/*

 * Copyright 2020-2025 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*

 * ECDH/ECDSA low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <string.h>

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/bn.h>

#include <openssl/err.h>

#include <openssl/objects.h>

#include <openssl/proverr.h>

#include <openssl/self_test.h>

#include "crypto/bn.h"

#include "crypto/ec.h"

#include "prov/implementations.h"

#include "prov/providercommon.h"

#include "prov/provider_ctx.h"

#include "prov/securitycheck.h"

#include "internal/fips.h"

#include "internal/param_build_set.h"

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

#  include "crypto/sm2.h"

# endif

#endif

static OSSL_FUNC_keymgmt_new_fn ec_newdata;

static OSSL_FUNC_keymgmt_gen_init_fn ec_gen_init;

static OSSL_FUNC_keymgmt_gen_set_template_fn ec_gen_set_template;

static OSSL_FUNC_keymgmt_gen_set_params_fn ec_gen_set_params;

static OSSL_FUNC_keymgmt_gen_settable_params_fn ec_gen_settable_params;

static OSSL_FUNC_keymgmt_gen_get_params_fn ec_gen_get_params;

static OSSL_FUNC_keymgmt_gen_gettable_params_fn ec_gen_gettable_params;

static OSSL_FUNC_keymgmt_gen_fn ec_gen;

static OSSL_FUNC_keymgmt_gen_cleanup_fn ec_gen_cleanup;

static OSSL_FUNC_keymgmt_load_fn ec_load;

static OSSL_FUNC_keymgmt_free_fn ec_freedata;

static OSSL_FUNC_keymgmt_get_params_fn ec_get_params;

static OSSL_FUNC_keymgmt_gettable_params_fn ec_gettable_params;

static OSSL_FUNC_keymgmt_set_params_fn ec_set_params;

static OSSL_FUNC_keymgmt_settable_params_fn ec_settable_params;

static OSSL_FUNC_keymgmt_has_fn ec_has;

static OSSL_FUNC_keymgmt_match_fn ec_match;

static OSSL_FUNC_keymgmt_validate_fn ec_validate;

static OSSL_FUNC_keymgmt_import_fn ec_import;

static OSSL_FUNC_keymgmt_import_types_fn ec_import_types;

static OSSL_FUNC_keymgmt_export_fn ec_export;

static OSSL_FUNC_keymgmt_export_types_fn ec_export_types;

static OSSL_FUNC_keymgmt_query_operation_name_fn ec_query_operation_name;

static OSSL_FUNC_keymgmt_dup_fn ec_dup;

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

static OSSL_FUNC_keymgmt_new_fn sm2_newdata;

static OSSL_FUNC_keymgmt_gen_init_fn sm2_gen_init;

static OSSL_FUNC_keymgmt_gen_fn sm2_gen;

static OSSL_FUNC_keymgmt_get_params_fn sm2_get_params;

static OSSL_FUNC_keymgmt_gettable_params_fn sm2_gettable_params;

static OSSL_FUNC_keymgmt_settable_params_fn sm2_settable_params;

static OSSL_FUNC_keymgmt_import_fn sm2_import;

static OSSL_FUNC_keymgmt_query_operation_name_fn sm2_query_operation_name;

static OSSL_FUNC_keymgmt_validate_fn sm2_validate;

# endif

#endif

#define EC_DEFAULT_MD "SHA256"

#define EC_POSSIBLE_SELECTIONS                                                 \

    (OSSL_KEYMGMT_SELECT_KEYPAIR | OSSL_KEYMGMT_SELECT_ALL_PARAMETERS)

#define SM2_DEFAULT_MD "SM3"

static

const char *ec_query_operation_name(int operation_id)

{

    switch (operation_id) {

    case OSSL_OP_KEYEXCH:

        return "ECDH";

    case OSSL_OP_SIGNATURE:

        return "ECDSA";

    }

    return NULL;

}

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

static

const char *sm2_query_operation_name(int operation_id)

{

    switch (operation_id) {

    case OSSL_OP_SIGNATURE:

        return "SM2";

    }

    return NULL;

}

# endif

#endif

/*

 * Callers of key_to_params MUST make sure that domparams_to_params is also

 * called!

 *

 * This function only exports the bare keypair, domain parameters and other

 * parameters are exported separately.

