Issues with TitanEngine StepInto()

[xSRTsect]

As far as I can understand StepInto() function in titanengine steps into a instruction and contains a call back to execute after stepping into has been done. My code doesn't do what I want, wich is basically keep in a vector all instructions it executes until reaching handler_start.

void vm::DoNothing(){
}

std::vector<std::string> vm::fetch_handler(){

	std::vector<std::string> handler;

	std::string disasm;

	static uint32_t eip_control = GetContextData(UE_EIP);

	void* dbg = 0;

	do {

		eip_control = GetContextData(UE_EIP);

		disasm.assign((const char*)Disassemble((LPVOID)eip_control));

		handler.push_back(disasm);

		StepInto(&DoNothing);

		dump_ << disasm <<std::endl;

	} while (eip_control != handler_start);
	return handler;

}

Basically GetContextData() doesn't really change the value of eip_control, making me think that the StepInto() did actually nothing. What do you think its wrong?

 

Best Regards.

[mrexodia]

Hi,

 

First of all I recommend compiling the latest TitanEngine yourself (in case you didn't do that already).

 

StepInto returns immediately, it only sets a few internal values. A blogpost of mine should give a little information about how TitanEngine works internally. http://mrexodia.cf/x64_dbg/2014/12/24/x64_dbg-from-top-to-bottom-1

Basically the callback you set will be called inside the debug loop, so code should look something like this:

void cbStep()

{

    StepInto((void*)cbStep); //returns immediately

    //log here

}

 

void cbEntryPoint()

{

    cbStep();

}

 

void Debug()

{

    //initialize some stuff here

    InitDebug(filename, cmdline, (void*)cbEntryPoint);

    DebugLoop(); //this one will not return until the program is terminated

}

 

Full example: https://forum.tuts4you.com/topic/34308-sdk-example-x64-mpresspespin-unpacker/

 

Greetings

[xSRTsect]

Yeah - I have changed it to something like 

void vm::cbOn_get_h(){

	handler_f.clear();

	fetch_handler();

	dump_ << std::endl;

}
void vm::fetch_handler(){
	std::string disasm;

	static uint32_t eip_control = GetContextData(UE_EIP);

	eip_control = GetContextData(UE_EIP);

	disasm.assign((const char*)Disassemble((LPVOID)eip_control));

	handler_f.push_back(disasm);

	if (eip_control != handler_start){

		StepInto(&fetch_handler);

	}

	dump_ << disasm <<std::endl;
}

And it seems to be working thank you.