/*

 * Copyright 2019-2023 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

 */

/*

 * DH low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <string.h> /* strcmp */

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/bn.h>

#include <openssl/err.h>

#include "prov/implementations.h"

#include "prov/providercommon.h"

#include "prov/provider_ctx.h"

#include "crypto/dh.h"

#include "internal/sizes.h"

static OSSL_FUNC_keymgmt_new_fn dh_newdata;

static OSSL_FUNC_keymgmt_free_fn dh_freedata;

static OSSL_FUNC_keymgmt_gen_init_fn dh_gen_init;

static OSSL_FUNC_keymgmt_gen_init_fn dhx_gen_init;

static OSSL_FUNC_keymgmt_gen_set_template_fn dh_gen_set_template;

static OSSL_FUNC_keymgmt_gen_set_params_fn dh_gen_set_params;

static OSSL_FUNC_keymgmt_gen_settable_params_fn dh_gen_settable_params;

static OSSL_FUNC_keymgmt_gen_fn dh_gen;

static OSSL_FUNC_keymgmt_gen_cleanup_fn dh_gen_cleanup;

static OSSL_FUNC_keymgmt_load_fn dh_load;

static OSSL_FUNC_keymgmt_get_params_fn dh_get_params;

static OSSL_FUNC_keymgmt_gettable_params_fn dh_gettable_params;

static OSSL_FUNC_keymgmt_set_params_fn dh_set_params;

static OSSL_FUNC_keymgmt_settable_params_fn dh_settable_params;

static OSSL_FUNC_keymgmt_has_fn dh_has;

static OSSL_FUNC_keymgmt_match_fn dh_match;

static OSSL_FUNC_keymgmt_validate_fn dh_validate;

static OSSL_FUNC_keymgmt_import_fn dh_import;

static OSSL_FUNC_keymgmt_import_types_fn dh_import_types;

static OSSL_FUNC_keymgmt_export_fn dh_export;

static OSSL_FUNC_keymgmt_export_types_fn dh_export_types;

static OSSL_FUNC_keymgmt_dup_fn dh_dup;

#define DH_POSSIBLE_SELECTIONS                                                 \

    (OSSL_KEYMGMT_SELECT_KEYPAIR | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS)

struct dh_gen_ctx {

    OSSL_LIB_CTX *libctx;

    FFC_PARAMS *ffc_params;

    int selection;

    /* All these parameters are used for parameter generation only */

    /* If there is a group name then the remaining parameters are not needed */

    int group_nid;

    size_t pbits;

    size_t qbits;

    unsigned char *seed; /* optional FIPS186-4 param for testing */

    size_t seedlen;

    int gindex; /* optional  FIPS186-4 generator index (ignored if -1) */

    int gen_type; /* see dhtype2id */

    int generator; /* Used by DH_PARAMGEN_TYPE_GENERATOR in non fips mode only */

    int pcounter;

    int hindex;

    int priv_len;

    char *mdname;

    char *mdprops;

    OSSL_CALLBACK *cb;

    void *cbarg;

    int dh_type;

};

static int dh_gen_type_name2id_w_default(const char *name, int type)

{

    if (strcmp(name, "default") == 0) {

#ifdef FIPS_MODULE

        if (type == DH_FLAG_TYPE_DHX)

            return DH_PARAMGEN_TYPE_FIPS_186_4;

        return DH_PARAMGEN_TYPE_GROUP;

#else

        if (type == DH_FLAG_TYPE_DHX)

            return DH_PARAMGEN_TYPE_FIPS_186_2;

        return DH_PARAMGEN_TYPE_GENERATOR;

#endif

    }

    return ossl_dh_gen_type_name2id(name, type);

}

static void *dh_newdata(void *provctx)

{

    DH *dh = NULL;

    if (ossl_prov_is_running()) {

        dh = ossl_dh_new_ex(PROV_LIBCTX_OF(provctx));

        if (dh != NULL) {

            DH_clear_flags(dh, DH_FLAG_TYPE_MASK);

            DH_set_flags(dh, DH_FLAG_TYPE_DH);

        }

    }

    return dh;

}

static void *dhx_newdata(void *provctx)

{

    DH *dh = NULL;

    dh = ossl_dh_new_ex(PROV_LIBCTX_OF(provctx));

    if (dh != NULL) {

        DH_clear_flags(dh, DH_FLAG_TYPE_MASK);

