/*************************************************************************
* Copyright (C) 2014 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.
//     Security Hash Standard
//     General Functionality
//
//  Contents:
//        ippsHashGetTag()
//
*/

#include "owndefs.h"
#include "owncp.h"
#include "hash/pcphash.h"
#include "pcptool.h"

/*F*
//    Name: ippsHashGetTag
//
// Purpose: Compute digest based on current state.
//          Note, that further digest update is possible
//
// Returns:                   Reason:
//    ippStsNullPtrErr           pTag == NULL
//                               pState == NULL
//    ippStsContextMatchErr      pState->idCtx != idCtxHash
//    ippStsLengthErr            hashSize < tagLen <1
//
//    ippStsNotSupportedModeErr  method from the SHA3 family
//
//    ippStsNoErr                no errors
//
// Parameters:
//    pTag     address of the output digest
//    tagLen   length of digest
//    pState   pointer to the SHS state
//
*F*/
IPPFUN(IppStatus, ippsHashGetTag, (Ipp8u * pTag, int tagLen, const IppsHashState* pState))
{
    /* test state pointer and ID */
    IPP_BAD_PTR2_RET(pTag, pState);
    /* test the context */
    IPP_BADARG_RET(!HASH_VALID_ID(pState, idCtxHash), ippStsContextMatchErr);
    /* check if the algorithm is from the sha3 family (SHA3 is not supported in non-rmf methods)*/
    IPP_BADARG_RET(cpIsSHA3AlgID(HASH_ALG_ID(pState)), ippStsNotSupportedModeErr);

    {
        /* size of hash */
        int hashSize = cpHashAlgAttr[HASH_ALG_ID(pState)].hashSize;
        if (tagLen < 1 || hashSize < tagLen)
            IPP_ERROR_RET(ippStsLengthErr);

        cpComputeDigest(pTag, tagLen, pState);
        return ippStsNoErr;
    }
}
