crypto/dh/dh_lib.c

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