 */

static ossl_inline

int key_to_params(const EC_KEY *eckey, OSSL_PARAM_BLD *tmpl,

                  OSSL_PARAM params[], int include_private,

                  unsigned char **pub_key)

{

    BIGNUM *x = NULL, *y = NULL;

    const BIGNUM *priv_key = NULL;

    const EC_POINT *pub_point = NULL;

    const EC_GROUP *ecg = NULL;

    size_t pub_key_len = 0;

    int ret = 0;

    BN_CTX *bnctx = NULL;

    if (eckey == NULL

        || (ecg = EC_KEY_get0_group(eckey)) == NULL)

        return 0;

    priv_key = EC_KEY_get0_private_key(eckey);

    pub_point = EC_KEY_get0_public_key(eckey);

    if (pub_point != NULL) {

        OSSL_PARAM *p = NULL, *px = NULL, *py = NULL;

        /*

         * EC_POINT_point2buf() can generate random numbers in some

         * implementations so we need to ensure we use the correct libctx.

         */

        bnctx = BN_CTX_new_ex(ossl_ec_key_get_libctx(eckey));

        if (bnctx == NULL)

            goto err;

        /* If we are doing a get then check first before decoding the point */

        if (tmpl == NULL) {

            p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_PUB_KEY);

            px = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_EC_PUB_X);

            py = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_EC_PUB_Y);

        }

        if (p != NULL || tmpl != NULL) {

            /* convert pub_point to a octet string according to the SECG standard */

            point_conversion_form_t format = EC_KEY_get_conv_form(eckey);

            if ((pub_key_len = EC_POINT_point2buf(ecg, pub_point,

                                                  format,

                                                  pub_key, bnctx)) == 0

                || !ossl_param_build_set_octet_string(tmpl, p,

                                                      OSSL_PKEY_PARAM_PUB_KEY,

                                                      *pub_key, pub_key_len))

                goto err;

        }

        if (px != NULL || py != NULL) {

            if (px != NULL) {

                x = BN_CTX_get(bnctx);

                if (x == NULL)

                    goto err;

            }

            if (py != NULL) {

                y = BN_CTX_get(bnctx);

                if (y == NULL)

                    goto err;

            }

            if (!EC_POINT_get_affine_coordinates(ecg, pub_point, x, y, bnctx))

                goto err;

            if (px != NULL

                && !ossl_param_build_set_bn(tmpl, px,

                                            OSSL_PKEY_PARAM_EC_PUB_X, x))

                goto err;

            if (py != NULL

                && !ossl_param_build_set_bn(tmpl, py,

                                            OSSL_PKEY_PARAM_EC_PUB_Y, y))

                goto err;

        }

    }

    if (priv_key != NULL && include_private) {

        size_t sz;

        int ecbits;

        /*

         * Key import/export should never leak the bit length of the secret

         * scalar in the key.

         *

         * For this reason, on export we use padded BIGNUMs with fixed length.

         *

         * When importing we also should make sure that, even if short lived,

         * the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as

         * soon as possible, so that any processing of this BIGNUM might opt for

         * constant time implementations in the backend.

         *

         * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have

         * to preallocate the BIGNUM internal buffer to a fixed public size big

         * enough that operations performed during the processing never trigger

         * a realloc which would leak the size of the scalar through memory

         * accesses.

         *

         * Fixed Length

         * ------------

         *

         * The order of the large prime subgroup of the curve is our choice for

         * a fixed public size, as that is generally the upper bound for

         * generating a private key in EC cryptosystems and should fit all valid

         * secret scalars.

         *

         * For padding on export we just use the bit length of the order

         * converted to bytes (rounding up).

         *

         * For preallocating the BIGNUM storage we look at the number of "words"

         * required for the internal representation of the order, and we

         * preallocate 2 extra "words" in case any of the subsequent processing

         * might temporarily overflow the order length.