        DH_set_flags(dh, DH_FLAG_TYPE_DHX);

    }

    return dh;

}

static void dh_freedata(void *keydata)

{

    DH_free(keydata);

}

static int dh_has(const void *keydata, int selection)

{

    const DH *dh = keydata;

    int ok = 1;

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

        return 0;

    if ((selection & DH_POSSIBLE_SELECTIONS) == 0)

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

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        ok = ok && (DH_get0_pub_key(dh) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        ok = ok && (DH_get0_priv_key(dh) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        ok = ok && (DH_get0_p(dh) != NULL && DH_get0_g(dh) != NULL);

    return ok;

}

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

{

    const DH *dh1 = keydata1;

    const DH *dh2 = keydata2;

    int ok = 1;

    if (!ossl_prov_is_running())

        return 0;

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

        int key_checked = 0;

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

            const BIGNUM *pa = DH_get0_pub_key(dh1);

            const BIGNUM *pb = DH_get0_pub_key(dh2);

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

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

                key_checked = 1;

            }

        }

        if (!key_checked

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

            const BIGNUM *pa = DH_get0_priv_key(dh1);

            const BIGNUM *pb = DH_get0_priv_key(dh2);

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

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

                key_checked = 1;

            }

        }

        ok = ok && key_checked;

    }

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

        FFC_PARAMS *dhparams1 = ossl_dh_get0_params((DH *)dh1);

        FFC_PARAMS *dhparams2 = ossl_dh_get0_params((DH *)dh2);

        ok = ok && ossl_ffc_params_cmp(dhparams1, dhparams2, 1);

    }

    return ok;

}

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

{

    DH *dh = keydata;

    int ok = 1;

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

        return 0;

    if ((selection & DH_POSSIBLE_SELECTIONS) == 0)

        return 0;

    /* a key without parameters is meaningless */

    ok = ok && ossl_dh_params_fromdata(dh, params);

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

        int include_private =

            selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && ossl_dh_key_fromdata(dh, params, include_private);

    }

    return ok;

}

static int dh_export(void *keydata, int selection, OSSL_CALLBACK *param_cb,

                     void *cbarg)

{

    DH *dh = keydata;

    OSSL_PARAM_BLD *tmpl = NULL;

    OSSL_PARAM *params = NULL;

    int ok = 1;

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

        return 0;

    if ((selection & DH_POSSIBLE_SELECTIONS) == 0)

        return 0;

    tmpl = OSSL_PARAM_BLD_new();

    if (tmpl == NULL)

        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_ALL_PARAMETERS) != 0)

        ok = ok && ossl_dh_params_todata(dh, tmpl, NULL);

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

        int include_private =

            selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && ossl_dh_key_todata(dh, tmpl, NULL, include_private);

    }

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

        ok = 0;

        goto err;

    }

    ok = param_cb(params, cbarg);

    OSSL_PARAM_free(params);

err:

    OSSL_PARAM_BLD_free(tmpl);

    return ok;

}

/* IMEXPORT = IMPORT + EXPORT */

# define DH_IMEXPORTABLE_PARAMETERS                                            \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_P, NULL, 0),                             \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_Q, NULL, 0),                             \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_G, NULL, 0),                             \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_FFC_COFACTOR, NULL, 0),                      \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_GINDEX, NULL),                          \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_PCOUNTER, NULL),                        \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_H, NULL),                               \

    OSSL_PARAM_int(OSSL_PKEY_PARAM_DH_PRIV_LEN, NULL),                         \

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_FFC_SEED, NULL, 0),                \

    OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_GROUP_NAME, NULL, 0)

# define DH_IMEXPORTABLE_PUBLIC_KEY                                            \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_PUB_KEY, NULL, 0)

# define DH_IMEXPORTABLE_PRIVATE_KEY                                           \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_PRIV_KEY, NULL, 0)

static const OSSL_PARAM dh_all_types[] = {

    DH_IMEXPORTABLE_PARAMETERS,

    DH_IMEXPORTABLE_PUBLIC_KEY,

    DH_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM dh_parameter_types[] = {

