Witness generation

packages/testing/src/execution_testing/cli/pytest_commands/plugins/filler/filler.py

@@ -1306,7 +1306,6 @@ def base_test_parametrizer_func(
         fixture_source_url: str,
         gas_benchmark_value: int,
         fixed_opcode_count: int | None,
-        witness_generator: Any,
     ) -> Any:
         """
         Fixture used to instantiate an auto-fillable BaseTest object from
@@ -1430,11 +1429,6 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
                     _info_metadata=t8n._info_metadata,
                 )
 
-                # Generate witness data if witness functionality is enabled via
-                # the witness plugin
-                if witness_generator is not None:
-                    witness_generator(fixture)
-
                 fixture_path = fixture_collector.add_fixture(
                     node_to_test_info(request.node),
                     fixture,

packages/testing/src/execution_testing/cli/pytest_commands/pytest_ini_files/pytest-fill.ini

@@ -10,7 +10,6 @@ addopts =
     -p execution_testing.cli.pytest_commands.plugins.forks.forks
     -p execution_testing.cli.pytest_commands.plugins.concurrency
     -p execution_testing.cli.pytest_commands.plugins.filler.pre_alloc
-    -p execution_testing.cli.pytest_commands.plugins.filler.witness
     -p execution_testing.cli.pytest_commands.plugins.filler.ported_tests
     -p execution_testing.cli.pytest_commands.plugins.filler.static_filler
     -p execution_testing.cli.pytest_commands.plugins.shared.benchmarking

packages/testing/src/execution_testing/client_clis/cli_types.py

@@ -25,6 +25,7 @@
     TransactionException,
     UndefinedException,
 )
+from execution_testing.fixtures.blockchain import ExecutionWitness
 from execution_testing.logging import (
     get_logger,
 )
@@ -289,6 +290,7 @@ class Result(CamelModel):
     ] = None
     traces: Traces | None = None
     opcode_count: OpcodeCount | None = None
+    execution_witness: ExecutionWitness | None = None
 
 
 TRaw = TypeVar("TRaw")

packages/testing/src/execution_testing/fixtures/blockchain.py

@@ -448,6 +448,14 @@ def from_fixture_header(
 ]
 
 
+class ExecutionWitness(CamelModel):
+    """Execution witness containing RLP-encoded trie nodes and bytecodes accessed during block execution."""
+
+    nodes: List[str]
+    bytecodes: List[str] = []
+    ancestors: List[str] = []
+
+
 class FixtureEngineNewPayload(CamelModel):
     """
     Representation of the `engine_newPayloadVX` information to be sent using
@@ -468,6 +476,7 @@ class FixtureEngineNewPayload(CamelModel):
         ]
         | None
     ) = None
+    execution_witness: ExecutionWitness | None = None
 
     def valid(self) -> bool:
         """Return whether the payload is valid."""
@@ -581,24 +590,6 @@ def from_withdrawal(cls, w: WithdrawalGeneric) -> Self:
         return cls(**w.model_dump())
 
 
-class WitnessChunk(CamelModel):
-    """Represents execution witness data for a block."""
-
-    state: List[str]
-    codes: List[str]
-    keys: List[str]
-    headers: List[str]
-
-    @classmethod
-    def parse_witness_chunks(cls, s: str) -> List[Self]:
-        """
-        Parse multiple witness chunks from JSON string.
-
-        Returns a list of WitnessChunk instances parsed from the JSON array.
-        """
-        return [cls(**obj) for obj in json.loads(s)]
-
-
 class FixtureBlockBase(CamelModel):
     """
     Representation of an Ethereum block within a test Fixture without RLP
@@ -625,7 +616,7 @@ def strip_block_number_computed_field(cls, data: Any) -> Any:
         default_factory=list, alias="uncleHeaders"
     )
     withdrawals: List[FixtureWithdrawal] | None = None
-    execution_witness: WitnessChunk | None = None
+    execution_witness: ExecutionWitness | None = None
     fork: Fork | None = Field(None, exclude=True)
 
     @computed_field(alias="blocknumber")  # type: ignore[prop-decorator]

packages/testing/src/execution_testing/specs/blockchain.py

@@ -96,6 +96,7 @@ def environment_from_parent_header(parent: "FixtureHeader") -> "Environment":
         parent_gas_limit=parent.gas_limit,
         parent_ommers_hash=parent.ommers_hash,
         block_hashes={parent.number: parent.block_hash},
+        block_headers={parent.number: parent.rlp},
     )
 
