def isValidTx(self, tx: Transaction) -> bool:
inputSum = decimal.Decimal()
pool = copy.deepcopy(self._pool)
for (index, inp) in enumerate(tx.inputs):
utxo = UTXO(inp.prevTxHash, inp.outputIndex)
if not pool.contains(utxo):
return False
output = pool.getTxOutput(utxo)
pubKey = output.address
message = tx.getRawDataToSign(index)
if not Crypto.verifySignature(pubKey, message, inp.signature):
return False
inputSum += output.value
pool.removeUTXO(utxo)
outputSum = decimal.Decimal()
for out in tx.outputs:
if out.value < 0:
return False
outputSum += out.value
return inputSum >= outputSum
def testTransaction(self):
tx = Transaction()
tx.addInput(b'genesis', 0)
assert tx.numInputs() == 1
opGenesis = Transaction.Output(5, genesisPublicKey)
tx.addOutput(opGenesis.value, opGenesis.address)
tx.addOutput(5, alicePublicKey)
tx.addOutput(10, bobPublicKey)
assert tx.numOutputs() == 3
tx.removeInput(0)
assert tx.numInputs() == 0
tx.addInput(b'genesis', 0)
signature0 = sign(genesisPrivateKey, tx, 0)
tx.addSignature(signature0, 0)
tx.finalize()
print(tx.hash)
print(hash(tx.getInput(0)))
print(tx.getInput(0).to_dict())
print(hash(tx.getOutput(0)))
print(tx.getOutput(0).to_dict())
print(verify(genesisPublicKey, binascii.hexlify(signature0).decode('ascii'), tx.getRawDataToSign(0)))