    DH_IMEXPORTABLE_PARAMETERS,

    OSSL_PARAM_END

};

static const OSSL_PARAM dh_key_types[] = {

    DH_IMEXPORTABLE_PUBLIC_KEY,

    DH_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM *dh_types[] = {

    NULL,                        /* Index 0 = none of them */

    dh_parameter_types,          /* Index 1 = parameter types */

    dh_key_types,                /* Index 2 = key types */

    dh_all_types                 /* Index 3 = 1 + 2 */

};

static const OSSL_PARAM *dh_imexport_types(int selection)

{

    int type_select = 0;

    if ((selection & OSSL_KEYMGMT_SELECT_ALL_PARAMETERS) != 0)

        type_select += 1;

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)

        type_select += 2;

    return dh_types[type_select];

}

static const OSSL_PARAM *dh_import_types(int selection)

{

    return dh_imexport_types(selection);

}

static const OSSL_PARAM *dh_export_types(int selection)

{

    return dh_imexport_types(selection);

}

static ossl_inline int dh_get_params(void *key, OSSL_PARAM params[])

{

    DH *dh = key;

    OSSL_PARAM *p;

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

        && !OSSL_PARAM_set_int(p, DH_bits(dh)))

        return 0;

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

        && !OSSL_PARAM_set_int(p, DH_security_bits(dh)))

        return 0;

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

        && !OSSL_PARAM_set_int(p, DH_size(dh)))

        return 0;

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

        if (p->data_type != OSSL_PARAM_OCTET_STRING)

            return 0;

        p->return_size = ossl_dh_key2buf(dh, (unsigned char **)&p->data,

                                         p->data_size, 0);

        if (p->return_size == 0)

            return 0;

    }

    return ossl_dh_params_todata(dh, NULL, params)

        && ossl_dh_key_todata(dh, NULL, params, 1);

}

static const OSSL_PARAM dh_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_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    DH_IMEXPORTABLE_PARAMETERS,

    DH_IMEXPORTABLE_PUBLIC_KEY,

    DH_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM *dh_gettable_params(void *provctx)

{

    return dh_params;

}

static const OSSL_PARAM dh_known_settable_params[] = {

    OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),

    OSSL_PARAM_END

};

static const OSSL_PARAM *dh_settable_params(void *provctx)

{

    return dh_known_settable_params;

}

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

{

    DH *dh = key;

    const OSSL_PARAM *p;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY);

    if (p != NULL

            && (p->data_type != OSSL_PARAM_OCTET_STRING

                || !ossl_dh_buf2key(dh, p->data, p->data_size)))

        return 0;

    return 1;

}

static int dh_validate_public(const DH *dh, int checktype)

{

    const BIGNUM *pub_key = NULL;

    int res = 0;

    DH_get0_key(dh, &pub_key, NULL);

    if (pub_key == NULL)

        return 0;

    /* The partial test is only valid for named group's with q = (p - 1) / 2 */

    if (checktype == OSSL_KEYMGMT_VALIDATE_QUICK_CHECK

        && ossl_dh_is_named_safe_prime_group(dh))

        return ossl_dh_check_pub_key_partial(dh, pub_key, &res);

    return DH_check_pub_key(dh, pub_key, &res);

}

static int dh_validate_private(const DH *dh)

{

    int status = 0;

    const BIGNUM *priv_key = NULL;

    DH_get0_key(dh, NULL, &priv_key);

    if (priv_key == NULL)

        return 0;

    return ossl_dh_check_priv_key(dh, priv_key, &status);;

}

static int dh_validate(const void *keydata, int selection, int checktype)

{

    const DH *dh = keydata;

    int ok = 1;

    if (!ossl_prov_is_running())

        return 0;

    if ((selection & DH_POSSIBLE_SELECTIONS) == 0)

        return 1; /* nothing to validate */

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

        /*

         * Both of these functions check parameters. DH_check_params_ex()

         * performs a lightweight check (e.g. it does not check that p is a

         * safe prime)

         */

        if (checktype == OSSL_KEYMGMT_VALIDATE_QUICK_CHECK)

            ok = ok && DH_check_params_ex(dh);

        else

            ok = ok && DH_check_ex(dh);

    }

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        ok = ok && dh_validate_public(dh, checktype);

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        ok = ok && dh_validate_private(dh);

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR)

            == OSSL_KEYMGMT_SELECT_KEYPAIR)

        ok = ok && ossl_dh_check_pairwise(dh);

    return ok;

