/*

 * Copyright 2019-2024 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

 */

/*

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

 * internal use.

 */

#include "internal/deprecated.h"

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/bn.h>

#include <openssl/err.h>

#include "prov/securitycheck.h"

#include "prov/providercommon.h"

#include "prov/implementations.h"

#include "prov/provider_ctx.h"

#include "crypto/dsa.h"

#include "internal/sizes.h"

#include "internal/nelem.h"

#include "internal/param_build_set.h"

static OSSL_FUNC_keymgmt_new_fn dsa_newdata;

static OSSL_FUNC_keymgmt_free_fn dsa_freedata;

static OSSL_FUNC_keymgmt_gen_init_fn dsa_gen_init;

static OSSL_FUNC_keymgmt_gen_set_template_fn dsa_gen_set_template;

static OSSL_FUNC_keymgmt_gen_set_params_fn dsa_gen_set_params;

static OSSL_FUNC_keymgmt_gen_settable_params_fn dsa_gen_settable_params;

static OSSL_FUNC_keymgmt_gen_get_params_fn dsa_gen_get_params;

static OSSL_FUNC_keymgmt_gen_gettable_params_fn dsa_gen_gettable_params;

static OSSL_FUNC_keymgmt_gen_fn dsa_gen;

static OSSL_FUNC_keymgmt_gen_cleanup_fn dsa_gen_cleanup;

static OSSL_FUNC_keymgmt_load_fn dsa_load;

static OSSL_FUNC_keymgmt_get_params_fn dsa_get_params;

static OSSL_FUNC_keymgmt_gettable_params_fn dsa_gettable_params;

static OSSL_FUNC_keymgmt_has_fn dsa_has;

static OSSL_FUNC_keymgmt_match_fn dsa_match;

static OSSL_FUNC_keymgmt_validate_fn dsa_validate;

static OSSL_FUNC_keymgmt_import_fn dsa_import;

static OSSL_FUNC_keymgmt_import_types_fn dsa_import_types;

static OSSL_FUNC_keymgmt_export_fn dsa_export;

static OSSL_FUNC_keymgmt_export_types_fn dsa_export_types;

static OSSL_FUNC_keymgmt_dup_fn dsa_dup;

#define DSA_DEFAULT_MD "SHA256"

#define DSA_POSSIBLE_SELECTIONS \

    (OSSL_KEYMGMT_SELECT_KEYPAIR | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS)

struct dsa_gen_ctx {

    OSSL_LIB_CTX *libctx;

    FFC_PARAMS *ffc_params;

    int selection;

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

    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; /* DSA_PARAMGEN_TYPE_FIPS_186_2 or DSA_PARAMGEN_TYPE_FIPS_186_4 */

    int pcounter;

    int hindex;

    char *mdname;

    char *mdprops;

    OSSL_CALLBACK *cb;

    void *cbarg;

    OSSL_FIPS_IND_DECLARE

};

typedef struct dh_name2id_st {

    const char *name;

    int id;

} DSA_GENTYPE_NAME2ID;

static const DSA_GENTYPE_NAME2ID dsatype2id[] = {

#ifdef FIPS_MODULE

    { "default", DSA_PARAMGEN_TYPE_FIPS_186_4 },

#else

    { "default", DSA_PARAMGEN_TYPE_FIPS_DEFAULT },

#endif

    { "fips186_4", DSA_PARAMGEN_TYPE_FIPS_186_4 },

    { "fips186_2", DSA_PARAMGEN_TYPE_FIPS_186_2 },

};

static int dsa_gen_type_name2id(const char *name)

{

    size_t i;

    for (i = 0; i < OSSL_NELEM(dsatype2id); ++i) {

        if (OPENSSL_strcasecmp(dsatype2id[i].name, name) == 0)

            return dsatype2id[i].id;

    }

    return -1;

}

static int dsa_key_todata(DSA *dsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[],

    int include_private)

{

    const BIGNUM *priv = NULL, *pub = NULL;

    if (dsa == NULL)

        return 0;

    DSA_get0_key(dsa, &pub, &priv);

    if (include_private

        && priv != NULL

        && !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_PRIV_KEY, priv))

        return 0;

    if (pub != NULL

        && !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_PUB_KEY, pub))

        return 0;

    return 1;

}

static void *dsa_newdata(void *provctx)

{

    if (!ossl_prov_is_running())

        return NULL;

    return ossl_dsa_new(PROV_LIBCTX_OF(provctx));

}

static void dsa_freedata(void *keydata)

{

    DSA_free(keydata);

