sandbox/win/src/policy_opcodes_unittest.cc

// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "sandbox/win/src/policy_engine_opcodes.h"

#include <stddef.h>
#include <stdint.h>

#include "sandbox/win/src/policy_engine_params.h"
#include "sandbox/win/src/sandbox_nt_types.h"
#include "sandbox/win/src/sandbox_types.h"
#include "testing/gtest/include/gtest/gtest.h"

#define INIT_GLOBAL_RTL(member)                                             \
  g_nt.member =                                                             \
      reinterpret_cast<member##Function>(::GetProcAddress(ntdll, #member)); \
  if (!g_nt.member)                                                         \
  return false

namespace sandbox {

const size_t kOpcodeMemory = 1024;

SANDBOX_INTERCEPT NtExports g_nt;

bool SetupNtdllImports() {
  HMODULE ntdll = ::GetModuleHandle(kNtdllName);

  INIT_GLOBAL_RTL(RtlAllocateHeap);
  INIT_GLOBAL_RTL(RtlAnsiStringToUnicodeString);
  INIT_GLOBAL_RTL(RtlCompareUnicodeString);
  INIT_GLOBAL_RTL(RtlCreateHeap);
  INIT_GLOBAL_RTL(RtlDestroyHeap);
  INIT_GLOBAL_RTL(RtlFreeHeap);
  INIT_GLOBAL_RTL(_strnicmp);
  INIT_GLOBAL_RTL(strlen);
  INIT_GLOBAL_RTL(wcslen);

  return true;
}

TEST(PolicyEngineTest, ParameterSetTest) {
  void* pv1 = reinterpret_cast<void*>(0x477EAA5);
  const void* pv2 = reinterpret_cast<void*>(0x987654);
  ParameterSet pset1 = ParamPickerMake(pv1);
  ParameterSet pset2 = ParamPickerMake(pv2);

  // Test that we can store and retrieve a void pointer:
  const void* result1 = 0;
  uint32_t result2 = 0;
  EXPECT_TRUE(pset1.Get(&result1));
  EXPECT_TRUE(pv1 == result1);
  EXPECT_FALSE(pset1.Get(&result2));
  EXPECT_TRUE(pset2.Get(&result1));
  EXPECT_TRUE(pv2 == result1);
  EXPECT_FALSE(pset2.Get(&result2));

  // Test that we can store and retrieve a uint32_t:
  uint32_t number = 12747;
  ParameterSet pset3 = ParamPickerMake(number);
  EXPECT_FALSE(pset3.Get(&result1));
  EXPECT_TRUE(pset3.Get(&result2));
  EXPECT_EQ(number, result2);

  // Test that we can store and retrieve a string:
  const wchar_t* txt = L"S231L";
  ParameterSet pset4 = ParamPickerMake(txt);
  const wchar_t* result3 = nullptr;
  EXPECT_TRUE(pset4.Get(&result3));
  EXPECT_EQ(0, wcscmp(txt, result3));
}

TEST(PolicyEngineTest, OpcodeConstraints) {
  // Test that PolicyOpcode has no virtual functions
  // because these objects are copied over to other processes
  // so they cannot have vtables.
  EXPECT_FALSE(__is_polymorphic(PolicyOpcode));
  // Keep developers from adding smarts to the opcodes which should
  // be pretty much a bag of bytes with a OO interface.
  EXPECT_TRUE(__has_trivial_destructor(PolicyOpcode));
  EXPECT_TRUE(__has_trivial_constructor(PolicyOpcode));
  EXPECT_TRUE(__has_trivial_copy(PolicyOpcode));
}

TEST(PolicyEngineTest, TrueFalseOpcodes) {
  void* dummy = nullptr;
  ParameterSet ppb1 = ParamPickerMake(dummy);
  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));

  // This opcode always evaluates to true.
  PolicyOpcode* op1 = opcode_maker.MakeOpAlwaysFalse(kPolNone);
  ASSERT_NE(nullptr, op1);
  EXPECT_EQ(EVAL_FALSE, op1->Evaluate(&ppb1, 1, nullptr));
  EXPECT_FALSE(op1->IsAction());

  // This opcode always evaluates to false.
  PolicyOpcode* op2 = opcode_maker.MakeOpAlwaysTrue(kPolNone);
  ASSERT_NE(nullptr, op2);
  EXPECT_EQ(EVAL_TRUE, op2->Evaluate(&ppb1, 1, nullptr));

