Files
hacklab/4/level1/level1.c
2026-01-05 03:42:05 +01:00

59 lines
1.3 KiB
C

// gcc -o level1 -no-pie -fno-stack-protector level1.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
struct topic {
char question[64];
char answer[32];
int (*check_response)(struct topic *topic);
};
void win() {
char *argv[2];
argv[0] = "/bin/sh";
argv[1] = NULL;
execve(argv[0], argv, NULL);
}
int check_math_response(struct topic *topic) {
int answer = atoi(topic->answer);
if (answer == 0x7a69) {
puts("You got it.");
return 0;
} else {
puts("Try again.");
return 1;
}
}
int check_weather_response(struct topic *topic) {
if (!strcmp(topic->answer, "Yes\n")) {
puts("It's inevitable.");
return 0;
} else {
puts("Are you sure about that?");
return 1;
}
}
int main(int argc, char **argv) {
// Disable output buffering. Not part of the challenge.
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stdin, NULL, _IONBF, 0);
struct topic topics[] = {
{"What is 3077 * 10 + 567?", "", check_math_response},
{"Will it ever rain this year?", "", check_weather_response}};
srand(time(NULL));
struct topic *topic = &topics[rand() % 2];
puts(topic->question);
fgets(topic->answer, sizeof(*topic), stdin);
printf("addr: %X\n", topic->check_response);
return topic->check_response(topic);
}