}

static void *dh_gen_init_base(void *provctx, int selection,

                              const OSSL_PARAM params[], int type)

{

    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(provctx);

    struct dh_gen_ctx *gctx = NULL;

    if (!ossl_prov_is_running())

        return NULL;

    if ((selection & (OSSL_KEYMGMT_SELECT_KEYPAIR

                      | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS)) == 0)

        return NULL;

    if ((gctx = OPENSSL_zalloc(sizeof(*gctx))) != NULL) {

        gctx->selection = selection;

        gctx->libctx = libctx;

        gctx->pbits = 2048;

        gctx->qbits = 224;

        gctx->mdname = NULL;

#ifdef FIPS_MODULE

        gctx->gen_type = (type == DH_FLAG_TYPE_DHX)

                         ? DH_PARAMGEN_TYPE_FIPS_186_4

                         : DH_PARAMGEN_TYPE_GROUP;

#else

        gctx->gen_type = (type == DH_FLAG_TYPE_DHX)

                         ? DH_PARAMGEN_TYPE_FIPS_186_2

                         : DH_PARAMGEN_TYPE_GENERATOR;

#endif

        gctx->gindex = -1;

        gctx->hindex = 0;

        gctx->pcounter = -1;

        gctx->generator = DH_GENERATOR_2;

        gctx->dh_type = type;

    }

    if (!dh_gen_set_params(gctx, params)) {

        OPENSSL_free(gctx);

        gctx = NULL;

    }

    return gctx;

}

static void *dh_gen_init(void *provctx, int selection,

                         const OSSL_PARAM params[])

{

    return dh_gen_init_base(provctx, selection, params, DH_FLAG_TYPE_DH);

}

static void *dhx_gen_init(void *provctx, int selection,

                          const OSSL_PARAM params[])

{

   return dh_gen_init_base(provctx, selection, params, DH_FLAG_TYPE_DHX);

}

static int dh_gen_set_template(void *genctx, void *templ)

{

    struct dh_gen_ctx *gctx = genctx;

    DH *dh = templ;

    if (!ossl_prov_is_running() || gctx == NULL || dh == NULL)

        return 0;

    gctx->ffc_params = ossl_dh_get0_params(dh);

    return 1;

}

static int dh_set_gen_seed(struct dh_gen_ctx *gctx, unsigned char *seed,

                           size_t seedlen)

{

    OPENSSL_clear_free(gctx->seed, gctx->seedlen);

    gctx->seed = NULL;

    gctx->seedlen = 0;

    if (seed != NULL && seedlen > 0) {

        gctx->seed = OPENSSL_memdup(seed, seedlen);

        if (gctx->seed == NULL)

            return 0;

        gctx->seedlen = seedlen;

    }

    return 1;

}

static int dh_gen_common_set_params(void *genctx, const OSSL_PARAM params[])

{

    struct dh_gen_ctx *gctx = genctx;

    const OSSL_PARAM *p;

    if (gctx == NULL)

        return 0;

    if (params == NULL)

        return 1;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_TYPE);

    if (p != NULL) {

        if (p->data_type != OSSL_PARAM_UTF8_STRING

            || ((gctx->gen_type =

                 dh_gen_type_name2id_w_default(p->data, gctx->dh_type)) == -1)) {

            ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);

            return 0;

        }

    }

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_GROUP_NAME);

    if (p != NULL) {

        const DH_NAMED_GROUP *group = NULL;

        if (p->data_type != OSSL_PARAM_UTF8_STRING

            || p->data == NULL

            || (group = ossl_ffc_name_to_dh_named_group(p->data)) == NULL

            || ((gctx->group_nid =

                 ossl_ffc_named_group_get_uid(group)) == NID_undef)) {

            ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);

            return 0;

        }

    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_PBITS)) != NULL

        && !OSSL_PARAM_get_size_t(p, &gctx->pbits))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_DH_PRIV_LEN);

    if (p != NULL && !OSSL_PARAM_get_int(p, &gctx->priv_len))

        return 0;

    return 1;

}

static const OSSL_PARAM *dh_gen_settable_params(ossl_unused void *genctx,

                                                ossl_unused void *provctx)

{

    static const OSSL_PARAM dh_gen_settable[] = {

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE, NULL, 0),

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_GROUP_NAME, NULL, 0),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_DH_PRIV_LEN, NULL),