  // Nulls not allowed on the params.
  EXPECT_EQ(EVAL_ERROR, op2->Evaluate(nullptr, 0, nullptr));
  EXPECT_EQ(EVAL_ERROR, op2->Evaluate(nullptr, 1, nullptr));

  // True and False opcodes do not 'require' a number of parameters
  EXPECT_EQ(EVAL_TRUE, op2->Evaluate(&ppb1, 0, nullptr));
  EXPECT_EQ(EVAL_TRUE, op2->Evaluate(&ppb1, 1, nullptr));

  // Test Inverting the logic. Note that inversion is done outside
  // any particular opcode evaluation so no need to repeat for all
  // opcodes.
  PolicyOpcode* op3 = opcode_maker.MakeOpAlwaysFalse(kPolNegateEval);
  ASSERT_NE(nullptr, op3);
  EXPECT_EQ(EVAL_TRUE, op3->Evaluate(&ppb1, 1, nullptr));
  PolicyOpcode* op4 = opcode_maker.MakeOpAlwaysTrue(kPolNegateEval);
  ASSERT_NE(nullptr, op4);
  EXPECT_EQ(EVAL_FALSE, op4->Evaluate(&ppb1, 1, nullptr));

  // Test that we clear the match context
  PolicyOpcode* op5 = opcode_maker.MakeOpAlwaysTrue(kPolClearContext);
  ASSERT_NE(nullptr, op5);
  MatchContext context;
  context.position = 1;
  context.options = kPolUseOREval;
  EXPECT_EQ(EVAL_TRUE, op5->Evaluate(&ppb1, 1, &context));
  EXPECT_EQ(0u, context.position);
  MatchContext context2;
  EXPECT_EQ(context2.options, context.options);
}

TEST(PolicyEngineTest, OpcodeMakerCase1) {
  // Testing that the opcode maker does not overrun the
  // supplied buffer. It should only be able to make 'count' opcodes.
  void* dummy = nullptr;
  ParameterSet ppb1 = ParamPickerMake(dummy);

  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));
  size_t count = sizeof(memory) / sizeof(PolicyOpcode);

  for (size_t ix = 0; ix != count; ++ix) {
    PolicyOpcode* op = opcode_maker.MakeOpAlwaysFalse(kPolNone);
    ASSERT_NE(nullptr, op);
    EXPECT_EQ(EVAL_FALSE, op->Evaluate(&ppb1, 1, nullptr));
  }
  // There should be no room more another opcode:
  PolicyOpcode* op1 = opcode_maker.MakeOpAlwaysFalse(kPolNone);
  ASSERT_EQ(nullptr, op1);
}

TEST(PolicyEngineTest, OpcodeMakerCase2) {
  SetupNtdllImports();
  // Testing that the opcode maker does not overrun the
  // supplied buffer. It should only be able to make 'count' opcodes.
  // The difference with the previous test is that this opcodes allocate
  // the string 'txt2' inside the same buffer.
  const wchar_t* txt1 = L"1234";
  const wchar_t txt2[] = L"123";

  ParameterSet ppb1 = ParamPickerMake(txt1);
  MatchContext mc1;

  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));
  size_t count = sizeof(memory) / (sizeof(PolicyOpcode) + sizeof(txt2));

  // Test that it does not overrun the buffer.
  for (size_t ix = 0; ix != count; ++ix) {
    PolicyOpcode* op = opcode_maker.MakeOpWStringMatch(
        0, txt2, 0, CASE_SENSITIVE, kPolClearContext);
    ASSERT_NE(nullptr, op);
    EXPECT_EQ(EVAL_TRUE, op->Evaluate(&ppb1, 1, &mc1));
  }

  // There should be no room more another opcode:
  PolicyOpcode* op1 =
      opcode_maker.MakeOpWStringMatch(0, txt2, 0, CASE_SENSITIVE, kPolNone);
  ASSERT_EQ(nullptr, op1);
}

TEST(PolicyEngineTest, IntegerOpcodes) {
  const wchar_t* txt = L"abcdef";
  uint32_t num1 = 42;
  uint32_t num2 = 113377;