         */

        ecbits = EC_GROUP_order_bits(ecg);

        if (ecbits <= 0)

            goto err;

        sz = (ecbits + 7) / 8;

        if (!ossl_param_build_set_bn_pad(tmpl, params,

                                         OSSL_PKEY_PARAM_PRIV_KEY,

                                         priv_key, sz))

            goto err;

    }

    ret = 1;

 err:

    BN_CTX_free(bnctx);

    return ret;

}

static ossl_inline

int otherparams_to_params(const EC_KEY *ec, OSSL_PARAM_BLD *tmpl,

                          OSSL_PARAM params[])

{

    int ecdh_cofactor_mode = 0, group_check = 0;

    const char *name = NULL;

    point_conversion_form_t format;

    if (ec == NULL)

        return 0;

    format = EC_KEY_get_conv_form(ec);

    name = ossl_ec_pt_format_id2name((int)format);

    if (name != NULL

        && !ossl_param_build_set_utf8_string(tmpl, params,

                                             OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT,

                                             name))

        return 0;

    group_check = EC_KEY_get_flags(ec) & EC_FLAG_CHECK_NAMED_GROUP_MASK;

    name = ossl_ec_check_group_type_id2name(group_check);

    if (name != NULL

        && !ossl_param_build_set_utf8_string(tmpl, params,

                                             OSSL_PKEY_PARAM_EC_GROUP_CHECK_TYPE,

                                             name))

        return 0;

    if ((EC_KEY_get_enc_flags(ec) & EC_PKEY_NO_PUBKEY) != 0

            && !ossl_param_build_set_int(tmpl, params,

                                         OSSL_PKEY_PARAM_EC_INCLUDE_PUBLIC, 0))

        return 0;

    ecdh_cofactor_mode =

        (EC_KEY_get_flags(ec) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;

    return ossl_param_build_set_int(tmpl, params,

                                    OSSL_PKEY_PARAM_USE_COFACTOR_ECDH,

                                    ecdh_cofactor_mode);

}

static

void *ec_newdata(void *provctx)

{

    if (!ossl_prov_is_running())

        return NULL;

    return EC_KEY_new_ex(PROV_LIBCTX_OF(provctx), NULL);

}

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

static

void *sm2_newdata(void *provctx)

{

    if (!ossl_prov_is_running())

        return NULL;

    return EC_KEY_new_by_curve_name_ex(PROV_LIBCTX_OF(provctx), NULL, NID_sm2);

}

# endif

#endif

static

void ec_freedata(void *keydata)

{

    EC_KEY_free(keydata);

}

static

int ec_has(const void *keydata, int selection)

{

    const EC_KEY *ec = keydata;

    int ok = 1;

    if (!ossl_prov_is_running() || ec == NULL)

        return 0;

    if ((selection & EC_POSSIBLE_SELECTIONS) == 0)

        return 1; /* the selection is not missing */

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        ok = ok && (EC_KEY_get0_public_key(ec) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        ok = ok && (EC_KEY_get0_private_key(ec) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        ok = ok && (EC_KEY_get0_group(ec) != NULL);

    /*

     * We consider OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS to always be

     * available, so no extra check is needed other than the previous one

     * against EC_POSSIBLE_SELECTIONS.

     */

    return ok;

}

static int ec_match(const void *keydata1, const void *keydata2, int selection)

{

    const EC_KEY *ec1 = keydata1;

    const EC_KEY *ec2 = keydata2;

    const EC_GROUP *group_a = EC_KEY_get0_group(ec1);

    const EC_GROUP *group_b = EC_KEY_get0_group(ec2);

    BN_CTX *ctx = NULL;

    int ok = 1;

    if (!ossl_prov_is_running())

        return 0;

    ctx = BN_CTX_new_ex(ossl_ec_key_get_libctx(ec1));

    if (ctx == NULL)

        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        ok = ok && group_a != NULL && group_b != NULL

            && EC_GROUP_cmp(group_a, group_b, ctx) == 0;

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {

        int key_checked = 0;

        if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0) {

            const EC_POINT *pa = EC_KEY_get0_public_key(ec1);

            const EC_POINT *pb = EC_KEY_get0_public_key(ec2);

            if (pa != NULL && pb != NULL) {

                ok = ok && EC_POINT_cmp(group_b, pa, pb, ctx) == 0;

                key_checked = 1;

            }

        }

        if (!key_checked

            && (selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {

            const BIGNUM *pa = EC_KEY_get0_private_key(ec1);

            const BIGNUM *pb = EC_KEY_get0_private_key(ec2);

            if (pa != NULL && pb != NULL) {

                ok = ok && BN_cmp(pa, pb) == 0;

                key_checked = 1;

            }

        }

        ok = ok && key_checked;

    }

    BN_CTX_free(ctx);

    return ok;

}

static int common_check_sm2(const EC_KEY *ec, int sm2_wanted)

