/* crypto/dsa/dsa_lib.c */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/bn.h>

#include <openssl/dsa.h>

#include <openssl/asn1.h>

#ifndef OPENSSL_NO_ENGINE

# include <openssl/engine.h>

#endif

#ifndef OPENSSL_NO_DH

# include <openssl/dh.h>

#endif

#ifdef OPENSSL_FIPS

# include <openssl/fips.h>

#endif

const char DSA_version[] = "DSA" OPENSSL_VERSION_PTEXT;

static const DSA_METHOD *default_DSA_method = NULL;

void DSA_set_default_method(const DSA_METHOD *meth)

{

    default_DSA_method = meth;

}

const DSA_METHOD *DSA_get_default_method(void)

{

    if (!default_DSA_method) {

#ifdef OPENSSL_FIPS

        if (FIPS_mode())

            return FIPS_dsa_openssl();

        else

            return DSA_OpenSSL();

#else

        default_DSA_method = DSA_OpenSSL();

#endif

    }

    return default_DSA_method;

}

DSA *DSA_new(void)

{

    return DSA_new_method(NULL);

}

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);

#ifndef OPENSSL_NO_ENGINE

    if (dsa->engine) {

        ENGINE_finish(dsa->engine);

        dsa->engine = NULL;

    }

#endif

    dsa->meth = meth;

    if (meth->init)

        meth->init(dsa);

    return 1;

}

DSA *DSA_new_method(ENGINE *engine)

{

    DSA *ret;

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

    if (ret == NULL) {

        DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);

        return (NULL);

    }

    ret->meth = DSA_get_default_method();

#ifndef OPENSSL_NO_ENGINE

    if (engine) {

        if (!ENGINE_init(engine)) {

            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);

            OPENSSL_free(ret);

            return NULL;

        }

        ret->engine = engine;

    } else

        ret->engine = ENGINE_get_default_DSA();

    if (ret->engine) {

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

        if (!ret->meth) {

            DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);

            ENGINE_finish(ret->engine);

            OPENSSL_free(ret);

            return NULL;

        }

    }

#endif

    ret->pad = 0;

    ret->version = 0;

    ret->write_params = 1;

    ret->p = NULL;

    ret->q = NULL;

    ret->g = NULL;

    ret->pub_key = NULL;

    ret->priv_key = NULL;

    ret->kinv = NULL;

    ret->r = NULL;

    ret->method_mont_p = NULL;

    ret->references = 1;

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

    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);

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

#ifndef OPENSSL_NO_ENGINE

        if (ret->engine)

            ENGINE_finish(ret->engine);

#endif

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

        OPENSSL_free(ret);

        ret = NULL;

    }

    return (ret);

}

void DSA_free(DSA *r)

{

    int i;

    if (r == NULL)

        return;

    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);

#ifdef REF_PRINT

    REF_PRINT("DSA", r);

#endif

    if (i > 0)

        return;

#ifdef REF_CHECK

    if (i < 0) {

        fprintf(stderr, "DSA_free, bad reference count\n");

        abort();

    }

#endif

    if (r->meth->finish)

        r->meth->finish(r);

#ifndef OPENSSL_NO_ENGINE

    if (r->engine)

        ENGINE_finish(r->engine);

#endif

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

    if (r->p != NULL)

        BN_clear_free(r->p);

    if (r->q != NULL)

        BN_clear_free(r->q);

    if (r->g != NULL)

        BN_clear_free(r->g);

    if (r->pub_key != NULL)

        BN_clear_free(r->pub_key);

    if (r->priv_key != NULL)

        BN_clear_free(r->priv_key);

    if (r->kinv != NULL)

        BN_clear_free(r->kinv);

    if (r->r != NULL)

        BN_clear_free(r->r);

    OPENSSL_free(r);

}

int DSA_up_ref(DSA *r)

{

    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);

#ifdef REF_PRINT

    REF_PRINT("DSA", r);

#endif

#ifdef REF_CHECK

    if (i < 2) {

        fprintf(stderr, "DSA_up_ref, bad reference count\n");

        abort();

    }

#endif

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

}

int DSA_size(const DSA *r)

{

    int ret, i;

    ASN1_INTEGER bs;

    unsigned char buf[4];       /* 4 bytes looks really small. However,

                                 * i2d_ASN1_INTEGER() will not look beyond

                                 * the first byte, as long as the second

                                 * parameter is NULL. */

    i = BN_num_bits(r->q);

    bs.length = (i + 7) / 8;

    bs.data = buf;

    bs.type = V_ASN1_INTEGER;

    /* If the top bit is set the asn1 encoding is 1 larger. */

    buf[0] = 0xff;

    i = i2d_ASN1_INTEGER(&bs, NULL);

    i += i;                     /* r and s */

    ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);

    return (ret);

}

int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,

                         CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)

{

    return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,

                                   new_func, dup_func, free_func);

}

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(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;

    if (r == NULL)

        goto err;

    ret = DH_new();

    if (ret == NULL)

        goto err;

    if (r->p != NULL)

        if ((ret->p = BN_dup(r->p)) == NULL)

            goto err;

    if (r->q != NULL) {

        ret->length = BN_num_bits(r->q);

        if ((ret->q = BN_dup(r->q)) == NULL)

            goto err;

    }

    if (r->g != NULL)

        if ((ret->g = BN_dup(r->g)) == NULL)

            goto err;

    if (r->pub_key != NULL)

        if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)

            goto err;

    if (r->priv_key != NULL)

        if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)

            goto err;

    return ret;

 err:

    if (ret != NULL)

        DH_free(ret);

    return NULL;

}

#endif