class BlockMessageSerializer(Serializer):
block_serializer = BlockSerializer()
def __init__(self):
pass
def serialize(self, block_msg):
return (self.block_serializer.serialize(block_msg.block))
def deserialize(self, data, cursor=0):
block, cursor = self.block_serializer.deserialize(data, cursor)
return (BlockMessage(block), cursor)
def __init__(self, runmode):
self.runmode = runmode
self.block_serializer = BlockSerializer()
self.tx_verifier = TxVerifier(self.runmode)
class BlockVerifier():
def __init__(self, runmode):
self.runmode = runmode
self.block_serializer = BlockSerializer()
self.tx_verifier = TxVerifier(self.runmode)
"""
basic_check: run tests that don't require context or the block parent.
"""
def basic_checks(self, hash, block):
self.check_size_limit(hash, block)
self.check_proof_of_work(hash, block)
self.check_coinbase(hash, block)
self.check_transactions(hash, block)
self.check_merkle_root(hash, block)
def check_size_limit(self, hash, block):
#FIXME: don't serialize the block here (add get_serialize_size() in serialize objects
#or cache previoulsy serialized block)
if (not block.rawdata):
block.rawdata = self.block_serializer.serialize(block)
if len(block.rawdata) > MAX_BLOCK_SIZE:
raise Exception("block size limit exceeded")
def check_proof_of_work(self, hash, block):
target = block.blockheader.target()
if (target <= Uint256.zero() or target > PROOF_OF_WORK_LIMIT[self.runmode]):
raise Exception("proof of work: value out of range : %x" % (block.blockheader.bits))
if (hash > target):
raise Exception("proof of work: hash doesn't match target hash:%s, target:%s" % (hash, target))
# not out of context: (check elsewhere)
# def check_timestamp(self, hash, block):
# block.blockheader.time > time.time
def check_coinbase(self, hash, block):
if not len(block.transactions):
raise Exception("Block has no transactions" )
if not block.transactions[0].iscoinbase():
raise Exception("block's first transactions is not coinbase" )
for tx in block.transactions[1:]:
if tx.iscoinbase():
raise Exception("more than one coinbase" )
def check_transactions(self, hash, block):
for tx in block.transactions:
err = self.tx_verifier.basic_checks(tx)
if err:
return err
def check_merkle_root(self, hash, block):
merkle = compute_merkle_root(block.transactions)
if merkle != block.blockheader.hash_merkle:
raise Exception("merkel root incorrect for block %s: %s != %s" % (str(hash), str(merkle), str(block.blockheader.hash_merkle)) )
"""
accept_block: check block after finding the parent block.
"""
#AcceptBlock: main.cpp:1445
def accept_block(self, hash, block, blockchain):
prevblockhandle = blockchain.get_block_handle(block.blockheader.hash_prev)
self.check_target(blockchain, prevblockhandle, hash, block)
self.check_timestamp(blockchain, prevblockhandle, hash, block)
self.check_tx_finalized(prevblockhandle, hash, block)
self.check_checkpoints(prevblockhandle, hash, block)
def check_target(self, blockchain, prevblockhandle, hash, block):
#Check proof of work target
if (blockchain.get_next_work_required(prevblockhandle.hash, block) != block.blockheader.bits):
raise Exception("Incorrect difficulty target, found:%08x != required:%08x in block %s" % (block.blockheader.bits, blockchain.get_next_work_required(prevblockhandle.hash, block), hash) )
def check_timestamp(self, blockchain, prevblockhandle, hash, block):
if (block.blockheader.time <= blockchain.get_median_time_past(prevblockhandle.hash)):
raise Exception("block's timestamp is smaller than the median of past %d block: %d <= %d" % (MEDIAN_TIME_SPAN, prevblockhandle.get_blockheader().time , prevblockhandle.get_median_time_past()))
def check_tx_finalized(self, prevblockhandle, hash, block):
height = prevblockhandle.get_height()+1
#Check that all transactions are finalized (can this be done somewhere else?)
for tx in block.transactions:
if not tx.isfinal(height, block.blockheader.time):
raise Exception("transaction is not final: %s" % str(hash_tx(tx)))
def check_checkpoints(self, prevblockhandle, hash, block):
height = prevblockhandle.get_height()+1
if not verify_checkpoints(self.runmode, height, hash):
raise Exception("blockchain checkpoint error: height:%d value:%s != %s" % (height, hash, str(get_checkpoint(self.runmode, height))))
def test_block_serialize(self):
blockheader = BlockHeader(
version=1,
hash_prev=Uint256.from_hexstr(
"000000000fec081581146e8b16b275bfa52150ac4174a246cdf62694671ea7a3"
),
hash_merkle=Uint256.from_hexstr(
"0d9da162550fc45b1aaa00e933b23b3cbc7f37a9b2d2070d61235eaec11a926a"
),
time=1301129903,
bits=470809215,
nonce=1280448751)
tx1 = Tx(
version=1,
in_list=[
TxIn(previous_output=Outpoint.null(),
script=Script([
Instruction(4, decodehexstr("7ffa0f1c")),
Instruction(1, decodehexstr("4e"))
]),
sequence=TxIn.NSEQUENCE_FINAL)
],
out_list=[
TxOut(
value=5002000000,
script=Script([
Instruction(
65,
decodehexstr(
"049cc3cae30927c40598032044b9e9e25f4739b0d7ade62803f5e9cf075debc817e6d29f42c70d0a1beb1c904eaaa50ef885b011f9fbaa16ef288a7ad193e11567"
)),
Instruction(OP_CHECKSIG)
]))
],
locktime=0)
tx2 = Tx(
version=1,
in_list=[
