def create_new_block(self):
"""
Create a fresh new block that contains all valid
pending transactions.
"""
newb = Block(self.blockchain.top().hash)
newb.index = self.blockchain.top().index + 1
newb.transactions.extend(self.blockchain.get_pending_transactions())
tx = Transaction(None, txtype=TxType.COINBASE)
tx.add_out(MINING_REWARD, self.reward_addr)
tx.finalize()
newb.transactions.append(tx)
return newb
def _test_fraudulent_tx(self, victim, blockchain):
"""
Try transaction from somebody else's "wallet"
"""
miner_key = generate_key()
perpetrator = generate_key()
utxo = blockchain.scan_unspent_transactions(victim.publickey())
perpetrator_owns = blockchain.scan_unspent_transactions(
perpetrator.publickey())
self.assertEqual(len(perpetrator_owns), 0) # Sanity check
# Let's handcraft tx that tries to steal victim's coins.
tx = Transaction(perpetrator) # Sign it with random key
utxo = blockchain.scan_unspent_transactions(
victim.publickey()) # Get victim's utxo
debit = sum(map(lambda x: x['value'], utxo))
for credit in utxo:
tx.add_in(credit['hash'], sign(perpetrator, credit['hash']),
victim.publickey(), credit['value'])
tx.add_out(debit, perpetrator.publickey())
try:
blockchain.add(tx)
self.fail("Should've thrown UnauthorizedTxException")
except UnauthorizedTxException:
pass
miner = Miner(blockchain)
miner.reward_addr = miner_key.publickey()
_ = miner._mine()
perpetrator_owns = blockchain.scan_unspent_transactions(
perpetrator.publickey())
# Should own nothing. This tx should've failed.
self.assertEqual(len(perpetrator_owns), 0)
def test_pending_transactions(self):
receiver = generate_key()
tx = Transaction(None, txtype=TxType.COINBASE)
tx.add_out(10, receiver.publickey())
blockchain = Blockchain()
blockchain.add(tx)
pending_tx = blockchain.get_pending_transactions()
self.assertEqual(len(filter(lambda x: tx.hash, pending_tx)), 1)
miner = Miner(blockchain)
miner.reward_addr = receiver.publickey()
newb = miner._mine()
pending_tx = blockchain.get_pending_transactions()
self.assertEqual(len(filter(lambda x: tx.hash, pending_tx)), 0)
self.assertEqual(len(filter(lambda x: tx.hash, newb.transactions)), 2)
