Merge pull request #366 from ethereum/eof-code-validation

EOF code validation (EIP-3670)

lib/evmone/eof.cpp

@@ -3,9 +3,11 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "eof.hpp"
+#include "instructions_traits.hpp"
 
 #include <array>
 #include <cassert>
+#include <limits>
 
 namespace evmone
 {
@@ -95,15 +97,46 @@ std::pair<EOFSectionHeaders, EOFValidationError> validate_eof_headers(bytes_view
     return {section_headers, EOFValidationError::success};
 }
 
-std::pair<EOF1Header, EOFValidationError> validate_eof1(bytes_view container) noexcept
+EOFValidationError validate_instructions(evmc_revision rev, bytes_view code) noexcept
 {
-    const auto [section_headers, error] = validate_eof_headers(container);
-    if (error != EOFValidationError::success)
-        return {{}, error};
+    assert(code.size() > 0);  // guaranteed by EOF headers validation
+
+    size_t i = 0;
+    uint8_t op = code[0];
+    while (i < code.size())
+    {
+        op = code[i];
+        const auto& since = instr::traits[op].since;
+        if (!since.has_value() || *since > rev)
+            return EOFValidationError::undefined_instruction;
+
+        i += instr::traits[op].immediate_size;
+        ++i;
+    }
+
+    if (!instr::traits[op].is_terminating)
+        return EOFValidationError::missing_terminating_instruction;
+
+    return EOFValidationError::success;
+}
+
+std::pair<EOF1Header, EOFValidationError> validate_eof1(
+    evmc_revision rev, bytes_view container) noexcept
+{
+    const auto [section_headers, error_header] = validate_eof_headers(container);
+    if (error_header != EOFValidationError::success)
+        return {{}, error_header};
+
+    EOF1Header header{section_headers[CODE_SECTION], section_headers[DATA_SECTION]};
+
+    const auto error_instr =
+        validate_instructions(rev, {&container[header.code_begin()], header.code_size});
+    if (error_instr != EOFValidationError::success)
+        return {{}, error_instr};
 
-    const EOF1Header header{section_headers[CODE_SECTION], section_headers[DATA_SECTION]};
     return {header, EOFValidationError::success};
 }
+
 }  // namespace
 
 size_t EOF1Header::code_begin() const noexcept
@@ -154,7 +187,7 @@ EOFValidationError validate_eof(evmc_revision rev, bytes_view container) noexcep
     {
         if (rev < EVMC_SHANGHAI)
             return EOFValidationError::eof_version_unknown;
-        return validate_eof1(container).second;
+        return validate_eof1(rev, container).second;
     }
     else
         return EOFValidationError::eof_version_unknown;

lib/evmone/eof.hpp

@@ -46,6 +46,8 @@ enum class EOFValidationError
     zero_section_size,
     section_headers_not_terminated,
     invalid_section_bodies_size,
+    undefined_instruction,
+    missing_terminating_instruction,
 
     impossible,
 };

test/unittests/eof_validation_test.cpp

@@ -3,17 +3,20 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include <evmone/eof.hpp>
+#include <evmone/instructions_traits.hpp>
 #include <gtest/gtest.h>
+#include <test/utils/bytecode.hpp>
 #include <test/utils/utils.hpp>
 
 using namespace evmone;
 
 namespace
 {
+// Can be called as validate_eof(string_view hex, rev) or validate_eof(bytes_view cont, rev).
 inline EOFValidationError validate_eof(
-    std::string_view code_hex, evmc_revision rev = EVMC_SHANGHAI) noexcept
+    const bytecode& container, evmc_revision rev = EVMC_SHANGHAI) noexcept
 {
-    return ::validate_eof(rev, from_hex(code_hex));
+    return evmone::validate_eof(rev, container);
 }
 }  // namespace
 
@@ -156,3 +159,77 @@ TEST(eof_validation, EOF1_trailing_bytes)
     EXPECT_EQ(validate_eof("EF0001 010001 020002 00 FE AABB DEADBEEF"),
         EOFValidationError::invalid_section_bodies_size);
 }
+
+TEST(eof_validation, EOF1_undefined_opcodes)
+{
+    auto cont = from_hex("EF0001 010002 00 0000");
+
+    const auto& gas_table = evmone::instr::gas_costs[EVMC_SHANGHAI];
+
+    for (uint16_t opcode = 0; opcode <= 0xff; ++opcode)
+    {
+        // PUSH* require immediate argument to be valid, checked in a separate test
+        if (opcode >= OP_PUSH1 && opcode <= OP_PUSH32)
+            continue;
+
+        cont[cont.size() - 2] = static_cast<uint8_t>(opcode);
+
+        const auto expected = (gas_table[opcode] == evmone::instr::undefined ?
+                                   EOFValidationError::undefined_instruction :
+                                   EOFValidationError::success);
+        EXPECT_EQ(validate_eof(cont), expected) << hex(cont);
+    }
+
+    EXPECT_EQ(validate_eof(from_hex("EF0001 010001 00 FE")), EOFValidationError::success);
+}
+
+TEST(eof_validation, EOF1_truncated_push)
+{
+    auto eof_header = from_hex("EF0001 010001 00");
+    auto& code_size_byte = eof_header[5];
+    for (uint8_t opcode = OP_PUSH1; opcode <= OP_PUSH32; ++opcode)
+    {
+        const auto required_bytes = static_cast<size_t>(opcode) - OP_PUSH1 + 1;
+        for (size_t i = 0; i < required_bytes; ++i)
+        {
+            const bytes code{opcode + bytes(i, 0)};
+            code_size_byte = static_cast<uint8_t>(code.size());
+            const auto container = eof_header + code;
+
+            EXPECT_EQ(validate_eof(container), EOFValidationError::missing_terminating_instruction)
+                << hex(container);
+        }
+
+        const bytes code{opcode + bytes(required_bytes, 0) + uint8_t{OP_STOP}};
+        code_size_byte = static_cast<uint8_t>(code.size());
+        const auto container = eof_header + code;
+
+        EXPECT_EQ(validate_eof(container), EOFValidationError::success) << hex(container);
+    }
+}
+
+TEST(eof_validation, EOF1_terminating_instructions)
+{
+    auto eof_header = from_hex("EF0001 010001 00");
+    auto& code_size_byte = eof_header[5];
+
+    const auto& traits = evmone::instr::traits;
+
+    for (uint16_t opcode = 0; opcode <= 0xff; ++opcode)
+    {
+        const auto& op_traits = traits[opcode];
+        // Skip undefined opcodes.
+        if (op_traits.name == nullptr)
+            continue;
+
+        bytes code{static_cast<uint8_t>(opcode) + bytes(op_traits.immediate_size, 0)};
+        code_size_byte = static_cast<uint8_t>(code.size());
+        const auto container = eof_header + code;
+
+        const auto expected = ((opcode == OP_STOP || opcode == OP_RETURN || opcode == OP_REVERT ||
+                                   opcode == OP_INVALID || opcode == OP_SELFDESTRUCT) ?
+                                   EOFValidationError::success :
+                                   EOFValidationError::missing_terminating_instruction);
+        EXPECT_EQ(validate_eof(container), expected) << hex(code);
+    }
+}