array(data)
self.tree.add_leaf(hashed)
def get_blockchain_data(self):
"""
Finalize tree and return byte array to issue on blockchain
:return:
"""
self.tree.make_tree()
merkle_root = self.tree.get_merkle_root()
return h2b(ensure_string(merkle_root))
def get_proof_generator(self, tx_id, chain=Chain.bitcoin_mainnet):
"""
Returns a generator (1-time iterator) of proofs in insertion order.
:param tx_id: blockchain transaction id
:return:
"""
root = ensure_string(self.tree.get_merkle_root())
node_count = len(self.tree.leaves)
for index in range(0, node_count):
proof = self.tree.get_proof(index)
proof2 = []
for p in proof:
dict2 = dict()
for key, value in p.items():
dict2[key] = ensure_string(value)
proof2.append(dict2)
target_hash = ensure_string(self.tree.get_leaf(index))
merkle_proof = {
"type": ['MerkleProof2017', 'Extension'],
"merkleRoot":
root,
"targetHash":
target_hash,
"proof":
proof2,
"anchors": [{
"sourceId": to_source_id(tx_id, chain),
"type": chain.blockchain_type.external_display_value,
"chain": chain.external_display_value
}]
}
yield merkle_proof
class MerkleTreeGenerator(object):
def __init__(self):
self.tree = MerkleTools(hash_type='sha256')
def populate(self, node_generator):
"""
Populate Merkle Tree with data from node_generator. This requires that node_generator yield byte[] elements.
Hashes, computes hex digest, and adds it to the Merkle Tree
:param node_generator:
:return:
"""
for data in node_generator:
hashed = hash_byte_array(data)
self.tree.add_leaf(hashed)
def get_blockchain_data(self):
"""
Finalize tree and return byte array to issue on blockchain
:return:
"""
self.tree.make_tree()
merkle_root = self.tree.get_merkle_root()
return h2b(ensure_string(merkle_root))
def get_proof_generator(self, tx_id, chain=Chain.bitcoin_mainnet):
"""
Returns a generator (1-time iterator) of proofs in insertion order.
:param tx_id: blockchain transaction id
:return:
"""
root = ensure_string(self.tree.get_merkle_root())
node_count = len(self.tree.leaves)
for index in range(0, node_count):
proof = self.tree.get_proof(index)
proof2 = []
for p in proof:
dict2 = dict()
for key, value in p.items():
dict2[key] = ensure_string(value)
proof2.append(dict2)
target_hash = ensure_string(self.tree.get_leaf(index))
merkle_proof = {
"type": ['MerkleProof2017', 'Extension'],
"merkleRoot": root,
"targetHash": target_hash,
"proof": proof2,
"anchors": [{
"sourceId": to_source_id(tx_id, chain),
"type": chain.blockchain_type.external_display_value,
"chain": chain.external_display_value
}]}
yield merkle_proof
class MerkleTree(object):
"""Representation of a Merkle Tree.
More at https://en.wikipedia.org/wiki/Merkle_tree.
"""
def __init__(self):
self.tree = MerkleTools(hash_type='sha256')
def populate(self, node_generator: Generator) -> None:
"""
Populate Merkle Tree with data from node_generator. This requires that node_generator yield byte[] elements.
Hashes, computes hex digest, and adds it to the Merkle Tree
:param node_generator:
:return:
"""
for data in node_generator:
hashed = hash_byte_array(data)
self.tree.add_leaf(hashed)
def get_root(self, binary=False) -> bytearray:
"""
Finalize tree and return the Root, a byte array to anchor on a blockchain tx.
:return:
"""
self.tree.make_tree()
merkle_root = self.tree.get_merkle_root()
if binary:
return h2b(ensure_string(merkle_root))
return ensure_string(merkle_root)
def get_proof_generator(self, tx_id: AnyStr, signature_type: AnyStr,
chain_name: AnyStr) -> Dict:
"""
Returns a generator of Merkle Proofs in insertion order.
:param tx_id: blockchain transaction id
:return:
"""
root = ensure_string(self.tree.get_merkle_root())
node_count = len(self.tree.leaves)
for index in range(0, node_count):
proof = self.tree.get_proof(index)
proof2 = []
for p in proof:
dict2 = dict()
for key, value in p.items():
dict2[key] = ensure_string(value)
proof2.append(dict2)
target_hash = ensure_string(self.tree.get_leaf(index))
merkle_proof = {
"type": ['MerkleProof2017', 'Extension'],
"merkleRoot":
root,
"targetHash":
target_hash,
"proof":
proof2,
"anchors": [{
"sourceId": tx_id,
"type": signature_type,
"chain": chain_name
}]
}
yield merkle_proof