/*************************************************************************
* Copyright (C) 2010 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
//     EC over GF(p^m) definitinons
//
//     Context:
//        ippsGFpECInitStd128r2()
//
*/

#include "owndefs.h"
#include "owncp.h"
#include "gfpec/pcpgfpecstuff.h"
#include "gfpec/pcpeccp.h"



static void cpGFpECSetStd(int aLen,
                          const BNU_CHUNK_T* pA,
                          int bLen,
                          const BNU_CHUNK_T* pB,
                          int xLen,
                          const BNU_CHUNK_T* pX,
                          int yLen,
                          const BNU_CHUNK_T* pY,
                          int rLen,
                          const BNU_CHUNK_T* pR,
                          BNU_CHUNK_T h,
                          IppsGFpECState* pEC)
{
    IppsGFpState* pGF = ECP_GFP(pEC);
    gsModEngine* pGFE = GFP_PMA(pGF);
    int elemLen       = GFP_FELEN(pGFE);

    IppsGFpElement elmA, elmB;
    __ALIGN8 IppsBigNumState R;
    __ALIGN8 IppsBigNumState H;

    /* convert A and B coeffs into GF elements */
    cpGFpElementConstruct(&elmA, cpGFpGetPool(1, pGFE), elemLen);
    cpGFpElementConstruct(&elmB, cpGFpGetPool(1, pGFE), elemLen);
    ippsGFpSetElement((Ipp32u*)pA, BITS2WORD32_SIZE(BITSIZE_BNU(pA, aLen)), &elmA, pGF);
    ippsGFpSetElement((Ipp32u*)pB, BITS2WORD32_SIZE(BITSIZE_BNU(pB, bLen)), &elmB, pGF);
    /* and set EC */
    ippsGFpECSet(&elmA, &elmB, pEC);

    /* construct R and H */
    cpConstructBN(&R, rLen, (BNU_CHUNK_T*)pR, NULL);
    cpConstructBN(&H, 1, &h, NULL);
    /* convert GX and GY coeffs into GF elements */
    ippsGFpSetElement((Ipp32u*)pX, BITS2WORD32_SIZE(BITSIZE_BNU(pX, xLen)), &elmA, pGF);
    ippsGFpSetElement((Ipp32u*)pY, BITS2WORD32_SIZE(BITSIZE_BNU(pY, yLen)), &elmB, pGF);
    /* and init EC subgroup */
    ippsGFpECSetSubgroup(&elmA, &elmB, &R, &H, pEC);
    cpGFpReleasePool(2, pGFE);
}

/*F*
// Name: ippsGFpECInitStd128r2
//
// Purpose: Initializes the context of EC128r2
//
// Returns:                   Reason:
//    ippStsNullPtrErr              NULL == pEC
//                                  NULL == pGFp
//
//    ippStsContextMatchErr         invalid pGFp->idCtx
//
//    ippStsBadArgErr               pGFp does not specify the finite field over which the given
//                                  standard elliptic curve is defined
//
//    ippStsNoErr                   no error
//
// Parameters:
//    pGFp       Pointer to the IppsGFpState context of the underlying finite field
//    pEC        Pointer to the context of the elliptic curve being initialized.
//
*F*/

IPPFUN(IppStatus, ippsGFpECInitStd128r2, (const IppsGFpState* pGFp, IppsGFpECState* pEC))
{
    IPP_BAD_PTR2_RET(pGFp, pEC);

    IPP_BADARG_RET(!GFP_VALID_ID(pGFp), ippStsContextMatchErr);

    {
        gsModEngine* pGFE = GFP_PMA(pGFp);

        /* test if GF is prime GF */
        IPP_BADARG_RET(!GFP_IS_BASIC(pGFE), ippStsBadArgErr);
        /* test underlying prime value*/
        /* clang-format off */
        IPP_BADARG_RET(cpCmp_BNU(secp128r2_p,
                                 BITS_BNU_CHUNK(128),
                                 GFP_MODULUS(pGFE),
                                 BITS_BNU_CHUNK(128)),
                       ippStsBadArgErr);
        /* clang-format on */

        ippsGFpECInit(pGFp, NULL, NULL, pEC);
        cpGFpECSetStd(BITS_BNU_CHUNK(128),
                      secp128r2_a,
                      BITS_BNU_CHUNK(128),
                      secp128r2_b,
                      BITS_BNU_CHUNK(128),
                      secp128r2_gx,
                      BITS_BNU_CHUNK(128),
                      secp128r2_gy,
                      BITS_BNU_CHUNK(128),
                      secp128r2_r,
                      secp128r2_h,
                      pEC);

        return ippStsNoErr;
    }
}
