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UnrealEngine POLYGON 全逆向笔记

发表于: 2024-7-19 15:10 7747

UnrealEngine POLYGON 全逆向笔记

Euarno

2024-7-19 15:10

7747

[!WARNING]

本文仅用于交流学习请勿用于不法用途，如有侵权联系Euarno@outlook.com或Euarno@qq.com要求删除

本文由Euarno原创，转载请标明出处

1.在Steam下载并安装POLYGON
2.找到游戏目录POLYGON\POLYGON\Binaries\Win64
3.找到游戏文件POLYGON-Win64-Shipping.exe
4.拖进IDA等待漫长分析过程

1.Visual Studio 2022
2.C++20

1.Cheat Engine
2.IDA Pro
3.Inject Tool

[!TIP]

游戏有EasyAntiCheat保护

[!NOTE]

在同一台设备上,Dx虚表位置**“固定”**

[!IMPORTANT]

有关GName的寻找原理请参见前文,本文不做赘述

先通过字符串熟练地找到void __fastcall FNamePool_FNamePool(__int64 a1)

分析交叉引用,如下表:

[!NOTE]

Down 表示当前函数调用了 FNamePool_FNamePool 函数。

Up 表示 FNamePool_FNamePool 函数被当前函数调用。

依次看看几个Up调用内容,不要找太长的函数,也尽量避开明显提到其他组件的函数,要时时刻刻切记我们寻找的只是简单的通过

这种方式进行的构造函数调用,在为数不多的Up调用中寻找到以下符合要求的伪函数

GName偏移通过计算 0x1480AD880-0x140000000=0x80AD880 得到,偏移为 0x80AD880

我们开CheatEngine简单检验一下,也确实是这个结果,我们有充分的理由认为,GName地址是 “POLYGON-Win64-Shipping.exe”+0x80AD880

通过以下代码验证GName正确性:

得到输出:

在UnrealEngine.cpp源代码中寻找如下函数

它以UWorld*作为返回值,在函数中有大量明文字符串可用来作为特征寻找该函数

[!NOTE]

如果你发现你在IDA中无法搜索到这些字符串,请设置一下识别的字符串风格,把unicode加进去

锁定return qword_1482ACFD0,直接计算0x1482ACFD0-0x0x140000000=0x82ACFD0,偏移为0x82ACFD0

还是先看引擎源码,在UObjectHash.cpp,有GObject的定义

分析对GUObjectArray的引用,有很多含有字符串的函数可以作为寻找UObject的跳板,我选择了这个函数

在IDA中定位到源码后,分析这部分

在MaxObjectsNotConsideredByGC = InMaxObjectsNotConsideredByGC时,类成员变量被赋值,对应伪代码

定位类索引首地址,就是类全局变量的地址,用0x148153F28-0x8-0x140000000=0x8153F20

ID	Description	VariableType	Address
0	无描述	4 Bytes	d3d11.dll
1	无描述	4 Bytes	d3d12.dll
2	无描述	4 Bytes	d3d9.dll

ID	Description	ShowAsSigned	ShowAsHex	VariableType	Address
0	SwapChain		1	8 Bytes	1C8BD143B20

ID	Description	LastState Value	LastState RealAddress	VariableType	Address	Offset(倒序)
0	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+08157630	0, 70, 90, 68, 10
1	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+08244B40	0, 70, 80, 528, 10
3	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+0827D5B8	0, 70, 20, 778, 110
4	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+0827D5C0	0, 70, 20, 778, 110
5	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+08296C30	0, 70, 20, 748, 110
6	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+08296C38	0, 70, 20, 748, 110
7	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082C7F60	0, 130, 10, 390, 110
8	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082C7F60	0, 130, 10, 398, 110
9	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082C7F68	0, 130, 10, 390, 110
10	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082C7F68	0, 130, 10, 398, 110
11	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+0817B270	0, 10, 0, 110, 160
12	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+0817B270	0, 10, 8, 110, 160
13	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082312C8	0, 10, 0, 110, 160
14	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"POLYGON-Win64-Shipping.exe"+082312C8	0, 10, 8, 110, 160
15	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"opencv_world455.dll"+02723310	0, 10, 0, 110, 3E8
16	指针扫描结果	618754048	1C8BD143B20	4 Bytes	"opencv_world455.dll"+02723310	0, 10, 8, 110, 3E8

