/*

 * Copyright 2000-2016 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 <openssl/bn.h>

#include "dh_local.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 != NULL)

            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_EMBED(DH, length, ZINT32),

} 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)

} static_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),

} static_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 public 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 == NULL)

        return NULL;

    dhx = d2i_int_dhx(NULL, pp, length);

    if (dhx == NULL) {

        DH_free(dh);

        return NULL;

    }

    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);

}