refactor(verification): finish moving all verification methods [part 5/5]

hathor/simulator/simulator.py

@@ -28,7 +28,14 @@
 from hathor.simulator.clock import HeapClock, MemoryReactorHeapClock
 from hathor.simulator.miner.geometric_miner import GeometricMiner
 from hathor.simulator.tx_generator import RandomTransactionGenerator
+from hathor.simulator.verification import (
+    SimulatorBlockVerifier,
+    SimulatorMergeMinedBlockVerifier,
+    SimulatorTokenCreationTransactionVerifier,
+    SimulatorTransactionVerifier,
+)
 from hathor.util import Random
+from hathor.verification.verification_service import VertexVerifiers
 from hathor.wallet import HDWallet
 
 if TYPE_CHECKING:
@@ -52,25 +59,17 @@ def _apply_patches(cls):
 
         Patches:
 
-        - disable pow verification
         - disable Transaction.resolve method
         - set DAA test-mode to DISABLED (will actually run the pow function, that won't actually verify the pow)
         - override AVG_TIME_BETWEEN_BLOCKS to 64
         """
         from hathor.transaction import BaseTransaction
 
-        def verify_pow(self: BaseTransaction, *args: Any, **kwargs: Any) -> None:
-            assert self.hash is not None
-            logger.new().debug('Skipping BaseTransaction.verify_pow() for simulator')
-
         def resolve(self: BaseTransaction, update_time: bool = True) -> bool:
             self.update_hash()
             logger.new().debug('Skipping BaseTransaction.resolve() for simulator')
             return True
 
-        cls._original_verify_pow = BaseTransaction.verify_pow
-        BaseTransaction.verify_pow = verify_pow
-
         cls._original_resolve = BaseTransaction.resolve
         BaseTransaction.resolve = resolve
 
@@ -85,7 +84,6 @@ def _remove_patches(cls):
         """ Remove the patches previously applied.
         """
         from hathor.transaction import BaseTransaction
-        BaseTransaction.verify_pow = cls._original_verify_pow
         BaseTransaction.resolve = cls._original_resolve
 
         from hathor import daa
@@ -170,10 +168,18 @@ def create_artifacts(self, builder: Optional[Builder] = None) -> BuildArtifacts:
         wallet = HDWallet(gap_limit=2)
         wallet._manually_initialize()
 
+        vertex_verifiers = VertexVerifiers(
+            block=SimulatorBlockVerifier(settings=self.settings),
+            merge_mined_block=SimulatorMergeMinedBlockVerifier(settings=self.settings),
+            tx=SimulatorTransactionVerifier(settings=self.settings),
+            token_creation_tx=SimulatorTokenCreationTransactionVerifier(settings=self.settings),
+        )
+
         artifacts = builder \
             .set_reactor(self._clock) \
             .set_rng(Random(self.rng.getrandbits(64))) \
             .set_wallet(wallet) \
+            .set_vertex_verifiers(vertex_verifiers) \
             .build()
 
         artifacts.manager.start()

hathor/simulator/verification.py

@@ -0,0 +1,54 @@
+#  Copyright 2023 Hathor Labs
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+from typing import Optional
+
+from structlog import get_logger
+
+from hathor.transaction import BaseTransaction
+from hathor.verification.block_verifier import BlockVerifier
+from hathor.verification.merge_mined_block_verifier import MergeMinedBlockVerifier
+from hathor.verification.token_creation_transaction_verifier import TokenCreationTransactionVerifier
+from hathor.verification.transaction_verifier import TransactionVerifier
+
+logger = get_logger()
+
+
+def verify_pow(vertex: BaseTransaction) -> None:
+    assert vertex.hash is not None
+    logger.new().debug('Skipping BaseTransaction.verify_pow() for simulator')
+
+
+class SimulatorBlockVerifier(BlockVerifier):
+    @classmethod
+    def verify_pow(cls, vertex: BaseTransaction, *, override_weight: Optional[float] = None) -> None:
+        verify_pow(vertex)
+
+
+class SimulatorMergeMinedBlockVerifier(MergeMinedBlockVerifier):
+    @classmethod
+    def verify_pow(cls, vertex: BaseTransaction, *, override_weight: Optional[float] = None) -> None:
+        verify_pow(vertex)
+
+
+class SimulatorTransactionVerifier(TransactionVerifier):
+    @classmethod
+    def verify_pow(cls, vertex: BaseTransaction, *, override_weight: Optional[float] = None) -> None:
+        verify_pow(vertex)
+
+
+class SimulatorTokenCreationTransactionVerifier(TokenCreationTransactionVerifier):
+    @classmethod
+    def verify_pow(cls, vertex: BaseTransaction, *, override_weight: Optional[float] = None) -> None:
+        verify_pow(vertex)

