/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifdef FREEBL_NO_DEPEND

#include "stubs.h"

#endif

#include "blapi.h"

#include "secoid.h"

#include "secitem.h"

#include "secerr.h"

#include "ec.h"

#include "ecl-curve.h"

#define CHECK_OK(func) \

    if (func == NULL)  \

    goto cleanup

#define CHECK_SEC_OK(func)         \

    if (SECSuccess != (rv = func)) \

    goto cleanup

/* Copy all of the fields from srcParams into dstParams

 */

SECStatus

EC_CopyParams(PLArenaPool *arena, ECParams *dstParams,

              const ECParams *srcParams)

{

    SECStatus rv = SECFailure;

    dstParams->arena = arena;

    dstParams->type = srcParams->type;

    dstParams->fieldID.size = srcParams->fieldID.size;

    dstParams->fieldID.type = srcParams->fieldID.type;

    if (srcParams->fieldID.type == ec_field_GFp ||

        srcParams->fieldID.type == ec_field_plain) {

        CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->fieldID.u.prime,

                                      &srcParams->fieldID.u.prime));

    } else {

        CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->fieldID.u.poly,

                                      &srcParams->fieldID.u.poly));

    }

    dstParams->fieldID.k1 = srcParams->fieldID.k1;

    dstParams->fieldID.k2 = srcParams->fieldID.k2;

    dstParams->fieldID.k3 = srcParams->fieldID.k3;

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->curve.a,

                                  &srcParams->curve.a));

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->curve.b,

                                  &srcParams->curve.b));

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->curve.seed,

                                  &srcParams->curve.seed));

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->base,

                                  &srcParams->base));

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->order,

                                  &srcParams->order));

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->DEREncoding,

                                  &srcParams->DEREncoding));

    dstParams->name = srcParams->name;

    CHECK_SEC_OK(SECITEM_CopyItem(arena, &dstParams->curveOID,

                                  &srcParams->curveOID));

    dstParams->cofactor = srcParams->cofactor;

    return SECSuccess;

cleanup:

    return SECFailure;

}

static SECStatus

gf_populate_params_bytes(ECCurveName name, ECFieldType field_type, ECParams *params)

{

    SECStatus rv = SECFailure;

    const ECCurveBytes *curveParams;

    if ((name < ECCurve_noName) || (name > ECCurve_pastLastCurve))

        goto cleanup;

    params->name = name;

    curveParams = ecCurve_map[params->name];

    CHECK_OK(curveParams);

    params->fieldID.size = curveParams->size;

    params->fieldID.type = field_type;

    if (field_type != ec_field_GFp && field_type != ec_field_plain) {

        return SECFailure;

    }

    params->fieldID.u.prime.len = curveParams->scalarSize;

    params->fieldID.u.prime.data = (unsigned char *)curveParams->irr;

    params->curve.a.len = curveParams->scalarSize;

    params->curve.a.data = (unsigned char *)curveParams->curvea;

    params->curve.b.len = curveParams->scalarSize;

    params->curve.b.data = (unsigned char *)curveParams->curveb;

    params->base.len = curveParams->pointSize;

    params->base.data = (unsigned char *)curveParams->base;

    params->order.len = curveParams->scalarSize;

    params->order.data = (unsigned char *)curveParams->order;

    params->cofactor = curveParams->cofactor;

    rv = SECSuccess;

cleanup:

    return rv;

}

SECStatus

EC_FillParams(PLArenaPool *arena, const SECItem *encodedParams,

              ECParams *params)

{

    SECStatus rv = SECFailure;

    SECOidTag tag;

    SECItem oid = { siBuffer, NULL, 0 };

#if EC_DEBUG

    int i;

    printf("Encoded params in EC_DecodeParams: ");

    for (i = 0; i < encodedParams->len; i++) {

        printf("%02x:", encodedParams->data[i]);

    }

    printf("\n");

#endif

    if ((encodedParams->len != ANSI_X962_CURVE_OID_TOTAL_LEN) &&

        (encodedParams->len != SECG_CURVE_OID_TOTAL_LEN) &&

        (encodedParams->len != PKIX_NEWCURVES_OID_TOTAL_LEN) &&

        (encodedParams->len != ED25519_OID_TOTAL_LEN)) {

        PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);

        return SECFailure;

    };

    oid.len = encodedParams->len - 2;

    oid.data = encodedParams->data + 2;

    if ((encodedParams->data[0] != SEC_ASN1_OBJECT_ID) ||

        ((tag = SECOID_FindOIDTag(&oid)) == SEC_OID_UNKNOWN)) {

        PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);

        return SECFailure;

