49 lines
862 B
C
49 lines
862 B
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
|
|
void segfault_handler() {
|
|
printf("Segfault Occurred, incorrect address.\n");
|
|
exit(0);
|
|
}
|
|
|
|
int win() {
|
|
FILE *fptr;
|
|
char c;
|
|
|
|
printf("You won!\n");
|
|
// Open file
|
|
fptr = fopen("flag.txt", "r");
|
|
if (fptr == NULL)
|
|
{
|
|
printf("Cannot open file.\n");
|
|
exit(0);
|
|
}
|
|
|
|
// Read contents from file
|
|
c = fgetc(fptr);
|
|
while (c != EOF)
|
|
{
|
|
printf ("%c", c);
|
|
c = fgetc(fptr);
|
|
}
|
|
|
|
printf("\n");
|
|
fclose(fptr);
|
|
}
|
|
|
|
int main() {
|
|
signal(SIGSEGV, segfault_handler);
|
|
setvbuf(stdout, NULL, _IONBF, 0); // _IONBF = Unbuffered
|
|
|
|
printf("Address of main: %p\n", &main);
|
|
|
|
unsigned long val;
|
|
printf("Enter the address to jump to, ex => 0x12345: ");
|
|
scanf("%lx", &val);
|
|
printf("Your input: %lx\n", val);
|
|
|
|
void (*foo)(void) = (void (*)())val;
|
|
foo();
|
|
} |