 
@@ -115,6 +116,9 @@ def apply_new_parent(
     block_hashes = env.block_hashes.copy()
     block_hashes[new_parent.number] = new_parent.block_hash
     updated["block_hashes"] = block_hashes
+    block_headers = env.block_headers.copy()
+    block_headers[new_parent.number] = new_parent.rlp
+    updated["block_headers"] = block_headers
     return env.copy(**updated)
 
 
@@ -380,6 +384,7 @@ def get_fixture_block(self) -> FixtureBlock | InvalidFixtureBlock:
                 if self.withdrawals is not None
                 else None
             ),
+            execution_witness=self.result.execution_witness,
             fork=self.fork,
         ).with_rlp(txs=self.txs)
 
@@ -414,6 +419,7 @@ def get_fixture_engine_new_payload(self) -> FixtureEngineNewPayload:
             else None,
             validation_error=self.expected_exception,
             error_code=self.engine_api_error_code,
+            execution_witness=self.result.execution_witness,
         )
 
     def verify_transactions(

packages/testing/src/execution_testing/test_types/block_types.py

@@ -137,6 +137,9 @@ def strip_computed_fields(cls, data: Any) -> Any:
     parent_beacon_block_root: Hash | None = Field(None)
 
     block_hashes: Dict[ZeroPaddedHexNumber, Hash] = Field(default_factory=dict)
+    block_headers: Dict[ZeroPaddedHexNumber, Bytes] = Field(
+        default_factory=dict
+    )
     ommers: List[Hash] = Field(default_factory=list)
     withdrawals: List[Withdrawal] | None = Field(None)
     extra_data: Bytes = Field(Bytes(b"\x00"), exclude=True)

src/ethereum/forks/osaka/fork.py

@@ -58,7 +58,10 @@
     increment_nonce,
     modify_state,
     set_account_balance,
+    set_witness_metadata,
     state_root,
+    track_block_hash_access,
+    track_bytecode_access,
 )
 from .transactions import (
     AccessListTransaction,
@@ -191,6 +194,36 @@ def get_last_256_block_hashes(chain: BlockChain) -> List[Hash32]:
     return recent_block_hashes
 
 
+def get_last_256_block_headers(chain: BlockChain) -> List[Bytes]:
+    """
+    Obtain the list of RLP-encoded headers of the previous 256 blocks.
+
+    This function will return less headers for the first 256 blocks.
+    The headers are parallel to the hashes from get_last_256_block_hashes.
+
+    Parameters
+    ----------
+    chain :
+        History and current state.
+
+    Returns
+    -------
+    recent_block_headers : `List[Bytes]`
+        RLP-encoded headers of recent 256 blocks in order of increasing number.
+
+    """
+    recent_blocks = chain.blocks[-256:]
+    if len(recent_blocks) == 0:
+        return []
+
+    recent_block_headers: List[Bytes] = []
+    for block in recent_blocks:
+        header_rlp = rlp.encode(block.header)
+        recent_block_headers.append(header_rlp)
+
+    return recent_block_headers
+
+
 def state_transition(chain: BlockChain, block: Block) -> None:
     """
     Attempts to apply a block to an existing block chain.
@@ -235,6 +268,13 @@ def state_transition(chain: BlockChain, block: Block) -> None:
         parent_beacon_block_root=block.header.parent_beacon_block_root,
     )
 
+    # Set witness metadata if tracking is enabled
+    set_witness_metadata(
+        block_env.state,
+        block.header.number,
+        get_last_256_block_headers(chain),
+    )
+
     block_output = apply_body(
         block_env=block_env,
         transactions=block.transactions,
@@ -676,6 +716,7 @@ def process_checked_system_transaction(
 
     """
     system_contract_code = get_account(block_env.state, target_address).code
+    track_bytecode_access(block_env.state, system_contract_code)
 
     if len(system_contract_code) == 0:
         raise InvalidBlock(
@@ -724,6 +765,7 @@ def process_unchecked_system_transaction(
 
     """
     system_contract_code = get_account(block_env.state, target_address).code
+    track_bytecode_access(block_env.state, system_contract_code)
     return process_system_transaction(
         block_env,
         target_address,
@@ -770,6 +812,9 @@ def apply_body(
         data=block_env.parent_beacon_block_root,
     )
 
+    # Track parent block access for witness (EIP-2935 system call)
+    track_block_hash_access(block_env.state, block_env.number - Uint(1))
+
     process_unchecked_system_transaction(
         block_env=block_env,
         target_address=HISTORY_STORAGE_ADDRESS,