1/* dh_asn1.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2000.
5 */
6/* ====================================================================
7 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <stdio.h>
61#include "cryptlib.h"
62#include <openssl/bn.h>
63#include <openssl/dh.h>
64#include <openssl/objects.h>
65#include <openssl/asn1t.h>
66
67/* Override the default free and new methods */
68static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
69                 void *exarg)
70{
71    if (operation == ASN1_OP_NEW_PRE) {
72        *pval = (ASN1_VALUE *)DH_new();
73        if (*pval)
74            return 2;
75        return 0;
76    } else if (operation == ASN1_OP_FREE_PRE) {
77        DH_free((DH *)*pval);
78        *pval = NULL;
79        return 2;
80    }
81    return 1;
82}
83
84ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
85        ASN1_SIMPLE(DH, p, BIGNUM),
86        ASN1_SIMPLE(DH, g, BIGNUM),
87        ASN1_OPT(DH, length, ZLONG),
88} ASN1_SEQUENCE_END_cb(DH, DHparams)
89
90IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
91
92/*
93 * Internal only structures for handling X9.42 DH: this gets translated to or
94 * from a DH structure straight away.
95 */
96
97typedef struct {
98    ASN1_BIT_STRING *seed;
99    BIGNUM *counter;
100} int_dhvparams;
101
102typedef struct {
103    BIGNUM *p;
104    BIGNUM *q;
105    BIGNUM *g;
106    BIGNUM *j;
107    int_dhvparams *vparams;
108} int_dhx942_dh;
109
110ASN1_SEQUENCE(DHvparams) = {
111        ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),
112        ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)
113} ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)
114
115ASN1_SEQUENCE(DHxparams) = {
116        ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM),
117        ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM),
118        ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM),
119        ASN1_OPT(int_dhx942_dh, j, BIGNUM),
120        ASN1_OPT(int_dhx942_dh, vparams, DHvparams),
121} ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)
122
123int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a,
124                           const unsigned char **pp, long length);
125int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp);
126
127IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh, DHxparams, int_dhx)
128
129/* Application leve function: read in X9.42 DH parameters into DH structure */
130
131DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
132{
133    int_dhx942_dh *dhx = NULL;
134    DH *dh = NULL;
135    dh = DH_new();
136    if (!dh)
137        return NULL;
138    dhx = d2i_int_dhx(NULL, pp, length);
139    if (!dhx) {
140        DH_free(dh);
141        return NULL;
142    }
143
144    if (a) {
145        if (*a)
146            DH_free(*a);
147        *a = dh;
148    }
149
150    dh->p = dhx->p;
151    dh->q = dhx->q;
152    dh->g = dhx->g;
153    dh->j = dhx->j;
154
155    if (dhx->vparams) {
156        dh->seed = dhx->vparams->seed->data;
157        dh->seedlen = dhx->vparams->seed->length;
158        dh->counter = dhx->vparams->counter;
159        dhx->vparams->seed->data = NULL;
160        ASN1_BIT_STRING_free(dhx->vparams->seed);
161        OPENSSL_free(dhx->vparams);
162        dhx->vparams = NULL;
163    }
164
165    OPENSSL_free(dhx);
166    return dh;
167}
168
169int i2d_DHxparams(const DH *dh, unsigned char **pp)
170{
171    int_dhx942_dh dhx;
172    int_dhvparams dhv;
173    ASN1_BIT_STRING bs;
174    dhx.p = dh->p;
175    dhx.g = dh->g;
176    dhx.q = dh->q;
177    dhx.j = dh->j;
178    if (dh->counter && dh->seed && dh->seedlen > 0) {
179        bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
180        bs.data = dh->seed;
181        bs.length = dh->seedlen;
182        dhv.seed = &bs;
183        dhv.counter = dh->counter;
184        dhx.vparams = &dhv;
185    } else
186        dhx.vparams = NULL;
187
188    return i2d_int_dhx(&dhx, pp);
189}
190