encrypted_queries_tools.py 文件源码

def decrypt(message, receiver_private_key):
    point = message[0:65]
    tag = message[65:81]
    ciphertext = message[81:]
    sender_public_numbers = ec.EllipticCurvePublicNumbers.from_encoded_point(ec.SECP256K1(), point)
    sender_public_key = sender_public_numbers.public_key(backend)
    shared_key = receiver_private_key.exchange(ec.ECDH(), sender_public_key)
    iv = '000000000000'
    xkdf = x963kdf.X963KDF(
        algorithm = hashes.SHA256(),
        length = 32,
        sharedinfo = '',
        backend = backend
        )
    key = xkdf.derive(shared_key)
    decryptor = Cipher(
        algorithms.AES(key),
        modes.GCM(iv,tag),
        backend = backend
        ).decryptor()
    message = decryptor.update(ciphertext) +  decryptor.finalize()
    return message