/* dh_asn1.c */

/*

 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project

 * 2000.

 */

/* ====================================================================

 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.

 *

 * 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 above 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 acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/bn.h>

#include <openssl/dh.h>

#include <openssl/objects.h>

#include <openssl/asn1t.h>

/* Override the default free and new methods */

static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,

                 void *exarg)

{

    if (operation == ASN1_OP_NEW_PRE) {

        *pval = (ASN1_VALUE *)DH_new();

        if (*pval)

            return 2;

        return 0;

    } else if (operation == ASN1_OP_FREE_PRE) {

        DH_free((DH *)*pval);

        *pval = NULL;

        return 2;

    }

    return 1;

}

ASN1_SEQUENCE_cb(DHparams, dh_cb) = {

        ASN1_SIMPLE(DH, p, BIGNUM),

        ASN1_SIMPLE(DH, g, BIGNUM),

        ASN1_OPT(DH, length, ZLONG),

} ASN1_SEQUENCE_END_cb(DH, DHparams)

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)

/*

 * Internal only structures for handling X9.42 DH: this gets translated to or

 * from a DH structure straight away.

 */

typedef struct {

    ASN1_BIT_STRING *seed;

    BIGNUM *counter;

} int_dhvparams;

typedef struct {

    BIGNUM *p;

    BIGNUM *q;

    BIGNUM *g;

    BIGNUM *j;

    int_dhvparams *vparams;

} int_dhx942_dh;

ASN1_SEQUENCE(DHvparams) = {

        ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),

        ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)

} ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)

ASN1_SEQUENCE(DHxparams) = {

        ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM),

        ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM),

        ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM),

        ASN1_OPT(int_dhx942_dh, j, BIGNUM),

        ASN1_OPT(int_dhx942_dh, vparams, DHvparams),

} ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)

int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a,

                           const unsigned char **pp, long length);

int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp);

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh, DHxparams, int_dhx)

/* Application leve function: read in X9.42 DH parameters into DH structure */

DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)

{

    int_dhx942_dh *dhx = NULL;

    DH *dh = NULL;

    dh = DH_new();

    if (!dh)

        return NULL;

    dhx = d2i_int_dhx(NULL, pp, length);

    if (!dhx) {

        DH_free(dh);

        return NULL;

    }

    if (a) {

        if (*a)

            DH_free(*a);

        *a = dh;

    }

    dh->p = dhx->p;

    dh->q = dhx->q;

    dh->g = dhx->g;

    dh->j = dhx->j;

    if (dhx->vparams) {

        dh->seed = dhx->vparams->seed->data;

        dh->seedlen = dhx->vparams->seed->length;

        dh->counter = dhx->vparams->counter;

        dhx->vparams->seed->data = NULL;

        ASN1_BIT_STRING_free(dhx->vparams->seed);

        OPENSSL_free(dhx->vparams);

        dhx->vparams = NULL;

    }

    OPENSSL_free(dhx);

    return dh;

}

int i2d_DHxparams(const DH *dh, unsigned char **pp)

{

    int_dhx942_dh dhx;

    int_dhvparams dhv;

    ASN1_BIT_STRING bs;

    dhx.p = dh->p;

    dhx.g = dh->g;

    dhx.q = dh->q;

    dhx.j = dh->j;

    if (dh->counter && dh->seed && dh->seedlen > 0) {

        bs.flags = ASN1_STRING_FLAG_BITS_LEFT;

        bs.data = dh->seed;

        bs.length = dh->seedlen;

        dhv.seed = &bs;

        dhv.counter = dh->counter;

        dhx.vparams = &dhv;

    } else

        dhx.vparams = NULL;

    return i2d_int_dhx(&dhx, pp);

}