ID	Description	LastState Value	LastState RealAddress	VariableType	Address	Offset(倒序)
0	指针扫描结果	618754048	1ED4E835FB0	4 Bytes	"POLYGON-Win64-Shipping.exe"+0817B270	0, 10, 0, 110, 160
1	指针扫描结果	618754048	1ED4E835FB0	4 Bytes	"POLYGON-Win64-Shipping.exe"+082312C8	0, 10, 0, 110, 160

ID	Description	VariableType	Address	Offset(倒序)
0	指针扫描结果	4 Bytes	"POLYGON-Win64-Shipping.exe"+0817B270	0, 10, 0, 110, 160

Direction	Type	Address	Text
Down	p	sub_142B09630+47	call FNamePool_FNamePool
Down	p	sub_142B09740+48	call FNamePool_FNamePool
Down	p	sub_142B0A890+30	call FNamePool_FNamePool
Down	p	sub_142B0A950+30	call FNamePool_FNamePool
Down	p	sub_142B0AA10+30	call FNamePool_FNamePool
Down	p	sub_142B0B100+4E	call FNamePool_FNamePool
Down	p	sub_142B0BCF0+4E	call FNamePool_FNamePool
Down	p	sub_142B0C260+30	call FNamePool_FNamePool
Down	p	sub_142B0CCB0+95	call FNamePool_FNamePool
Down	p	sub_142B0CE90+1F	call FNamePool_FNamePool
Down	p	sub_142B0D0B0+21	call FNamePool_FNamePool
Down	p	sub_142B0D110+21	call FNamePool_FNamePool
Down	p	sub_142B0D540+28	call FNamePool_FNamePool
Down	p	sub_142B0D5D0+28	call FNamePool_FNamePool
Down	p	sub_142B0D670+28	call FNamePool_FNamePool
Down	p	sub_142B0D700+28	call FNamePool_FNamePool
Down	p	sub_142B0DA90+28	call FNamePool_FNamePool
Down	p	sub_142B10080+72	call FNamePool_FNamePool
Down	p	sub_142B159A0+25B	call FNamePool_FNamePool
Down	p	sub_142B16D10+3A	call FNamePool_FNamePool
Down	p	sub_142B16D10+D1	call FNamePool_FNamePool
Down	p	sub_142B16EA0+3F	call FNamePool_FNamePool
Down	p	sub_142B16F90+30	call FNamePool_FNamePool
Down	o	.pdata:0000000148513348	RUNTIME_FUNCTION <rva FNamePool_FNamePool, rva algn_142B092C5,
Up	p	sub_1407D8E60+154	call FNamePool_FNamePool
Up	p	sub_1407D90C0+154	call FNamePool_FNamePool
Up	p	sub_142B04A20+A3	call FNamePool_FNamePool
Up	p	sub_142B04B20+C3	call FNamePool_FNamePool
Up	p	sub_142B04D00+FE	call FNamePool_FNamePool
Up	p	sub_142B04D00+25B	call FNamePool_FNamePool
Up	p	sub_142B05050+A5	call FNamePool_FNamePool

static bool bNamePoolInitialized;

alignas(FNamePool) static uint8 NamePoolData[sizeof(FNamePool)];

static bool bNamePoolInitialized;

alignas(FNamePool) static uint8 NamePoolData[sizeof(FNamePool)];

_DWORD *__fastcall sub_142B04A20(_DWORD *a1, _BYTE *a2)
{

  bool v2; // zf

  _BYTE *v3; // r8

  __int64 v5; // rax

  int v6; // eax

  RTL_SRWLOCK *v7; // rax

  _DWORD *result; // rax

  const char *v9; // [rsp+20h] [rbp-18h] BYREF

  int v10; // [rsp+28h] [rbp-10h]

  char v11; // [rsp+2Ch] [rbp-Ch]

  int v12; // [rsp+40h] [rbp+8h] BYREF

  int v13; // [rsp+44h] [rbp+Ch]
 
  v2 = *a2 == 0;

  v3 = a2 + 2;

  v9 = a2 + 2;

  v5 = -1i64;

  if ( v2 )

  {

    do

      ++v5;

    while ( v3[v5] );

    v11 = 0;

  }

  else

  {

    do

      ++v5;

    while ( *(_WORD *)&v3[2 * v5] );

    v11 = 1;

  }

  v10 = v5;

  if ( (unsigned int)v5 < 0x400 )

  {

    if ( byte_148089CF9 )

