crypto/dh/dh_asn1.c

   1 /*
   2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   3  * 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 "internal/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 != NULL)
  73             return 2;
  74         return 0;
  75     } else if (operation == ASN1_OP_FREE_PRE) {
  76         DH_free((DH *)*pval);
  77         *pval = NULL;
  78         return 2;
  79     }
  80     return 1;
  81 }
  82
  83 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
  84         ASN1_SIMPLE(DH, p, BIGNUM),
  85         ASN1_SIMPLE(DH, g, BIGNUM),
  86         ASN1_OPT(DH, length, ZLONG),
  87 } static_ASN1_SEQUENCE_END_cb(DH, DHparams)
  88
  89 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
  90
  91 /*
  92  * Internal only structures for handling X9.42 DH: this gets translated to or
  93  * from a DH structure straight away.
  94  */
  95
  96 typedef struct {
  97     ASN1_BIT_STRING *seed;
  98     BIGNUM *counter;
  99 } int_dhvparams;
 100
 101 typedef struct {
 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 } static_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 } static_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 public 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 == NULL)
 136         return NULL;
 137     dhx = d2i_int_dhx(NULL, pp, length);
 138     if (dhx == NULL) {
 139         DH_free(dh);
 140         return NULL;
 141     }
 142
 143     if (a) {
 144         DH_free(*a);
 145         *a = dh;
 146     }
 147
 148     dh->p = dhx->p;
 149     dh->q = dhx->q;
 150     dh->g = dhx->g;
 151     dh->j = dhx->j;
 152
 153     if (dhx->vparams) {
 154         dh->seed = dhx->vparams->seed->data;
 155         dh->seedlen = dhx->vparams->seed->length;
 156         dh->counter = dhx->vparams->counter;
 157         dhx->vparams->seed->data = NULL;
 158         ASN1_BIT_STRING_free(dhx->vparams->seed);
 159         OPENSSL_free(dhx->vparams);
 160         dhx->vparams = NULL;
 161     }
 162
 163     OPENSSL_free(dhx);
 164     return dh;
 165 }
 166
 167 int i2d_DHxparams(const DH *dh, unsigned char **pp)
 168 {
 169     int_dhx942_dh dhx;
 170     int_dhvparams dhv;
 171     ASN1_BIT_STRING bs;
 172     dhx.p = dh->p;
 173     dhx.g = dh->g;
 174     dhx.q = dh->q;
 175     dhx.j = dh->j;
 176     if (dh->counter && dh->seed && dh->seedlen > 0) {
 177         bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
 178         bs.data = dh->seed;
 179         bs.length = dh->seedlen;
 180         dhv.seed = &bs;
 181         dhv.counter = dh->counter;
 182         dhx.vparams = &dhv;
 183     } else
 184         dhx.vparams = NULL;
 185
 186     return i2d_int_dhx(&dhx, pp);
 187 }