.. _hashinit:


HashInit
========


Initializes user-supplied memory as IppsHashState or IppsHashState_rmf
context for future use.


Syntax
------


IppStatus ippsHashInit(IppsHashState\* pCtx, IppHashAlgId hashAlg);


IppStatus ippsHashInit_rmf(IppsHashState_rmf\* pCtx, IppsHashMethod\*
pMethod);


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


``ippcp.h``


Parameters
----------


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

   * -     pCtx   
     -  Pointer to the IppsHashState or IppsHashState_rmf context being intialized.
   * -     hashAlg   
     -  Identifier of the hash algorithm.
   * -     pMethod   
     -  Pointer to the hash method.




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


The function initializes the memory pointed by pCtx as IppsHashState or
IppsHashState_rmf context. The hashAlg and pMethod parameters define the
hash algorithm to be used in subsequent calls to
`HashUpdate <hashupdate.html>`__
,
`HashFinal <hashfinal.html>`__,
or
`HashGetTag <hashgettag.html>`__
functions. The hashAlg parameter can take one of the values listed in
table `Supported Hash
Algorithms <one-way-hash-primitives.html>`__.
To get a value for the pMethod parameter, call one of the
`HashMethod <hashmethod.html>`__
functions.


.. note::


   This function has a *reduced memory footprint* version. To learn
   more, see `Reduced Memory Footprint
   Functions <one-way-hash-primitives.html>`__.


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.   
   * -     ippStsNotSupportedModeErr   
     -     Indicates an error condition if the hashAlg parameter does not match any value of IppHashAlg listed in table `Supported Hash Algorithms <one-way-hash-primitives.html>`__.   




.. rubric:: Related Information

:ref:`data-security-considerations`