crypto/dh/dh_lib.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/bn.h>
  13 #include "dh_locl.h"
  14 #include <openssl/engine.h>
  15
  16 static const DH_METHOD *default_DH_method = NULL;
  17
  18 void DH_set_default_method(const DH_METHOD *meth)
  19 {
  20     default_DH_method = meth;
  21 }
  22
  23 const DH_METHOD *DH_get_default_method(void)
  24 {
  25     if (!default_DH_method)
  26         default_DH_method = DH_OpenSSL();
  27     return default_DH_method;
  28 }
  29
  30 int DH_set_method(DH *dh, const DH_METHOD *meth)
  31 {
  32     /*
  33      * NB: The caller is specifically setting a method, so it's not up to us
  34      * to deal with which ENGINE it comes from.
  35      */
  36     const DH_METHOD *mtmp;
  37     mtmp = dh->meth;
  38     if (mtmp->finish)
  39         mtmp->finish(dh);
  40 #ifndef OPENSSL_NO_ENGINE
  41     ENGINE_finish(dh->engine);
  42     dh->engine = NULL;
  43 #endif
  44     dh->meth = meth;
  45     if (meth->init)
  46         meth->init(dh);
  47     return 1;
  48 }
  49
  50 DH *DH_new(void)
  51 {
  52     return DH_new_method(NULL);
  53 }
  54
  55 DH *DH_new_method(ENGINE *engine)
  56 {
  57     DH *ret = OPENSSL_zalloc(sizeof(*ret));
  58
  59     if (ret == NULL) {
  60         DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  61         return NULL;
  62     }
  63
  64     ret->references = 1;
  65     ret->lock = CRYPTO_THREAD_lock_new();
  66     if (ret->lock == NULL) {
  67         OPENSSL_free(ret);
  68         return NULL;
  69     }
  70
  71     ret->meth = DH_get_default_method();
  72 #ifndef OPENSSL_NO_ENGINE
  73     ret->flags = ret->meth->flags;  /* early default init */
  74     if (engine) {
  75         if (!ENGINE_init(engine)) {
  76             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
  77             goto err;
  78         }
  79         ret->engine = engine;
  80     } else
  81         ret->engine = ENGINE_get_default_DH();
  82     if (ret->engine) {
  83         ret->meth = ENGINE_get_DH(ret->engine);
  84         if (ret->meth == NULL) {
  85             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
  86             goto err;
  87         }
  88     }
  89 #endif
  90
  91     ret->flags = ret->meth->flags;
  92
  93     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data))
  94         goto err;
  95
  96     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
  97         DHerr(DH_F_DH_NEW_METHOD, ERR_R_INIT_FAIL);
  98 err:
  99         DH_free(ret);
 100         ret = NULL;
 101     }
 102
 103     return ret;
 104 }
 105
 106 void DH_free(DH *r)
 107 {
 108     int i;
 109
 110     if (r == NULL)
 111         return;
 112
 113     CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
 114     REF_PRINT_COUNT("DH", r);
 115     if (i > 0)
 116         return;
 117     REF_ASSERT_ISNT(i < 0);
 118
 119     if (r->meth->finish)
 120         r->meth->finish(r);
 121 #ifndef OPENSSL_NO_ENGINE
 122     ENGINE_finish(r->engine);
 123 #endif
 124
 125     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 126
 127     CRYPTO_THREAD_lock_free(r->lock);
 128
 129     BN_clear_free(r->p);
 130     BN_clear_free(r->g);
 131     BN_clear_free(r->q);
 132     BN_clear_free(r->j);
 133     OPENSSL_free(r->seed);
 134     BN_clear_free(r->counter);
 135     BN_clear_free(r->pub_key);
 136     BN_clear_free(r->priv_key);
 137     OPENSSL_free(r);
 138 }
 139
 140 int DH_up_ref(DH *r)
 141 {
 142     int i;
 143