TxIn(previous_output=Outpoint(hash=Uint256.from_hexstr(
"17c5cb687ba453ab65e12cdc0d8721c70ab4678665eb200c50cb9f1e3207090e"
),
index=0),
script=Script([
Instruction(
72,
decodehexstr(
"3045022100ab2dc8932ca1d26f4cdac1feae09020a60ccc4d17b14e5fc5b21f3ab8c3a9cee022040a7208c172d19a19902280d66201c7fe2c3d8b2df7e23cc4e5b70fd52ecba2c01"
)),
Instruction(
65,
decodehexstr(
"04b77dd1f3a21cb3d067a7e76982a609d7310f8692f5d61346f3225323c425604a0c12862755335c49e392673106adfc5dfdee1e4d367f10353e8911fac687db3e"
))
]),
sequence=TxIn.NSEQUENCE_FINAL)
],
out_list=[
TxOut(value=24990000000,
script=Script([
Instruction(OP_DUP),
Instruction(OP_HASH160),
Instruction(
20,
decodehexstr(
"4d8b17fbce571614be89df4bd872de892a479844")),
Instruction(OP_EQUALVERIFY),
Instruction(OP_CHECKSIG)
])),
TxOut(value=5000000000,
script=Script([
Instruction(OP_DUP),
Instruction(OP_HASH160),
Instruction(
20,
decodehexstr(
"fadad27c40adbe230f5e3c04d44a292975084831")),
Instruction(OP_EQUALVERIFY),
Instruction(OP_CHECKSIG)
]))
],
locktime=0)
blk = Block(blockheader, [tx1, tx2])
data = BlockSerializer().serialize(blk)
self.assertEquals(
data,
decodehexstr(
"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"
))
def __init__(self, runmode):
self.runmode = runmode
self.block_serializer = BlockSerializer()
self.tx_verifier = TxVerifier(self.runmode)
class BlockVerifier():
def __init__(self, runmode):
self.runmode = runmode
self.block_serializer = BlockSerializer()
self.tx_verifier = TxVerifier(self.runmode)
"""
basic_check: run tests that don't require context or the block parent.
"""
def basic_checks(self, hash, block):
self.check_size_limit(hash, block)
self.check_proof_of_work(hash, block)
self.check_coinbase(hash, block)
self.check_transactions(hash, block)
self.check_merkle_root(hash, block)
def check_size_limit(self, hash, block):
#FIXME: don't serialize the block here (add get_serialize_size() in serialize objects
#or cache previoulsy serialized block)
if (not block.rawdata):
block.rawdata = self.block_serializer.serialize(block)
if len(block.rawdata) > MAX_BLOCK_SIZE:
raise Exception("block size limit exceeded")
def check_proof_of_work(self, hash, block):
target = block.blockheader.target()
if (target <= Uint256.zero()
or target > PROOF_OF_WORK_LIMIT[self.runmode]):
raise Exception("proof of work: value out of range : %x" %
(block.blockheader.bits))
if (hash > target):
raise Exception(
"proof of work: hash doesn't match target hash:%s, target:%s" %
(hash, target))
# not out of context: (check elsewhere)
# def check_timestamp(self, hash, block):
# block.blockheader.time > time.time
def check_coinbase(self, hash, block):
if not len(block.transactions):
raise Exception("Block has no transactions")
if not block.transactions[0].iscoinbase():
raise Exception("block's first transactions is not coinbase")
for tx in block.transactions[1:]:
if tx.iscoinbase():
raise Exception("more than one coinbase")
def check_transactions(self, hash, block):
for tx in block.transactions:
err = self.tx_verifier.basic_checks(tx)
if err:
return err
def check_merkle_root(self, hash, block):
merkle = compute_merkle_root(block.transactions)
if merkle != block.blockheader.hash_merkle:
raise Exception(
"merkel root incorrect for block %s: %s != %s" %
(str(hash), str(merkle), str(block.blockheader.hash_merkle)))
"""
accept_block: check block after finding the parent block.
"""
#AcceptBlock: main.cpp:1445
def accept_block(self, hash, block, blockchain):
prevblockhandle = blockchain.get_block_handle(
block.blockheader.hash_prev)
self.check_target(blockchain, prevblockhandle, hash, block)
self.check_timestamp(blockchain, prevblockhandle, hash, block)
self.check_tx_finalized(prevblockhandle, hash, block)
self.check_checkpoints(prevblockhandle, hash, block)
def check_target(self, blockchain, prevblockhandle, hash, block):
#Check proof of work target
if (blockchain.get_next_work_required(prevblockhandle.hash, block) !=
block.blockheader.bits):
raise Exception(
"Incorrect difficulty target, found:%08x != required:%08x in block %s"
% (block.blockheader.bits,
blockchain.get_next_work_required(prevblockhandle.hash,
block), hash))
def check_timestamp(self, blockchain, prevblockhandle, hash, block):
if (block.blockheader.time <= blockchain.get_median_time_past(
prevblockhandle.hash)):
raise Exception(
"block's timestamp is smaller than the median of past %d block: %d <= %d"
% (MEDIAN_TIME_SPAN, prevblockhandle.get_blockheader().time,
prevblockhandle.get_median_time_past()))
def check_tx_finalized(self, prevblockhandle, hash, block):
height = prevblockhandle.get_height() + 1
#Check that all transactions are finalized (can this be done somewhere else?)
for tx in block.transactions:
if not tx.isfinal(height, block.blockheader.time):
raise Exception("transaction is not final: %s" %
str(hash_tx(tx)))
def check_checkpoints(self, prevblockhandle, hash, block):
height = prevblockhandle.get_height() + 1
if not verify_checkpoints(self.runmode, height, hash):
raise Exception(
"blockchain checkpoint error: height:%d value:%s != %s" %
(height, hash, str(get_checkpoint(self.runmode, height))))
