/*************************************************************************
* Copyright (C) 2002 Intel Corporation
*
* Licensed under the Apache License,  Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law  or agreed  to  in  writing,  software
* distributed under  the License  is  distributed  on  an  "AS IS"  BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the  specific  language  governing  permissions  and
* limitations under the License.
*************************************************************************/

/* 
// 
//  Purpose:
//     Cryptography Primitive.
//     Digesting message according to SHA256
// 
//  Contents:
//        ippsSHA256GetTag()
//
*/

#include "owndefs.h"
#include "owncp.h"
#include "pcphash.h"
#include "pcphash_rmf.h"
#include "pcptool.h"
#include "pcpsha256stuff.h"

/*F*
//    Name: ippsSHA256GetTag
//
// Purpose: Compute digest based on current state.
//          Note, that further digest update is possible
//
// Returns:                Reason:
//    ippStsNullPtrErr        pTag == NULL
//                            pState == NULL
//    ippStsContextMatchErr   pState->idCtx != idCtxSHA256
//    ippStsLengthErr         max_SHA_digestLen < tagLen <1
//    ippStsNoErr             no errors
//
// Parameters:
//    pTag        address of the output digest
//    tagLen      length of digest
//    pState      pointer to the SHA256 state
//
*F*/
IPPFUN(IppStatus, ippsSHA256GetTag,(Ipp8u* pTag, Ipp32u tagLen, const IppsSHA256State* pState))
{
   /* test state pointer and ID */
   IPP_BAD_PTR1_RET(pState);
   IPP_BADARG_RET(!HASH_VALID_ID(pState, idCtxSHA256), ippStsContextMatchErr);

   /* test digest pointer */
   IPP_BAD_PTR1_RET(pTag);
   IPP_BADARG_RET((tagLen<1)||(sizeof(DigestSHA256)<tagLen), ippStsLengthErr);

   {
      DigestSHA256 digest;
      CopyBlock(HASH_VALUE(pState), digest, sizeof(DigestSHA256));
      cpFinalizeSHA256(digest, HASH_BUFF(pState), HASH_BUFFIDX(pState), HASH_LENLO(pState));
      digest[0] = ENDIANNESS32(digest[0]);
      digest[1] = ENDIANNESS32(digest[1]);
      digest[2] = ENDIANNESS32(digest[2]);
      digest[3] = ENDIANNESS32(digest[3]);
      digest[4] = ENDIANNESS32(digest[4]);
      digest[5] = ENDIANNESS32(digest[5]);
      digest[6] = ENDIANNESS32(digest[6]);
      digest[7] = ENDIANNESS32(digest[7]);
      CopyBlock(digest, pTag, (cpSize)tagLen);

      return ippStsNoErr;
   }
}
