pull/1168/head
Andrew Kozlik
4 years ago
committed by
Andrew Kozlik
parent
00258f2d4d
commit
d6ee542deb
@ -0,0 +1,98 @@
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from micropython import const
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from trezor import wire
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from trezor.messages.SignTx import SignTx
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from trezor.messages.TxInputType import TxInputType
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from trezor.messages.TxOutputType import TxOutputType
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from apps.common import coininfo
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from .. import addresses
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from . import helpers, tx_weight
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# An Approver object computes the transaction totals and either prompts the user
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# to confirm transaction parameters (output addresses, amounts and fees) or uses
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# an Authorization object to verify that the user authorized a transaction with
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# these parameters to be executed.
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class Approver:
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def __init__(self, tx: SignTx, coin: coininfo.CoinInfo) -> None:
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self.tx = tx
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self.coin = coin
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self.weight = tx_weight.TxWeightCalculator(tx.inputs_count, tx.outputs_count)
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# amounts
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self.total_in = 0 # sum of input amounts
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self.external_in = 0 # sum of external input amounts
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self.total_out = 0 # sum of output amounts
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self.change_out = 0 # change output amount
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async def add_internal_input(self, txi: TxInputType, amount: int) -> None:
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self.weight.add_input(txi)
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self.total_in += amount
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def add_external_input(self, txi: TxInputType) -> None:
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self.weight.add_input(txi)
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self.total_in += txi.amount
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self.external_in += txi.amount
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def add_change_output(self, txo: TxOutputType, script_pubkey: bytes) -> None:
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self.weight.add_output(script_pubkey)
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self.total_out += txo.amount
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self.change_out += txo.amount
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async def add_external_output(
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self, txo: TxOutputType, script_pubkey: bytes
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) -> None:
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self.weight.add_output(script_pubkey)
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self.total_out += txo.amount
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async def approve_tx(self) -> None:
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raise NotImplementedError
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class BasicApprover(Approver):
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# the maximum number of change-outputs allowed without user confirmation
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MAX_SILENT_CHANGE_COUNT = const(2)
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def __init__(self, tx: SignTx, coin: coininfo.CoinInfo) -> None:
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super().__init__(tx, coin)
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self.change_count = 0 # the number of change-outputs
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async def add_internal_input(self, txi: TxInputType, amount: int) -> None:
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if not addresses.validate_full_path(txi.address_n, self.coin, txi.script_type):
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await helpers.confirm_foreign_address(txi.address_n)
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await super().add_internal_input(txi, amount)
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def add_change_output(self, txo: TxOutputType, script_pubkey: bytes) -> None:
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super().add_change_output(txo, script_pubkey)
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self.change_count += 1
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async def add_external_output(
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self, txo: TxOutputType, script_pubkey: bytes
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) -> None:
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await super().add_external_output(txo, script_pubkey)
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await helpers.confirm_output(txo, self.coin)
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async def approve_tx(self) -> None:
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fee = self.total_in - self.total_out
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# some coins require negative fees for reward TX
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if fee < 0 and not self.coin.negative_fee:
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raise wire.NotEnoughFunds("Not enough funds")
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total = self.total_in - self.change_out
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spending = total - self.external_in
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# fee > (coin.maxfee per byte * tx size)
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if fee > (self.coin.maxfee_kb / 1000) * (self.weight.get_total() / 4):
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await helpers.confirm_feeoverthreshold(fee, self.coin)
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if self.change_count > self.MAX_SILENT_CHANGE_COUNT:
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await helpers.confirm_change_count_over_threshold(self.change_count)
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if self.tx.lock_time > 0:
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await helpers.confirm_nondefault_locktime(self.tx.lock_time)
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if not self.external_in:
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await helpers.confirm_total(total, fee, self.coin)
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else:
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await helpers.confirm_joint_total(spending, total, self.coin)
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