        OSSL_PARAM_size_t(OSSL_PKEY_PARAM_FFC_PBITS, NULL),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_DH_GENERATOR, NULL),

        OSSL_PARAM_END

    };

    return dh_gen_settable;

}

static const OSSL_PARAM *dhx_gen_settable_params(ossl_unused void *genctx,

                                                 ossl_unused void *provctx)

{

    static const OSSL_PARAM dhx_gen_settable[] = {

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE, NULL, 0),

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_GROUP_NAME, NULL, 0),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_DH_PRIV_LEN, NULL),

        OSSL_PARAM_size_t(OSSL_PKEY_PARAM_FFC_PBITS, NULL),

        OSSL_PARAM_size_t(OSSL_PKEY_PARAM_FFC_QBITS, NULL),

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST, NULL, 0),

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST_PROPS, NULL, 0),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_GINDEX, NULL),

        OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_FFC_SEED, NULL, 0),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_PCOUNTER, NULL),

        OSSL_PARAM_int(OSSL_PKEY_PARAM_FFC_H, NULL),

        OSSL_PARAM_END

    };

    return dhx_gen_settable;

}

static int dhx_gen_set_params(void *genctx, const OSSL_PARAM params[])

{

    struct dh_gen_ctx *gctx = genctx;

    const OSSL_PARAM *p;

    if (!dh_gen_common_set_params(genctx, params))

        return 0;

    /* Parameters related to fips186-4 and fips186-2 */

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_GINDEX);

    if (p != NULL && !OSSL_PARAM_get_int(p, &gctx->gindex))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_PCOUNTER);

    if (p != NULL && !OSSL_PARAM_get_int(p, &gctx->pcounter))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_H);

    if (p != NULL && !OSSL_PARAM_get_int(p, &gctx->hindex))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_SEED);

    if (p != NULL

        && (p->data_type != OSSL_PARAM_OCTET_STRING

            || !dh_set_gen_seed(gctx, p->data, p->data_size)))

            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_QBITS)) != NULL

        && !OSSL_PARAM_get_size_t(p, &gctx->qbits))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_DIGEST);

    if (p != NULL) {

        if (p->data_type != OSSL_PARAM_UTF8_STRING)

            return 0;

        OPENSSL_free(gctx->mdname);

        gctx->mdname = OPENSSL_strdup(p->data);

        if (gctx->mdname == NULL)

            return 0;

    }

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_DIGEST_PROPS);

    if (p != NULL) {

        if (p->data_type != OSSL_PARAM_UTF8_STRING)

            return 0;

        OPENSSL_free(gctx->mdprops);

        gctx->mdprops = OPENSSL_strdup(p->data);

        if (gctx->mdprops == NULL)

            return 0;

    }

    /* Parameters that are not allowed for DHX */

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_DH_GENERATOR);

    if (p != NULL) {

        ERR_raise(ERR_LIB_PROV, ERR_R_UNSUPPORTED);

        return 0;

    }

    return 1;

}

static int dh_gen_set_params(void *genctx, const OSSL_PARAM params[])

{

    struct dh_gen_ctx *gctx = genctx;

    const OSSL_PARAM *p;

    if (!dh_gen_common_set_params(genctx, params))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_DH_GENERATOR);

    if (p != NULL && !OSSL_PARAM_get_int(p, &gctx->generator))

        return 0;

    /* Parameters that are not allowed for DH */

    if (OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_GINDEX) != NULL

        || OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_PCOUNTER) != NULL

        || OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_H) != NULL

        || OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_SEED) != NULL

        || OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_QBITS) != NULL

        || OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_DIGEST) != NULL

        || OSSL_PARAM_locate_const(params,

                                   OSSL_PKEY_PARAM_FFC_DIGEST_PROPS) != NULL) {

        ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

    return 1;

}

static int dh_gencb(int p, int n, BN_GENCB *cb)

{

    struct dh_gen_ctx *gctx = BN_GENCB_get_arg(cb);

    OSSL_PARAM params[] = { OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END };

    params[0] = OSSL_PARAM_construct_int(OSSL_GEN_PARAM_POTENTIAL, &p);

    params[1] = OSSL_PARAM_construct_int(OSSL_GEN_PARAM_ITERATION, &n);

    return gctx->cb(params, gctx->cbarg);

}

static void *dh_gen(void *genctx, OSSL_CALLBACK *osslcb, void *cbarg)

{

    int ret = 0;

    struct dh_gen_ctx *gctx = genctx;

    DH *dh = NULL;

    BN_GENCB *gencb = NULL;

    FFC_PARAMS *ffc;

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

        return NULL;

    /*

     * If a group name is selected then the type is group regardless of what the

     * the user selected. This overrides rather than errors for backwards

     * compatibility.

