review changes

Author: glevco

hathor/transaction/scripts/execute.py

@@ -13,6 +13,7 @@
 #  limitations under the License.
 
 import struct
+from dataclasses import dataclass
 from typing import TYPE_CHECKING, NamedTuple, Optional, Union
 
 from hathor.conf.get_settings import get_global_settings
@@ -23,11 +24,21 @@
     from hathor.transaction.scripts.script_context import ScriptContext
 
 
-class ScriptExtras(NamedTuple):
+@dataclass(slots=True, frozen=True, kw_only=True)
+class ScriptExtras:
+    """
+    A simple container for auxiliary data that may be used during execution of scripts.
+    """
     tx: Transaction
-    txin: TxInput
-    spent_tx: BaseTransaction
     input_index: int
+    spent_tx: BaseTransaction
+
+    @property
+    def txin(self) -> TxInput:
+        return self.tx.inputs[self.input_index]
+
+    def __post_init__(self) -> None:
+        assert self.txin.tx_id == self.spent_tx.hash
 
 
 # XXX: Because the Stack is a heterogeneous list of bytes and int, and some OPs only work for when the stack has some
@@ -96,7 +107,7 @@ def evaluate_final_stack(stack: Stack, log: list[str]) -> None:
         raise FinalStackInvalid('\n'.join(log))
 
 
-def script_eval(tx: Transaction, txin: TxInput, spent_tx: BaseTransaction, *, input_index: int) -> 'ScriptContext':
+def script_eval(tx: Transaction, spent_tx: BaseTransaction, *, input_index: int) -> 'ScriptContext':
     """Evaluates the output script and input data according to
     a very limited subset of Bitcoin's scripting language.
 
@@ -111,10 +122,10 @@ def script_eval(tx: Transaction, txin: TxInput, spent_tx: BaseTransaction, *, in
 
     :raises ScriptError: if script verification fails
     """
-    input_data = txin.data
-    output_script = spent_tx.outputs[txin.index].script
+    extras = ScriptExtras(tx=tx, input_index=input_index, spent_tx=spent_tx)
+    input_data = extras.txin.data
+    output_script = spent_tx.outputs[extras.txin.index].script
     log: list[str] = []
-    extras = ScriptExtras(tx=tx, txin=txin, spent_tx=spent_tx, input_index=input_index)
 
     from hathor.transaction.scripts import MultiSig
     if MultiSig.re_match.search(output_script):
@@ -123,7 +134,7 @@ def script_eval(tx: Transaction, txin: TxInput, spent_tx: BaseTransaction, *, in
         # we can't use input_data + output_script because it will end with an invalid stack
         # i.e. the signatures will still be on the stack after ouput_script is executed
         redeem_script_pos = MultiSig.get_multisig_redeem_script_pos(input_data)
-        full_data = txin.data[redeem_script_pos:] + output_script
+        full_data = extras.txin.data[redeem_script_pos:] + output_script
         execute_eval(full_data, log, extras)
 
         # Second, we need to validate that the signatures on the input_data solves the redeem_script

hathor/transaction/scripts/opcode.py

@@ -16,6 +16,7 @@
 import struct
 from enum import IntEnum
 
+import pydantic
 from cryptography.exceptions import InvalidSignature
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.asymmetric import ec
@@ -643,7 +644,7 @@ def op_sighash_bitmask(context: ScriptContext) -> None:
             inputs=bytes_to_int(inputs),
             outputs=bytes_to_int(outputs)
         )
-    except Exception as e:
+    except pydantic.ValidationError as e:
         raise CustomSighashModelInvalid('Could not construct sighash bitmask.') from e
 
     if context.extras.input_index not in sighash.get_input_indexes():
@@ -669,7 +670,7 @@ def op_max_inputs_outputs(context: ScriptContext) -> None:
             max_inputs=bytes_to_int(max_inputs),
             max_outputs=bytes_to_int(max_outputs)
         )
-    except Exception as e:
+    except pydantic.ValidationError as e:
         raise InputsOutputsLimitModelInvalid("Could not construct inputs and outputs limits.") from e
 
     tx_inputs_len = len(context.extras.tx.inputs)

hathor/transaction/token_creation_tx.py

@@ -133,8 +133,8 @@ def get_sighash_all(self) -> bytes:
         :return: Serialization of the inputs, outputs and tokens
         :rtype: bytes
         """
-        if self._sighash_cache:
-            return self._sighash_cache
+        if self._sighash_all_cache:
+            return self._sighash_all_cache
 
         struct_bytes = pack(
             _SIGHASH_ALL_FORMAT_STRING,
@@ -155,7 +155,7 @@ def get_sighash_all(self) -> bytes:
         struct_bytes += b''.join(tx_outputs)
 
