crypto/dh/dh_lib.c

   1 /* crypto/dh/dh_lib.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include "internal/cryptlib.h"
  61 #include <openssl/bn.h>
  62 #include <openssl/dh.h>
  63 #ifndef OPENSSL_NO_ENGINE
  64 # include <openssl/engine.h>
  65 #endif
  66
  67 static const DH_METHOD *default_DH_method = NULL;
  68
  69 void DH_set_default_method(const DH_METHOD *meth)
  70 {
  71     default_DH_method = meth;
  72 }
  73
  74 const DH_METHOD *DH_get_default_method(void)
  75 {
  76     if (!default_DH_method)
  77         default_DH_method = DH_OpenSSL();
  78     return default_DH_method;
  79 }
  80
  81 int DH_set_method(DH *dh, const DH_METHOD *meth)
  82 {
  83     /*
  84      * NB: The caller is specifically setting a method, so it's not up to us
  85      * to deal with which ENGINE it comes from.
  86      */
  87     const DH_METHOD *mtmp;
  88     mtmp = dh->meth;
  89     if (mtmp->finish)
  90         mtmp->finish(dh);
  91 #ifndef OPENSSL_NO_ENGINE
  92     if (dh->engine) {
  93         ENGINE_finish(dh->engine);
  94         dh->engine = NULL;
  95     }
  96 #endif
  97     dh->meth = meth;
  98     if (meth->init)
  99         meth->init(dh);
 100     return 1;
 101 }
 102
 103 DH *DH_new(void)
 104 {
 105     return DH_new_method(NULL);
 106 }
 107
 108 DH *DH_new_method(ENGINE *engine)
 109 {
 110     DH *ret = OPENSSL_zalloc(sizeof(*ret));
 111
 112     if (ret == NULL) {
 113         DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
 114         return (NULL);
 115     }
 116
 117     ret->meth = DH_get_default_method();
 118 #ifndef OPENSSL_NO_ENGINE
 119     if (engine) {
 120         if (!ENGINE_init(engine)) {
 121             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 122             OPENSSL_free(ret);
 123             return NULL;
 124         }
 125         ret->engine = engine;
 126     } else
 127         ret->engine = ENGINE_get_default_DH();
 128     if (ret->engine) {
 129         ret->meth = ENGINE_get_DH(ret->engine);
 130         if (!ret->meth) {
 131             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 132             ENGINE_finish(ret->engine);
 133             OPENSSL_free(ret);
 134             return NULL;
 135         }
 136     }
 137 #endif
 138
 139     ret->references = 1;
 140     ret->flags = ret->meth->flags;
 141     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 142     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 143 #ifndef OPENSSL_NO_ENGINE
 144         if (ret->engine)
 145             ENGINE_finish(ret->engine);
 146 #endif
 147         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 148         OPENSSL_free(ret);
 149         ret = NULL;
 150     }
 151     return (ret);
 152 }
 153
 154 void DH_free(DH *r)
 155 {
 156     int i;
 157
 158     if (r == NULL)
 159         return;
 160     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
 161 #ifdef REF_PRINT
 162     REF_PRINT("DH", r);
 163 #endif
 164     if (i > 0)
 165         return;
 166 #ifdef REF_CHECK
 167     if (i < 0) {
 168         fprintf(stderr, "DH_free, bad reference count\n");
 169         abort();
 170     }
 171 #endif
 172
 173     if (r->meth->finish)
 174         r->meth->finish(r);
 175 #ifndef OPENSSL_NO_ENGINE
 176     if (r->engine)
 177         ENGINE_finish(r->engine);
 178 #endif
 179
 180     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 181
 182     BN_clear_free(r->p);
 183     BN_clear_free(r->g);
 184     BN_clear_free(r->q);
 185     BN_clear_free(r->j);
 186     OPENSSL_free(r->seed);
 187     BN_clear_free(r->counter);
 188     BN_clear_free(r->pub_key);
 189     BN_clear_free(r->priv_key);
 190     OPENSSL_free(r);
 191 }
 192
 193 int DH_up_ref(DH *r)
 194 {
 195     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
 196 #ifdef REF_PRINT
 197     REF_PRINT("DH", r);
 198 #endif
 199 #ifdef REF_CHECK
 200     if (i < 2) {
 201         fprintf(stderr, "DH_up, bad reference count\n");
 202         abort();
 203     }
 204 #endif
 205     return ((i > 1) ? 1 : 0);
 206 }
 207
 208 int DH_set_ex_data(DH *d, int idx, void *arg)
 209 {
 210     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 211 }
 212
 213 void *DH_get_ex_data(DH *d, int idx)
 214 {
 215     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 216 }
 217
 218 int DH_bits(const DH *dh)
 219 {
 220     return BN_num_bits(dh->p);
 221 }
 222
 223 int DH_size(const DH *dh)
 224 {
 225     return (BN_num_bytes(dh->p));
 226 }
 227
 228 int DH_security_bits(const DH *dh)
 229 {
 230     int N;
 231     if (dh->q)
 232         N = BN_num_bits(dh->q);
 233     else if (dh->length)
 234         N = dh->length;
 235     else
 236         N = -1;
 237     return BN_security_bits(BN_num_bits(dh->p), N);
 238 }