     */

    if (gctx->group_nid != NID_undef)

        gctx->gen_type = DH_PARAMGEN_TYPE_GROUP;

    /* For parameter generation - If there is a group name just create it */

    if (gctx->gen_type == DH_PARAMGEN_TYPE_GROUP

            && gctx->ffc_params == NULL) {

        /* Select a named group if there is not one already */

        if (gctx->group_nid == NID_undef)

            gctx->group_nid = ossl_dh_get_named_group_uid_from_size(gctx->pbits);

        if (gctx->group_nid == NID_undef)

            return NULL;

        dh = ossl_dh_new_by_nid_ex(gctx->libctx, gctx->group_nid);

        if (dh == NULL)

            return NULL;

        ffc = ossl_dh_get0_params(dh);

    } else {

        dh = ossl_dh_new_ex(gctx->libctx);

        if (dh == NULL)

            return NULL;

        ffc = ossl_dh_get0_params(dh);

        /* Copy the template value if one was passed */

        if (gctx->ffc_params != NULL

            && !ossl_ffc_params_copy(ffc, gctx->ffc_params))

            goto end;

        if (!ossl_ffc_params_set_seed(ffc, gctx->seed, gctx->seedlen))

            goto end;

        if (gctx->gindex != -1) {

            ossl_ffc_params_set_gindex(ffc, gctx->gindex);

            if (gctx->pcounter != -1)

                ossl_ffc_params_set_pcounter(ffc, gctx->pcounter);

        } else if (gctx->hindex != 0) {

            ossl_ffc_params_set_h(ffc, gctx->hindex);

        }

        if (gctx->mdname != NULL) {

            if (!ossl_ffc_set_digest(ffc, gctx->mdname, gctx->mdprops))

                goto end;

        }

        gctx->cb = osslcb;

        gctx->cbarg = cbarg;

        gencb = BN_GENCB_new();

        if (gencb != NULL)

            BN_GENCB_set(gencb, dh_gencb, genctx);

        if ((gctx->selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0) {

            /*

             * NOTE: The old safe prime generator code is not used in fips mode,

             * (i.e internally it ignores the generator and chooses a named

             * group based on pbits.

             */

            if (gctx->gen_type == DH_PARAMGEN_TYPE_GENERATOR)

                ret = DH_generate_parameters_ex(dh, gctx->pbits,

                                                gctx->generator, gencb);

            else

                ret = ossl_dh_generate_ffc_parameters(dh, gctx->gen_type,

                                                      gctx->pbits, gctx->qbits,

                                                      gencb);

            if (ret <= 0)

                goto end;

        }

    }

    if ((gctx->selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0) {

        if (ffc->p == NULL || ffc->g == NULL)

            goto end;

        if (gctx->priv_len > 0)

            DH_set_length(dh, (long)gctx->priv_len);

        ossl_ffc_params_enable_flags(ffc, FFC_PARAM_FLAG_VALIDATE_LEGACY,

                                     gctx->gen_type == DH_PARAMGEN_TYPE_FIPS_186_2);

        if (DH_generate_key(dh) <= 0)

            goto end;

    }

    DH_clear_flags(dh, DH_FLAG_TYPE_MASK);

    DH_set_flags(dh, gctx->dh_type);

    ret = 1;

end:

    if (ret <= 0) {

        DH_free(dh);

        dh = NULL;

    }

    BN_GENCB_free(gencb);

    return dh;

}

static void dh_gen_cleanup(void *genctx)

{

    struct dh_gen_ctx *gctx = genctx;

    if (gctx == NULL)

        return;

    OPENSSL_free(gctx->mdname);

    OPENSSL_free(gctx->mdprops);

    OPENSSL_clear_free(gctx->seed, gctx->seedlen);

    OPENSSL_free(gctx);

}

static void *dh_load(const void *reference, size_t reference_sz)

