def _login_common(self, res, password):
if res in (-2, -9):
raise MegaIncorrectPasswordExcetion(
"Incorrect e-mail and/or password.")
enc_master_key = base64_to_a32(res['k'])
self.master_key = decrypt_key(enc_master_key, password)
if 'tsid' in res:
tsid = base64urldecode(res['tsid'])
key_encrypted = a32_to_str(
encrypt_key(str_to_a32(tsid[:16]), self.master_key))
if key_encrypted == tsid[-16:]:
self.sid = res['tsid']
elif 'csid' in res:
enc_rsa_priv_key = base64_to_a32(res['privk'])
rsa_priv_key = decrypt_key(enc_rsa_priv_key, self.master_key)
privk = a32_to_str(rsa_priv_key)
self.rsa_priv_key = [0, 0, 0, 0]
for i in range(4):
l = ((privk[0] * 256 + privk[1] + 7) // 8) + 2
self.rsa_priv_key[i] = mpi2int(privk[:l])
privk = privk[l:]
enc_sid = mpi2int(base64urldecode(res['csid']))
decrypter = RSA.construct(
(self.rsa_priv_key[0] * self.rsa_priv_key[1], 0,
self.rsa_priv_key[2], self.rsa_priv_key[0],
self.rsa_priv_key[1]))
sid = '%x' % decrypter.key._decrypt(enc_sid)
sid = binascii.unhexlify('0' + sid if len(sid) % 2 else sid)
self.sid = base64urlencode(sid[:43])
def login_ephemeral(self):
random_master_key = [random.randint(0, 0xFFFFFFFF)] * 4
random_password_key = [random.randint(0, 0xFFFFFFFF)] * 4
random_session_self_challenge = [random.randint(0, 0xFFFFFFFF)] * 4
user_handle = self.api_req({
'a':
'up',
'k':
a32_to_base64(encrypt_key(random_master_key, random_password_key)),
'ts':
base64urlencode(
a32_to_str(random_session_self_challenge) + a32_to_str(
encrypt_key(random_session_self_challenge,
random_master_key)))
})
res = self.api_req({'a': 'us', 'user': user_handle})
self._login_common(res, random_password_key)
def download_file(self, file_id, file_key, public=False, store_path=None):
if public:
file_key = base64_to_a32(file_key)
file_data = self.api_req({'a': 'g', 'g': 1, 'p': file_id})
else:
file_data = self.api_req({'a': 'g', 'g': 1, 'n': file_id})
k = (file_key[0] ^ file_key[4], file_key[1] ^ file_key[5],
file_key[2] ^ file_key[6], file_key[3] ^ file_key[7])
iv = file_key[4:6] + (0, 0)
meta_mac = file_key[6:8]
file_url = file_data['g']
file_size = file_data['s']
attributes = base64urldecode(file_data['at'])
attributes = dec_attr(attributes, k)
file_name = attributes['n']
infile = requests.get(file_url, stream=True).raw
if store_path:
file_name = os.path.join(store_path, file_name)
outfile = open(file_name, 'wb')
counter = Counter.new(128, initial_value=((iv[0] << 32) + iv[1]) << 64)
decryptor = AES.new(a32_to_str(k), AES.MODE_CTR, counter=counter)
file_mac = (0, 0, 0, 0)
for chunk_start, chunk_size in sorted(get_chunks(file_size).items()):
chunk = infile.read(chunk_size)
chunk = decryptor.decrypt(chunk)
outfile.write(chunk)
chunk_mac = [iv[0], iv[1], iv[0], iv[1]]
for i in range(0, len(chunk), 16):
block = chunk[i:i + 16]
if len(block) % 16:
block += b'\0' * (16 - (len(block) % 16))
block = str_to_a32(block)
chunk_mac = [
chunk_mac[0] ^ block[0], chunk_mac[1] ^ block[1],
