bugku 蜘蛛侠

链接

蜘蛛侠

思路

1. 查看hint
2. decode key.jpg

• import os

  data_jpg = open('file.jpg', 'wb')
  def jpg_encode():
  with open('file.jpg', 'rb') as handle:
  size = os.path.getsize('file.jpg')
  print(size)
  i = 0
  while i<size:
  bytedata = handle.read(1)
  process_data = data_encode(bytedata)
  data_write(process_data)
  i = i + 1

  def data_encode(bytedata):
  data = int.from_bytes(bytedata,byteorder='big')
  if (data % 2 == 0):
  data = (data + 1) ^ 128
  else:
  data = (data - 1) ^ 128
  data = bytes([data])
  return data

  def data_decode(bytedata):
  data = int.from_bytes(bytedata,byteorder='big')
  if (data % 2 == 0):
  data = (data - 1) ^ 128
  else:
  data = (data + 1) ^ 128
  data = bytes([data])
  return data

  def jpg_decode():
  with open('key.jpg', 'rb') as handle:
  size = os.path.getsize('key.jpg')
  print(size)
  i = 0
  while i<size:
  bytedata = handle.read(1)
  process_data = data_encode(bytedata)
  data_write(process_data)
  i = i + 1

  def data_write(process_data):
  data_jpg.write(process_data)

  if __name__ == '__main__':
  jpg_decode()
  data_jpg.close()

1. 得到file的jpg

1. 010查看发现ffd9后有一串IQ2?kEcY/KK#ojDrHoR'seBbase92编码
2. 解码得到提示silenteye，下载软件解密得到flag