}

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

{

    const DSA *dsa = keydata;

    int ok = 1;

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

        return 0;

    if ((selection & DSA_POSSIBLE_SELECTIONS) == 0)

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

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        ok = ok && (DSA_get0_pub_key(dsa) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        ok = ok && (DSA_get0_priv_key(dsa) != NULL);

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        ok = ok && (DSA_get0_p(dsa) != NULL && DSA_get0_g(dsa) != NULL);

    return ok;

}

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

{

    const DSA *dsa1 = keydata1;

    const DSA *dsa2 = 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 = DSA_get0_pub_key(dsa1);

            const BIGNUM *pb = DSA_get0_pub_key(dsa2);

            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 = DSA_get0_priv_key(dsa1);

            const BIGNUM *pb = DSA_get0_priv_key(dsa2);

            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 *dsaparams1 = ossl_dsa_get0_params((DSA *)dsa1);

        FFC_PARAMS *dsaparams2 = ossl_dsa_get0_params((DSA *)dsa2);

        ok = ok && ossl_ffc_params_cmp(dsaparams1, dsaparams2, 1);

    }

    return ok;

}

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

{

    DSA *dsa = keydata;

    int ok = 1;

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

        return 0;

    if ((selection & DSA_POSSIBLE_SELECTIONS) == 0)

        return 0;

    /* a key without parameters is meaningless */

    ok = ok && ossl_dsa_ffc_params_fromdata(dsa, params);

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

        int include_private = selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && ossl_dsa_key_fromdata(dsa, params, include_private);

    }

    return ok;

}

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

    void *cbarg)

{

    DSA *dsa = keydata;

    OSSL_PARAM_BLD *tmpl;

    OSSL_PARAM *params = NULL;

    int ok = 1;

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

        return 0;

    if ((selection & DSA_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_ffc_params_todata(ossl_dsa_get0_params(dsa), tmpl, NULL);

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

        int include_private = selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY ? 1 : 0;

        ok = ok && dsa_key_todata(dsa, 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 DSA_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_octet_string(OSSL_PKEY_PARAM_FFC_SEED, NULL, 0)

#define DSA_IMEXPORTABLE_PUBLIC_KEY \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_PUB_KEY, NULL, 0)

#define DSA_IMEXPORTABLE_PRIVATE_KEY \

    OSSL_PARAM_BN(OSSL_PKEY_PARAM_PRIV_KEY, NULL, 0)

static const OSSL_PARAM dsa_all_types[] = {

    DSA_IMEXPORTABLE_PARAMETERS,

    DSA_IMEXPORTABLE_PUBLIC_KEY,

    DSA_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM dsa_parameter_types[] = {

    DSA_IMEXPORTABLE_PARAMETERS,

    OSSL_PARAM_END

};

static const OSSL_PARAM dsa_key_types[] = {

    DSA_IMEXPORTABLE_PUBLIC_KEY,

    DSA_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM *dsa_types[] = {

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

    dsa_parameter_types, /* Index 1 = parameter types */

    dsa_key_types, /* Index 2 = key types */

    dsa_all_types /* Index 3 = 1 + 2 */

};

static const OSSL_PARAM *dsa_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 dsa_types[type_select];

}

static const OSSL_PARAM *dsa_import_types(int selection)

{

    return dsa_imexport_types(selection);

}

static const OSSL_PARAM *dsa_export_types(int selection)

{

    return dsa_imexport_types(selection);

}

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

{

    DSA *dsa = key;

    OSSL_PARAM *p;

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

        && !OSSL_PARAM_set_int(p, DSA_bits(dsa)))

        return 0;

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

        && !OSSL_PARAM_set_int(p, DSA_security_bits(dsa)))

        return 0;

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

        && !OSSL_PARAM_set_int(p, DSA_size(dsa)))

        return 0;

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

        && !OSSL_PARAM_set_utf8_string(p, DSA_DEFAULT_MD))

        return 0;

    return ossl_ffc_params_todata(ossl_dsa_get0_params(dsa), NULL, params)

        && dsa_key_todata(dsa, NULL, params, 1);

}

static const OSSL_PARAM dsa_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),

    DSA_IMEXPORTABLE_PARAMETERS,

    DSA_IMEXPORTABLE_PUBLIC_KEY,

    DSA_IMEXPORTABLE_PRIVATE_KEY,

    OSSL_PARAM_END

};

static const OSSL_PARAM *dsa_gettable_params(void *provctx)

{

    return dsa_params;

}

static int dsa_validate_domparams(const DSA *dsa, int checktype)