{

    DH *dh = NULL;

    if (ossl_prov_is_running() && reference_sz == sizeof(dh)) {

        /* The contents of the reference is the address to our object */

        dh = *(DH **)reference;

        /* We grabbed, so we detach it */

        *(DH **)reference = NULL;

        return dh;

    }

    return NULL;

}

static void *dh_dup(const void *keydata_from, int selection)

{

    if (ossl_prov_is_running())

        return ossl_dh_dup(keydata_from, selection);

    return NULL;

}

const OSSL_DISPATCH ossl_dh_keymgmt_functions[] = {

    { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))dh_newdata },

    { OSSL_FUNC_KEYMGMT_GEN_INIT, (void (*)(void))dh_gen_init },

    { OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE, (void (*)(void))dh_gen_set_template },

    { OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS, (void (*)(void))dh_gen_set_params },

    { OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS,

      (void (*)(void))dh_gen_settable_params },

    { OSSL_FUNC_KEYMGMT_GEN, (void (*)(void))dh_gen },

    { OSSL_FUNC_KEYMGMT_GEN_CLEANUP, (void (*)(void))dh_gen_cleanup },

    { OSSL_FUNC_KEYMGMT_LOAD, (void (*)(void))dh_load },

    { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))dh_freedata },

    { OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*) (void))dh_get_params },

    { OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void (*) (void))dh_gettable_params },

    { OSSL_FUNC_KEYMGMT_SET_PARAMS, (void (*) (void))dh_set_params },

    { OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS, (void (*) (void))dh_settable_params },

    { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))dh_has },

    { OSSL_FUNC_KEYMGMT_MATCH, (void (*)(void))dh_match },

    { OSSL_FUNC_KEYMGMT_VALIDATE, (void (*)(void))dh_validate },

    { OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))dh_import },

    { OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))dh_import_types },

    { OSSL_FUNC_KEYMGMT_EXPORT, (void (*)(void))dh_export },

    { OSSL_FUNC_KEYMGMT_EXPORT_TYPES, (void (*)(void))dh_export_types },

    { OSSL_FUNC_KEYMGMT_DUP, (void (*)(void))dh_dup },

    { 0, NULL }

};

/* For any DH key, we use the "DH" algorithms regardless of sub-type. */

static const char *dhx_query_operation_name(int operation_id)

{

    return "DH";

}

const OSSL_DISPATCH ossl_dhx_keymgmt_functions[] = {

    { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))dhx_newdata },

    { OSSL_FUNC_KEYMGMT_GEN_INIT, (void (*)(void))dhx_gen_init },

    { OSSL_FUNC_KEYMGMT_GEN_SET_TEMPLATE, (void (*)(void))dh_gen_set_template },

    { OSSL_FUNC_KEYMGMT_GEN_SET_PARAMS, (void (*)(void))dhx_gen_set_params },

    { OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS,

      (void (*)(void))dhx_gen_settable_params },

    { OSSL_FUNC_KEYMGMT_GEN, (void (*)(void))dh_gen },

    { OSSL_FUNC_KEYMGMT_GEN_CLEANUP, (void (*)(void))dh_gen_cleanup },

    { OSSL_FUNC_KEYMGMT_LOAD, (void (*)(void))dh_load },

    { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))dh_freedata },

    { OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*) (void))dh_get_params },

    { OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void (*) (void))dh_gettable_params },

    { OSSL_FUNC_KEYMGMT_SET_PARAMS, (void (*) (void))dh_set_params },

    { OSSL_FUNC_KEYMGMT_SETTABLE_PARAMS, (void (*) (void))dh_settable_params },

    { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))dh_has },

    { OSSL_FUNC_KEYMGMT_MATCH, (void (*)(void))dh_match },

    { OSSL_FUNC_KEYMGMT_VALIDATE, (void (*)(void))dh_validate },

    { OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))dh_import },

    { OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))dh_import_types },

    { OSSL_FUNC_KEYMGMT_EXPORT, (void (*)(void))dh_export },

    { OSSL_FUNC_KEYMGMT_EXPORT_TYPES, (void (*)(void))dh_export_types },

    { OSSL_FUNC_KEYMGMT_QUERY_OPERATION_NAME,

      (void (*)(void))dhx_query_operation_name },

    { OSSL_FUNC_KEYMGMT_DUP, (void (*)(void))dh_dup },

    { 0, NULL }

};