Files
python-teos/pisa/encrypted_blob.py
Sergi Delgado Segura d2a07d6519 More clean up
2019-10-07 15:36:58 +01:00

32 lines
1.1 KiB
Python

from hashlib import sha256
from binascii import unhexlify, hexlify
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
from pisa import logging
class EncryptedBlob:
def __init__(self, data):
self.data = data
def decrypt(self, key):
# master_key = H(tx_id | tx_id)
master_key = sha256(key + key).digest()
# The 16 MSB of the master key will serve as the AES GCM 128 secret key. The 16 LSB will serve as the IV.
sk = master_key[:16]
nonce = master_key[16:]
logging.info("[Watcher] creating new blob")
logging.info("[Watcher] master key: {}".format(hexlify(master_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