Help/Support How to call the function? (iOS jailbreak)

[nngot44 5 iPhone 5s 11.0]

Hi I'm trying to call a function in the game Hide N Seek : Mini Games.

Here is my code, (I just need to call any function):

function dump:

//RVA: 0x11FE288 Offset: 0x11FE288 VA: 0x11FE288
   private void Update() { }


#include <unistd.h>
#include <dispatch/dispatch.h>
#include <mach-o/dyld.h>

uintptr_t getExecAddr(uintptr_t addr)
{
 const struct mach_header* header = _dyld_get_image_header(341); // this is the library index, it's so big because I'm              using a debugger so far.
 if (header == NULL){return 0;}

 uintptr_t libLoadAddr = (uintptr_t)header;
 uintptr_t exec_addr = libLoadAddr + addr;

 return exec_addr;
}

void (*Update)();

%ctor { 

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

  sleep(15); // wait for all libraries to load

  Update = (void(*)())getExecAddr(0x11FE288);

  Update();

 });
 
}

The game crashes when the moment comes to call the function. What am I doing wrong?

[Saitama 25.4k iPhone 6s Plus 15.7.9]

Keep It Simple - using this one

u dont need header index etc
u need library name
 

[menu setFrameworkName:"UnityFramework"];

next is

void (*Update)(void *inst) = (void(*)(void *))getRealOffset(0x11FE288);

and call of this is

Update(inst);

Why inst?
Because its not static function - and this function is called from some class
*inst is a class that has this function and the first arg is for call

[nngot44 5 iPhone 5s 11.0]

Thanks for the answer! but i did not understand where to call the function, if this is done in the same place where the pointer is declared, the compiler will gile the error "use of undeclared identifier 'inst'' for Update(inst);

[Saitama 25.4k iPhone 6s Plus 15.7.9]

20 hours ago, nngot44 said:

Thanks for the answer! but i did not understand where to call the function, if this is done in the same place where the pointer is declared, the compiler will gile the error "use of undeclared identifier 'inst'' for Update(inst);

because u dont declare this variable and dont get the pointer of object created by this class

also dont know why u need to call exact this function 
in Unity games this function basically called automatically each frame (if the class inherits MonoBehaviour class)
 

[Saitama 25.4k iPhone 6s Plus 15.7.9]

the main logic is
var someClass = new SomeClass(); //or other c# initialisation 
someClass.SomeMethod();

SomeMethod() cant be called from no where

Example #1

public class SomeClass : MonoBehaviour 
{
	// Fields
	...

	// Properties
	...

	// Methods
	...
	// RVA: 0x100400 Offset: 0x100400 VA: 0x100400
	public static SomeClass get_Instance() { }

	// RVA: 0x100500 Offset: 0x100500 VA: 0x100500
	public void SomeMethod() // address 0x100500

	// RVA: 0x100600 Offset: 0x100600 VA: 0x100600
	public static void SomeStaticMethod() // address 0x100600
	...
}

 

void* (*SomeClass$$get_Instance)() = (void(*)())getRealOffset(0x100400);
void (*SomeClass$$SomeMethod)(void *SomeClass) = (void(*)(void *))getRealOffset(0x100500);

void* SomeClassInstance = SomeClass$$get_Instance();
SomeClass$$SomeMethod(SomeClassInstance);

 

void (*SomeClass$$SomeStaticMethod)() = (void(*)())getRealOffset(0x100600);

SomeClass$$SomeStaticMethod();

Example #2

public class SomeOtherClass : MonoBehaviour 
{
	// Fields
	...

	// Properties
	...

	// Methods
	...
	// RVA: 0x100300 Offset: 0x100300 VA: 0x100300
	public void InitWithSomeClass(SomeClass someClassInstance) { }
	...
}

 

void* SomeClassInstance = NULL;
void (*SomeOtherClass$$InitWithSomeClass_original)(void *SomeOtherClassInstance, void* someClassInstance);
void _SomeOtherClass$$InitWithSomeClass_hook(void *SomeOtherClassInstance, void* someClassInstance) 
{
	SomeClassInstance = someClassInstance;
	SomeOtherClass$$InitWithSomeClass_original(SomeOtherClassInstance, someClassInstance);
}

HOOK(0x100300, _SomeOtherClass$$InitWithSomeClass_hook, SomeOtherClass$$InitWithSomeClass_original);

 

Updated June 5, 2023 by Saitama

[Saitama 25.4k iPhone 6s Plus 15.7.9]

Example #3

public class SomeThirdClass : MonoBehaviour 
{
	// Fields
	...
	public SomeClass SomeClassField // 0x100
	...

	// Properties
	...

	// Methods
	...
	// RVA: 0x100200 Offset: 0x100200 VA: 0x100200
	public void Update() { }
	...
}

 

void* SomeClassInstance = NULL;
void (*SomeThirdClass$$Update_original)(void *SomeThirdClassInstance);
void _SomeThirdClass$$Update_hook(void *SomeThirdClassInstance) 
{
	void* someClassInstance = *(void **)((uint64_t)SomeThirdClassInstance + 0x100);
	if(someClassInstance != NULL)
    {
		SomeClassInstance = someClassInstance;
    }
	SomeThirdClass$$Update_hook(SomeThirdClassInstance);
}

HOOK(0x100200, _SomeThirdClass$$Update_hook, SomeThirdClass$$Update_original);

 

 

Updated June 5, 2023 by Saitama

[nngot44 5 iPhone 5s 11.0]

Thanks for these examples, I'm new and still learning how to make dylib libraries for games. I tried to call the Update function because I thought it would be the easiest to call

[nngot44 5 iPhone 5s 11.0]

I used your advice and wrote this code (i hope my method returns the correct address) :

#include <unistd.h>
#include <dispatch/dispatch.h>
#include <mach-o/dyld.h>

uintptr_t getExecAddr(uintptr_t addr)
{
    const struct mach_header* header = _dyld_get_image_header(341);
    if (header == NULL){return 0;}

    uintptr_t libLoadAddr = (uintptr_t)header;
    uintptr_t exec_addr = libLoadAddr + addr;

    return exec_addr;
}

%ctor 
{

	dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

		sleep(150);

		void* (*VELights$$get_Instance)() = (void* (*)())getExecAddr(0x12FD104);
		void (*VELights$$ResetMainSunLightAngle)(void *VELights) = (void(*)(void *))getExecAddr(0x12FD4B8);

		void* VELightsInstance = VELights$$get_Instance();
		VELights$$ResetMainSunLightAngle(VELightsInstance);
		
	});	

}	

 

In the debugger, I always get rather strange errors, for example, from the libobjc.A.dylib'objc_retain library. 

I thought it would be easier for me if it was possible to disable ASLR for this game. Is it possible to do this on iOS 13?

 

Updated June 6, 2023 by nngot44

[Saitama 25.4k iPhone 6s Plus 15.7.9]

basically start from doing some easier things
for example change values from 
public int get_someGold();
and setter
public void set_someGold(int goldVal);

its will be easier to understand that call some function

[nngot44 5 iPhone 5s 11.0]

Thank you for not passing by my question, the information that you provided is very useful!