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 */ 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) 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 } 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 } 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 } 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) 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 } 168 169 int 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