test_bal_cross_block_ripemd160_state_leak()

Documentation for tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_cross_block_ripemd160_state_leak@892e6d1e.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_cross_block_ripemd160_state_leak --fork Amsterdam

Ensure internal EVM state for RIMPEMD-160 precompile handling does not leak between blocks.

The EVM may track internal state related to the Parity Touch Bug (EIP-161) when calling RIPEMD-160 (0x03) with zero value. If this state is not properly reset between blocks, it can cause incorrect BAL entries in subsequent blocks.

Prerequisites for triggering the bug: 1. RIPEMD-160 (0x03) must already exist in state before the call. 2. Block 1 must call RIPEMD-160 with zero value and complete successfully. 3. Block 2 must have a TX that triggers an exception (not REVERT).

Expected behavior: - Block 1: RIPEMD-160 in BAL (legitimate access) - Block 2: RIPEMD-160 NOT in BAL (never touched in this block)

Bug behavior: - Block 2 incorrectly has RIPEMD-160 in its BAL due to leaked internal state.

Source code in tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py

def test_bal_cross_block_ripemd160_state_leak(
    pre: Alloc,
    blockchain_test: BlockchainTestFiller,
) -> None:
    """
    Ensure internal EVM state for RIMPEMD-160 precompile handling does not
    leak between blocks.

    The EVM may track internal state related to the Parity Touch Bug (EIP-161)
    when calling RIPEMD-160 (0x03) with zero value. If this state is not
    properly reset between blocks, it can cause incorrect BAL entries in
    subsequent blocks.

    Prerequisites for triggering the bug:
    1. RIPEMD-160 (0x03) must already exist in state before the call.
    2. Block 1 must call RIPEMD-160 with zero value and complete successfully.
    3. Block 2 must have a TX that triggers an exception (not REVERT).

    Expected behavior:
    - Block 1: RIPEMD-160 in BAL (legitimate access)
    - Block 2: RIPEMD-160 NOT in BAL (never touched in this block)

    Bug behavior:
    - Block 2 incorrectly has RIPEMD-160 in its BAL due to leaked
      internal state.
    """
    alice = pre.fund_eoa()
    bob = pre.fund_eoa()
    # Pre-fund RIPEMD-160 so it exists before the call.
    # This is required to trigger the internal state tracking.
    ripemd160_addr = Address(0x03)
    pre.fund_address(ripemd160_addr, amount=1)

    # Contract that calls RIPEMD-160 with zero value
    ripemd_caller = pre.deploy_contract(
        code=Op.CALL(50_000, ripemd160_addr, 0, 0, 0, 0, 0) + Op.STOP
    )
    # Contract that triggers an exception
    # (stack underflow from ADD on empty stack)
    exception_contract = pre.deploy_contract(code=Op.ADD)

    # Block 1: Call RIPEMD-160 successfully
    block1 = Block(
        txs=[
            Transaction(
                sender=alice,
                to=ripemd_caller,
                gas_limit=100_000,
            )
        ],
        expected_block_access_list=BlockAccessListExpectation(
            account_expectations={
                alice: BalAccountExpectation(
                    nonce_changes=[
                        BalNonceChange(block_access_index=1, post_nonce=1)
                    ]
                ),
                bob: None,
                ripemd_caller: BalAccountExpectation.empty(),
                ripemd160_addr: BalAccountExpectation.empty(),
            }
        ),
    )

    # Block 2: Exception triggers internal exception handling.
    # If internal state leaked from Block 1, RIPEMD-160 would incorrectly
    # appear in Block 2's BAL.
    block2 = Block(
        txs=[
            Transaction(
                sender=bob,
                to=exception_contract,
                gas_limit=100_000,
            )
        ],
        expected_block_access_list=BlockAccessListExpectation(
            account_expectations={
                alice: None,
                bob: BalAccountExpectation(
                    nonce_changes=[
                        BalNonceChange(block_access_index=1, post_nonce=1)
                    ]
                ),
                # this is the important check
                ripemd160_addr: None,
            }
        ),
    )

    blockchain_test(
        pre=pre,
        blocks=[block1, block2],
        post={
            alice: Account(nonce=1),
            bob: Account(nonce=1),
            ripemd160_addr: Account(balance=1),
        },
    )

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.