.. _sha256pack-sha256unpack:


SHA256Pack, SHA256Unpack
========================


Packs/unpacks the IppsSHA256State context into/from a user-defined
buffer.


Syntax
------


IppStatus ippsSHA256Pack (const IppsSHA256State\* pCtx, Ipp8u\*
pBuffer);


IppStatus ippsSHA256Unpack (const Ipp8u\* pBuffer, IppsSHA256State\*
pCtx);


Include Files
-------------


``ippcp.h``


Parameters
----------


.. list-table:: 
   :header-rows: 0

   * -     pCtx   
     -  Pointer to the IppsSHA256State context.
   * -     pBuffer   
     -  Pointer to the user-defined buffer.




Description
-----------


The SHA256Pack function transforms the \*pCtx context to a
position-independent form and stores it in the \*pBuffer buffer. The
SHA256Unpack function performs the inverse operation, that is,
transforms the contents of the \*pBuffer buffer into a normal
IppsSHA256State context. The SHA256Pack and SHA256Unpack functions
enable replacing the position-dependent IppsSHA256State context in the
memory.


Call the
`SHA256GetSize <sha256getsize.html>`__
function prior to SHA256Pack/SHA256Unpack to determine the size of the
buffer.


Return Values
-------------


.. list-table:: 
   :header-rows: 0

   * -     ippStsNoErr   
     -  Indicates no error. Any other value indicates an error or warning.
   * -     ippStsNullPtrErr   
     -  Indicates an error condition if any of the specified pointers is NULL.