lib/libcrypto/dsa/dsa_lib.c

   1 /* $OpenBSD: dsa_lib.c,v 1.23 2017/01/29 17:49:22 beck 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 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
  60
  61 #include <stdio.h>
  62
  63 #include <openssl/opensslconf.h>
  64
  65 #include <openssl/asn1.h>
  66 #include <openssl/bn.h>
  67 #include <openssl/dsa.h>
  68 #include <openssl/err.h>
  69
  70 #ifndef OPENSSL_NO_DH
  71 #include <openssl/dh.h>
  72 #endif
  73 #ifndef OPENSSL_NO_ENGINE
  74 #include <openssl/engine.h>
  75 #endif
  76
  77 static const DSA_METHOD *default_DSA_method = NULL;
  78
  79 void
  80 DSA_set_default_method(const DSA_METHOD *meth)
  81 {
  82         default_DSA_method = meth;
  83 }
  84
  85 const DSA_METHOD *
  86 DSA_get_default_method(void)
  87 {
  88         if (!default_DSA_method)
  89                 default_DSA_method = DSA_OpenSSL();
  90         return default_DSA_method;
  91 }
  92
  93 DSA *
  94 DSA_new(void)
  95 {
  96         return DSA_new_method(NULL);
  97 }
  98
  99 int
 100 DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
 101 {
 102         /*
 103          * NB: The caller is specifically setting a method, so it's not up to us
 104          * to deal with which ENGINE it comes from.
 105          */
 106         const DSA_METHOD *mtmp;
 107         mtmp = dsa->meth;
 108         if (mtmp->finish)
 109                 mtmp->finish(dsa);
 110 #ifndef OPENSSL_NO_ENGINE
 111         if (dsa->engine) {
 112                 ENGINE_finish(dsa->engine);
 113                 dsa->engine = NULL;
 114         }
 115 #endif
 116         dsa->meth = meth;
 117         if (meth->init)
 118                 meth->init(dsa);
 119         return 1;
 120 }
 121
 122 DSA *
 123 DSA_new_method(ENGINE *engine)
 124 {
 125         DSA *ret;
 126
 127         ret = malloc(sizeof(DSA));
 128         if (ret == NULL) {
 129                 DSAerror(ERR_R_MALLOC_FAILURE);
 130                 return NULL;
 131         }
 132         ret->meth = DSA_get_default_method();
 133 #ifndef OPENSSL_NO_ENGINE
 134         if (engine) {
 135                 if (!ENGINE_init(engine)) {
 136                         DSAerror(ERR_R_ENGINE_LIB);
 137                         free(ret);
 138                         return NULL;
 139                 }
 140                 ret->engine = engine;
 141         } else
 142                 ret->engine = ENGINE_get_default_DSA();
 143         if (ret->engine) {
 144                 ret->meth = ENGINE_get_DSA(ret->engine);
 145                 if (!ret->meth) {
 146                         DSAerror(ERR_R_ENGINE_LIB);
 147                         ENGINE_finish(ret->engine);
 148                         free(ret);
 149                         return NULL;
 150                 }
 151         }
 152 #endif
 153
 154         ret->pad = 0;
 155         ret->version = 0;
 156         ret->write_params = 1;
 157         ret->p = NULL;
 158         ret->q = NULL;
 159         ret->g = NULL;
 160
 161         ret->pub_key = NULL;
 162         ret->priv_key = NULL;
 163
 164         ret->kinv = NULL;
 165         ret->r = NULL;
 166         ret->method_mont_p = NULL;
 167
 168         ret->references = 1;
 169         ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
 170         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 171         if (ret->meth->init != NULL && !ret->meth->init(ret)) {
 172 #ifndef OPENSSL_NO_ENGINE
 173                 if (ret->engine)
 174                         ENGINE_finish(ret->engine);
 175 #endif
 176                 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 177                 free(ret);
 178                 ret = NULL;
 179         }
 180
 181         return ret;
 182 }
 183
 184 void
 185 DSA_free(DSA *r)
 186 {
 187         int i;
 188
 189         if (r == NULL)
 190                 return;
 191
 192         i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
 193         if (i > 0)
 194                 return;
 195
 196         if (r->meth->finish)
 197                 r->meth->finish(r);
 198 #ifndef OPENSSL_NO_ENGINE
 199         if (r->engine)
 200                 ENGINE_finish(r->engine);
 201 #endif
 202
 203         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 204
 205         BN_clear_free(r->p);
 206         BN_clear_free(r->q);
 207         BN_clear_free(r->g);
 208         BN_clear_free(r->pub_key);
 209         BN_clear_free(r->priv_key);
 210         BN_clear_free(r->kinv);
 211         BN_clear_free(r->r);
 212         free(r);
 213 }
 214
 215 int
 216 DSA_up_ref(DSA *r)
 217 {
 218         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
 219         return i > 1 ? 1 : 0;
 220 }
 221
 222 int
 223 DSA_size(const DSA *r)
 224 {
 225         int ret, i;
 226         ASN1_INTEGER bs;
 227         unsigned char buf[4];   /* 4 bytes looks really small.
 228                                    However, i2d_ASN1_INTEGER() will not look
 229                                    beyond the first byte, as long as the second
 230                                    parameter is NULL. */
 231
 232         i = BN_num_bits(r->q);
 233         bs.length = (i + 7) / 8;
 234         bs.data = buf;
 235         bs.type = V_ASN1_INTEGER;
 236         /* If the top bit is set the asn1 encoding is 1 larger. */
 237         buf[0] = 0xff;
 238
 239         i = i2d_ASN1_INTEGER(&bs, NULL);
 240         i += i; /* r and s */
 241         ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 242         return ret;
 243 }
 244
 245 int
 246 DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 247     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 248 {
 249         return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
 250             new_func, dup_func, free_func);
 251 }
 252
 253 int
 254 DSA_set_ex_data(DSA *d, int idx, void *arg)
 255 {
 256         return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 257 }
 258
 259 void *
 260 DSA_get_ex_data(DSA *d, int idx)
 261 {
 262         return CRYPTO_get_ex_data(&d->ex_data, idx);
 263 }
 264
 265 #ifndef OPENSSL_NO_DH
 266 DH *
 267 DSA_dup_DH(const DSA *r)
 268 {
 269         /*
 270          * DSA has p, q, g, optional pub_key, optional priv_key.
 271          * DH has p, optional length, g, optional pub_key, optional priv_key,
 272          * optional q.
 273          */
 274         DH *ret = NULL;
 275
 276         if (r == NULL)
 277                 goto err;
 278         ret = DH_new();
 279         if (ret == NULL)
 280                 goto err;
 281         if (r->p != NULL)
 282                 if ((ret->p = BN_dup(r->p)) == NULL)
 283                         goto err;
 284         if (r->q != NULL) {
 285                 ret->length = BN_num_bits(r->q);
 286                 if ((ret->q = BN_dup(r->q)) == NULL)
 287                         goto err;
 288         }
 289         if (r->g != NULL)
 290                 if ((ret->g = BN_dup(r->g)) == NULL)
 291                         goto err;
 292         if (r->pub_key != NULL)
 293                 if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
 294                         goto err;
 295         if (r->priv_key != NULL)
 296                 if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
 297                         goto err;
 298
 299         return ret;
 300
 301 err:
 302         DH_free(ret);
 303         return NULL;
 304 }
 305 #endif