def hash_blockheader(blockheader):
if blockheader.hash:
return blockheader.hash
if not blockheader.rawdata:
blockheader.rawdata = BLOCK_SERIALIZE.serialize(blockheader)
blockheader.hash = Uint256.from_bytestr(doublesha256(blockheader.rawdata))
return blockheader.hash
def hash_tx(tx):
if tx.hash:
return tx.hash
if not tx.rawdata:
tx.rawdata = TX_SERIALIZE.serialize(tx)
tx.hash = Uint256.from_bytestr(doublesha256(tx.rawdata))
return tx.hash
def mine_block(hash_prev,
block_height,
time_source,
difficulty_bits,
transactions,
coinbase_txout_list,
coinbase_flags=["/P2SH/"],
nonce_changer=default_nonce_changer):
template = BlockheaderTemplate(hash_prev,
block_height,
coinbase_txout_list,
transactions,
time_source.get_time(),
difficulty_bits,
coinbase_flags=coinbase_flags)
difficulty_target = uint256_difficulty(difficulty_bits)
hash_found = False
while not hash_found:
hash = Uint256.from_bytestr(doublesha256(
template.get_serialized()))
if (hash <= difficulty_target):
hash_found = True
else:
nonce_changer(template)
return (template.get_block(), template)
def check_merkle_branch(txhash, merkle_branch, index_tx):
"""Return True if the merkle branch is valid for txhash and index_tx.
Attributes:
txhash(Uint256): Hash of a Transaction
merkle_branch(list of Uint256): Merkle Branch
index_tx(int): Index of the transaction in the block.
"""
hash = txhash.get_bytestr()
index = index_tx
otherside_branch, merkle_root = merkle_branch[:-1], merkle_branch[-1]
for otherside in otherside_branch:
if index & 1:
hash = double_sha256_2_input(otherside.get_bytestr(), hash)
else:
hash = double_sha256_2_input(hash, otherside.get_bytestr())
index = index >> 1
print "u", Uint256.from_bytestr(hash)
return (Uint256.from_bytestr(hash) == merkle_root)
def check_merkle_branch(txhash, merkle_branch, index_tx):
"""Return True if the merkle branch is valid for txhash and index_tx.
Attributes:
txhash(Uint256): Hash of a Transaction
merkle_branch(list of Uint256): Merkle Branch
index_tx(int): Index of the transaction in the block.
"""
hash = txhash.get_bytestr()
index = index_tx
otherside_branch, merkle_root = merkle_branch[:-1], merkle_branch[-1]
for otherside in otherside_branch:
if index & 1:
hash = double_sha256_2_input(otherside.get_bytestr(), hash)
else:
hash = double_sha256_2_input(hash, otherside.get_bytestr())
index = index >> 1
print "u", Uint256.from_bytestr(hash)
return (Uint256.from_bytestr(hash) == merkle_root)
def get_merkle_branch(block, index_tx):
"""Get the merkle branch of a transaction.
block: block that contains the transaction
index_tx: index of the transaction in the block
Return value: [list of Uint256]
The first element is a hash of a transaction at the bottom of the merkle tree.
The last element is the merkle root.
The algorithm uses XOR 1, to select the opposite element at each level.
"""
merkle_branch = []
merkle_tree = get_merkle_tree(block)
for level in merkle_tree:
merkle_branch.append(Uint256.from_bytestr(level[min(index_tx^1, len(level)-1)]))
index_tx = index_tx >> 1
return (merkle_branch)
def get_merkle_branch(block, index_tx):
"""Get the merkle branch of a transaction.
block: block that contains the transaction
index_tx: index of the transaction in the block
Return value: [list of Uint256]
The first element is a hash of a transaction at the bottom of the merkle tree.
The last element is the merkle root.
The algorithm uses XOR 1, to select the opposite element at each level.
"""
merkle_branch = []
merkle_tree = get_merkle_tree(block)
for level in merkle_tree:
merkle_branch.append(
Uint256.from_bytestr(level[min(index_tx ^ 1,
len(level) - 1)]))
index_tx = index_tx >> 1
return (merkle_branch)
def mine_block(hash_prev,
block_height,
time_source,
difficulty_bits,
transactions,
coinbase_txout_list,
coinbase_flags=["/P2SH/"],
nonce_changer=default_nonce_changer):
template = BlockheaderTemplate(hash_prev,
block_height,
coinbase_txout_list,
transactions,
time_source.get_time(),
difficulty_bits,
coinbase_flags=coinbase_flags)
difficulty_target = uint256_difficulty(difficulty_bits)
hash_found = False
while not hash_found:
hash = Uint256.from_bytestr(doublesha256(template.get_serialized()))
if (hash <= difficulty_target):
hash_found = True
else:
nonce_changer(template)
return (template.get_block(), template)
def get_hashbestchain(self):
return Uint256.from_bytestr(self.db.get("\x0dhashBestChain", txn=self.dbtxn))
def deserialize(self, data, cursor=0):
if (len(data) - cursor) < 32:
raise MissingDataException("%s: Not enought data for uint256" %
(self.desc))
bytestr, = struct.unpack_from("32s", data, cursor)
return (Uint256.from_bytestr(bytestr), cursor + 32)
def get_hashbestchain(self):
return Uint256.from_bytestr(
self.db.get("\x0dhashBestChain", txn=self.dbtxn))
def deserialize(self, data, cursor=0):
if (len(data) - cursor) < 32:
raise MissingDataException("%s: Not enought data for uint256" % (self.desc))
bytestr, = struct.unpack_from("32s", data, cursor)
return (Uint256.from_bytestr(bytestr), cursor + 32)
def compute_merkle_root(transactions):
hashes = [hash_tx(tx).get_bytestr() for tx in transactions]
while (len(hashes) != 1):
hashes = next_merkle_level(hashes)
return (Uint256.from_bytestr(hashes[0]))
def compute_merkle_root(transactions):
hashes = [hash_tx(tx).get_bytestr() for tx in transactions]
while (len(hashes) != 1):
hashes = next_merkle_level(hashes)
return (Uint256.from_bytestr(hashes[0]))
