o j*@spdZdgZddlmZddlmZmZmZmZm Z m Z m Z m Z ddl mZeddZGdddeZd d Zd S) z' Ciphertext Block Chaining (CBC) mode. CbcMode) _copy_bytes)load_pycryptodome_raw_lib VoidPointercreate_string_bufferget_raw_buffer SmartPointerc_size_t c_uint8_ptris_writeable_buffer)get_random_byteszCryptodome.Cipher._raw_cbca int CBC_start_operation(void *cipher, const uint8_t iv[], size_t iv_len, void **pResult); int CBC_encrypt(void *cbcState, const uint8_t *in, uint8_t *out, size_t data_len); int CBC_decrypt(void *cbcState, const uint8_t *in, uint8_t *out, size_t data_len); int CBC_stop_operation(void *state); c@s,eZdZdZddZd ddZd ddZdS) ra[*Cipher-Block Chaining (CBC)*. Each of the ciphertext blocks depends on the current and all previous plaintext blocks. An Initialization Vector (*IV*) is required. See `NIST SP800-38A`_ , Section 6.2 . .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf :undocumented: __init__ cCst|_t|t|tt||j}|rt d|t |jtj |_| t||_ tdd||_ |j|_ ddg|_dS)aCreate a new block cipher, configured in CBC 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 unpredictable**. Ideally it is picked randomly. Reusing the *IV* for encryptions performed with the same key compromises confidentiality. z)Error %d while instantiating the CBC modeNencryptdecrypt)r_state raw_cbc_libCBC_start_operationgetr r len address_of ValueErrorrCBC_stop_operationrelease block_sizerivIV_next)self block_cipherrresultr/root/aizidognhua/tmp/workspace/projects/ec89d86c-575f-41c9-af57-ac45cbdbf775/venv/lib/python3.10/site-packages/Cryptodome/Cipher/_mode_cbc.py__init__Ns*    zCbcMode.__init__NcCsd|jvr tddg|_|durtt|}n|}t|s"tdt|t|kr2tdt|t|j t |t |t t|}|rX|dkrRtd|j td||dur`t |SdS) aEncrypt 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) That also means that you cannot reuse an object for encrypting or decrypting other data with the same key. This function does not add any padding to the plaintext. :Parameters: plaintext : bytes/bytearray/memoryview The piece of data to encrypt. Its lenght must be multiple of the cipher block size. :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()N4output must be a bytearray or a writeable memoryview9output must have the same length as the input (%d bytes)3Data must be padded to %d byte boundary in CBC modez%Error %d while encrypting in CBC mode)r TypeErrorrrr rr CBC_encryptrrr r rr)r plaintextoutput ciphertextrrrr r }s0 $   zCbcMode.encryptcCsd|jvr tddg|_|durtt|}n|}t|s"tdt|t|kr2tdt|t|j t |t |t t|}|rX|dkrRtd|j td||dur`t |SdS) aDecrypt data with the key and the parameters set at initialization. A cipher object is stateful: once you have decrypted a message you cannot decrypt (or encrypt) another message with the same object. The data to decrypt can be broken up in two or more pieces and `decrypt` can be called multiple times. That is, the statement: >>> c.decrypt(a) + c.decrypt(b) is equivalent to: >>> c.decrypt(a+b) This function does not remove any padding from the plaintext. :Parameters: ciphertext : bytes/bytearray/memoryview The piece of data to decrypt. Its length must be multiple of the cipher block size. :Keywords: output : bytearray/memoryview The location where the plaintext must be written to. If ``None``, the plaintext is returned. :Return: If ``output`` is ``None``, the plaintext is returned as ``bytes``. Otherwise, ``None``. rz*decrypt() cannot be called after encrypt()Nr"r#r$r%z%Error %d while decrypting in CBC mode)rr&rrr rr CBC_decryptrrr r rr)rr*r)r(rrrr rs0 !   zCbcMode.decrypt)N)__name__ __module__ __qualname____doc__r!r rrrrr r?s  /BcKs||}|dd}|dd}d||fkrt|j}|dur)|dur(tdn|}t||jkr9td|j|rCtdt|t||S)aInstantiate a cipher object that performs CBC encryption/decryption. :Parameters: factory : module The underlying block cipher, a module from ``Cryptodome.Cipher``. :Keywords: iv : bytes/bytearray/memoryview The IV to use for CBC. IV : bytes/bytearray/memoryview Alias for ``iv``. Any other keyword will be passed to the underlying block cipher. See the relevant documentation for details (at least ``key`` will need to be present). rNr)NNz*You must either use 'iv' or 'IV', not bothz.Incorrect IV length (it must be %d bytes long)zUnknown parameters for CBC: %s) _create_base_cipherpopr rr&rrstrr)factorykwargs cipher_staterrrrr _create_cbc_ciphers"      r6N)r/__all__Cryptodome.Util.py3compatrCryptodome.Util._raw_apirrrrrr r r Cryptodome.Randomr robjectrr6rrrr s (   A