 144     if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
 145         return 0;
 146
 147     REF_PRINT_COUNT("DH", r);
 148     REF_ASSERT_ISNT(i < 2);
 149     return ((i > 1) ? 1 : 0);
 150 }
 151
 152 int DH_set_ex_data(DH *d, int idx, void *arg)
 153 {
 154     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 155 }
 156
 157 void *DH_get_ex_data(DH *d, int idx)
 158 {
 159     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 160 }
 161
 162 int DH_bits(const DH *dh)
 163 {
 164     return BN_num_bits(dh->p);
 165 }
 166
 167 int DH_size(const DH *dh)
 168 {
 169     return (BN_num_bytes(dh->p));
 170 }
 171
 172 int DH_security_bits(const DH *dh)
 173 {
 174     int N;
 175     if (dh->q)
 176         N = BN_num_bits(dh->q);
 177     else if (dh->length)
 178         N = dh->length;
 179     else
 180         N = -1;
 181     return BN_security_bits(BN_num_bits(dh->p), N);
 182 }
 183
 184
 185 void DH_get0_pqg(const DH *dh, BIGNUM **p, BIGNUM **q, BIGNUM **g)
 186 {
 187     if (p != NULL)
 188         *p = dh->p;
 189     if (q != NULL)
 190         *q = dh->q;
 191     if (g != NULL)
 192         *g = dh->g;
 193 }
 194
 195 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 196 {
 197     /* If the fields p and g in d are NULL, the corresponding input
 198      * parameters MUST be non-NULL.  q may remain NULL.
 199      *
 200      * It is an error to give the results from get0 on d
 201      * as input parameters.
 202      */
 203     if (p == dh->p || (dh->q != NULL && q == dh->q) || g == dh->g)
 204         return 0;
 205
 206     if (p != NULL) {
 207         BN_free(dh->p);
 208         dh->p = p;
 209     }
 210     if (q != NULL) {
 211         BN_free(dh->q);
 212         dh->q = q;
 213     }
 214     if (g != NULL) {
 215         BN_free(dh->g);
 216         dh->g = g;
 217     }
 218
 219     if (q != NULL) {
 220         dh->length = BN_num_bits(q);
 221     }
 222
 223     return 1;
 224 }
 225
 226 long DH_get_length(const DH *dh)
 227 {
 228     return dh->length;
 229 }
 230
 231 int DH_set_length(DH *dh, long length)
 232 {
 233     dh->length = length;
 234     return 1;
 235 }
 236
 237 void DH_get0_key(const DH *dh, BIGNUM **pub_key, BIGNUM **priv_key)
 238 {
 239     if (pub_key != NULL)
 240         *pub_key = dh->pub_key;
 241     if (priv_key != NULL)
 242         *priv_key = dh->priv_key;
 243 }
 244
 245 int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)
 246 {
 247     /* If the pub_key in dh is NULL, the corresponding input
 248      * parameters MUST be non-NULL.  The priv_key field may
 249      * be left NULL.
 250      *
 251      * It is an error to give the results from get0 on dh
 252      * as input parameters.
 253      */
 254     if (dh->pub_key == pub_key
 255         || (dh->priv_key != NULL && priv_key == dh->priv_key))
 256         return 0;
 257
 258     if (pub_key != NULL) {
 259         BN_free(dh->pub_key);
 260         dh->pub_key = pub_key;
 261     }
 262     if (priv_key != NULL) {
 263         BN_free(dh->priv_key);
 264         dh->priv_key = priv_key;
 265     }
 266
 267     return 1;
 268 }
 269
 270 void DH_clear_flags(DH *dh, int flags)
 271 {
 272     dh->flags &= ~flags;
 273 }
 274
 275 int DH_test_flags(const DH *dh, int flags)
 276 {
 277     return dh->flags & flags;
 278 }
 279
 280 void DH_set_flags(DH *dh, int flags)
 281 {
 282     dh->flags |= flags;
 283 }
 284
 285 ENGINE *DH_get0_engine(DH *dh)
 286 {
 287     return dh->engine;
 288 }