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         DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  68         OPENSSL_free(ret);
  69         return NULL;
  70     }
  71
  72     ret->meth = DH_get_default_method();
  73 #ifndef OPENSSL_NO_ENGINE
  74     ret->flags = ret->meth->flags;  /* early default init */
  75     if (engine) {
  76         if (!ENGINE_init(engine)) {
  77             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
  78             goto err;
  79         }
  80         ret->engine = engine;
  81     } else
  82         ret->engine = ENGINE_get_default_DH();
  83     if (ret->engine) {
  84         ret->meth = ENGINE_get_DH(ret->engine);
  85         if (ret->meth == NULL) {
  86             DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
  87             goto err;
  88         }
  89     }
  90 #endif
  91
  92     ret->flags = ret->meth->flags;
  93
  94     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data))
  95         goto err;
  96
  97     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
  98         DHerr(DH_F_DH_NEW_METHOD, ERR_R_INIT_FAIL);
  99 err:
 100         DH_free(ret);
 101         ret = NULL;
 102     }
 103
 104     return ret;
 105 }
 106
 107 void DH_free(DH *r)
 108 {
 109     int i;
 110
 111     if (r == NULL)
 112         return;
 113
 114     CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
 115     REF_PRINT_COUNT("DH", r);
 116     if (i > 0)
 117         return;
 118     REF_ASSERT_ISNT(i < 0);
 119
 120     if (r->meth->finish)
 121         r->meth->finish(r);
 122 #ifndef OPENSSL_NO_ENGINE
 123     ENGINE_finish(r->engine);
 124 #endif
 125
 126     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 127
 128     CRYPTO_THREAD_lock_free(r->lock);
 129
 130     BN_clear_free(r->p);
 131     BN_clear_free(r->g);
 132     BN_clear_free(r->q);
 133     BN_clear_free(r->j);
 134     OPENSSL_free(r->seed);
 135     BN_clear_free(r->counter);
 136     BN_clear_free(r->pub_key);
 137     BN_clear_free(r->priv_key);
 138     OPENSSL_free(r);
 139 }
 140
 141 int DH_up_ref(DH *r)
 142 {
 143     int i;
 144
 145     if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
 146         return 0;
 147
 148     REF_PRINT_COUNT("DH", r);
 149     REF_ASSERT_ISNT(i < 2);
 150     return ((i > 1) ? 1 : 0);
 151 }
 152
 153 int DH_set_ex_data(DH *d, int idx, void *arg)
 154 {
 155     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 156 }
 157
 158 void *DH_get_ex_data(DH *d, int idx)
 159 {
 160     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 161 }
 162
 163 int DH_bits(const DH *dh)
 164 {
 165     return BN_num_bits(dh->p);
 166 }
 167
 168 int DH_size(const DH *dh)
 169 {
 170     return (BN_num_bytes(dh->p));
 171 }
 172
 173 int DH_security_bits(const DH *dh)
 174 {
 175     int N;
 176     if (dh->q)
 177         N = BN_num_bits(dh->q);
 178     else if (dh->length)
 179         N = dh->length;
 180     else
 181         N = -1;
 182     return BN_security_bits(BN_num_bits(dh->p), N);
 183 }
 184
 185
 186 void DH_get0_pqg(const DH *dh,
 187                  const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 188 {
 189     if (p != NULL)
 190         *p = dh->p;
 191     if (q != NULL)
 192         *q = dh->q;
 193     if (g != NULL)
 194         *g = dh->g;
 195 }
 196
 197 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 198 {
 199     /* If the fields p and g in d are NULL, the corresponding input
 200      * parameters MUST be non-NULL.  q may remain NULL.
 201      */
 202     if (dh->p == NULL && p == NULL
 203         || dh->g == NULL && g == NULL)
 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, const BIGNUM **pub_key, const 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 field 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     if (dh->pub_key == NULL && pub_key == NULL)
 252         return 0;
 253
 254     if (pub_key != NULL) {
 255         BN_free(dh->pub_key);
 256         dh->pub_key = pub_key;
 257     }
 258     if (priv_key != NULL) {
 259         BN_free(dh->priv_key);
 260         dh->priv_key = priv_key;
 261     }
 262
 263     return 1;
 264 }
 265
 266 void DH_clear_flags(DH *dh, int flags)
 267 {
 268     dh->flags &= ~flags;
 269 }
 270
 271 int DH_test_flags(const DH *dh, int flags)
 272 {
 273     return dh->flags & flags;
 274 }
 275
 276 void DH_set_flags(DH *dh, int flags)
 277 {
 278     dh->flags |= flags;
 279 }
 280
 281 ENGINE *DH_get0_engine(DH *dh)
 282 {
 283     return dh->engine;
 284 }