Challenge for SlashRoot CTF Final at STIKOM Bali Jimbaran hosted by UKM KSL
Du kannst nicht mehr als 25 Themen auswählen Themen müssen entweder mit einem Buchstaben oder einer Ziffer beginnen. Sie können Bindestriche („-“) enthalten und bis zu 35 Zeichen lang sein.
 
 

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2.3 KiB

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <setjmp.h>
/*
* SIGFPE bisa nempel di CPU, perlu dicari solusi
* Test openssl lewat socat
*/
void signal_handler(int sig)
{
signal(SIGFPE, signal_handler);
system("/bin/sh");
exit(1);
}
int main(int argc, char const *argv[])
{
int i_a = 0;
int i_b = 0;
int total = 0;
setvbuf(stdin, NULL, _IONBF, 0);
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
signal(SIGFPE, signal_handler);
puts("Welcome to Online Calculator v3.1");
puts("");
puts("Operator supported: + - * /");
puts("ex: 2 + 2");
puts("ex: 2 + a //'a' to use last results");
puts("");
puts("------------------------------------");
while (1)
{
char c_a[11] = "";
char c_b[11] = "";
char opt = 0;
printf(">");
if (scanf("%10s %c %10s", c_a, &opt, c_b) < 3)
{
puts("Failed to parse expression!");
return 0;
}
else
{
int r1_a = sscanf(c_a, "%d", &i_a);
int r2_a = strcmp("a", c_a) == 0;
int r1_b = sscanf(c_b, "%d", &i_b);
int r2_b = strcmp("a", c_b) == 0;
if ((i_b == 0 && r2_a) && opt == '/')
{
puts("Floating point exception (core dumped)");
return 0;
}
if (r2_a)
{
i_a = total;
}
if (r2_b)
{
i_b = total;
}
if ((r1_a || r2_a) && (r1_b || r2_b))
{
switch (opt)
{
case '+':
total = i_a + i_b;
break;
case '-':
total = i_a - i_b;
break;
case '*':
total = i_a * i_b;
break;
case '/':
total = i_a / i_b;
break;
default:
puts("Unknown operator!");
return 0;
}
printf("=%d\n", total);
}
else
{
puts("Failed to parse operand!");
return 0;
}
}
}
return 0;
}