{

    int status = 0;

    return ossl_dsa_check_params(dsa, checktype, &status);

}

static int dsa_validate_public(const DSA *dsa)

{

    int status = 0;

    const BIGNUM *pub_key = NULL;

    DSA_get0_key(dsa, &pub_key, NULL);

    if (pub_key == NULL)

        return 0;

    return ossl_dsa_check_pub_key(dsa, pub_key, &status);

}

static int dsa_validate_private(const DSA *dsa)

{

    int status = 0;

    const BIGNUM *priv_key = NULL;

    DSA_get0_key(dsa, NULL, &priv_key);

    if (priv_key == NULL)

        return 0;

    return ossl_dsa_check_priv_key(dsa, priv_key, &status);

}

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

{

    const DSA *dsa = keydata;

    int ok = 1;

    if (!ossl_prov_is_running())

        return 0;

    if ((selection & DSA_POSSIBLE_SELECTIONS) == 0)

        return 1; /* nothing to validate */

    if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0)

        ok = ok && dsa_validate_domparams(dsa, checktype);

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)

        ok = ok && dsa_validate_public(dsa);

    if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)

        ok = ok && dsa_validate_private(dsa);

    /* If the whole key is selected, we do a pairwise validation */

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR)

        == OSSL_KEYMGMT_SELECT_KEYPAIR)

        ok = ok && ossl_dsa_check_pairwise(dsa);

    return ok;

}

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

    const OSSL_PARAM params[])

{

    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(provctx);

    struct dsa_gen_ctx *gctx = NULL;

    if (!ossl_prov_is_running() || (selection & DSA_POSSIBLE_SELECTIONS) == 0)

        return NULL;

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

        gctx->selection = selection;

        gctx->libctx = libctx;

        gctx->pbits = 2048;

        gctx->qbits = 224;

#ifdef FIPS_MODULE

        gctx->gen_type = DSA_PARAMGEN_TYPE_FIPS_186_4;

#else

        gctx->gen_type = DSA_PARAMGEN_TYPE_FIPS_DEFAULT;

#endif

        gctx->gindex = -1;

        gctx->pcounter = -1;

        gctx->hindex = 0;

        OSSL_FIPS_IND_INIT(gctx)

    }

    if (!dsa_gen_set_params(gctx, params)) {

        dsa_gen_cleanup(gctx);

        gctx = NULL;

    }

    return gctx;

}

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

{

    struct dsa_gen_ctx *gctx = genctx;

    DSA *dsa = templ;

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

        return 0;

    gctx->ffc_params = ossl_dsa_get0_params(dsa);

    return 1;

}

static int dsa_set_gen_seed(struct dsa_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 dsa_gen_set_params(void *genctx, const OSSL_PARAM params[])

{

    struct dsa_gen_ctx *gctx = genctx;

    const OSSL_PARAM *p;

    int gen_type = -1;

    if (gctx == NULL)

        return 0;

    if (params == NULL)

        return 1;

    if (!OSSL_FIPS_IND_SET_CTX_PARAM(gctx, OSSL_FIPS_IND_SETTABLE0, params,

            OSSL_PKEY_PARAM_FIPS_SIGN_CHECK))

        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_TYPE);

    if (p != NULL) {

        if (p->data_type != OSSL_PARAM_UTF8_STRING

            || ((gen_type = dsa_gen_type_name2id(p->data)) == -1)) {

            ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);

            return 0;

        }

        /*

         * Only assign context gen_type if it was set by dsa_gen_type_name2id

         * must be in range:

         * DSA_PARAMGEN_TYPE_FIPS_186_4 <= gen_type <= DSA_PARAMGEN_TYPE_FIPS_DEFAULT

         */

        if (gen_type != -1)

            gctx->gen_type = gen_type;

    }

    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

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

        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;

    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;

    }

    return 1;

}

static const OSSL_PARAM *dsa_gen_settable_params(ossl_unused void *genctx,

    ossl_unused void *provctx)

{

    static OSSL_PARAM settable[] = {

        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE, NULL, 0),

        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_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_PKEY_PARAM_FIPS_SIGN_CHECK)

            OSSL_PARAM_END

    };

    return settable;

}

static int dsa_gen_get_params(void *genctx, OSSL_PARAM *params)

{

    struct dsa_gen_ctx *gctx = genctx;

    if (gctx == NULL)

        return 0;

    if (params == NULL)

        return 1;

    if (!OSSL_FIPS_IND_GET_CTX_PARAM(gctx, params))

        return 0;

    return 1;