         struct_bytes += self.serialize_token_info()
-        self._sighash_cache = struct_bytes
+        self._sighash_all_cache = struct_bytes
 
         return struct_bytes
 

hathor/transaction/transaction.py

@@ -75,7 +75,7 @@ def __init__(self,
         super().__init__(nonce=nonce, timestamp=timestamp, signal_bits=signal_bits, version=version, weight=weight,
                          inputs=inputs or [], outputs=outputs or [], parents=parents or [], hash=hash, storage=storage)
         self.tokens = tokens or []
-        self._sighash_cache: Optional[bytes] = None
+        self._sighash_all_cache: Optional[bytes] = None
         self._sighash_data_cache: Optional[bytes] = None
 
     @property
@@ -215,11 +215,11 @@ def get_sighash_all(self) -> bytes:
         # This method does not depend on the input itself, however we call it for each one to sign it.
         # For transactions that have many inputs there is a significant decrease on the verify time
         # when using this cache, so we call this method only once.
-        if self._sighash_cache:
-            return self._sighash_cache
+        if self._sighash_all_cache:
+            return self._sighash_all_cache
 
         sighash = self._get_sighash(inputs=self.inputs, outputs=self.outputs)
-        self._sighash_cache = sighash
+        self._sighash_all_cache = sighash
 
         return sighash
 

hathor/verification/transaction_verifier.py

@@ -156,8 +156,7 @@ def verify_script(
         """
         from hathor.transaction.scripts import script_eval
         try:
-            input_tx = tx.inputs[input_index]
-            return script_eval(tx, input_tx, spent_tx, input_index=input_index)
+            return script_eval(tx, spent_tx, input_index=input_index)
         except ScriptError as e:
             raise InvalidInputData(e) from e
 

tests/tx/test_multisig.py

@@ -134,7 +134,7 @@ def test_spend_multisig(self):
         expected_dict = {'type': 'MultiSig', 'address': self.multisig_address_b58, 'timelock': None}
         self.assertEqual(cls_script.to_human_readable(), expected_dict)
 
-        script_eval(tx, tx_input, tx1, input_index=0)
+        script_eval(tx, tx1, input_index=0)
 
         # Script error
         with self.assertRaises(ScriptError):

tests/tx/test_nano_contracts.py

@@ -36,6 +36,6 @@ def test_match_values(self):
         input_data = NanoContractMatchValues.create_input_data(
             base64.b64decode(oracle_data), base64.b64decode(oracle_signature), base64.b64decode(pubkey))
         txin = TxInput(b'aa', 0, input_data)
-        spent_tx = Transaction(outputs=[TxOutput(20, script)])
-        tx = Transaction(outputs=[TxOutput(20, P2PKH.create_output_script(address))])
-        script_eval(tx, txin, spent_tx, input_index=0)
+        spent_tx = Transaction(hash=b'aa', outputs=[TxOutput(20, script)])
+        tx = Transaction(inputs=[txin], outputs=[TxOutput(20, P2PKH.create_output_script(address))])
+        script_eval(tx, spent_tx, input_index=0)

tests/tx/test_scripts.py

@@ -253,7 +253,7 @@ def test_checksig(self):
         signature = self.genesis_private_key.sign(hashed_data, ec.ECDSA(hashes.SHA256()))
         pubkey_bytes = get_public_key_bytes_compressed(self.genesis_public_key)
 
-        extras = ScriptExtras(tx=tx, txin=Mock(), spent_tx=Mock(), input_index=0)
+        extras = ScriptExtras(tx=tx, spent_tx=block, input_index=0)
 
         # wrong signature puts False (0) on stack
         stack = [b'aaaaaaaaa', pubkey_bytes]
@@ -278,7 +278,7 @@ def test_checksig_cache(self):
         signature = self.genesis_private_key.sign(hashed_data, ec.ECDSA(hashes.SHA256()))
         pubkey_bytes = get_public_key_bytes_compressed(self.genesis_public_key)
 
-        extras = ScriptExtras(tx=tx, txin=Mock(), spent_tx=Mock(), input_index=0)
+        extras = ScriptExtras(tx=tx, spent_tx=block, input_index=0)
 
         stack = [signature, pubkey_bytes]
         self.assertIsNone(tx._sighash_data_cache)
@@ -508,34 +508,40 @@ def test_find_p2pkh(self):
         out_genesis = P2PKH.create_output_script(genesis_address)
 
         from hathor.transaction import Transaction, TxInput, TxOutput
-        spent_tx = Transaction(outputs=[TxOutput(1, b'nano_contract_code')])
-        txin = TxInput(b'dont_care', 0, b'data')
+        spent_tx = Transaction(hash=b'some_hash', outputs=[TxOutput(1, b'nano_contract_code')])
+        txin = TxInput(b'some_hash', 0, b'data')
 
