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     ENGINE_finish(dh->engine);
  92     dh->engine = NULL;
  93 #endif
  94     dh->meth = meth;
  95     if (meth->init)
  96         meth->init(dh);
  97     return 1;
  98 }
  99
 100 DH *DH_new(void)
 101 {
 102     return DH_new_method(NULL);
 103 }
 104
 105 DH *DH_new_method(ENGINE *engine)
 106 {
 107     DH *ret = OPENSSL_zalloc(sizeof(*ret));
 108
 109     if (ret == NULL) {
 110         DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
 111         return (NULL);
 112     }
 113
 114     ret->meth = DH_get_default_method();
 115 #ifndef OPENSSL_NO_ENGINE
 116     if (engine) {
 117         if (!ENGINE_init(engine)) {
 118             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 119             OPENSSL_free(ret);
 120             return NULL;
 121         }
 122         ret->engine = engine;
 123     } else
 124         ret->engine = ENGINE_get_default_DH();
 125     if (ret->engine) {
 126         ret->meth = ENGINE_get_DH(ret->engine);
 127         if (ret->meth == NULL) {
 128             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 129             ENGINE_finish(ret->engine);
 130             OPENSSL_free(ret);
 131             return NULL;
 132         }
 133     }
 134 #endif
 135
 136     ret->references = 1;
 137     ret->flags = ret->meth->flags;
 138     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 139     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 140 #ifndef OPENSSL_NO_ENGINE
 141         ENGINE_finish(ret->engine);
 142 #endif
 143         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 144         OPENSSL_free(ret);
 145         ret = NULL;
 146     }
 147     return (ret);
 148 }
 149
 150 void DH_free(DH *r)
 151 {
 152     int i;
 153
 154     if (r == NULL)
 155         return;
 156     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
 157     REF_PRINT_COUNT("DH", r);
 158     if (i > 0)
 159         return;
 160     REF_ASSERT_ISNT(i < 0);
 161
 162     if (r->meth->finish)
 163         r->meth->finish(r);
 164 #ifndef OPENSSL_NO_ENGINE
 165     ENGINE_finish(r->engine);
 166 #endif
 167
 168     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 169
 170     BN_clear_free(r->p);
 171     BN_clear_free(r->g);
 172     BN_clear_free(r->q);
 173     BN_clear_free(r->j);
 174     OPENSSL_free(r->seed);
 175     BN_clear_free(r->counter);
 176     BN_clear_free(r->pub_key);
 177     BN_clear_free(r->priv_key);
 178     OPENSSL_free(r);
 179 }
 180
 181 int DH_up_ref(DH *r)
 182 {
 183     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
 184
 185     REF_PRINT_COUNT("DH", r);
 186     REF_ASSERT_ISNT(i < 2);
 187     return ((i > 1) ? 1 : 0);
 188 }
 189
 190 int DH_set_ex_data(DH *d, int idx, void *arg)
 191 {
 192     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 193 }
 194
 195 void *DH_get_ex_data(DH *d, int idx)
 196 {
 197     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 198 }
 199
 200 int DH_bits(const DH *dh)
 201 {
 202     return BN_num_bits(dh->p);
 203 }
 204
 205 int DH_size(const DH *dh)
 206 {
 207     return (BN_num_bytes(dh->p));
 208 }
 209
 210 int DH_security_bits(const DH *dh)
 211 {
 212     int N;
 213     if (dh->q)
 214         N = BN_num_bits(dh->q);
 215     else if (dh->length)
 216         N = dh->length;
 217     else
 218         N = -1;
 219     return BN_security_bits(BN_num_bits(dh->p), N);
 220 }