lib/libcrypto/dh/dh_lib.c

   1 /* $OpenBSD: dh_lib.c,v 1.30.2.1 2018/05/02 16:57:35 tb Exp $ */
   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 <limits.h>
  60 #include <stdio.h>
  61
  62 #include <openssl/opensslconf.h>
  63
  64 #include <openssl/bn.h>
  65 #include <openssl/dh.h>
  66 #include <openssl/err.h>
  67
  68 #ifndef OPENSSL_NO_ENGINE
  69 #include <openssl/engine.h>
  70 #endif
  71
  72 static const DH_METHOD *default_DH_method = NULL;
  73
  74 void
  75 DH_set_default_method(const DH_METHOD *meth)
  76 {
  77         default_DH_method = meth;
  78 }
  79
  80 const DH_METHOD *
  81 DH_get_default_method(void)
  82 {
  83         if (!default_DH_method)
  84                 default_DH_method = DH_OpenSSL();
  85         return default_DH_method;
  86 }
  87
  88 int
  89 DH_set_method(DH *dh, const DH_METHOD *meth)
  90 {
  91         /*
  92          * NB: The caller is specifically setting a method, so it's not up to us
  93          * to deal with which ENGINE it comes from.
  94          */
  95         const DH_METHOD *mtmp;
  96
  97         mtmp = dh->meth;
  98         if (mtmp->finish)
  99                 mtmp->finish(dh);
 100 #ifndef OPENSSL_NO_ENGINE
 101         if (dh->engine) {
 102                 ENGINE_finish(dh->engine);
 103                 dh->engine = NULL;
 104         }
 105 #endif
 106         dh->meth = meth;
 107         if (meth->init)
 108                 meth->init(dh);
 109         return 1;
 110 }
 111
 112 DH *
 113 DH_new(void)
 114 {
 115         return DH_new_method(NULL);
 116 }
 117
 118 DH *
 119 DH_new_method(ENGINE *engine)
 120 {
 121         DH *ret;
 122
 123         ret = malloc(sizeof(DH));
 124         if (ret == NULL) {
 125                 DHerror(ERR_R_MALLOC_FAILURE);
 126                 return NULL;
 127         }
 128
 129         ret->meth = DH_get_default_method();
 130 #ifndef OPENSSL_NO_ENGINE
 131         if (engine) {
 132                 if (!ENGINE_init(engine)) {
 133                         DHerror(ERR_R_ENGINE_LIB);
 134                         free(ret);
 135                         return NULL;
 136                 }
 137                 ret->engine = engine;
 138         } else
 139                 ret->engine = ENGINE_get_default_DH();
 140         if(ret->engine) {
 141                 ret->meth = ENGINE_get_DH(ret->engine);
 142                 if (!ret->meth) {
 143                         DHerror(ERR_R_ENGINE_LIB);
 144                         ENGINE_finish(ret->engine);
 145                         free(ret);
 146                         return NULL;
 147                 }
 148         }
 149 #endif
 150
 151         ret->pad = 0;
 152         ret->version = 0;
 153         ret->p = NULL;
 154         ret->g = NULL;
 155         ret->length = 0;
 156         ret->pub_key = NULL;
 157         ret->priv_key = NULL;
 158         ret->q = NULL;
 159         ret->j = NULL;
 160         ret->seed = NULL;
 161         ret->seedlen = 0;
 162         ret->counter = NULL;
 163         ret->method_mont_p=NULL;
 164         ret->references = 1;
 165         ret->flags = ret->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
 166         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 167         if (ret->meth->init != NULL && !ret->meth->init(ret)) {
 168 #ifndef OPENSSL_NO_ENGINE
 169                 if (ret->engine)
 170                         ENGINE_finish(ret->engine);
 171 #endif
 172                 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
 173                 free(ret);
 174                 ret = NULL;
 175         }
 176         return ret;
 177 }
 178
 179 void
 180 DH_free(DH *r)
 181 {
 182         int i;
 183
 184         if (r == NULL)
 185                 return;
