def check_authorities_and_deposit(
self, token_dict: Dict[bytes, TokenInfo]) -> None:
"""Verify that the sum of outputs is equal of the sum of inputs, for each token. If sum of inputs
and outputs is not 0, make sure inputs have mint/melt authority.
token_dict sums up all tokens present in the tx and their properties (amount, can_mint, can_melt)
amount = outputs - inputs, thus:
- amount < 0 when melting
- amount > 0 when minting
:raises InputOutputMismatch: if sum of inputs is not equal to outputs and there's no mint/melt
"""
withdraw = 0
deposit = 0
for token_uid, token_info in token_dict.items():
if token_uid == settings.HATHOR_TOKEN_UID:
continue
if token_info.amount == 0:
# that's the usual behavior, nothing to do
pass
elif token_info.amount < 0:
# tokens have been melted
if not token_info.can_melt:
raise InputOutputMismatch(
'{} {} tokens melted, but there is no melt authority input'
.format(token_info.amount, token_uid.hex()))
withdraw += get_withdraw_amount(token_info.amount)
else:
# tokens have been minted
if not token_info.can_mint:
raise InputOutputMismatch(
'{} {} tokens minted, but there is no mint authority input'
.format((-1) * token_info.amount, token_uid.hex()))
deposit += get_deposit_amount(token_info.amount)
# check whether the deposit/withdraw amount is correct
htr_expected_amount = withdraw - deposit
htr_info = token_dict[settings.HATHOR_TOKEN_UID]
if htr_info.amount != htr_expected_amount:
raise InputOutputMismatch(
'HTR balance is different than expected. (amount={}, expected={})'
.format(
htr_info.amount,
htr_expected_amount,
))
def test_token_melt(self):
wallet = self.manager.wallet
tx = create_tokens(self.manager, self.address_b58)
token_uid = tx.tokens[0]
parents = self.manager.get_new_tx_parents()
script = P2PKH.create_output_script(self.address)
# melt tokens and transfer melt authority
melt_amount = 100
new_amount = tx.outputs[0].value - melt_amount
withdraw_amount = get_withdraw_amount(melt_amount)
_input1 = TxInput(tx.hash, 0, b'')
_input2 = TxInput(tx.hash, 2, b'')
token_output1 = TxOutput(new_amount, script, 1)
token_output2 = TxOutput(TxOutput.TOKEN_MELT_MASK, script, 0b10000001)
withdraw_output = TxOutput(withdraw_amount, script, 0)
tx2 = Transaction(
weight=1,
inputs=[_input1, _input2],
outputs=[token_output1, token_output2, withdraw_output],
parents=parents,
tokens=[token_uid],
storage=self.manager.tx_storage,
timestamp=int(self.clock.seconds()))
data_to_sign = tx2.get_sighash_all()
public_bytes, signature = wallet.get_input_aux_data(
data_to_sign, wallet.get_private_key(self.address_b58))
data = P2PKH.create_input_data(public_bytes, signature)
tx2.inputs[0].data = data
tx2.inputs[1].data = data
tx2.resolve()
tx2.verify()
self.manager.propagate_tx(tx2)
self.run_to_completion()
# check tokens index
tokens_index = self.manager.tx_storage.indexes.tokens.get_token_info(
token_uid)
mint = list(tokens_index.iter_mint_utxos())
melt = list(tokens_index.iter_melt_utxos())
self.assertIn(TokenUtxoInfo(tx.hash, 1), mint)
self.assertIn(TokenUtxoInfo(tx2.hash, 1), melt)
# there should only be one element on the indexes for the token
self.assertEqual(1, len(mint))
self.assertEqual(1, len(melt))
# check total amount of tokens
self.assertEqual(new_amount, tokens_index.get_total())
# melt tokens and withdraw more than what's allowed
melt_amount = 100
withdraw_amount = get_withdraw_amount(melt_amount)
_input1 = TxInput(tx.hash, 0, b'')
_input2 = TxInput(tx.hash, 2, b'')
token_output1 = TxOutput(tx.outputs[0].value - melt_amount, script, 1)
token_output2 = TxOutput(TxOutput.TOKEN_MELT_MASK, script, 0b10000001)
withdraw_output = TxOutput(withdraw_amount + 1, script, 0)
tx3 = Transaction(
weight=1,
inputs=[_input1, _input2],
outputs=[token_output1, token_output2, withdraw_output],
parents=parents,
tokens=[token_uid],
storage=self.manager.tx_storage,
timestamp=int(self.clock.seconds()))
data_to_sign = tx3.get_sighash_all()
public_bytes, signature = wallet.get_input_aux_data(
data_to_sign, wallet.get_private_key(self.address_b58))
data = P2PKH.create_input_data(public_bytes, signature)
tx3.inputs[0].data = data
tx3.inputs[1].data = data
tx3.resolve()
with self.assertRaises(InputOutputMismatch):
tx3.verify()
# try to melt using mint authority UTXO
_input1 = TxInput(tx.hash, 0, b'')
_input2 = TxInput(tx.hash, 1, b'')
token_output = TxOutput(tx.outputs[0].value - 1, script, 1)
tx4 = Transaction(weight=1,
inputs=[_input1, _input2],
outputs=[token_output],
parents=parents,
tokens=[token_uid],
storage=self.manager.tx_storage,
timestamp=int(self.clock.seconds()))
data_to_sign = tx4.get_sighash_all()
public_bytes, signature = wallet.get_input_aux_data(
data_to_sign, wallet.get_private_key(self.address_b58))
data = P2PKH.create_input_data(public_bytes, signature)
tx4.inputs[0].data = data
tx4.inputs[1].data = data
tx4.resolve()
with self.assertRaises(InputOutputMismatch):
tx4.verify()