/*************************************************************************
* Copyright (C) 2018 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.
*************************************************************************/

/*
//     Intel(R) Cryptography Primitives Library
//     Operations over GF(p).
//
//     Context:
//        ippsGFpGetElementOctString()
//
*/
#include "owndefs.h"
#include "owncp.h"

#include "gfpec/pcpgfpstuff.h"
#include "gfpec/pcpgfpxstuff.h"
#include "pcptool.h"


/*F*
// Name: ippsGFpGetElementOctString
//
// Purpose: Get GF Element to the octet string
//
// Returns:                   Reason:
//    ippStsNullPtrErr           NULL == pGFp
//                               NULL == pStr
//                               NULL == pA
//
//    ippStsContextMatchErr      invalid pGFp->idCtx
//                               invalid pA->idCtx
//                               invalid pR->idCtx
//
//    ippStsOutOfRangeErr        GFPE_ROOM() != GFP_FELEN()
//
//    ippStsSizeErr              !(0<lenA && lenA>=GFP_FELEN32(pGFE))
//
//    ippStsNoErr                no error
//
// Parameters:
//    pA       Pointer to the context of the finite field element.
//    pStr     Pointer to the octet string.
//    strSize  Size of the octet string buffer in bytes.
//    pGFp     Pointer to the context of the finite field.
//
*F*/

/* clang-format off */
IPPFUN(IppStatus, ippsGFpGetElementOctString,(const IppsGFpElement* pA,
                                              Ipp8u* pStr,
                                              int strSize,
                                              IppsGFpState* pGFp))
/* clang-format on */
{
    IPP_BAD_PTR3_RET(pStr, pA, pGFp);
    IPP_BADARG_RET(!GFP_VALID_ID(pGFp), ippStsContextMatchErr);
    IPP_BADARG_RET(!GFPE_VALID_ID(pA), ippStsContextMatchErr);
    IPP_BADARG_RET(0 >= strSize, ippStsSizeErr);
    {
        gsModEngine* pGFE = GFP_PMA(pGFp);
        IPP_BADARG_RET(GFPE_ROOM(pA) != GFP_FELEN(pGFE), ippStsOutOfRangeErr);
        {
            gsModEngine* pBasicGFE = cpGFpBasic(pGFE);
            int basicDeg           = cpGFpBasicDegreeExtension(pGFE);
            int basicElemLen       = GFP_FELEN(pBasicGFE);
            int basicSize =
                BITS2WORD8_SIZE(BITSIZE_BNU(GFP_MODULUS(pBasicGFE), GFP_FELEN(pBasicGFE)));

            BNU_CHUNK_T* pDataElm = GFPE_DATA(pA);
            int deg, error;
            for (deg = 0, error = 0; deg < basicDeg && !error; deg++) {
                int size = IPP_MIN(strSize, basicSize);
                error    = (NULL == cpGFpGetOctString(pStr, size, pDataElm, pBasicGFE));

                pDataElm += basicElemLen;
                pStr += size;
                strSize -= size;
            }

            return error ? ippStsSizeErr : ippStsNoErr;
        }
    }
}
