def __init__(self, key: RSA.RsaKey = None):
if not key:
self.key = RSA.generate(4096, Random.new().read)
elif key and isinstance(key, RSA.RsaKey) and key.has_private():
self.key: RSA.RsaKey = key
else:
raise TypeError('key must be private RSA key')
def unpack(self,
raw: Union[bytes, bytearray],
key: RSA.RsaKey = None) -> Packet:
if isinstance(raw, (bytes, bytearray)):
if isinstance(raw, bytes):
raw = bytearray(raw)
header: Header = self.unpack_header(raw[:HEADER_SIZE])
if header.checksum != hashlib.blake2s(raw[HEADER_SIZE:]).digest():
raise PacketError('Data is corrupted (Bad checksum)')
if header.flags.encrypted:
cipher: PKCS1_OAEP.PKCS1OAEP_Cipher = PKCS1_OAEP.new(
key if key and key.has_private() else self.key, SHA3_256)
chunk: int = header.flags.cluster
decrypted = bytearray()
try:
for i in (raw[HEADER_SIZE:][i:i + chunk]
for i in range(0,
raw.__len__() -
HEADER_SIZE, chunk)):
decrypted.extend(cipher.decrypt(i))
except ValueError:
raise DamageError(f'Encrypted data is damaged')
header.flags.size = len(
decrypted) if header.flags.encrypted else len(
raw[HEADER_SIZE:])
return Packet(
header,
decrypted if header.flags.encrypted else raw[HEADER_SIZE:],
bytes(raw[44:76]) if header.flags.encrypted else None)
else:
raise TypeError('Raw must be bytes or bytearray')
def from_rsa_obj(cls, rsa: RSA.RsaKey):
if not rsa.has_private():
return XeCrypt_RSA(n=rsa._n, e=rsa._e)
else:
return XeCrypt_RSA(n=rsa._n, e=rsa._e, d=rsa._d, p=rsa._p, q=rsa._q, u=rsa._u)