hathor/transaction/base_transaction.py

@@ -28,19 +28,7 @@
 
 from hathor.checkpoint import Checkpoint
 from hathor.conf.get_settings import get_settings
-from hathor.transaction.exceptions import (
-    DuplicatedParents,
-    IncorrectParents,
-    InvalidOutputScriptSize,
-    InvalidOutputValue,
-    InvalidToken,
-    ParentDoesNotExist,
-    PowError,
-    TimestampError,
-    TooManyOutputs,
-    TooManySigOps,
-    WeightError,
-)
+from hathor.transaction.exceptions import InvalidOutputValue, WeightError
 from hathor.transaction.transaction_metadata import TransactionMetadata
 from hathor.transaction.util import VerboseCallback, int_to_bytes, unpack, unpack_len
 from hathor.transaction.validation_state import ValidationState
@@ -70,14 +58,6 @@
 # Weight (d), timestamp (I), and parents len (B)
 _GRAPH_FORMAT_STRING = '!dIB'
 
-# tx should have 2 parents, both other transactions
-_TX_PARENTS_TXS = 2
-_TX_PARENTS_BLOCKS = 0
-
-# blocks have 3 parents, 2 txs and 1 block
-_BLOCK_PARENTS_TXS = 2
-_BLOCK_PARENTS_BLOCKS = 1
-
 # The int value of one byte
 _ONE_BYTE = 0xFF
 
@@ -540,137 +520,6 @@ def verify_checkpoint(self, checkpoints: list[Checkpoint]) -> None:
         To be implemented by tx/block, used by `self.validate_checkpoint`. Should not modify the validation state."""
         raise NotImplementedError
 