{

    const EC_GROUP *ecg = NULL;

    /*

     * sm2_wanted: import the keys or domparams only on SM2 Curve

     * !sm2_wanted: import the keys or domparams only not on SM2 Curve

     */

    if ((ecg = EC_KEY_get0_group(ec)) == NULL

        || (sm2_wanted ^ (EC_GROUP_get_curve_name(ecg) == NID_sm2)))

        return 0;

    return 1;

}

static

int common_import(void *keydata, int selection, const OSSL_PARAM params[],

                  int sm2_wanted)

{

    EC_KEY *ec = keydata;

    int ok = 1;

    if (!ossl_prov_is_running() || ec == NULL)

        return 0;

    /*

     * In this implementation, we can export/import only keydata in the

     * following combinations:

     *   - domain parameters (+optional other params)

     *   - public key with associated domain parameters (+optional other params)

     *   - private key with associated domain parameters and optional public key

     *         (+optional other params)

     *

     * This means:

     *   - domain parameters must always be requested

     *   - private key must be requested alongside public key

     *   - other parameters are always optional

     */

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) == 0)

        return 0;

    ok = ok && ossl_ec_group_fromdata(ec, params);

    if (!common_check_sm2(ec, sm2_wanted))

        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {

        int include_private =

            selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && ossl_ec_key_fromdata(ec, params, include_private);

    }

    if ((selection & OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS) != 0)

        ok = ok && ossl_ec_key_otherparams_fromdata(ec, params);

#ifdef FIPS_MODULE

    if (ok > 0

            && !ossl_fips_self_testing()

            && EC_KEY_get0_public_key(ec) != NULL

            && EC_KEY_get0_private_key(ec) != NULL

            && EC_KEY_get0_group(ec) != NULL) {

        BN_CTX *bnctx = BN_CTX_new_ex(ossl_ec_key_get_libctx(ec));

        ok = bnctx != NULL && ossl_ec_key_pairwise_check(ec, bnctx);

        BN_CTX_free(bnctx);

        if (ok <= 0)

            ossl_set_error_state(OSSL_SELF_TEST_TYPE_PCT);

    }

#endif  /* FIPS_MODULE */

    return ok;

}

static

int ec_import(void *keydata, int selection, const OSSL_PARAM params[])

{

    return common_import(keydata, selection, params, 0);

}

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

static

int sm2_import(void *keydata, int selection, const OSSL_PARAM params[])

{

    return common_import(keydata, selection, params, 1);

}

# endif

#endif

static

int ec_export(void *keydata, int selection, OSSL_CALLBACK *param_cb,

              void *cbarg)

{

    EC_KEY *ec = keydata;

    OSSL_PARAM_BLD *tmpl = NULL;

    OSSL_PARAM *params = NULL;

    unsigned char *pub_key = NULL, *genbuf = NULL;

    BN_CTX *bnctx = NULL;

    int ok = 1;

    if (!ossl_prov_is_running() || ec == NULL)

        return 0;

    /*

     * In this implementation, we can export/import only keydata in the

     * following combinations:

     *   - domain parameters (+optional other params)

     *   - public key with associated domain parameters (+optional other params)

     *   - private key with associated public key and domain parameters

     *         (+optional other params)

     *

     * This means:

     *   - domain parameters must always be requested

     *   - private key must be requested alongside public key

     *   - other parameters are always optional

     */

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) == 0)

        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0

            && (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) == 0)

        return 0;

    tmpl = OSSL_PARAM_BLD_new();

    if (tmpl == NULL)

        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0) {

        bnctx = BN_CTX_new_ex(ossl_ec_key_get_libctx(ec));

        if (bnctx == NULL) {

            ok = 0;

            goto end;

        }

        BN_CTX_start(bnctx);

        ok = ok && ossl_ec_group_todata(EC_KEY_get0_group(ec), tmpl, NULL,

                                        ossl_ec_key_get_libctx(ec),

                                        ossl_ec_key_get0_propq(ec),

                                        bnctx, &genbuf);

    }

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {

        int include_private =

            selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && key_to_params(ec, tmpl, NULL, include_private, &pub_key);

    }

    if ((selection & OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS) != 0)

        ok = ok && otherparams_to_params(ec, tmpl, NULL);

    if (!ok || (params = OSSL_PARAM_BLD_to_param(tmpl)) == NULL) {

        ok = 0;

        goto end;

