m:Rf*dZdgZddlmZddlmZmZmZmZm Z m Z m Z m Z ddl mZeddZGddeZd 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_byteszCrypto.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(eZdZdZdZddZddZdS)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__ c Ft|_t|t |t t||j}|rtd|zt|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 ValueErrorr CBC_stop_operationrelease block_sizerivIV_next)self block_cipherrresults J/var/www/bsim/venv/lib/python3.11/site-packages/Crypto/Cipher/_mode_cbc.py__init__zCbcMode.__init__Ns ""mm 001A1A1C1C1>> 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``. rz*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 ciphertextr!s r"rzCbcMode.encrypt}sOH DJ & &HII I[ >-c)nn==JJJ&v.. X VWWW9~~V,, "025i.."ABBB(():):)4Y)?)?)4Z)@)@)1#i..)A)ACC  O{{ !VY]Yh!hiiiDvMNN N >!*-- -4r$c d|jvrtddg|_|tt|}n_|}t |stdt|t|krt dt|zt |j t|t|tt|}|r/|dkrt d|j zt d|z|t|SdS) aDecrypt data with the key and the parameters set at initialization. A cipher object is stateful: once you have decrypted a message you cannot decrypt (or encrypt) another message with the same object. The data to decrypt can be broken up in two or more pieces and `decrypt` can be called multiple times. That is, the statement: >>> c.decrypt(a) + c.decrypt(b) is equivalent to: >>> c.decrypt(a+b) This function does not remove any padding from the plaintext. :Parameters: ciphertext : bytes/bytearray/memoryview The piece of data to decrypt. Its length must be multiple of the cipher block size. :Keywords: output : bytearray/memoryview The location where the plaintext must be written to. If ``None``, the plaintext is returned. :Return: If ``output`` is ``None``, the plaintext is returned as ``bytes``. Otherwise, ``None``. rz*decrypt() cannot be called after encrypt()Nr&r'r(r)z%Error %d while decrypting in CBC mode)rr*rrr rr CBC_decryptrrr r rr)rr.r-r,r!s r"rzCbcMode.decryptsOB DJ & &HII I[ >,S__==III&v.. X VWWW:#f++-- "025i.."ABBB(():):)4Z)@)@)4Y)?)?)1#j//)B)BDD  O{{ !VY]Yh!hiiiDvMNN N >!),, ,4r$)N)__name__ __module__ __qualname____doc__r#rrr$r"rr?s[  -,-,-,^@@@@D======r$c ||}|dd}|dd}d||fkrt|j}||t dn|}t ||jkrt d|jz|rt dt|zt||S)aInstantiate a cipher object that performs CBC encryption/decryption. :Parameters: factory : module The underlying block cipher, a module from ``Crypto.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_staterrs r"_create_cbc_cipherr=s&..v66L D$  B D$  BBx g0 1 1 ~ >HII I  2ww'$$$I +,-- -H83v;;FGGG < $ $$r$N)r4__all__Crypto.Util.py3compatrCrypto.Util._raw_apirrrrr r r r Crypto.Randomr robjectrr=r5r$r"rCs > +------77777777777777777777 +*****''(@C $}}}}}f}}}@&%&%&%&%&%r$