chunk_mac[2] ^ block[2], chunk_mac[3] ^ block[3]
]
chunk_mac = aes_cbc_encrypt_a32(chunk_mac, k)
file_mac = [
file_mac[0] ^ chunk_mac[0], file_mac[1] ^ chunk_mac[1],
file_mac[2] ^ chunk_mac[2], file_mac[3] ^ chunk_mac[3]
]
file_mac = aes_cbc_encrypt_a32(file_mac, k)
outfile.close()
# Integrity check
if (file_mac[0] ^ file_mac[1], file_mac[2] ^ file_mac[3]) != meta_mac:
raise ValueError('MAC mismatch')
return file_name
def uploadfile(self, filename, dst=None):
if not dst:
root_id = getattr(self, 'root_id', None)
if root_id == None:
self.get_files()
dst = self.root_id
infile = open(filename, 'rb')
size = os.path.getsize(filename)
ul_url = self.api_req({'a': 'u', 's': size})['p']
ul_key = [random.randint(0, 0xFFFFFFFF) for _ in range(6)]
counter = Counter.new(
128, initial_value=((ul_key[4] << 32) + ul_key[5]) << 64)
encryptor = AES.new(a32_to_str(ul_key[:4]),
AES.MODE_CTR,
counter=counter)
file_mac = [0, 0, 0, 0]
for chunk_start, chunk_size in sorted(get_chunks(size).items()):
chunk = infile.read(chunk_size)
chunk_mac = [ul_key[4], ul_key[5], ul_key[4], ul_key[5]]
for i in range(0, len(chunk), 16):
block = chunk[i:i + 16]
if len(block) % 16:
block += b'\0' * (16 - len(block) % 16)
block = str_to_a32(block)
chunk_mac = [
chunk_mac[0] ^ block[0], chunk_mac[1] ^ block[1],
chunk_mac[2] ^ block[2], chunk_mac[3] ^ block[3]
]
chunk_mac = aes_cbc_encrypt_a32(chunk_mac, ul_key[:4])
file_mac = [
file_mac[0] ^ chunk_mac[0], file_mac[1] ^ chunk_mac[1],
file_mac[2] ^ chunk_mac[2], file_mac[3] ^ chunk_mac[3]
]
file_mac = aes_cbc_encrypt_a32(file_mac, ul_key[:4])
chunk = encryptor.encrypt(chunk)
url = '%s/%s' % (ul_url, str(chunk_start))
outfile = requests.post(url, data=chunk, stream=True).raw
# assume utf-8 encoding. Maybe this entire section can be simplified
# by not looking at the raw output
# (http://docs.python-requests.org/en/master/user/advanced/#body-content-workflow)
completion_handle = outfile.read().decode('utf-8')
infile.close()
meta_mac = (file_mac[0] ^ file_mac[1], file_mac[2] ^ file_mac[3])
attributes = {'n': os.path.basename(filename)}
enc_attributes = base64urlencode(enc_attr(attributes, ul_key[:4]))
key = [
ul_key[0] ^ ul_key[4], ul_key[1] ^ ul_key[5],
ul_key[2] ^ meta_mac[0], ul_key[3] ^ meta_mac[1], ul_key[4],
ul_key[5], meta_mac[0], meta_mac[1]
]
encrypted_key = a32_to_base64(encrypt_key(key, self.master_key))
data = self.api_req({
'a':
'p',
't':
dst,
'n': [{
'h': completion_handle,
't': 0,
'a': enc_attributes,
'k': encrypted_key
}]
})
return data
def dec_attr(attr, key):
attr = aes_cbc_decrypt(attr, a32_to_str(key)).decode('utf-8').rstrip('\0')
return json.loads(attr[4:])
def enc_attr(attr, key):
attr = 'MEGA' + json.dumps(attr)
if len(attr) % 16:
attr += '\0' * (16 - len(attr) % 16)
return aes_cbc_encrypt(attr, a32_to_str(key))
def aes_cbc_decrypt_a32(data, key):
return str_to_a32(aes_cbc_decrypt(a32_to_str(data), a32_to_str(key)))
