crypto/dh/dh_asn1.c

   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 "internal/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 */
  68 static 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 != NULL)
  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
  84 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
  85         ASN1_SIMPLE(DH, p, BIGNUM),
  86         ASN1_SIMPLE(DH, g, BIGNUM),
  87         ASN1_OPT(DH, length, ZLONG),
  88 } static_ASN1_SEQUENCE_END_cb(DH, DHparams)
  89
  90 IMPLEMENT_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
  97 typedef struct {
  98     ASN1_BIT_STRING *seed;
  99     BIGNUM *counter;
 100 } int_dhvparams;
 101
 102 typedef struct {
 103     BIGNUM *p;
 104     BIGNUM *q;
 105     BIGNUM *g;
 106     BIGNUM *j;
 107     int_dhvparams *vparams;
 108 } int_dhx942_dh;
 109
 110 ASN1_SEQUENCE(DHvparams) = {
 111         ASN1_SIMPLE(int_dhvparams, seed, ASN1_BIT_STRING),
 112         ASN1_SIMPLE(int_dhvparams, counter, BIGNUM)
 113 } static_ASN1_SEQUENCE_END_name(int_dhvparams, DHvparams)
 114
 115 ASN1_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 } static_ASN1_SEQUENCE_END_name(int_dhx942_dh, DHxparams)
 122
 123 int_dhx942_dh *d2i_int_dhx(int_dhx942_dh **a,
 124                            const unsigned char **pp, long length);
 125 int i2d_int_dhx(const int_dhx942_dh *a, unsigned char **pp);
 126
 127 IMPLEMENT_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
 131 DH *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 == NULL)
 137         return NULL;
 138     dhx = d2i_int_dhx(NULL, pp, length);
 139     if (dhx == NULL) {
 140         DH_free(dh);
 141         return NULL;
 142     }
 143
 144     if (a) {
 145         DH_free(*a);
 146         *a = dh;
 147     }
 148
 149     dh->p = dhx->p;
 150     dh->q = dhx->q;
 151     dh->g = dhx->g;
 152     dh->j = dhx->j;
 153
 154     if (dhx->vparams) {
 155         dh->seed = dhx->vparams->seed->data;
 156         dh->seedlen = dhx->vparams->seed->length;
 157         dh->counter = dhx->vparams->counter;
 158         dhx->vparams->seed->data = NULL;
 159         ASN1_BIT_STRING_free(dhx->vparams->seed);
 160         OPENSSL_free(dhx->vparams);
 161         dhx->vparams = NULL;
 162     }
 163
 164     OPENSSL_free(dhx);
 165     return dh;
 166 }
 167
 168 int i2d_DHxparams(const DH *dh, unsigned char **pp)
 169 {
 170     int_dhx942_dh dhx;
 171     int_dhvparams dhv;
 172     ASN1_BIT_STRING bs;
 173     dhx.p = dh->p;
 174     dhx.g = dh->g;
 175     dhx.q = dh->q;
 176     dhx.j = dh->j;
 177     if (dh->counter && dh->seed && dh->seedlen > 0) {
 178         bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
 179         bs.data = dh->seed;
 180         bs.length = dh->seedlen;
 181         dhv.seed = &bs;
 182         dhv.counter = dh->counter;
 183         dhx.vparams = &dhv;
 184     } else
 185         dhx.vparams = NULL;
 186
 187     return i2d_int_dhx(&dhx, pp);
 188 }