    }

    params->arena = arena;

    params->cofactor = 0;

    params->type = ec_params_named;

    params->name = ECCurve_noName;

    /* Fill out curveOID */

    params->curveOID.len = oid.len;

    params->curveOID.data = (unsigned char *)PORT_ArenaAlloc(arena, oid.len);

    if (params->curveOID.data == NULL)

        goto cleanup;

    memcpy(params->curveOID.data, oid.data, oid.len);

#if EC_DEBUG

    printf("Curve: %s\n", SECOID_FindOIDTagDescription(tag));

#endif

    switch (tag) {

        case SEC_OID_ANSIX962_EC_PRIME256V1:

            /* Populate params for prime256v1 aka secp256r1

             * (the NIST P-256 curve)

             */

            CHECK_SEC_OK(gf_populate_params_bytes(ECCurve_X9_62_PRIME_256V1,

                                                  ec_field_plain, params));

            break;

        case SEC_OID_SECG_EC_SECP384R1:

            /* Populate params for secp384r1

             * (the NIST P-384 curve)

             */

            CHECK_SEC_OK(gf_populate_params_bytes(ECCurve_SECG_PRIME_384R1,

                                                  ec_field_GFp, params));

            break;

        case SEC_OID_SECG_EC_SECP521R1:

            /* Populate params for secp521r1

             * (the NIST P-521 curve)

             */

            CHECK_SEC_OK(gf_populate_params_bytes(ECCurve_SECG_PRIME_521R1,

                                                  ec_field_GFp, params));

            break;

        case SEC_OID_ED25519_PUBLIC_KEY:

            params->type = ec_params_edwards_named;

            CHECK_SEC_OK(gf_populate_params_bytes(ECCurve_Ed25519,

                                                  ec_field_plain, params));

            break;

        case SEC_OID_CURVE25519:

            /* Populate params for Curve25519 */

            params->type = ec_params_montgomery_named;

            CHECK_SEC_OK(gf_populate_params_bytes(ECCurve25519,

                                                  ec_field_plain,

                                                  params));

            break;

        default:

            break;

    };

cleanup:

    if (!params->cofactor) {

        PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);

#if EC_DEBUG

        printf("Unrecognized curve, returning NULL params\n");

#endif

    }

    return rv;

}

SECStatus

EC_DecodeParams(const SECItem *encodedParams, ECParams **ecparams)

{

    PLArenaPool *arena;

    ECParams *params;

    SECStatus rv = SECFailure;

    /* Initialize an arena for the ECParams structure */

    if (!(arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE)))

        return SECFailure;

    params = (ECParams *)PORT_ArenaZAlloc(arena, sizeof(ECParams));

    if (!params) {

        PORT_FreeArena(arena, PR_TRUE);

        return SECFailure;

    }

    /* Copy the encoded params */

    SECITEM_AllocItem(arena, &(params->DEREncoding),

                      encodedParams->len);

    memcpy(params->DEREncoding.data, encodedParams->data, encodedParams->len);

    /* Fill out the rest of the ECParams structure based on

     * the encoded params

     */

    rv = EC_FillParams(arena, encodedParams, params);

    if (rv == SECFailure) {

        PORT_FreeArena(arena, PR_TRUE);

        return SECFailure;

    } else {

        *ecparams = params;

        ;

        return SECSuccess;

    }

}

int

EC_GetPointSize(const ECParams *params)

{

    ECCurveName name = params->name;

    const ECCurveBytes *curveParams;

    if ((name < ECCurve_noName) || (name > ECCurve_pastLastCurve) ||

        ((curveParams = ecCurve_map[name]) == NULL)) {

        /* unknown curve, calculate point size from params. assume standard curves with 2 points

         * and a point compression indicator byte */

        int sizeInBytes = (params->fieldID.size + 7) / 8;

        return sizeInBytes * 2 + 1;

    }

    if (params->type == ec_params_edwards_named || params->type == ec_params_montgomery_named) {

        return curveParams->scalarSize;

    }

    return curveParams->pointSize - 1;

}

int

EC_GetScalarSize(const ECParams *params)

{

    ECCurveName name = params->name;

    const ECCurveBytes *curveParams;

    if ((name < ECCurve_noName) || (name > ECCurve_pastLastCurve) ||

        ((curveParams = ecCurve_map[name]) == NULL)) {

        /* unknown curve, calculate scalar size from field size in params */

        int sizeInBytes = (params->fieldID.size + 7) / 8;

        return sizeInBytes;

    }

    return curveParams->scalarSize;

}