    {

      v7 = &stru_1480AD880;

    }

    else

    {

      FNamePool_FNamePool((__int64)&stru_1480AD880);

      byte_148089CF9 = 1;

    }

    sub_142B16A60(v7, &v12, &v9);

    v13 = v12;

    v6 = v12;

  }

  else

  {

    v10 = 24;

    v9 = "ERROR_NAME_SIZE_EXCEEDED";

    v11 = 0;

    v6 = sub_142B0CCB0(&v9, 1i64);

  }

  *a1 = v6;

  result = a1;

  a1[1] = 0;

  return result;
}

_DWORD *__fastcall sub_142B04A20(_DWORD *a1, _BYTE *a2)

{

bool v2; // zf

_BYTE *v3; // r8

__int64 v5; // rax

int v6; // eax

RTL_SRWLOCK *v7; // rax

_DWORD *result; // rax

const char *v9; // [rsp+20h] [rbp-18h] BYREF

int v10; // [rsp+28h] [rbp-10h]

char v11; // [rsp+2Ch] [rbp-Ch]

int v12; // [rsp+40h] [rbp+8h] BYREF

int v13; // [rsp+44h] [rbp+Ch]

v2 = *a2 == 0;

v3 = a2 + 2;

v9 = a2 + 2;

v5 = -1i64;

if ( v2 )

{

do

++v5;

while ( v3[v5] );

v11 = 0;

}

else

{

do

++v5;

while ( *(_WORD *)&v3[2 * v5] );

v11 = 1;

}

v10 = v5;

if ( (unsigned int)v5 < 0x400 )

{

if ( byte_148089CF9 )

{

v7 = &stru_1480AD880;

}

else

{

FNamePool_FNamePool((__int64)&stru_1480AD880);

byte_148089CF9 = 1;

}

sub_142B16A60(v7, &v12, &v9);

v13 = v12;

v6 = v12;

}

else

{

v10 = 24;

v9 = "ERROR_NAME_SIZE_EXCEEDED";

v11 = 0;

v6 = sub_142B0CCB0(&v9, 1i64);

}

*a1 = v6;

result = a1;

a1[1] = 0;

return result;

}

std::string GetName(uint32_t Id)
{

    uint32_t Block = Id >> 16;

    uint32_t Offset = Id & 65535;

    uint8_t* GameBase = (uint8_t*)GetModuleHandleA("POLYGON-Win64-Shipping.exe");
 
    uint8_t** GName = (uint8_t**)(GameBase + 0x80AD880);

    FNameEntry* Info = (FNameEntry*)((GName)[2 + Block] + 2 * Offset);
 
    return std::string(Info->AnsiName, Info->Len);
}
 
 printf("Name:%s\n", GetName(0).c_str());

std::string GetName(uint32_t Id)

{

uint32_t Block = Id >> 16;

uint32_t Offset = Id & 65535;

uint8_t* GameBase = (uint8_t*)GetModuleHandleA("POLYGON-Win64-Shipping.exe");

uint8_t** GName = (uint8_t**)(GameBase + 0x80AD880);

FNameEntry* Info = (FNameEntry*)((GName)[2 + Block] + 2 * Offset);

return std::string(Info->AnsiName, Info->Len);

}

printf("Name:%s\n", GetName(0).c_str());

Name:None

UWorld* UEngine::GetWorldFromContextObject(const UObject* Object, EGetWorldErrorMode ErrorMode) const
{

    if (Object == nullptr)

    {

        switch (ErrorMode)

        {

        case EGetWorldErrorMode::Assert:

            check(Object);

            break;

        case EGetWorldErrorMode::LogAndReturnNull:

            FFrame::KismetExecutionMessage(TEXT("A null object was passed as a world context object to UEngine::GetWorldFromContextObject()."), ELogVerbosity::Warning);

            //UE_LOG(LogEngine, Warning, TEXT("UEngine::GetWorldFromContextObject() passed a nullptr"));

            break;

        case EGetWorldErrorMode::ReturnNull:

            break;

        }

        return nullptr;

    }
 
    bool bSupported = true;

    UWorld* World = (ErrorMode == EGetWorldErrorMode::Assert) ? Object->GetWorldChecked(/*out*/ bSupported) : Object->GetWorld();

    if (bSupported && (World == nullptr) && (ErrorMode == EGetWorldErrorMode::LogAndReturnNull))