  ParameterSet pp_wrong1 = ParamPickerMake(txt);
  ParameterSet pp_num1 = ParamPickerMake(num1);
  ParameterSet pp_num2 = ParamPickerMake(num2);

  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));

  // Test basic match for uint32s 42 == 42 and 42 != 113377.
  PolicyOpcode* op_m42 = opcode_maker.MakeOpNumberMatch(0, 42UL, kPolNone);
  ASSERT_NE(nullptr, op_m42);
  EXPECT_EQ(EVAL_TRUE, op_m42->Evaluate(&pp_num1, 1, nullptr));
  EXPECT_EQ(EVAL_FALSE, op_m42->Evaluate(&pp_num2, 1, nullptr));
  EXPECT_EQ(EVAL_ERROR, op_m42->Evaluate(&pp_wrong1, 1, nullptr));

  // Test basic match for void pointers.
  const void* vp = nullptr;
  ParameterSet pp_num3 = ParamPickerMake(vp);
  PolicyOpcode* op_vp_null =
      opcode_maker.MakeOpVoidPtrMatch(0, nullptr, kPolNone);
  ASSERT_NE(nullptr, op_vp_null);
  EXPECT_EQ(EVAL_TRUE, op_vp_null->Evaluate(&pp_num3, 1, nullptr));
  EXPECT_EQ(EVAL_FALSE, op_vp_null->Evaluate(&pp_num1, 1, nullptr));
  EXPECT_EQ(EVAL_ERROR, op_vp_null->Evaluate(&pp_wrong1, 1, nullptr));

  // Basic range test [41 43] (inclusive).
  PolicyOpcode* op_range1 =
      opcode_maker.MakeOpNumberMatchRange(0, 41, 43, kPolNone);
  ASSERT_NE(nullptr, op_range1);
  EXPECT_EQ(EVAL_TRUE, op_range1->Evaluate(&pp_num1, 1, nullptr));
  EXPECT_EQ(EVAL_FALSE, op_range1->Evaluate(&pp_num2, 1, nullptr));
  EXPECT_EQ(EVAL_ERROR, op_range1->Evaluate(&pp_wrong1, 1, nullptr));
}

TEST(PolicyEngineTest, LogicalOpcodes) {
  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));

  uint32_t num1 = 0x10100702;
  ParameterSet pp_num1 = ParamPickerMake(num1);

  PolicyOpcode* op_and1 =
      opcode_maker.MakeOpNumberAndMatch(0, 0x00100000, kPolNone);
  ASSERT_NE(nullptr, op_and1);
  EXPECT_EQ(EVAL_TRUE, op_and1->Evaluate(&pp_num1, 1, nullptr));
  PolicyOpcode* op_and2 =
      opcode_maker.MakeOpNumberAndMatch(0, 0x00000001, kPolNone);
  ASSERT_NE(nullptr, op_and2);
  EXPECT_EQ(EVAL_FALSE, op_and2->Evaluate(&pp_num1, 1, nullptr));
}

TEST(PolicyEngineTest, WCharOpcodes1) {
  SetupNtdllImports();

  const wchar_t* txt1 = L"the quick fox jumps over the lazy dog";
  const wchar_t txt2[] = L"the quick";
  const wchar_t txt3[] = L" fox jumps";
  const wchar_t txt4[] = L"the lazy dog";
  const wchar_t txt5[] = L"jumps over";
  const wchar_t txt6[] = L"g";

  ParameterSet pp_tc1 = ParamPickerMake(txt1);
  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));

  PolicyOpcode* op1 =
      opcode_maker.MakeOpWStringMatch(0, txt2, 0, CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op1);

  // Simplest substring match from pos 0. It should be a successful match
  // and the match context should be updated.
  MatchContext mc1;
  EXPECT_EQ(EVAL_TRUE, op1->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_TRUE(_countof(txt2) == mc1.position + 1);

  // Matching again should fail and the context should be unmodified.
  EXPECT_EQ(EVAL_FALSE, op1->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_TRUE(_countof(txt2) == mc1.position + 1);

  // Using the same match context we should continue where we left
  // in the previous successful match,
  PolicyOpcode* op3 =
      opcode_maker.MakeOpWStringMatch(0, txt3, 0, CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op3);
  EXPECT_EQ(EVAL_TRUE, op3->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_TRUE(_countof(txt3) + _countof(txt2) == mc1.position + 2);