         # try with just 1 output
         stack = [genesis_address]
-        tx = Transaction(outputs=[TxOutput(1, out_genesis)])
-        extras = ScriptExtras(tx=tx, txin=txin, spent_tx=spent_tx, input_index=0)
+        tx = Transaction(inputs=[txin], outputs=[TxOutput(1, out_genesis)])
+        extras = ScriptExtras(tx=tx, spent_tx=spent_tx, input_index=0)
         op_find_p2pkh(ScriptContext(stack=stack, logs=[], extras=extras, settings=Mock()))
         self.assertEqual(stack.pop(), 1)
 
         # several outputs and correct output among them
         stack = [genesis_address]
-        tx = Transaction(outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(1, out_genesis), TxOutput(1, out3)])
-        extras = ScriptExtras(tx=tx, txin=txin, spent_tx=spent_tx, input_index=0)
+        tx = Transaction(
+            inputs=[txin],
+            outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(1, out_genesis), TxOutput(1, out3)]
+        )
+        extras = ScriptExtras(tx=tx, spent_tx=spent_tx, input_index=0)
         op_find_p2pkh(ScriptContext(stack=stack, logs=[], extras=extras, settings=Mock()))
         self.assertEqual(stack.pop(), 1)
 
         # several outputs without correct amount output
         stack = [genesis_address]
-        tx = Transaction(outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(2, out_genesis), TxOutput(1, out3)])
-        extras = ScriptExtras(tx=tx, txin=txin, spent_tx=spent_tx, input_index=0)
+        tx = Transaction(
+            inputs=[txin],
+            outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(2, out_genesis), TxOutput(1, out3)]
+        )
+        extras = ScriptExtras(tx=tx, spent_tx=spent_tx, input_index=0)
         with self.assertRaises(VerifyFailed):
             op_find_p2pkh(ScriptContext(stack=stack, logs=[], extras=extras, settings=Mock()))
 
         # several outputs without correct address output
         stack = [genesis_address]
-        tx = Transaction(outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(1, out3)])
-        extras = ScriptExtras(tx=tx, txin=txin, spent_tx=spent_tx, input_index=0)
+        tx = Transaction(inputs=[txin], outputs=[TxOutput(1, out1), TxOutput(1, out2), TxOutput(1, out3)])
+        extras = ScriptExtras(tx=tx, spent_tx=spent_tx, input_index=0)
         with self.assertRaises(VerifyFailed):
             op_find_p2pkh(ScriptContext(stack=stack, logs=[], extras=extras, settings=Mock()))
 
@@ -545,11 +551,13 @@ def test_greaterthan_timestamp(self):
 
         timestamp = 1234567
 
-        from hathor.transaction import Transaction
-        tx = Transaction()
+        from hathor.transaction import Transaction, TxInput
+        spent_tx = Transaction(hash=b'some_hash')
+        tx_input = TxInput(tx_id=b'some_hash', index=0, data=b'')
+        tx = Transaction(inputs=[tx_input])
 
         stack = [struct.pack('!I', timestamp)]
-        extras = ScriptExtras(tx=tx, txin=Mock(), spent_tx=Mock(), input_index=0)
+        extras = ScriptExtras(tx=tx, spent_tx=spent_tx, input_index=0)
 
         with self.assertRaises(TimeLocked):
             tx.timestamp = timestamp - 1
@@ -575,7 +583,7 @@ def test_checkmultisig(self):
         tx = Transaction(inputs=[txin], outputs=[txout])
 
         data_to_sign = tx.get_sighash_all()
-        extras = ScriptExtras(tx=tx, txin=Mock(), spent_tx=Mock(), input_index=0)
+        extras = ScriptExtras(tx=tx, spent_tx=block, input_index=0)
 
         wallet = HDWallet()
         wallet._manually_initialize()

tests/tx/test_tx.py

@@ -1044,7 +1044,7 @@ def test_wallet_index(self):
         self.assertEqual(len(self.tx_storage.indexes.addresses.get_from_address(output3_address_b58)), 1)
         self.assertEqual(len(self.tx_storage.indexes.addresses.get_from_address(new_address_b58)), 1)
 
-    def test_sighash_cache(self):
+    def test_sighash_all_cache(self):
         from unittest import mock
 
         address = get_address_from_public_key(self.genesis_public_key)