-    def verify_parents(self) -> None:
-        """All parents must exist and their timestamps must be smaller than ours.
-
-        Also, txs should have 2 other txs as parents, while blocks should have 2 txs + 1 block.
-
-        Parents must be ordered with blocks first, followed by transactions.
-
-        :raises TimestampError: when our timestamp is less or equal than our parent's timestamp
-        :raises ParentDoesNotExist: when at least one of our parents does not exist
-        :raises IncorrectParents: when tx does not confirm the correct number/type of parent txs
-        """
-        from hathor.transaction.storage.exceptions import TransactionDoesNotExist
-
-        assert self.storage is not None
-
-        # check if parents are duplicated
-        parents_set = set(self.parents)
-        if len(self.parents) > len(parents_set):
-            raise DuplicatedParents('Tx has duplicated parents: {}', [tx_hash.hex() for tx_hash in self.parents])
-
-        my_parents_txs = 0      # number of tx parents
-        my_parents_blocks = 0   # number of block parents
-        min_timestamp: Optional[int] = None
-
-        for parent_hash in self.parents:
-            try:
-                parent = self.storage.get_transaction(parent_hash)
-                assert parent.hash is not None
-                if self.timestamp <= parent.timestamp:
-                    raise TimestampError('tx={} timestamp={}, parent={} timestamp={}'.format(
-                        self.hash_hex,
-                        self.timestamp,
-                        parent.hash_hex,
-                        parent.timestamp,
-                    ))
-
-                if parent.is_block:
-                    if self.is_block and not parent.is_genesis:
-                        if self.timestamp - parent.timestamp > self._settings.MAX_DISTANCE_BETWEEN_BLOCKS:
-                            raise TimestampError('Distance between blocks is too big'
-                                                 ' ({} seconds)'.format(self.timestamp - parent.timestamp))
-                    if my_parents_txs > 0:
-                        raise IncorrectParents('Parents which are blocks must come before transactions')
-                    for pi_hash in parent.parents:
-                        pi = self.storage.get_transaction(parent_hash)
-                        if not pi.is_block:
-                            min_timestamp = (
-                                min(min_timestamp, pi.timestamp) if min_timestamp is not None
-                                else pi.timestamp
-                            )
-                    my_parents_blocks += 1
-                else:
-                    if min_timestamp and parent.timestamp < min_timestamp:
-                        raise TimestampError('tx={} timestamp={}, parent={} timestamp={}, min_timestamp={}'.format(
-                            self.hash_hex,
-                            self.timestamp,
-                            parent.hash_hex,
-                            parent.timestamp,
-                            min_timestamp
-                        ))
-                    my_parents_txs += 1
-            except TransactionDoesNotExist:
-                raise ParentDoesNotExist('tx={} parent={}'.format(self.hash_hex, parent_hash.hex()))
-
-        # check for correct number of parents
-        if self.is_block:
-            parents_txs = _BLOCK_PARENTS_TXS
-            parents_blocks = _BLOCK_PARENTS_BLOCKS
-        else:
-            parents_txs = _TX_PARENTS_TXS
-            parents_blocks = _TX_PARENTS_BLOCKS
-        if my_parents_blocks != parents_blocks:
-            raise IncorrectParents('wrong number of parents (block type): {}, expecting {}'.format(
-                my_parents_blocks, parents_blocks))
-        if my_parents_txs != parents_txs:
-            raise IncorrectParents('wrong number of parents (tx type): {}, expecting {}'.format(
-                my_parents_txs, parents_txs))
-
-    def verify_pow(self, override_weight: Optional[float] = None) -> None:
-        """Verify proof-of-work
-
-        :raises PowError: when the hash is equal or greater than the target
-        """
-        assert self.hash is not None
-        numeric_hash = int(self.hash_hex, self.HEX_BASE)
-        minimum_target = self.get_target(override_weight)
-        if numeric_hash >= minimum_target:
-            raise PowError(f'Transaction has invalid data ({numeric_hash} < {minimum_target})')
-
-    def verify_number_of_outputs(self) -> None:
-        """Verify number of outputs does not exceeds the limit"""
-        if len(self.outputs) > self._settings.MAX_NUM_OUTPUTS:
-            raise TooManyOutputs('Maximum number of outputs exceeded')
-
-    def verify_sigops_output(self) -> None:
-        """ Count sig operations on all outputs and verify that the total sum is below the limit
-        """
-        from hathor.transaction.scripts import get_sigops_count
-        n_txops = 0
-
-        for tx_output in self.outputs:
-            n_txops += get_sigops_count(tx_output.script)
-
-        if n_txops > self._settings.MAX_TX_SIGOPS_OUTPUT:
-            raise TooManySigOps('TX[{}]: Maximum number of sigops for all outputs exceeded ({})'.format(
-                self.hash_hex, n_txops))
-
-    def verify_outputs(self) -> None:
-        """Verify there are no hathor authority UTXOs and outputs are all positive
-
-        :raises InvalidToken: when there's a hathor authority utxo
-        :raises InvalidOutputValue: output has negative value
-        :raises TooManyOutputs: when there are too many outputs
-        """
-        self.verify_number_of_outputs()
-        for index, output in enumerate(self.outputs):
-            # no hathor authority UTXO
-            if (output.get_token_index() == 0) and output.is_token_authority():
-                raise InvalidToken('Cannot have authority UTXO for hathor tokens: {}'.format(
-                    output.to_human_readable()))
-
-            # output value must be positive
-            if output.value <= 0:
-                raise InvalidOutputValue('Output value must be a positive integer. Value: {} and index: {}'.format(
-                    output.value, index))
-
-            if len(output.script) > self._settings.MAX_OUTPUT_SCRIPT_SIZE:
-                raise InvalidOutputScriptSize('size: {} and max-size: {}'.format(
-                    len(output.script), self._settings.MAX_OUTPUT_SCRIPT_SIZE
-                ))
-
     def resolve(self, update_time: bool = False) -> bool:
         """Run a CPU mining looking for the nonce that solves the proof-of-work
 

