/*

 * Copyright 1995-2026 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/bn.h>

#include "internal/cryptlib.h"

#include "internal/refcount.h"

#include "internal/common.h"

#include "crypto/dsa.h"

#include "crypto/dh.h" /* required by DSA_dup_DH() */

#include "dsa_local.h"

static DSA *dsa_new_intern(OSSL_LIB_CTX *libctx);

#ifndef FIPS_MODULE

int DSA_set_ex_data(DSA *d, int idx, void *arg)

{

    return CRYPTO_set_ex_data(&d->ex_data, idx, arg);

}

void *DSA_get_ex_data(const DSA *d, int idx)

{

    return CRYPTO_get_ex_data(&d->ex_data, idx);

}

#ifndef OPENSSL_NO_DH

DH *DSA_dup_DH(const DSA *r)

{

    /*

     * DSA has p, q, g, optional pub_key, optional priv_key.

     * DH has p, optional length, g, optional pub_key,

     * optional priv_key, optional q.

     */

    DH *ret = NULL;

    BIGNUM *pub_key = NULL, *priv_key = NULL;

    if (r == NULL)

        goto err;

    ret = DH_new();

    if (ret == NULL)

        goto err;

    if (!ossl_ffc_params_copy(ossl_dh_get0_params(ret), &r->params))

        goto err;

    if (r->pub_key != NULL) {

        pub_key = BN_dup(r->pub_key);

        if (pub_key == NULL)

            goto err;

        if (r->priv_key != NULL) {

            priv_key = BN_dup(r->priv_key);

            if (priv_key == NULL)

                goto err;

        }

        if (!DH_set0_key(ret, pub_key, priv_key))

            goto err;

    } else if (r->priv_key != NULL) {

        /* Shouldn't happen */

        goto err;

    }

    return ret;

err:

    BN_free(pub_key);

    BN_free(priv_key);

    DH_free(ret);

    return NULL;

}

#endif /*  OPENSSL_NO_DH */

void DSA_clear_flags(DSA *d, int flags)

{

    d->flags &= ~flags;

}

int DSA_test_flags(const DSA *d, int flags)

{

    return d->flags & flags;

}

void DSA_set_flags(DSA *d, int flags)

{

    d->flags |= flags;

}

int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)

{

    /*

     * NB: The caller is specifically setting a method, so it's not up to us

     * to deal with which ENGINE it comes from.

     */

    const DSA_METHOD *mtmp;

    mtmp = dsa->meth;

    if (mtmp->finish)

        mtmp->finish(dsa);

    dsa->meth = meth;

    if (meth->init)

        meth->init(dsa);

    return 1;

}

#endif /* FIPS_MODULE */

const DSA_METHOD *DSA_get_method(DSA *d)

{

    return d->meth;

}

static DSA *dsa_new_intern(OSSL_LIB_CTX *libctx)

{

    DSA *ret = OPENSSL_zalloc(sizeof(*ret));

    if (ret == NULL)

        return NULL;

    ret->lock = CRYPTO_THREAD_lock_new();

    if (ret->lock == NULL) {

        ERR_raise(ERR_LIB_DSA, ERR_R_CRYPTO_LIB);

        OPENSSL_free(ret);

        return NULL;

    }

    if (!CRYPTO_NEW_REF(&ret->references, 1)) {

        CRYPTO_THREAD_lock_free(ret->lock);

        OPENSSL_free(ret);

        return NULL;

    }

    ret->libctx = libctx;

    ret->meth = DSA_get_default_method();

    ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;

#ifndef FIPS_MODULE

    if (!ossl_crypto_new_ex_data_ex(libctx, CRYPTO_EX_INDEX_DSA, ret,

            &ret->ex_data))

        goto err;

#endif

    ossl_ffc_params_init(&ret->params);

    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {

        ERR_raise(ERR_LIB_DSA, ERR_R_INIT_FAIL);

        goto err;

    }

    return ret;

err:

    DSA_free(ret);

    return NULL;

}

DSA *DSA_new_method(ENGINE *engine)

{

    if (!ossl_assert(engine == NULL))

        return NULL;

    return dsa_new_intern(NULL);

