From 857c3fa4d733535f32e9f17250d5790dd7ab5a76 Mon Sep 17 00:00:00 2001
From: Peter Miller <ultratwo@gmail.com>
Date: Mon, 2 Dec 2024 12:38:49 +0000
Subject: [PATCH] Make EXTCODE* operations not follow delegations

---
 src/ethereum/prague/vm/eoa_delegation.py      | 27 +++++++++++++++++++
 .../prague/vm/instructions/environment.py     | 11 +++-----
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/ethereum/prague/vm/eoa_delegation.py b/src/ethereum/prague/vm/eoa_delegation.py
index ce13b891ab..d7aaac8da4 100644
--- a/src/ethereum/prague/vm/eoa_delegation.py
+++ b/src/ethereum/prague/vm/eoa_delegation.py
@@ -12,6 +12,7 @@
 from ethereum.crypto.hash import keccak256
 from ethereum.exceptions import InvalidBlock
 
+from ...utils.hexadecimal import hex_to_bytes
 from ..fork_types import Address, Authorization
 from ..state import account_exists, get_account, increment_nonce, set_code
 from ..utils.hexadecimal import hex_to_address
@@ -144,6 +145,32 @@ def access_delegation(
     return True, address, code, access_gas_cost
 
 
+def access_delegation_read(
+    evm: Evm,
+    address: Address,
+) -> Bytes:
+    """
+    Get the code from an address, as read by the EXTCODE* opcodes
+
+    Parameters
+    ----------
+    evm : `Evm`
+        The execution frame.
+    address : `Address`
+        The address to get the delegation from.
+
+    Returns
+    -------
+    code : Bytes
+    """
+    code = get_account(evm.env.state, address).code
+
+    if is_valid_delegation(code):
+        return hex_to_bytes("0xef01")
+    else:
+        return code
+
+
 def set_delegation(message: Message, env: Environment) -> U256:
     """
     Set the delegation code for the authorities in the message.
diff --git a/src/ethereum/prague/vm/instructions/environment.py b/src/ethereum/prague/vm/instructions/environment.py
index 17c21d509f..489ae82924 100644
--- a/src/ethereum/prague/vm/instructions/environment.py
+++ b/src/ethereum/prague/vm/instructions/environment.py
@@ -19,7 +19,7 @@
 from ...fork_types import EMPTY_ACCOUNT
 from ...state import get_account
 from ...utils.address import to_address
-from ...vm.eoa_delegation import access_delegation
+from ...vm.eoa_delegation import access_delegation_read
 from ...vm.memory import buffer_read, memory_write
 from .. import Evm
 from ..exceptions import OutOfBoundsRead
@@ -347,8 +347,7 @@ def extcodesize(evm: Evm) -> None:
         evm.accessed_addresses.add(address)
         access_gas_cost = GAS_COLD_ACCOUNT_ACCESS
 
-    _, address, code, designation_access_cost = access_delegation(evm, address)
-    access_gas_cost += designation_access_cost
+    code = access_delegation_read(evm, address)
     charge_gas(evm, access_gas_cost)
 
     # OPERATION
@@ -388,8 +387,7 @@ def extcodecopy(evm: Evm) -> None:
         evm.accessed_addresses.add(address)
         access_gas_cost = GAS_COLD_ACCOUNT_ACCESS
 
-    _, address, code, designation_access_cost = access_delegation(evm, address)
-    access_gas_cost += designation_access_cost
+    code = access_delegation_read(evm, address)
 
     charge_gas(evm, access_gas_cost + copy_gas_cost + extend_memory.cost)
 
@@ -476,8 +474,7 @@ def extcodehash(evm: Evm) -> None:
         evm.accessed_addresses.add(address)
         access_gas_cost = GAS_COLD_ACCOUNT_ACCESS
 
-    _, address, code, designation_access_cost = access_delegation(evm, address)
-    access_gas_cost += designation_access_cost
+    code = access_delegation_read(evm, address)
 
     charge_gas(evm, access_gas_cost)