96ea475c638b96043884185ca6fa53fd98bab5a5
[openssl.git] / crypto / dh / dh_asn1.c
1 /* dh_asn1.c */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer. 
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58
59 #include <stdio.h>
60 #include "cryptlib.h"
61 #include <openssl/bn.h>
62 #include <openssl/dh.h>
63 #include <openssl/objects.h>
64 #include <openssl/asn1t.h>
65
66 /* Override the default free and new methods */
67 static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
68                                                 void *exarg)
69 {
70         if(operation == ASN1_OP_NEW_PRE) {
71                 *pval = (ASN1_VALUE *)DH_new();
72                 if(*pval) return 2;
73                 return 0;
74         } else if(operation == ASN1_OP_FREE_PRE) {
75                 DH_free((DH *)*pval);
76                 *pval = NULL;
77                 return 2;
78         }
79         return 1;
80 }
81
82 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
83         ASN1_SIMPLE(DH, p, BIGNUM),
84         ASN1_SIMPLE(DH, g, BIGNUM),
85         ASN1_OPT(DH, length, ZLONG),
86 } ASN1_SEQUENCE_END_cb(DH, DHparams)
87
88 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
89
90 /* Internal only structures for handling X9.42 DH: this gets translated
91  * to or from a DH structure straight away.
92  */
93
94 typedef struct
95         {
96         ASN1_BIT_STRING *seed;
97         BIGNUM *counter;
98         } int_dhvparams;
99
100 typedef struct 
101         {
102         BIGNUM *p;
103         BIGNUM *q;
104         BIGNUM *g;
105         BIGNUM *j;
106         int_dhvparams *vparams;
107         } int_dhx942_dh;
108
109 ASN1_SEQUENCE(DHvparams) = {
110         ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),
111         ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)
112 } ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)
113
114 ASN1_SEQUENCE(DHxparams) = {
115         ASN1_SIMPLE(int_dhx942_dh, p, BIGNUM),
116         ASN1_SIMPLE(int_dhx942_dh, g, BIGNUM),
117         ASN1_SIMPLE(int_dhx942_dh, q, BIGNUM),
118         ASN1_OPT(int_dhx942_dh, j, BIGNUM),
119         ASN1_OPT(int_dhx942_dh, vparams, DHvparams),
120 } ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)
121
122 int_dhx942_dh * d2i_int_dhx(int_dhx942_dh **a,
123                                 const unsigned char **pp, long length);
124 int     i2d_int_dhx(const int_dhx942_dh *a,unsigned char **pp);
125
126 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(int_dhx942_dh, DHxparams, int_dhx)
127
128 /* Application leve function: read in X9.42 DH parameters into DH structure */
129
130 DH *    d2i_DHxparams(DH **a,const unsigned char **pp, long length)
131         {
132         int_dhx942_dh *dhx = NULL;
133         DH *dh = NULL;
134         dh = DH_new();
135         if (!dh)
136                 return NULL;
137         dhx = d2i_int_dhx(NULL, pp, length);
138         if (!dhx)
139                 {
140                 DH_free(dh);
141                 return NULL;
142                 }
143
144         if (a)
145                 {
146                 if (*a)
147                         DH_free(*a);
148                 *a = dh;
149                 }
150
151         dh->p = dhx->p;
152         dh->q = dhx->q;
153         dh->g = dhx->g;
154         dh->j = dhx->j;
155
156         if (dhx->vparams)
157                 {
158                 dh->seed = dhx->vparams->seed->data;
159                 dh->seedlen = dhx->vparams->seed->length;
160                 dh->counter = dhx->vparams->counter;
161                 dhx->vparams->seed->data = NULL;
162                 ASN1_BIT_STRING_free(dhx->vparams->seed);
163                 OPENSSL_free(dhx->vparams);
164                 dhx->vparams = NULL;
165                 }
166
167         OPENSSL_free(dhx);
168         return dh;
169         }
170
171 int     i2d_DHxparams(const DH *dh,unsigned char **pp)
172         {
173         int_dhx942_dh dhx;
174         int_dhvparams dhv;
175         ASN1_BIT_STRING bs;
176         dhx.p = dh->p;
177         dhx.g = dh->g;
178         dhx.q = dh->q;
179         dhx.j = dh->j;
180         if (dh->counter && dh->seed && dh->seedlen > 0)
181                 {
182                 bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
183                 bs.data = dh->seed;
184                 bs.length = dh->seedlen;
185                 dhv.seed = &bs;
186                 dhv.counter = dh->counter;
187                 dhx.vparams = &dhv;
188                 }
189         else
190                 dhx.vparams = NULL;
191
192         return i2d_int_dhx(&dhx, pp);
193         }