#define MAX_SIZE 32
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>



unsigned int a = 1103515245;
unsigned int c = 12345;
unsigned int m = 2147483647;
unsigned int seed = 1337;

unsigned char user_input[MAX_SIZE];
const unsigned int STATE[4] = {0x1e48add6, 0xaaa7550c, 0x18df53bf, 0xe6af1116};

unsigned int start[] = {0x0, 0x0, 0x0, 0x0};

unsigned int gen_random(void) {
  seed = (unsigned int)(((unsigned int)a * (unsigned int)seed + (unsigned int)c) % m);
  return (unsigned int)seed;
}

void setup() {
  printf("==================================================");
  printf("=               SECURE LOCK - v0.5               =");
  printf("==================================================");
}

int check_pass(unsigned int start[]) {
    //printf("checking\n");
    unsigned int temp = 0;
    for (int i = 0; i < 4; ++i) {
      temp = start[i];
      temp *= (unsigned int)0xcafebeef;
      temp += (unsigned int)gen_random();
      temp *= (unsigned int)0xfacefeed;
      temp ^= (unsigned int)gen_random();

      if ((unsigned int)temp != (unsigned int)STATE[i]) {
        return 0;
      }
    }
    return 1;
}

void main(){
  
  memset(user_input,0,MAX_SIZE);
  memset(start, 0, 16);
  read(0, user_input, MAX_SIZE);

  //printf("%X ",user_input);
  //printf("\n");
  for (int i = 0; i < 4; i++) {

    start[i] |= ((unsigned int)user_input[(i * 4)]   << 24);
    start[i] |= ((unsigned int)user_input[(i * 4)+1] << 16);
    start[i] |= ((unsigned int)user_input[(i * 4)+2] << 8);
    start[i] |= ((unsigned int)user_input[(i * 4)+3] << 0);

    //printf("%X ",start[i]);
  }

  //printf("\n");

  if (check_pass(start) == 1) {
    //printf("Thats it!\r\nSubmit in the format FLAG{");
    for (int i = 0; i < 4; i++) {
          //printf("%X",start[i]);
    }
    //printf("}\n");
  }

  // Failed, just spin
  printf("Incorrect password!");
}