  // We now keep on matching but now we skip 6 characters which means
  // we skip the string ' over '. And we zero the match context. This is
  // the primitive that we use to build '??'.
  PolicyOpcode* op4 = opcode_maker.MakeOpWStringMatch(
      0, txt4, 6, CASE_SENSITIVE, kPolClearContext);
  ASSERT_NE(nullptr, op4);
  EXPECT_EQ(EVAL_TRUE, op4->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(0u, mc1.position);

  // Test that we can properly match the last part of the string
  PolicyOpcode* op4b = opcode_maker.MakeOpWStringMatch(
      0, txt4, kSeekToEnd, CASE_SENSITIVE, kPolClearContext);
  ASSERT_NE(nullptr, op4b);
  EXPECT_EQ(EVAL_TRUE, op4b->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(0u, mc1.position);

  // Test matching 'jumps over' over the entire string. This is the
  // primitive we build '*' from.
  PolicyOpcode* op5 = opcode_maker.MakeOpWStringMatch(0, txt5, kSeekForward,
                                                      CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op5);
  EXPECT_EQ(EVAL_TRUE, op5->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(24u, mc1.position);

  // Test that we don't match because it is not at the end of the string
  PolicyOpcode* op5b = opcode_maker.MakeOpWStringMatch(
      0, txt5, kSeekToEnd, CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op5b);
  EXPECT_EQ(EVAL_FALSE, op5b->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(24u, mc1.position);

  // Test that we function if the string does not fit. In this case we
  // try to match 'the lazy dog' against 'he lazy dog'.
  PolicyOpcode* op6 =
      opcode_maker.MakeOpWStringMatch(0, txt4, 2, CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op6);
  EXPECT_EQ(EVAL_FALSE, op6->Evaluate(&pp_tc1, 1, &mc1));

  // Testing matching against 'g' which should be the last char.
  MatchContext mc2;
  PolicyOpcode* op7 = opcode_maker.MakeOpWStringMatch(0, txt6, kSeekForward,
                                                      CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op7);
  EXPECT_EQ(EVAL_TRUE, op7->Evaluate(&pp_tc1, 1, &mc2));
  EXPECT_EQ(37u, mc2.position);

  // Trying to match again should fail since we are in the last char.
  // This also covers a couple of boundary conditions.
  EXPECT_EQ(EVAL_FALSE, op7->Evaluate(&pp_tc1, 1, &mc2));
  EXPECT_EQ(37u, mc2.position);
}

TEST(PolicyEngineTest, WCharOpcodes2) {
  SetupNtdllImports();

  const wchar_t* path1 = L"c:\\documents and settings\\Microsoft\\BLAH.txt";
  const wchar_t txt1[] = L"Settings\\microsoft";
  ParameterSet pp_tc1 = ParamPickerMake(path1);

  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));
  MatchContext mc1;

  // Testing case-insensitive does not buy us much since it this option
  // is just passed to the Microsoft API that we use normally, but just for
  // coverage, here it is:
  PolicyOpcode* op1s = opcode_maker.MakeOpWStringMatch(
      0, txt1, kSeekForward, CASE_SENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op1s);
  PolicyOpcode* op1i = opcode_maker.MakeOpWStringMatch(
      0, txt1, kSeekForward, CASE_INSENSITIVE, kPolNone);
  ASSERT_NE(nullptr, op1i);
  EXPECT_EQ(EVAL_FALSE, op1s->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(EVAL_TRUE, op1i->Evaluate(&pp_tc1, 1, &mc1));
  EXPECT_EQ(35u, mc1.position);
}

TEST(PolicyEngineTest, ActionOpcodes) {
  char memory[kOpcodeMemory];
  OpcodeFactory opcode_maker(memory, sizeof(memory));
  MatchContext mc1;
  void* dummy = nullptr;
  ParameterSet ppb1 = ParamPickerMake(dummy);

  PolicyOpcode* op1 = opcode_maker.MakeOpAction(ASK_BROKER, kPolNone);
  ASSERT_NE(nullptr, op1);
  EXPECT_TRUE(op1->IsAction());
  EXPECT_EQ(ASK_BROKER, op1->Evaluate(&ppb1, 1, &mc1));
}

}  // namespace sandbox