    }

    ok = param_cb(params, cbarg);

    OSSL_PARAM_free(params);

end:

    OSSL_PARAM_BLD_free(tmpl);

    OPENSSL_free(pub_key);

    OPENSSL_free(genbuf);

    BN_CTX_end(bnctx);

    BN_CTX_free(bnctx);

    return ok;

}

/* IMEXPORT = IMPORT + EXPORT */

# define EC_IMEXPORTABLE_DOM_PARAMETERS                                        \

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_GROUP_NAME, NULL, 0),               \

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_ENCODING, NULL, 0),              \

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, NULL, 0),\

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_FIELD_TYPE, NULL, 0),            \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_P, NULL, 0),                              \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_A, NULL, 0),                              \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_B, NULL, 0),                              \

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_EC_GENERATOR, NULL, 0),            \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_ORDER, NULL, 0),                          \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_COFACTOR, NULL, 0),                       \

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_EC_SEED, NULL, 0),                 \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS, NULL)

# define EC_IMEXPORTABLE_PUBLIC_KEY                                            \

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_PUB_KEY, NULL, 0)

# define EC_IMEXPORTABLE_PRIVATE_KEY                                           \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_PRIV_KEY, NULL, 0)

# define EC_IMEXPORTABLE_OTHER_PARAMETERS                                      \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_USE_COFACTOR_ECDH, NULL),                   \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_INCLUDE_PUBLIC, NULL)

/*

 * Include all the possible combinations of OSSL_PARAM arrays for

 * ec_imexport_types().

 *

 * They are in a separate file as it is ~100 lines of unreadable and

 * uninteresting machine generated stuff.

 */

#include "ec_kmgmt_imexport.inc"

static ossl_inline

const OSSL_PARAM *ec_imexport_types(int selection)

{

    int type_select = 0;

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        type_select += 1;

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        type_select += 2;

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        type_select += 4;

    if ((selection & OSSL_KEYMGMT_SELECT_OTHER_PARAMETERS) != 0)

        type_select += 8;

    return ec_types[type_select];

}

static

const OSSL_PARAM *ec_import_types(int selection)

{

    return ec_imexport_types(selection);

}

static

const OSSL_PARAM *ec_export_types(int selection)

{

    return ec_imexport_types(selection);

}

static int ec_get_ecm_params(const EC_GROUP *group, OSSL_PARAM params[])

{

#ifdef OPENSSL_NO_EC2M

    return 1;

#else

    int ret = 0, m;

    unsigned int k1 = 0, k2 = 0, k3 = 0;

    int basis_nid;

    const char *basis_name = NULL;

    int fid = EC_GROUP_get_field_type(group);

    if (fid != NID_X9_62_characteristic_two_field)

        return 1;

    basis_nid = EC_GROUP_get_basis_type(group);

    if (basis_nid == NID_X9_62_tpBasis)

        basis_name = SN_X9_62_tpBasis;

    else if (basis_nid == NID_X9_62_ppBasis)

        basis_name = SN_X9_62_ppBasis;

    else

        goto err;

    m = EC_GROUP_get_degree(group);

    if (!ossl_param_build_set_int(NULL, params, OSSL_PKEY_PARAM_EC_CHAR2_M, m)

        || !ossl_param_build_set_utf8_string(NULL, params,

                                             OSSL_PKEY_PARAM_EC_CHAR2_TYPE,

                                             basis_name))

        goto err;

    if (basis_nid == NID_X9_62_tpBasis) {

        if (!EC_GROUP_get_trinomial_basis(group, &k1)

            || !ossl_param_build_set_int(NULL, params,

                                         OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS,

                                         (int)k1))

            goto err;

    } else {

        if (!EC_GROUP_get_pentanomial_basis(group, &k1, &k2, &k3)

            || !ossl_param_build_set_int(NULL, params,

                                         OSSL_PKEY_PARAM_EC_CHAR2_PP_K1, (int)k1)

            || !ossl_param_build_set_int(NULL, params,

                                         OSSL_PKEY_PARAM_EC_CHAR2_PP_K2, (int)k2)

            || !ossl_param_build_set_int(NULL, params,

                                         OSSL_PKEY_PARAM_EC_CHAR2_PP_K3, (int)k3))

            goto err;

    }

    ret = 1;

err:

    return ret;

