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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 ( e Zd ZdZd ZddZddZdS )r a[ *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 F t | _ t | t | t
t | | j }|rt d|z t | j t j | _ | t | | _
t dd| | _ | j | _ ddg| _ dS )a Create 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
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block_sizer ivIV_next)self block_cipherr results y/builddir/build/BUILD/imunify360-venv-2.6.2/opt/imunify360/venv/lib64/python3.11/site-packages/Crypto/Cipher/_mode_cbc.py__init__zCbcMode.__init__N s " "mm 00 1A1A1C1C1>> 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 TypeErrorr r r r r CBC_encryptr r r r
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d| j vrt d dg| _ | t t | }n_|}t | st d t | t | k r t dt | z t | j t | t | t t | }|r/|dk rt d| j z t d|z |t | S dS ) a Decrypt 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``.
r z*decrypt() cannot be called after encrypt()Nr& r' r( r) z%Error %d while decrypting in CBC mode)r r* r r r r r CBC_decryptr r r r
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__module__ __qualname____doc__r# r r r$ r" r r ? s[ -, -, -,^@ @ @ @D= = = = = =r$ c | | }| dd }| dd }d||fk rt | j }||t d n|}t | | j k rt
d| j z |r t dt | z t || S )a Instantiate 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).
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