hathor/transaction/block.py

@@ -23,7 +23,7 @@
 from hathor.feature_activation.model.feature_state import FeatureState
 from hathor.profiler import get_cpu_profiler
 from hathor.transaction import BaseTransaction, TxOutput, TxVersion
-from hathor.transaction.exceptions import BlockWithTokensError, CheckpointError
+from hathor.transaction.exceptions import CheckpointError
 from hathor.transaction.util import VerboseCallback, int_to_bytes, unpack, unpack_len
 from hathor.util import not_none
 from hathor.utils.int import get_bit_list
@@ -328,12 +328,6 @@ def verify_checkpoint(self, checkpoints: list[Checkpoint]) -> None:
             # TODO: check whether self is a parent of any checkpoint-valid block, this is left for a future PR
             pass
 
-    def verify_outputs(self) -> None:
-        super().verify_outputs()
-        for output in self.outputs:
-            if output.get_token_index() > 0:
-                raise BlockWithTokensError('in output: {}'.format(output.to_human_readable()))
-
     def get_base_hash(self) -> bytes:
         from hathor.merged_mining.bitcoin import sha256d_hash
         return sha256d_hash(self.get_header_without_nonce())

hathor/transaction/transaction.py

@@ -22,7 +22,6 @@
 from hathor.profiler import get_cpu_profiler
 from hathor.transaction import BaseTransaction, Block, TxInput, TxOutput, TxVersion
 from hathor.transaction.base_transaction import TX_HASH_SIZE
-from hathor.transaction.exceptions import InvalidToken
 from hathor.transaction.util import VerboseCallback, unpack, unpack_len
 from hathor.types import TokenUid, VertexId
 from hathor.util import not_none
@@ -279,17 +278,6 @@ def verify_checkpoint(self, checkpoints: list[Checkpoint]) -> None:
         raise InvalidNewTransaction(f'Invalid new transaction {self.hash_hex}: expected to reach a checkpoint but '
                                     'none of its children is checkpoint-valid')
 
-    def verify_outputs(self) -> None:
-        """Verify outputs reference an existing token uid in the tokens list
-
-        :raises InvalidToken: output references non existent token uid
-        """
-        super().verify_outputs()
-        for output in self.outputs:
-            # check index is valid
-            if output.get_token_index() > len(self.tokens):
-                raise InvalidToken('token uid index not available: index {}'.format(output.get_token_index()))
-
     def get_token_info_from_inputs(self) -> dict[TokenUid, TokenInfo]:
         """Sum up all tokens present in the inputs and their properties (amount, can_mint, can_melt)
         """

hathor/verification/block_verifier.py

@@ -17,6 +17,7 @@
 from hathor.transaction import BaseTransaction, Block
 from hathor.transaction.exceptions import (
     BlockWithInputs,
+    BlockWithTokensError,
     InvalidBlockReward,
     RewardLocked,
     TransactionDataError,
@@ -97,7 +98,11 @@ def verify_no_inputs(self, block: Block) -> None:
             raise BlockWithInputs('number of inputs {}'.format(len(inputs)))
 
     def verify_outputs(self, block: BaseTransaction) -> None:
-        block.verify_outputs()
+        assert isinstance(block, Block)
+        super().verify_outputs(block)
+        for output in block.outputs:
+            if output.get_token_index() > 0:
+                raise BlockWithTokensError('in output: {}'.format(output.to_human_readable()))
 
     def verify_data(self, block: Block) -> None:
         if len(block.data) > self._settings.BLOCK_DATA_MAX_SIZE:

hathor/verification/transaction_verifier.py

@@ -223,7 +223,12 @@ def verify_outputs(self, tx: BaseTransaction) -> None:
 
         :raises InvalidToken: output references non existent token uid
         """
-        tx.verify_outputs()
+        assert isinstance(tx, Transaction)
+        super().verify_outputs(tx)
+        for output in tx.outputs:
+            # check index is valid
+            if output.get_token_index() > len(tx.tokens):
+                raise InvalidToken('token uid index not available: index {}'.format(output.get_token_index()))
 
     def verify_authorities_and_deposit(self, token_dict: dict[TokenUid, TokenInfo]) -> None:
         """Verify that the sum of outputs is equal of the sum of inputs, for each token. If sum of inputs