 186         i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
 187         if (i > 0)
 188                 return;
 189
 190         if (r->meth->finish)
 191                 r->meth->finish(r);
 192 #ifndef OPENSSL_NO_ENGINE
 193         if (r->engine)
 194                 ENGINE_finish(r->engine);
 195 #endif
 196
 197         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 198
 199         BN_clear_free(r->p);
 200         BN_clear_free(r->g);
 201         BN_clear_free(r->q);
 202         BN_clear_free(r->j);
 203         free(r->seed);
 204         BN_clear_free(r->counter);
 205         BN_clear_free(r->pub_key);
 206         BN_clear_free(r->priv_key);
 207         free(r);
 208 }
 209
 210 int
 211 DH_up_ref(DH *r)
 212 {
 213         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
 214
 215         return i > 1 ? 1 : 0;
 216 }
 217
 218 int
 219 DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 220     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 221 {
 222         return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp, new_func,
 223             dup_func, free_func);
 224 }
 225
 226 int
 227 DH_set_ex_data(DH *d, int idx, void *arg)
 228 {
 229         return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 230 }
 231
 232 void *
 233 DH_get_ex_data(DH *d, int idx)
 234 {
 235         return CRYPTO_get_ex_data(&d->ex_data, idx);
 236 }
 237
 238 int
 239 DH_size(const DH *dh)
 240 {
 241         return BN_num_bytes(dh->p);
 242 }
 243
 244 int
 245 DH_bits(const DH *dh)
 246 {
 247         return BN_num_bits(dh->p);
 248 }
 249
 250 ENGINE *
 251 DH_get0_engine(DH *dh)
 252 {
 253         return dh->engine;
 254 }
 255
 256 void
 257 DH_get0_pqg(const DH *dh, const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 258 {
 259         if (p != NULL)
 260                 *p = dh->p;
 261         if (q != NULL)
 262                 *q = dh->q;
 263         if (g != NULL)
 264                 *g = dh->g;
 265 }
 266
 267 int
 268 DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 269 {
 270         if ((dh->p == NULL && p == NULL) || (dh->g == NULL && g == NULL))
 271                 return 0;
 272
 273         if (p != NULL) {
 274                 BN_free(dh->p);
 275                 dh->p = p;
 276         }
 277         if (q != NULL) {
 278                 BN_free(dh->q);
 279                 dh->q = q;
 280         }
 281         if (g != NULL) {
 282                 BN_free(dh->g);
 283                 dh->g = g;
 284         }
 285
 286         return 1;
 287 }
 288
 289 void
 290 DH_get0_key(const DH *dh, const BIGNUM **pub_key, const BIGNUM **priv_key)
 291 {
 292         if (pub_key != NULL)
 293                 *pub_key = dh->pub_key;
 294         if (priv_key != NULL)
 295                 *priv_key = dh->priv_key;
 296 }
 297
 298 int
 299 DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)
 300 {
 301         if (pub_key != NULL) {
 302                 BN_free(dh->pub_key);
 303                 dh->pub_key = pub_key;
 304         }
 305         if (priv_key != NULL) {
 306                 BN_free(dh->priv_key);
 307                 dh->priv_key = priv_key;
 308         }
 309
 310         return 1;
 311 }
 312
 313 void
 314 DH_clear_flags(DH *dh, int flags)
 315 {
 316         dh->flags &= ~flags;
 317 }
 318
 319 int
 320 DH_test_flags(const DH *dh, int flags)
 321 {
 322         return dh->flags & flags;
 323 }
 324
 325 void
 326 DH_set_flags(DH *dh, int flags)
 327 {
 328         dh->flags |= flags;
 329 }
 330
 331 int
 332 DH_set_length(DH *dh, long length)
 333 {
 334         if (length < 0 || length > INT_MAX)
 335                 return 0;
 336
 337         dh->length = length;
 338         return 1;
 339 }