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,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  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         }