#endif /* OPENSSL_NO_EC2M */

}

static

int common_get_params(void *key, OSSL_PARAM params[], int sm2)

{

    int ret = 0;

    EC_KEY *eck = key;

    const EC_GROUP *ecg = NULL;

    OSSL_PARAM *p;

    unsigned char *pub_key = NULL, *genbuf = NULL;

    OSSL_LIB_CTX *libctx;

    const char *propq;

    BN_CTX *bnctx = NULL;

    ecg = EC_KEY_get0_group(eck);

    if (ecg == NULL) {

        ERR_raise(ERR_LIB_PROV, PROV_R_NO_PARAMETERS_SET);

        return 0;

    }

    libctx = ossl_ec_key_get_libctx(eck);

    propq = ossl_ec_key_get0_propq(eck);

    bnctx = BN_CTX_new_ex(libctx);

    if (bnctx == NULL)

        return 0;

    BN_CTX_start(bnctx);

    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_MAX_SIZE)) != NULL

        && !OSSL_PARAM_set_int(p, ECDSA_size(eck)))

        goto err;

    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_BITS)) != NULL

        && !OSSL_PARAM_set_int(p, EC_GROUP_order_bits(ecg)))

        goto err;

    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_SECURITY_BITS)) != NULL) {

        int ecbits, sec_bits;

        ecbits = EC_GROUP_order_bits(ecg);

        /*

         * The following estimates are based on the values published

         * in Table 2 of "NIST Special Publication 800-57 Part 1 Revision 4"

         * at http://dx.doi.org/10.6028/NIST.SP.800-57pt1r4 .

         *

         * Note that the above reference explicitly categorizes algorithms in a

         * discrete set of values {80, 112, 128, 192, 256}, and that it is

         * relevant only for NIST approved Elliptic Curves, while OpenSSL

         * applies the same logic also to other curves.

         *

         * Classifications produced by other standardazing bodies might differ,

         * so the results provided for "bits of security" by this provider are

         * to be considered merely indicative, and it is the users'

         * responsibility to compare these values against the normative

         * references that may be relevant for their intent and purposes.

         */

        if (ecbits >= 512)

            sec_bits = 256;

        else if (ecbits >= 384)

            sec_bits = 192;

        else if (ecbits >= 256)

            sec_bits = 128;

        else if (ecbits >= 224)

            sec_bits = 112;

        else if (ecbits >= 160)

            sec_bits = 80;

        else

            sec_bits = ecbits / 2;

        if (!OSSL_PARAM_set_int(p, sec_bits))

            goto err;

    }

    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_SECURITY_CATEGORY)) != NULL)

        if (!OSSL_PARAM_set_int(p, 0))

            goto err;

    if ((p = OSSL_PARAM_locate(params,

                               OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS))

            != NULL) {

        int explicitparams = EC_KEY_decoded_from_explicit_params(eck);

        if (explicitparams < 0

             || !OSSL_PARAM_set_int(p, explicitparams))

            goto err;

    }

    if (!sm2) {

        if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_DEFAULT_DIGEST)) != NULL

                && !OSSL_PARAM_set_utf8_string(p, EC_DEFAULT_MD))

            goto err;

    } else {

        if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_DEFAULT_DIGEST)) != NULL

                && !OSSL_PARAM_set_utf8_string(p, SM2_DEFAULT_MD))

            goto err;

    }

    /* SM2 doesn't support this PARAM */

    if (!sm2) {

        p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_USE_COFACTOR_ECDH);

        if (p != NULL) {

            int ecdh_cofactor_mode = 0;

            ecdh_cofactor_mode =

                (EC_KEY_get_flags(eck) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0;

            if (!OSSL_PARAM_set_int(p, ecdh_cofactor_mode))

                goto err;

        }

    }

    if ((p = OSSL_PARAM_locate(params,

                               OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY)) != NULL) {

        const EC_POINT *ecp = EC_KEY_get0_public_key(key);

        if (ecp == NULL) {

            ERR_raise(ERR_LIB_PROV, PROV_R_NOT_A_PUBLIC_KEY);

            goto err;

        }

        p->return_size = EC_POINT_point2oct(ecg, ecp,

                                            POINT_CONVERSION_UNCOMPRESSED,

                                            p->data, p->data_size, bnctx);

        if (p->return_size == 0)

            goto err;

    }

    ret = ec_get_ecm_params(ecg, params)

