Reject DELEGATECALL EOF → legacy

The code targeted by DELEGATECALL from an EOF must also be an EOF.
This restriction has been added to EIP-3540 in
ethereum/EIPs#6359.

Author: chfast

lib/evmone/instructions_calls.cpp

@@ -2,6 +2,7 @@
 // Copyright 2019 The evmone Authors.
 // SPDX-License-Identifier: Apache-2.0
 
+#include "eof.hpp"
 #include "instructions.hpp"
 
 namespace evmone::instr::core
@@ -95,6 +96,21 @@ Result call_impl(StackTop stack, int64_t gas_left, ExecutionState& state) noexce
     if (has_value && intx::be::load<uint256>(state.host.get_balance(state.msg->recipient)) < value)
         return {EVMC_SUCCESS, gas_left};  // "Light" failure.
 
+    if constexpr (Op == OP_DELEGATECALL)
+    {
+        if (state.rev >= EVMC_CANCUN && is_eof_container(state.original_code))
+        {
+            // The code targeted by DELEGATECALL must also be an EOF.
+            // This restriction has been added to EIP-3540 in
+            // https://github.com/ethereum/EIPs/pull/6359
+            uint8_t target_code_prefix[2];
+            const auto s = state.host.copy_code(
+                msg.code_address, 0, target_code_prefix, std::size(target_code_prefix));
+            if (!is_eof_container({target_code_prefix, s}))
+                return {EVMC_SUCCESS, gas_left};
+        }
+    }
+
     const auto result = state.host.call(msg);
     state.return_data.assign(result.output_data, result.output_size);
     stack.top() = result.status_code == EVMC_SUCCESS;

test/unittests/CMakeLists.txt

@@ -21,6 +21,7 @@ target_sources(
     evm_eip3855_push0_test.cpp
     evm_eip3860_initcode_test.cpp
     evm_eof_test.cpp
+    evm_eof_calls_test.cpp
     evm_eof_function_test.cpp
     evm_eof_rjump_test.cpp
     evm_memory_test.cpp

test/unittests/evm_eof_calls_test.cpp

@@ -0,0 +1,47 @@
+// evmone: Fast Ethereum Virtual Machine implementation
+// Copyright 2023 The evmone Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+#include "evm_fixture.hpp"
+#include "evmone/eof.hpp"
+
+using evmone::test::evm;
+using namespace evmc::literals;
+
+TEST_P(evm, eof1_delegatecall_eof1)
+{
+    rev = EVMC_CANCUN;
+    constexpr auto callee = 0xca11ee_address;
+    host.accounts[callee].code = eof1_bytecode(OP_STOP);
+    bytes call_output{0x01, 0x02, 0x03};
+    host.call_result.output_data = std::data(call_output);
+    host.call_result.output_size = std::size(call_output);
+    host.call_result.gas_left = 100;
+    host.call_result.status_code = EVMC_SUCCESS;
+
+    const auto code = eof1_bytecode(delegatecall(callee) + OP_RETURNDATASIZE + OP_PUSH0 + OP_PUSH0 +
+                                    OP_RETURNDATACOPY + ret(0, evmone::OP_RETURNDATASIZE));
+
+    execute(code);
+    EXPECT_STATUS(EVMC_SUCCESS);
+    EXPECT_EQ(hex({result.output_data, result.output_size}), "010203");
+}
+
+TEST_P(evm, eof1_delegatecall_legacy)
+{
+    rev = EVMC_CANCUN;
+    constexpr auto callee = 0xca11ee_address;
+    host.access_account(callee);
+
+    for (const auto& target_code : {""_hex, "EF"_hex, "EF01"_hex, "000000"_hex})
+    {
+        SCOPED_TRACE("target code: " + hex(target_code));
+        host.accounts[callee].code = target_code;
+
+        const auto code = eof1_bytecode(delegatecall(callee) + ret_top());
+
+        execute(code);
+        EXPECT_GAS_USED(EVMC_SUCCESS, 133);  // Low gas usage because DELEGATECALL fails lightly.
+        EXPECT_OUTPUT_INT(0);
+    }
+}