72 lines
2.4 KiB
Python
72 lines
2.4 KiB
Python
import urllib2
|
|
|
|
class Cursor(object):
|
|
def __init__(self, file):
|
|
self._file=file
|
|
self.pos=0
|
|
self.conn =None
|
|
self.initial_value = file.initial_value
|
|
self.k = file.k
|
|
|
|
def mega_request(self,offset, retry=False):
|
|
if not self._file.url or retry:
|
|
if self._file.folder_id :
|
|
file = self._file._client.api_req({"a":"g","g":1,"n":self._file.file_id},"&n="+self._file.folder_id)
|
|
self._file.url= file["g"]
|
|
else:
|
|
file = self._file._client.api_req({'a': 'g', 'g': 1, 'p': self._file.file_id})
|
|
self._file.url= file["g"]
|
|
|
|
req = urllib2.Request(self._file.url)
|
|
req.headers['Range'] = 'bytes=%s-' % (offset)
|
|
try:
|
|
self.conn = urllib2.urlopen(req)
|
|
self.prepare_decoder(offset)
|
|
except:
|
|
#La url del archivo expira transcurrido un tiempo, si da error 403, reintenta volviendo a solicitar la url mediante la API
|
|
self.mega_request(offset, True)
|
|
|
|
def read(self,n=None):
|
|
if not self.conn:
|
|
return
|
|
res=self.conn.read(n)
|
|
if res:
|
|
res = self.decode(res)
|
|
self.pos+=len(res)
|
|
return res
|
|
|
|
|
|
def seek(self,n):
|
|
if n>self._file.size:
|
|
n=self._file.size
|
|
elif n<0:
|
|
raise ValueError('Seeking negative')
|
|
self.mega_request(n)
|
|
self.pos=n
|
|
|
|
def tell(self):
|
|
return self.pos
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self,exc_type, exc_val, exc_tb):
|
|
self._file.cursors.remove(self)
|
|
if len(self._file.cursors) == 0: self._file.cursor = False
|
|
|
|
def decode(self, data):
|
|
return self.decryptor.decrypt(data)
|
|
|
|
def prepare_decoder(self,offset):
|
|
initial_value = self.initial_value + int(offset/16)
|
|
try:
|
|
from Crypto.Cipher import AES
|
|
from Crypto.Util import Counter
|
|
self.decryptor = AES.new(self._file._client.a32_to_str(self.k), AES.MODE_CTR, counter = Counter.new(128, initial_value = initial_value))
|
|
except:
|
|
from pyaes import aes
|
|
self.decryptor = aes.AESModeOfOperationCTR(f=self,key=self._client.a32_to_str(self.k),counter=aes.Counter(initial_value=initial_value))
|
|
|
|
rest = offset - int(offset/16)*16
|
|
if rest:
|
|
self.decode(str(0)*rest) |