    {

        FFrame::KismetExecutionMessage(*FString::Printf(TEXT("No world was found for object (%s) passed in to UEngine::GetWorldFromContextObject()."), *GetPathNameSafe(Object)), ELogVerbosity::Warning);

    }

    return (bSupported ? World : GWorld);
}

UWorld* UEngine::GetWorldFromContextObject(const UObject* Object, EGetWorldErrorMode ErrorMode) const

{

if (Object == nullptr)

{

switch (ErrorMode)

{

case EGetWorldErrorMode::Assert:

check(Object);

break;

case EGetWorldErrorMode::LogAndReturnNull:

FFrame::KismetExecutionMessage(TEXT("A null object was passed as a world context object to UEngine::GetWorldFromContextObject()."), ELogVerbosity::Warning);

//UE_LOG(LogEngine, Warning, TEXT("UEngine::GetWorldFromContextObject() passed a nullptr"));

break;

case EGetWorldErrorMode::ReturnNull:

break;

}

return nullptr;

}

bool bSupported = true;

UWorld* World = (ErrorMode == EGetWorldErrorMode::Assert) ? Object->GetWorldChecked(/*out*/ bSupported) : Object->GetWorld();

if (bSupported && (World == nullptr) && (ErrorMode == EGetWorldErrorMode::LogAndReturnNull))

{

FFrame::KismetExecutionMessage(*FString::Printf(TEXT("No world was found for object (%s) passed in to UEngine::GetWorldFromContextObject()."), *GetPathNameSafe(Object)), ELogVerbosity::Warning);

}

return (bSupported ? World : GWorld);

}

.rdata:00000001470E6BE0 aANullObjectWas:                        ; DATA XREF: sub_144FEE480+1F↑o

.rdata:00000001470E6BE0                 text "UTF-16LE", 'A null object was passed as a world context object '

.rdata:00000001470E6C46                 text "UTF-16LE", 'to UEngine::GetWorldFromContextObject().',0

.rdata:00000001470E6BE0 aANullObjectWas: ; DATA XREF: sub_144FEE480+1F↑o

.rdata:00000001470E6BE0 text "UTF-16LE", 'A null object was passed as a world context object '

.rdata:00000001470E6C46 text "UTF-16LE", 'to UEngine::GetWorldFromContextObject().',0

__int64 __fastcall sub_144FEE480(__int64 a1, __int64 a2, int a3)
{

  __int64 v4; // rsi

  __int64 v6; // rax

  __int64 v7; // rdi

  const wchar_t *v8; // rbx

  const wchar_t *v9; // r8

  __int64 v10; // rdx

  const wchar_t *v11; // [rsp+20h] [rbp-28h] BYREF

  int v12; // [rsp+28h] [rbp-20h]

  const wchar_t *v13; // [rsp+30h] [rbp-18h] BYREF

  int v14; // [rsp+38h] [rbp-10h]

  __int64 v15; // [rsp+58h] [rbp+10h] BYREF
 
  v4 = a2;

  if ( a2 )

  {

    LOBYTE(v15) = 1;

    if ( a3 == 2 )

      v6 = sub_142C63C80(a2, &v15);

    else

      v6 = (*(__int64 (__fastcall **)(__int64))(*(_QWORD *)a2 + 392i64))(a2);

    v7 = v6;

    if ( !(_BYTE)v15 )

      return qword_1482ACFD0;

    if ( !v6 && a3 == 1 )

    {

      sub_142CD1520(v4, &v13, 0i64);

      v8 = &chText;

      v9 = &chText;

      if ( v14 != (_DWORD)v7 )

        v9 = v13;

      sub_1429C9990(&v11, L"No world was found for object (%s) passed in to UEngine::GetWorldFromContextObject().", v9);

      LOBYTE(v10) = 3;

      if ( v12 != (_DWORD)v7 )

        v8 = v11;

      sub_142CAF290(v8, v10, 0i64);

      if ( v11 )

        sub_142A062C0();

      if ( v13 )

        sub_142A062C0();

    }

    if ( !(_BYTE)v15 )

      return qword_1482ACFD0;

    return v7;

  }

  else

  {

    if ( a3 == 1 )

    {

      v15 = 0i64;

      LOBYTE(a2) = 3;

      sub_142CAF290(

        L"A null object was passed as a world context object to UEngine::GetWorldFromContextObject().",

        a2,

        0i64);

    }

    return 0i64;

  }
}