}

DSA *ossl_dsa_new(OSSL_LIB_CTX *libctx)

{

    return dsa_new_intern(libctx);

}

#ifndef FIPS_MODULE

DSA *DSA_new(void)

{

    return dsa_new_intern(NULL);

}

#endif

void DSA_free(DSA *r)

{

    int i;

    if (r == NULL)

        return;

    CRYPTO_DOWN_REF(&r->references, &i);

    REF_PRINT_COUNT("DSA", i, r);

    if (i > 0)

        return;

    REF_ASSERT_ISNT(i < 0);

    if (r->meth != NULL && r->meth->finish != NULL)

        r->meth->finish(r);

#ifndef FIPS_MODULE

    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);

#endif

    CRYPTO_THREAD_lock_free(r->lock);

    CRYPTO_FREE_REF(&r->references);

    ossl_ffc_params_cleanup(&r->params);

    BN_clear_free(r->pub_key);

    BN_clear_free(r->priv_key);

    OPENSSL_free(r);

}

int DSA_up_ref(DSA *r)

{

    int i;

    if (!CRYPTO_UP_REF(&r->references, &i))

        return 0;

    REF_PRINT_COUNT("DSA", i, r);

    REF_ASSERT_ISNT(i < 2);

    return ((i > 1) ? 1 : 0);

}

OSSL_LIB_CTX *ossl_dsa_get0_libctx(const DSA *d)

{

    return d->libctx;

}

void ossl_dsa_set0_libctx(DSA *d, OSSL_LIB_CTX *libctx)

{

    d->libctx = libctx;

}

void DSA_get0_pqg(const DSA *d,

    const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)

{

    ossl_ffc_params_get0_pqg(&d->params, p, q, g);

}

int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)

{

    /* If the fields p, q and g in d are NULL, the corresponding input

     * parameters MUST be non-NULL.

     */

    if ((d->params.p == NULL && p == NULL)

        || (d->params.q == NULL && q == NULL)

        || (d->params.g == NULL && g == NULL))

        return 0;

    ossl_ffc_params_set0_pqg(&d->params, p, q, g);

    d->dirty_cnt++;

    return 1;

}

const BIGNUM *DSA_get0_p(const DSA *d)

{

    return d->params.p;

}

const BIGNUM *DSA_get0_q(const DSA *d)

{

    return d->params.q;

}

const BIGNUM *DSA_get0_g(const DSA *d)

{

    return d->params.g;

}

const BIGNUM *DSA_get0_pub_key(const DSA *d)

{

    return d->pub_key;

}

const BIGNUM *DSA_get0_priv_key(const DSA *d)

{

    return d->priv_key;

}

void DSA_get0_key(const DSA *d,

    const BIGNUM **pub_key, const BIGNUM **priv_key)

{

    if (pub_key != NULL)

        *pub_key = d->pub_key;

    if (priv_key != NULL)

        *priv_key = d->priv_key;

}

int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)

{

    if (pub_key != NULL) {

        BN_free(d->pub_key);

        d->pub_key = pub_key;

    }

    if (priv_key != NULL) {

        BN_free(d->priv_key);

        d->priv_key = priv_key;

    }

    d->dirty_cnt++;

    return 1;

}

int DSA_security_bits(const DSA *d)

{

    if (d->params.p != NULL && d->params.q != NULL)

        return BN_security_bits(BN_num_bits(d->params.p),

            BN_num_bits(d->params.q));

    return -1;

}

int DSA_bits(const DSA *dsa)

{

    if (dsa->params.p != NULL)

        return BN_num_bits(dsa->params.p);

    return -1;

}

FFC_PARAMS *ossl_dsa_get0_params(DSA *dsa)

{

    return &dsa->params;

}

int ossl_dsa_ffc_params_fromdata(DSA *dsa, const OSSL_PARAM params[])

{

    int ret;

    FFC_PARAMS *ffc = ossl_dsa_get0_params(dsa);

    ret = ossl_ffc_params_fromdata(ffc, params);

    if (ret)

        dsa->dirty_cnt++;

    return ret;

}