/*

 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include "internal/refcount.h"

#include <openssl/bn.h>

#include "dh_locl.h"

#include <openssl/engine.h>

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);

#ifndef OPENSSL_NO_ENGINE

    ENGINE_finish(dh->engine);

    dh->engine = NULL;

#endif

    dh->meth = meth;

    if (meth->init)

        meth->init(dh);

    return 1;

}

DH *DH_new(void)

{

    return DH_new_method(NULL);

}

DH *DH_new_method(ENGINE *engine)

{

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

    if (ret == NULL) {

        DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    ret->references = 1;

    ret->lock = CRYPTO_THREAD_lock_new();

    if (ret->lock == NULL) {

        DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);

        OPENSSL_free(ret);

        return NULL;

    }

    ret->meth = DH_get_default_method();

#ifndef OPENSSL_NO_ENGINE

    ret->flags = ret->meth->flags;  /* early default init */

    if (engine) {

        if (!ENGINE_init(engine)) {

            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);

            goto err;

        }

        ret->engine = engine;

    } else

        ret->engine = ENGINE_get_default_DH();

    if (ret->engine) {

        ret->meth = ENGINE_get_DH(ret->engine);

        if (ret->meth == NULL) {

            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);

            goto err;

        }

    }

#endif

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

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

        goto err;

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

        DHerr(DH_F_DH_NEW_METHOD, ERR_R_INIT_FAIL);

err:

        DH_free(ret);

        ret = NULL;

    }

    return ret;

}

void DH_free(DH *r)

{

    int i;

    if (r == NULL)

        return;

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

    REF_PRINT_COUNT("DH", r);

    if (i > 0)

        return;

    REF_ASSERT_ISNT(i < 0);

    if (r->meth->finish)

        r->meth->finish(r);

#ifndef OPENSSL_NO_ENGINE

    ENGINE_finish(r->engine);

#endif

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

    CRYPTO_THREAD_lock_free(r->lock);

    BN_clear_free(r->p);

    BN_clear_free(r->g);

    BN_clear_free(r->q);

    BN_clear_free(r->j);

    OPENSSL_free(r->seed);

    BN_clear_free(r->counter);

    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, r->lock) <= 0)

        return 0;

    REF_PRINT_COUNT("DH", r);

    REF_ASSERT_ISNT(i < 2);

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

}

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(DH *d, int idx)

{

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

}

int DH_bits(const DH *dh)

{

    return BN_num_bits(dh->p);

}

int DH_size(const DH *dh)

{

    return BN_num_bytes(dh->p);

}

int DH_security_bits(const DH *dh)

{

    int N;

    if (dh->q)

        N = BN_num_bits(dh->q);

    else if (dh->length)

        N = dh->length;

    else

        N = -1;

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

}

void DH_get0_pqg(const DH *dh,

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

{

    if (p != NULL)

        *p = dh->p;

    if (q != NULL)

        *q = dh->q;

    if (g != NULL)

        *g = dh->g;

}

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

{

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

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

     */

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

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

        return 0;

    if (p != NULL) {

        BN_free(dh->p);

        dh->p = p;

    }

    if (q != NULL) {

        BN_free(dh->q);

        dh->q = q;

    }

    if (g != NULL) {

        BN_free(dh->g);

        dh->g = g;

    }

    if (q != NULL) {

        dh->length = BN_num_bits(q);

    }

    return 1;

}

long DH_get_length(const DH *dh)

{

    return dh->length;

}

int DH_set_length(DH *dh, long length)

{

    dh->length = length;

    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_free(dh->pub_key);

        dh->pub_key = pub_key;

    }

    if (priv_key != NULL) {

        BN_free(dh->priv_key);

        dh->priv_key = priv_key;

    }

    return 1;

}

const BIGNUM *DH_get0_p(const DH *dh)

{

    return dh->p;

}

const BIGNUM *DH_get0_q(const DH *dh)

{

    return dh->q;

}

const BIGNUM *DH_get0_g(const DH *dh)

{

    return dh->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;

}

ENGINE *DH_get0_engine(DH *dh)

{

    return dh->engine;

}