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 #include <openssl/engine.h>
  63
  64 static const DH_METHOD *default_DH_method = NULL;
  65
  66 void DH_set_default_method(const DH_METHOD *meth)
  67 {
  68     default_DH_method = meth;
  69 }
  70
  71 const DH_METHOD *DH_get_default_method(void)
  72 {
  73     if (!default_DH_method)
  74         default_DH_method = DH_OpenSSL();
  75     return default_DH_method;
  76 }
  77
  78 int DH_set_method(DH *dh, const DH_METHOD *meth)
  79 {
  80     /*
  81      * NB: The caller is specifically setting a method, so it's not up to us
  82      * to deal with which ENGINE it comes from.
  83      */
  84     const DH_METHOD *mtmp;
  85     mtmp = dh->meth;
  86     if (mtmp->finish)
  87         mtmp->finish(dh);
  88 #ifndef OPENSSL_NO_ENGINE
  89     ENGINE_finish(dh->engine);
  90     dh->engine = NULL;
  91 #endif
  92     dh->meth = meth;
  93     if (meth->init)
  94         meth->init(dh);
  95     return 1;
  96 }
  97
  98 DH *DH_new(void)
  99 {
 100     return DH_new_method(NULL);
 101 }
 102
 103 DH *DH_new_method(ENGINE *engine)
 104 {
 105     DH *ret = OPENSSL_zalloc(sizeof(*ret));
 106
 107     if (ret == NULL) {
 108         DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
 109         return NULL;
 110     }
 111
 112     ret->meth = DH_get_default_method();
 113 #ifndef OPENSSL_NO_ENGINE
 114     if (engine) {
 115         if (!ENGINE_init(engine)) {
 116             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 117             OPENSSL_free(ret);
 118             return NULL;
 119         }
 120         ret->engine = engine;
 121     } else
 122         ret->engine = ENGINE_get_default_DH();
 123     if (ret->engine) {
 124         ret->meth = ENGINE_get_DH(ret->engine);
 125         if (ret->meth == NULL) {
 126             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
 127             ENGINE_finish(ret->engine);
 128             OPENSSL_free(ret);
 129             return NULL;
 130         }
 131     }
 132 #endif
 133
 134     ret->references = 1;
 135     ret->flags = ret->meth->flags;
 136
 137     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 138
 139     ret->lock = CRYPTO_THREAD_lock_new();
 140     if (ret->lock == NULL) {
 141 #ifndef OPENSSL_NO_ENGINE
 142         ENGINE_finish(ret->engine);
 143 #endif
 144         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 145         OPENSSL_free(ret);
 146         return NULL;
 147     }
 148
 149     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 150         DH_free(ret);
 151         ret = NULL;
 152     }
 153
 154     return ret;
 155 }
 156
 157 void DH_free(DH *r)
 158 {
 159     int i;
 160
 161     if (r == NULL)
 162         return;
 163
 164     CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
 165     REF_PRINT_COUNT("DH", r);
 166     if (i > 0)
 167         return;
 168     REF_ASSERT_ISNT(i < 0);
 169
 170     if (r->meth->finish)
 171         r->meth->finish(r);
 172 #ifndef OPENSSL_NO_ENGINE
 173     ENGINE_finish(r->engine);
 174 #endif
 175
 176     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 177
 178     CRYPTO_THREAD_lock_free(r->lock);
 179
 180     BN_clear_free(r->p);
 181     BN_clear_free(r->g);
 182     BN_clear_free(r->q);
 183     BN_clear_free(r->j);
 184     OPENSSL_free(r->seed);
 185     BN_clear_free(r->counter);
 186     BN_clear_free(r->pub_key);
 187     BN_clear_free(r->priv_key);
 188     OPENSSL_free(r);
 189 }
 190
 191 int DH_up_ref(DH *r)
 192 {
 193     int i;
 194
 195     if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
 196         return 0;
 197
 198     REF_PRINT_COUNT("DH", r);
 199     REF_ASSERT_ISNT(i < 2);
 200     return ((i > 1) ? 1 : 0);
 201 }
 202
 203 int DH_set_ex_data(DH *d, int idx, void *arg)
 204 {
 205     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 206 }
 207
 208 void *DH_get_ex_data(DH *d, int idx)
 209 {
 210     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 211 }
 212
 213 int DH_bits(const DH *dh)
 214 {
 215     return BN_num_bits(dh->p);
 216 }
 217
 218 int DH_size(const DH *dh)
 219 {
 220     return (BN_num_bytes(dh->p));
 221 }
 222
 223 int DH_security_bits(const DH *dh)
 224 {
 225     int N;
 226     if (dh->q)
 227         N = BN_num_bits(dh->q);
 228     else if (dh->length)
 229         N = dh->length;
 230     else
 231         N = -1;
 232     return BN_security_bits(BN_num_bits(dh->p), N);
 233 }