/*

 * 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

 */

/*

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

 * internal use.

 */

#include "internal/deprecated.h"

#include <stdio.h>

#include <openssl/bn.h>

#include <openssl/obj_mac.h>

#include <openssl/core_names.h>

#include "internal/cryptlib.h"

#include "internal/refcount.h"

#include "internal/common.h"

#include "crypto/evp.h"

#include "crypto/dh.h"

#include "dh_local.h"

static DH *dh_new_intern(OSSL_LIB_CTX *libctx);

#ifndef FIPS_MODULE

int DH_set_method(DH *dh, const DH_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 DH_METHOD *mtmp;

    mtmp = dh->meth;

    if (mtmp->finish)

        mtmp->finish(dh);

    dh->meth = meth;

    if (meth->init)

        meth->init(dh);

    return 1;

}

const DH_METHOD *ossl_dh_get_method(const DH *dh)

{

    return dh->meth;

}

#ifndef OPENSSL_NO_DEPRECATED_3_0

DH *DH_new(void)

{

    return dh_new_intern(NULL);

}

#endif

DH *DH_new_method(ENGINE *engine)

{

    if (!ossl_assert(engine == NULL))

        return NULL;

    return dh_new_intern(NULL);

}

#endif /* !FIPS_MODULE */

DH *ossl_dh_new_ex(OSSL_LIB_CTX *libctx)

{

    return dh_new_intern(libctx);

}

static DH *dh_new_intern(OSSL_LIB_CTX *libctx)

{

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

    if (ret == NULL)

        return NULL;

    ret->lock = CRYPTO_THREAD_lock_new();

    if (ret->lock == NULL) {

        ERR_raise(ERR_LIB_DH, 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 = DH_get_default_method();

    ret->flags = ret->meth->flags;

#ifndef FIPS_MODULE

    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data))

        goto err;

#endif /* FIPS_MODULE */

    ossl_ffc_params_init(&ret->params);

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

        ERR_raise(ERR_LIB_DH, ERR_R_INIT_FAIL);

        goto err;

    }

    return ret;

err:

    DH_free(ret);

    return NULL;

}

void DH_free(DH *r)

{

    int i;

    if (r == NULL)

        return;

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

    REF_PRINT_COUNT("DH", i, r);

    if (i > 0)

        return;

    REF_ASSERT_ISNT(i < 0);

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

        r->meth->finish(r);

#if !defined(FIPS_MODULE)

    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, 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 DH_up_ref(DH *r)

{

    int i;

    if (CRYPTO_UP_REF(&r->references, &i) <= 0)

        return 0;

    REF_PRINT_COUNT("DH", i, r);

    REF_ASSERT_ISNT(i < 2);

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

}

OSSL_LIB_CTX *ossl_dh_get0_libctx(const DH *dh)

{

    return dh->libctx;

}

void ossl_dh_set0_libctx(DH *d, OSSL_LIB_CTX *libctx)

{

    d->libctx = libctx;

}

#ifndef FIPS_MODULE

int DH_set_ex_data(DH *d, int idx, void *arg)

{

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

}

void *DH_get_ex_data(const DH *d, int idx)

{

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

}

#endif

int DH_bits(const DH *dh)

{

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

        return BN_num_bits(dh->params.p);

    return -1;

}

int DH_size(const DH *dh)

{

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

        return BN_num_bytes(dh->params.p);

    return -1;

}

int DH_security_bits(const DH *dh)

{

    int N;

    if (dh->params.q != NULL)

        N = BN_num_bits(dh->params.q);

    else if (dh->length)

        N = dh->length;

    else

        N = -1;

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

        return BN_security_bits(BN_num_bits(dh->params.p), N);

    return -1;

}

void DH_get0_pqg(const DH *dh,

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

{

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

}

int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)

{

    /*

     * If the fields p and g in dh are NULL, the corresponding input

     * parameters MUST be non-NULL.  q may remain NULL.

     */

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

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

        return 0;

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

    ossl_dh_cache_named_group(dh);

    dh->dirty_cnt++;

    return 1;

}

long DH_get_length(const DH *dh)

{

    return dh->length;

}

int DH_set_length(DH *dh, long length)

{

    dh->length = length;

    dh->dirty_cnt++;

    return 1;

}

void DH_get0_key(const DH *dh, const BIGNUM **pub_key, const BIGNUM **priv_key)

{

    if (pub_key != NULL)

        *pub_key = dh->pub_key;

    if (priv_key != NULL)

        *priv_key = dh->priv_key;

}

int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)

{

    if (pub_key != NULL) {

        BN_clear_free(dh->pub_key);

        dh->pub_key = pub_key;

    }

    if (priv_key != NULL) {

        BN_clear_free(dh->priv_key);

        dh->priv_key = priv_key;

    }

    dh->dirty_cnt++;

    return 1;

}

const BIGNUM *DH_get0_p(const DH *dh)

{

    return dh->params.p;

}

const BIGNUM *DH_get0_q(const DH *dh)

{

    return dh->params.q;

}

const BIGNUM *DH_get0_g(const DH *dh)

{

    return dh->params.g;

}

const BIGNUM *DH_get0_priv_key(const DH *dh)

{

    return dh->priv_key;

}

const BIGNUM *DH_get0_pub_key(const DH *dh)

{

    return dh->pub_key;

}

void DH_clear_flags(DH *dh, int flags)

{

    dh->flags &= ~flags;

}

int DH_test_flags(const DH *dh, int flags)

{

    return dh->flags & flags;

}

void DH_set_flags(DH *dh, int flags)

{

    dh->flags |= flags;

}

FFC_PARAMS *ossl_dh_get0_params(DH *dh)

{

    return &dh->params;

}

int ossl_dh_get0_nid(const DH *dh)

{

    return dh->params.nid;

}