picoctf/rev/picker_1/picker-I.py

import sys



def getRandomNumber():
  print(4)  # Chosen by fair die roll.
            # Guaranteed to be random.
            # (See XKCD)

def exit():
  sys.exit(0)
  
def esoteric1():
  esoteric = \
  '''
  int query_apm_bios(void)
{
	struct biosregs ireg, oreg;

	/* APM BIOS installation check */
	initregs(&ireg);
	ireg.ah = 0x53;
	intcall(0x15, &ireg, &oreg);

	if (oreg.flags & X86_EFLAGS_CF)
		return -1;		/* No APM BIOS */

	if (oreg.bx != 0x504d)		/* "PM" signature */
		return -1;

	if (!(oreg.cx & 0x02))		/* 32 bits supported? */
		return -1;

	/* Disconnect first, just in case */
	ireg.al = 0x04;
	intcall(0x15, &ireg, NULL);

	/* 32-bit connect */
	ireg.al = 0x03;
	intcall(0x15, &ireg, &oreg);

	boot_params.apm_bios_info.cseg        = oreg.ax;
	boot_params.apm_bios_info.offset      = oreg.ebx;
	boot_params.apm_bios_info.cseg_16     = oreg.cx;
	boot_params.apm_bios_info.dseg        = oreg.dx;
	boot_params.apm_bios_info.cseg_len    = oreg.si;
	boot_params.apm_bios_info.cseg_16_len = oreg.hsi;
	boot_params.apm_bios_info.dseg_len    = oreg.di;

	if (oreg.flags & X86_EFLAGS_CF)
		return -1;

	/* Redo the installation check as the 32-bit connect;
	   some BIOSes return different flags this way... */

	ireg.al = 0x00;
	intcall(0x15, &ireg, &oreg);

	if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) {
		/* Failure with 32-bit connect, try to disconnect and ignore */
		ireg.al = 0x04;
		intcall(0x15, &ireg, NULL);
		return -1;
	}

	boot_params.apm_bios_info.version = oreg.ax;
	boot_params.apm_bios_info.flags   = oreg.cx;
	return 0;
}
  '''
  print(esoteric)


def win():
  # This line will not work locally unless you create your own 'flag.txt' in
  #   the same directory as this script
  flag = open('flag.txt', 'r').read()
  #flag = flag[:-1]
  flag = flag.strip()
  str_flag = ''
  for c in flag:
    str_flag += str(hex(ord(c))) + ' '
  print(str_flag)
  
  
def esoteric2():
  esoteric = \
  '''
#include "boot.h"

#define MAX_8042_LOOPS	100000
#define MAX_8042_FF	32

static int empty_8042(void)
{
	u8 status;
	int loops = MAX_8042_LOOPS;
	int ffs   = MAX_8042_FF;

	while (loops--) {
		io_delay();

		status = inb(0x64);
		if (status == 0xff) {
			/* FF is a plausible, but very unlikely status */
			if (!--ffs)
				return -1; /* Assume no KBC present */
		}
		if (status & 1) {
			/* Read and discard input data */
			io_delay();
			(void)inb(0x60);
		} else if (!(status & 2)) {
			/* Buffers empty, finished! */
			return 0;
		}
	}

	return -1;
}

/* Returns nonzero if the A20 line is enabled.  The memory address
   used as a test is the int $0x80 vector, which should be safe. */

#define A20_TEST_ADDR	(4*0x80)
#define A20_TEST_SHORT  32
#define A20_TEST_LONG	2097152	/* 2^21 */

static int a20_test(int loops)
{
	int ok = 0;
	int saved, ctr;

	set_fs(0x0000);
	set_gs(0xffff);

	saved = ctr = rdfs32(A20_TEST_ADDR);

	while (loops--) {
		wrfs32(++ctr, A20_TEST_ADDR);
		io_delay();	/* Serialize and make delay constant */
		ok = rdgs32(A20_TEST_ADDR+0x10) ^ ctr;
		if (ok)
			break;
	}

	wrfs32(saved, A20_TEST_ADDR);
	return ok;
}

/* Quick test to see if A20 is already enabled */
static int a20_test_short(void)
{
	return a20_test(A20_TEST_SHORT);
}
  '''
  print(esoteric)


while(True):
  try:
    print('Try entering "getRandomNumber" without the double quotes...')
    user_input = input('==> ')
    eval(user_input + '()')
  except Exception as e:
    print(e)
    break