mirror of
https://github.com/aljazceru/python-teos.git
synced 2026-01-14 03:44:25 +01:00
42 lines
1.4 KiB
Python
42 lines
1.4 KiB
Python
from binascii import unhexlify, hexlify
|
|
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
|
|
from cryptography.hazmat.primitives.kdf.hkdf import HKDF
|
|
from cryptography.hazmat.primitives import hashes
|
|
from cryptography.hazmat.backends import default_backend
|
|
from conf import SALT
|
|
|
|
|
|
class EncryptedBlob:
|
|
def __init__(self, data):
|
|
self.data = data
|
|
|
|
def decrypt(self, key, debug, logging):
|
|
# Extend the key using HKDF
|
|
hkdf = HKDF(
|
|
algorithm=hashes.SHA256(),
|
|
length=32,
|
|
salt=SALT.encode(),
|
|
info=None,
|
|
backend=default_backend()
|
|
)
|
|
|
|
extended_key = hkdf.derive(key)
|
|
|
|
# The 16 MSB of the extended key will serve as the AES GCM 128 secret key. The 16 LSB will serve as the IV.
|
|
sk = extended_key[:16]
|
|
nonce = extended_key[16:]
|
|
|
|
if debug:
|
|
logging.info("[Watcher] creating new blob")
|
|
logging.info("[Watcher] master key: {}".format(hexlify(key).decode()))
|
|
logging.info("[Watcher] sk: {}".format(hexlify(sk).decode()))
|
|
logging.info("[Watcher] nonce: {}".format(hexlify(nonce).decode()))
|
|
logging.info("[Watcher] encrypted_blob: {}".format(self.data))
|
|
|
|
# Decrypt
|
|
aesgcm = AESGCM(sk)
|
|
data = unhexlify(self.data.encode())
|
|
raw_tx = aesgcm.decrypt(nonce=nonce, data=data, associated_data=None)
|
|
|
|
return raw_tx
|