def __init__(self, factory, key, nonce, kwargs):
self.block_size = factory.block_size
"""The block size of the underlying cipher, in bytes."""
self._factory = factory
self._nonce = nonce
self._cipher_params = kwargs
if len(key) not in (32, 48, 64):
raise ValueError("Incorrect key length (%d bytes)" % len(key))
if nonce is not None:
if isinstance(nonce, unicode):
raise TypeError(
"When provided, the nonce must be a byte string")
if len(nonce) == 0:
raise ValueError("When provided, the nonce must be non-empty")
self.nonce = bstr(nonce)
"""Public attribute is only available in case of non-deterministic
encryption."""
subkey_size = len(key) // 2
self._mac_tag = None # Cache for MAC tag
self._kdf = _S2V(key[:subkey_size],
ciphermod=factory,
cipher_params=self._cipher_params)
self._subkey_cipher = key[subkey_size:]
# Purely for the purpose of verifying that cipher_params are OK
factory.new(key[:subkey_size], factory.MODE_ECB, **kwargs)
# Allowed transitions after initialization
self._next = [
self.update, self.encrypt, self.decrypt, self.digest, self.verify
]
def __init__(self, factory, key, nonce, kwargs):
self.block_size = factory.block_size
"""The block size of the underlying cipher, in bytes."""
self._factory = factory
self._nonce = nonce
self._cipher_params = kwargs
if len(key) not in (32, 48, 64):
raise ValueError("Incorrect key length (%d bytes)" % len(key))
if nonce is not None:
if not byte_string(nonce):
raise TypeError("When provided, the nonce must be a byte string")
if len(nonce) == 0:
raise ValueError("When provided, the nonce must be non-empty")
self.nonce = nonce
"""Public attribute is only available in case of non-deterministic
encryption."""
subkey_size = len(key) // 2
self._mac_tag = None # Cache for MAC tag
self._kdf = _S2V(key[:subkey_size],
ciphermod=factory,
cipher_params=self._cipher_params)
self._subkey_cipher = key[subkey_size:]
# Purely for the purpose of verifying that cipher_params are OK
factory.new(key[:subkey_size], factory.MODE_ECB, **kwargs)
# Allowed transitions after initialization
self._next = [self.update, self.encrypt, self.decrypt,
self.digest, self.verify]