150 lines
4.5 KiB
C
150 lines
4.5 KiB
C
/* Unicorn Emulator Engine */
|
|
/* By Nguyen Anh Quynh & Dang Hoang Vu, 2015 */
|
|
|
|
/* Sample code to trace code with Linux code with syscall */
|
|
|
|
#include <unicorn/unicorn.h>
|
|
#include <string.h>
|
|
|
|
|
|
// code to be emulated
|
|
#define X86_CODE32 "\xeb\x19\x31\xc0\x31\xdb\x31\xd2\x31\xc9\xb0\x04\xb3\x01\x59\xb2\x05\xcd\x80\x31\xc0\xb0\x01\x31\xdb\xcd\x80\xe8\xe2\xff\xff\xff\x68\x65\x6c\x6c\x6f"
|
|
|
|
#define X86_CODE32_SELF "\xeb\x1c\x5a\x89\xd6\x8b\x02\x66\x3d\xca\x7d\x75\x06\x66\x05\x03\x03\x89\x02\xfe\xc2\x3d\x41\x41\x41\x41\x75\xe9\xff\xe6\xe8\xdf\xff\xff\xff\x31\xd2\x6a\x0b\x58\x99\x52\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x52\x53\x89\xe1\xca\x7d\x41\x41\x41\x41\x41\x41\x41\x41"
|
|
|
|
// memory address where emulation starts
|
|
#define ADDRESS 0x1000000
|
|
|
|
#define MIN(a, b) (a < b? a : b)
|
|
// callback for tracing instruction
|
|
static void hook_code(uc_engine *uc, uint64_t address, uint32_t size, void *user_data)
|
|
{
|
|
int r_eip;
|
|
uint8_t tmp[16];
|
|
|
|
printf("Tracing instruction at 0x%"PRIx64 ", instruction size = 0x%x\n", address, size);
|
|
|
|
uc_reg_read(uc, UC_X86_REG_EIP, &r_eip);
|
|
printf("*** EIP = %x ***: ", r_eip);
|
|
|
|
size = MIN(sizeof(tmp), size);
|
|
if (!uc_mem_read(uc, address, tmp, size)) {
|
|
uint32_t i;
|
|
for (i=0; i<size; i++) {
|
|
printf("%x ", tmp[i]);
|
|
}
|
|
printf("\n");
|
|
}
|
|
}
|
|
|
|
// callback for handling interrupt
|
|
// ref: http://syscalls.kernelgrok.com/
|
|
static void hook_intr(uc_engine *uc, uint32_t intno, void *user_data)
|
|
{
|
|
int32_t r_eax, r_ecx, r_eip;
|
|
uint32_t r_edx, size;
|
|
unsigned char buffer[256];
|
|
|
|
// only handle Linux syscall
|
|
if (intno != 0x80)
|
|
return;
|
|
|
|
uc_reg_read(uc, UC_X86_REG_EAX, &r_eax);
|
|
uc_reg_read(uc, UC_X86_REG_EIP, &r_eip);
|
|
|
|
switch(r_eax) {
|
|
default:
|
|
printf(">>> 0x%x: interrupt 0x%x, EAX = 0x%x\n", r_eip, intno, r_eax);
|
|
break;
|
|
case 1: // sys_exit
|
|
printf(">>> 0x%x: interrupt 0x%x, SYS_EXIT. quit!\n\n", r_eip, intno);
|
|
uc_emu_stop(uc);
|
|
break;
|
|
case 4: // sys_write
|
|
// ECX = buffer address
|
|
uc_reg_read(uc, UC_X86_REG_ECX, &r_ecx);
|
|
|
|
// EDX = buffer size
|
|
uc_reg_read(uc, UC_X86_REG_EDX, &r_edx);
|
|
|
|
// read the buffer in
|
|
size = MIN(sizeof(buffer)-1, r_edx);
|
|
|
|
if (!uc_mem_read(uc, r_ecx, buffer, size)) {
|
|
buffer[size] = '\0';
|
|
printf(">>> 0x%x: interrupt 0x%x, SYS_WRITE. buffer = 0x%x, size = %u, content = '%s'\n",
|
|
r_eip, intno, r_ecx, r_edx, buffer);
|
|
} else {
|
|
printf(">>> 0x%x: interrupt 0x%x, SYS_WRITE. buffer = 0x%x, size = %u (cannot get content)\n",
|
|
r_eip, intno, r_ecx, r_edx);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void test_i386(void)
|
|
{
|
|
uc_engine *uc;
|
|
uc_err err;
|
|
uc_hook trace1, trace2;
|
|
|
|
int r_esp = ADDRESS + 0x200000; // ESP register
|
|
|
|
printf("Emulate i386 code\n");
|
|
|
|
// Initialize emulator in X86-32bit mode
|
|
err = uc_open(UC_ARCH_X86, UC_MODE_32, &uc);
|
|
if (err) {
|
|
printf("Failed on uc_open() with error returned: %u\n", err);
|
|
return;
|
|
}
|
|
|
|
// map 2MB memory for this emulation
|
|
uc_mem_map(uc, ADDRESS, 2 * 1024 * 1024, UC_PROT_ALL);
|
|
|
|
// write machine code to be emulated to memory
|
|
if (uc_mem_write(uc, ADDRESS, X86_CODE32_SELF, sizeof(X86_CODE32_SELF) - 1)) {
|
|
printf("Failed to write emulation code to memory, quit!\n");
|
|
return;
|
|
}
|
|
|
|
// initialize machine registers
|
|
uc_reg_write(uc, UC_X86_REG_ESP, &r_esp);
|
|
|
|
// tracing all instructions by having @begin > @end
|
|
uc_hook_add(uc, &trace1, UC_HOOK_CODE, hook_code, NULL, 1, 0);
|
|
|
|
// handle interrupt ourself
|
|
uc_hook_add(uc, &trace2, UC_HOOK_INTR, hook_intr, NULL, 1, 0);
|
|
|
|
printf("\n>>> Start tracing this Linux code\n");
|
|
|
|
// emulate machine code in infinite time
|
|
// err = uc_emu_start(uc, ADDRESS, ADDRESS + sizeof(X86_CODE32_SELF), 0, 12); <--- emulate only 12 instructions
|
|
err = uc_emu_start(uc, ADDRESS, ADDRESS + sizeof(X86_CODE32_SELF) - 1, 0, 0);
|
|
if (err) {
|
|
printf("Failed on uc_emu_start() with error returned %u: %s\n",
|
|
err, uc_strerror(err));
|
|
}
|
|
|
|
printf("\n>>> Emulation done.\n");
|
|
|
|
uc_close(uc);
|
|
}
|
|
|
|
int main(int argc, char **argv, char **envp)
|
|
{
|
|
if (argc == 2) {
|
|
if (!strcmp(argv[1], "-32")) {
|
|
test_i386();
|
|
}
|
|
else if (!strcmp(argv[1], "-h")) {
|
|
printf("Syntax: %s <-32|-64>\n", argv[0]);
|
|
}
|
|
} else {
|
|
test_i386();
|
|
}
|
|
|
|
return 0;
|
|
}
|