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편집 파일: _mode_ofb.cpython-311.pyc
� �E�M���� � � d Z dgZddlmZ ddlmZmZmZmZm Z m Z mZmZ ddl mZ edd� � Z G d� de� � Zd � Zd S )z Output Feedback (CFB) mode. �OfbMode� )�_copy_bytes)�load_pycryptodome_raw_lib�VoidPointer�create_string_buffer�get_raw_buffer�SmartPointer�c_size_t�c_uint8_ptr�is_writeable_buffer)�get_random_byteszCrypto.Cipher._raw_ofba int OFB_start_operation(void *cipher, const uint8_t iv[], size_t iv_len, void **pResult); int OFB_encrypt(void *ofbState, const uint8_t *in, uint8_t *out, size_t data_len); int OFB_decrypt(void *ofbState, const uint8_t *in, uint8_t *out, size_t data_len); int OFB_stop_operation(void *state); c �( � e Zd ZdZd� Zdd�Zdd�ZdS )r a� *Output FeedBack (OFB)*. This mode is very similar to CBC, but it transforms the underlying block cipher into a stream cipher. The keystream is the iterated block encryption of the previous ciphertext block. An Initialization Vector (*IV*) is required. See `NIST SP800-38A`_ , Section 6.4. .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf :undocumented: __init__ c �F � t � � | _ t � |� � � t |� � t t |� � � � | j � � � � � }|rt d|z � � �t | j � � � t j � � | _ |� � � t |� � | _ t dd|� � | _ | j | _ ddg| _ dS )aS Create a new block cipher, configured in OFB mode. :Parameters: block_cipher : C pointer A smart pointer to the low-level block cipher instance. iv : bytes/bytearray/memoryview The initialization vector to use for encryption or decryption. It is as long as the cipher block. **The IV must be a nonce, to to be reused for any other message**. It shall be a nonce or a random value. Reusing the *IV* for encryptions performed with the same key compromises confidentiality. z)Error %d while instantiating the OFB modeN�encrypt�decrypt)r �_state�raw_ofb_lib�OFB_start_operation�getr r �len� address_of� ValueErrorr �OFB_stop_operation�release� block_sizer �iv�IV�_next)�self�block_cipherr �results �y/builddir/build/BUILD/imunify360-venv-2.5.2/opt/imunify360/venv/lib64/python3.11/site-packages/Crypto/Cipher/_mode_ofb.py�__init__zOfbMode.__init__I s � �$ "�m�m����0�0��1A�1A�1C�1C�1<�R���19�#�b�'�'�1B�1B�15��1G�1G�1I�1I�K� K�� � '��H�%�&� '� '� '� #�4�;�?�?�#4�#4�#.�#A�C� C��� �������b�'�'���@��d�D�"�-�-��� &� �'������+�� � � � Nc �\ � d| j vrt d� � �dg| _ |�t t |� � � � }n_|}t |� � st d� � �t |� � t |� � k rt dt |� � z � � �t � | j � � � t |� � t |� � t t |� � � � � � }|rt d|z � � �|�t |� � S dS )a� Encrypt data with the key and the parameters set at initialization. A cipher object is stateful: once you have encrypted a message you cannot encrypt (or decrypt) another message using the same object. The data to encrypt can be broken up in two or more pieces and `encrypt` can be called multiple times. That is, the statement: >>> c.encrypt(a) + c.encrypt(b) is equivalent to: >>> c.encrypt(a+b) This function does not add any padding to the plaintext. :Parameters: plaintext : bytes/bytearray/memoryview The piece of data to encrypt. It can be of any length. :Keywords: output : bytearray/memoryview The location where the ciphertext must be written to. If ``None``, the ciphertext is returned. :Return: If ``output`` is ``None``, the ciphertext is returned as ``bytes``. Otherwise, ``None``. r z*encrypt() cannot be called after decrypt()N�4output must be a bytearray or a writeable memoryview�9output must have the same length as the input (%d bytes)z%Error %d while encrypting in OFB mode) r � TypeErrorr r r r r �OFB_encryptr r r r r )r � plaintext�output� ciphertextr! s r"