15// gcc pwnable.c

10#10include15 15<stdio.h>
10#10include15 15<stdlib.h>
10#10include15 15<string.h>
10#10include15 15<unistd.h>
10#10include15 15<sys/mman.h>

10long15 07compute(10int15 c)15 {
15  10long15 i15 =15 020;
15  02while15 (c15 >15 021)15 {
15    i++;
15    02if15 (c%02215 ==15 020)15 c15 /=15 022;
15    02else15 c15 =15 023*c15 +15 021;
15  }

15  02return15 i;
}

10int15 07main()15 {
15  10int15 uid15 =15 020;
15  10void*15 buffer15 =15 mmap(10NULL,15 020x1000,15 PROT_WRITE15 |15 PROT_EXEC,15 MAP_ANON15 |15 MAP_PRIVATE,15 02-1,15 020);

15  puts(05"05Welcome to AIC Factory Terminal.05");
15  puts(05"05WARNING: The power system is about to reach its capacity limit.05");
15  puts(05"05WARNING: To prevent draining, your power usage for this session will be limited.05");
15  puts(05"05Now waiting for input.05");

15  10ssize_t15 input_size15 =15 read(STDIN_FILENO,15 buffer,15 020x1000);

15  02if15 (input_size15 >15 020)15 {
15    10long15 10long15 accu15 =15 020;
15    10unsigned15 10char15 *buf_ptr15 =15 (10unsigned15 10char15 *)buffer;
15    02for15 (10int15 i15 =15 020;15 i15 <15 input_size;15 i++)15 {
15      10long15 cur15 =15 compute(buf_ptr[i]);
15      15// printf("%ld %d\n", cur, buf_ptr[i]);

15      02if15 (cur15 >15 0235)15 {
15    	puts(05"05Consuming too much computational power. Aborting...05");
15    	exit(021);
15      }
15      accu15 +=15 cur;
15    }

15    15// Length limit perhaps
15    02if15 (accu15 >15 02200)15 {
15	puts(05"05Accumulative power usage is too high. Aborting...05");
15	exit(021);
15    }
15  }15 02else15 {
15    puts(05"05Error reading input.05");
15  }

15  puts(05"05Now executing...05");

15  ((10void15 (*)(10void))buffer)();

15  02if15 (uid15 ==15 020x1337)15 {
15    puts(05"05Power user detected. Granting full access...05");
15  }

15  02return15 020;
}