codes/THCTT24_running_number/rewrite/running_number_rewrite.c

39 lines
852 B
C

#include <stdio.h>
#include <stdlib.h>
// This is rewrite of 'running_number' with help from ghidra
// while ensuring the integrity of program flows and so on
int main(void) {
int seed;
int rand_var;
int i;
int md5_answer;
printf("Time: ");
scanf("%u", &seed);
srand(seed);
long sum = 0;
for (i = 0xa07; i > 0x7e7; i--) { // 2567 2023
if (i % 3 != 0) {
rand_var = rand();
sum = sum + rand_var;
}
}
if (sum == 0x5aad48bfa6) { // 389454282662
printf("THCTT24{");
for (i = 10; i < 0x4a; i++) { // 74
if ((i & 1) == 0) {
rand_var = rand();
md5_answer = rand_var % 0x10;
printf("%x", md5_answer); // 16
}
}
puts("}");
} else {
puts("No Flag");
}
}