Second CTFs part

canary/04_secret_library/main.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+void setup() {
+    setvbuf(stdin, NULL, _IONBF, 0);
+    setvbuf(stdout, NULL, _IONBF, 0);
+    setvbuf(stderr, NULL, _IONBF, 0);
+}
+
+void win() {
+    printf("You've discovered the forbidden section!\n");
+    system("/bin/sh");
+}
+
+void vuln() {
+    char buf[128];
+    
+    printf("Sign the guestbook: ");
+    read(0, buf, 127);
+    buf[127] = '\0';
+    printf("Hello, ");
+    printf(buf);
+    
+    printf("\nLeave a review: ");
+    read(0, buf, 512);
+}
+
+int main() {
+    setup();
+    printf("Welcome to the Secret Library!\n");
+    vuln();
+    return 0;
+}