          && ossl_ec_group_todata(ecg, NULL, params, libctx, propq, bnctx,

                                  &genbuf)

          && key_to_params(eck, NULL, params, 1, &pub_key)

          && otherparams_to_params(eck, NULL, params);

err:

    OPENSSL_free(genbuf);

    OPENSSL_free(pub_key);

    BN_CTX_end(bnctx);

    BN_CTX_free(bnctx);

    return ret;

}

static

int ec_get_params(void *key, OSSL_PARAM params[])

{

    return common_get_params(key, params, 0);

}

#ifndef OPENSSL_NO_EC2M

# define EC2M_GETTABLE_DOM_PARAMS                                              \

        OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_CHAR2_M, NULL),                      \

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_CHAR2_TYPE, NULL, 0),        \

        OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_CHAR2_TP_BASIS, NULL),               \

        OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_CHAR2_PP_K1, NULL),                  \

        OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_CHAR2_PP_K2, NULL),                  \

        OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_CHAR2_PP_K3, NULL),

#else

# define EC2M_GETTABLE_DOM_PARAMS

#endif

static const OSSL_PARAM ec_known_gettable_params[] = {

    OSSL_PARAM_int(OSSL_PKEY_PARAM_BITS, NULL),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_SECURITY_BITS, NULL),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_MAX_SIZE, NULL),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_SECURITY_CATEGORY, NULL),

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS, NULL),

    EC_IMEXPORTABLE_DOM_PARAMETERS,

    EC2M_GETTABLE_DOM_PARAMS

    EC_IMEXPORTABLE_PUBLIC_KEY,

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_PUB_X, NULL, 0),

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_PUB_Y, NULL, 0),

    EC_IMEXPORTABLE_PRIVATE_KEY,

    EC_IMEXPORTABLE_OTHER_PARAMETERS,

    OSSL_PARAM_END

};

static

const OSSL_PARAM *ec_gettable_params(void *provctx)

{

    return ec_known_gettable_params;

}

static const OSSL_PARAM ec_known_settable_params[] = {

    OSSL_PARAM_int(OSSL_PKEY_PARAM_USE_COFACTOR_ECDH, NULL),

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_ENCODING, NULL, 0),

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_EC_SEED, NULL, 0),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_INCLUDE_PUBLIC, NULL),

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_GROUP_CHECK_TYPE, NULL, 0),

    OSSL_PARAM_END

};

static

const OSSL_PARAM *ec_settable_params(void *provctx)

{

    return ec_known_settable_params;

}

static

int ec_set_params(void *key, const OSSL_PARAM params[])

{

    EC_KEY *eck = key;

    const OSSL_PARAM *p;

    if (key == NULL)

        return 0;

    if (ossl_param_is_empty(params))

        return 1;

    if (!ossl_ec_group_set_params((EC_GROUP *)EC_KEY_get0_group(key), params))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY);

    if (p != NULL) {

        BN_CTX *ctx = BN_CTX_new_ex(ossl_ec_key_get_libctx(key));

        int ret = 1;

        if (ctx == NULL

                || p->data_type != OSSL_PARAM_OCTET_STRING

                || !EC_KEY_oct2key(key, p->data, p->data_size, ctx))

            ret = 0;

        BN_CTX_free(ctx);

        if (!ret)

            return 0;

    }

    return ossl_ec_key_otherparams_fromdata(eck, params);

}

#ifndef FIPS_MODULE

# ifndef OPENSSL_NO_SM2

static

int sm2_get_params(void *key, OSSL_PARAM params[])

{

    return common_get_params(key, params, 1);

}

static const OSSL_PARAM sm2_known_gettable_params[] = {

    OSSL_PARAM_int(OSSL_PKEY_PARAM_BITS, NULL),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_SECURITY_BITS, NULL),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_MAX_SIZE, NULL),

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    OSSL_PARAM_int(OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS, NULL),

    EC_IMEXPORTABLE_DOM_PARAMETERS,

    EC_IMEXPORTABLE_PUBLIC_KEY,

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_EC_PUB_X, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_EC_PUB_Y, NULL, 0),

    EC_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static

const OSSL_PARAM *sm2_gettable_params(ossl_unused void *provctx)

{

    return sm2_known_gettable_params;

}

static const OSSL_PARAM sm2_known_settable_params[] = {

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    OSSL_PARAM_END

};