}

static const OSSL_PARAM *dsa_gen_gettable_params(ossl_unused void *ctx,

    ossl_unused void *provctx)

{

    static const OSSL_PARAM dsa_gen_gettable_params_table[] = {

        OSSL_FIPS_IND_GETTABLE_CTX_PARAM()

            OSSL_PARAM_END

    };

    return dsa_gen_gettable_params_table;

}

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

{

    struct dsa_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 *dsa_gen(void *genctx, OSSL_CALLBACK *osslcb, void *cbarg)

{

    struct dsa_gen_ctx *gctx = genctx;

    DSA *dsa = NULL;

    BN_GENCB *gencb = NULL;

    int ret = 0;

    FFC_PARAMS *ffc;

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

        return NULL;

#ifdef FIPS_MODULE

    /*

     * DSA signing is not approved in FIPS 140-3, so there is no

     * need for DSA keygen either.

     */

    if (!OSSL_FIPS_IND_ON_UNAPPROVED(gctx, OSSL_FIPS_IND_SETTABLE0,

            gctx->libctx, "DSA", "Keygen",

            ossl_fips_config_dsa_sign_disallowed))

        return 0;

#endif

    dsa = ossl_dsa_new(gctx->libctx);

    if (dsa == NULL)

        return NULL;

    if (gctx->gen_type == DSA_PARAMGEN_TYPE_FIPS_DEFAULT)

        gctx->gen_type = (gctx->pbits >= 2048 ? DSA_PARAMGEN_TYPE_FIPS_186_4 : DSA_PARAMGEN_TYPE_FIPS_186_2);

    /*

     * Do a bounds check on context gen_type. Must be in range:

     * DSA_PARAMGEN_TYPE_FIPS_186_4 <= gen_type <= DSA_PARAMGEN_TYPE_FIPS_DEFAULT

     * Noted here as this needs to be adjusted if a new type is

     * added.

     */

    if (!ossl_assert((gctx->gen_type >= DSA_PARAMGEN_TYPE_FIPS_186_4)

            && (gctx->gen_type <= DSA_PARAMGEN_TYPE_FIPS_DEFAULT))) {

        ERR_raise_data(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR,

            "gen_type set to unsupported value %d", gctx->gen_type);

        goto end;

    }

    gctx->cb = osslcb;

    gctx->cbarg = cbarg;

    gencb = BN_GENCB_new();

    if (gencb != NULL)

        BN_GENCB_set(gencb, dsa_gencb, genctx);

    ffc = ossl_dsa_get0_params(dsa);

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

    if (gctx->ffc_params != NULL

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

        goto end;

    if (gctx->seed != NULL

        && !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)

        ossl_ffc_set_digest(ffc, gctx->mdname, gctx->mdprops);

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

        if (ossl_dsa_generate_ffc_parameters(dsa, gctx->gen_type,

                gctx->pbits, gctx->qbits,

                gencb)

            <= 0)

            goto end;

    }

    ossl_ffc_params_enable_flags(ffc, FFC_PARAM_FLAG_VALIDATE_LEGACY,

        gctx->gen_type == DSA_PARAMGEN_TYPE_FIPS_186_2);

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

        if (ffc->p == NULL

            || ffc->q == NULL

            || ffc->g == NULL)

            goto end;

        if (DSA_generate_key(dsa) <= 0)

            goto end;

    }

    ret = 1;

end:

    if (ret <= 0) {

        DSA_free(dsa);

        dsa = NULL;

    }

    BN_GENCB_free(gencb);

    return dsa;

}

static void dsa_gen_cleanup(void *genctx)

{

    struct dsa_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 *dsa_load(const void *reference, size_t reference_sz)

{

    DSA *dsa = NULL;

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

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

        dsa = *(DSA **)reference;

        /* We grabbed, so we detach it */

        *(DSA **)reference = NULL;

        return dsa;

    }

    return NULL;

}

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

{

    if (ossl_prov_is_running())

        return ossl_dsa_dup(keydata_from, selection);

    return NULL;

}

const OSSL_DISPATCH ossl_dsa_keymgmt_functions[] = {

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

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

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

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

    { OSSL_FUNC_KEYMGMT_GEN_SETTABLE_PARAMS,

        (void (*)(void))dsa_gen_settable_params },

    { OSSL_FUNC_KEYMGMT_GEN_GET_PARAMS, (void (*)(void))dsa_gen_get_params },

    { OSSL_FUNC_KEYMGMT_GEN_GETTABLE_PARAMS,

        (void (*)(void))dsa_gen_gettable_params },

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    OSSL_DISPATCH_END

};