lib/libcrypto/dsa/dsa_lib.c

   1 /* $OpenBSD: dsa_lib.c,v 1.29 2018/04/14 07:09:21 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 /* 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         ENGINE_finish(dsa->engine);
 112         dsa->engine = NULL;
 113 #endif
 114         dsa->meth = meth;
 115         if (meth->init)
 116                 meth->init(dsa);
 117         return 1;
 118 }
 119
 120 DSA *
 121 DSA_new_method(ENGINE *engine)
 122 {
 123         DSA *ret;
 124
 125         ret = malloc(sizeof(DSA));
 126         if (ret == NULL) {
 127                 DSAerror(ERR_R_MALLOC_FAILURE);
 128                 return NULL;
 129         }
 130         ret->meth = DSA_get_default_method();
 131 #ifndef OPENSSL_NO_ENGINE
 132         if (engine) {
 133                 if (!ENGINE_init(engine)) {
 134                         DSAerror(ERR_R_ENGINE_LIB);
 135                         free(ret);
 136                         return NULL;
 137                 }
 138                 ret->engine = engine;
 139         } else
 140                 ret->engine = ENGINE_get_default_DSA();
 141         if (ret->engine) {
 142                 ret->meth = ENGINE_get_DSA(ret->engine);
 143                 if (ret->meth == NULL) {
 144                         DSAerror(ERR_R_ENGINE_LIB);
 145                         ENGINE_finish(ret->engine);
 146                         free(ret);
 147                         return NULL;
 148                 }
 149         }
 150 #endif
 151
 152         ret->pad = 0;
 153         ret->version = 0;
 154         ret->write_params = 1;
 155         ret->p = NULL;
 156         ret->q = NULL;
 157         ret->g = NULL;
 158
 159         ret->pub_key = NULL;
 160         ret->priv_key = NULL;
 161
 162         ret->kinv = NULL;
 163         ret->r = NULL;
 164         ret->method_mont_p = NULL;
 165
 166         ret->references = 1;
 167         ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
 168         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 169         if (ret->meth->init != NULL && !ret->meth->init(ret)) {
 170 #ifndef OPENSSL_NO_ENGINE
 171                 ENGINE_finish(ret->engine);
 172 #endif
 173                 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 174                 free(ret);
 175                 ret = NULL;
 176         }
 177
 178         return ret;
 179 }
 180
 181 void
 182 DSA_free(DSA *r)
 183 {
 184         int i;
 185
 186         if (r == NULL)
 187                 return;
 188
 189         i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
 190         if (i > 0)
 191                 return;
 192
 193         if (r->meth->finish)
 194                 r->meth->finish(r);
 195 #ifndef OPENSSL_NO_ENGINE
 196         ENGINE_finish(r->engine);
 197 #endif
 198
 199         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 200
 201         BN_clear_free(r->p);
 202         BN_clear_free(r->q);
 203         BN_clear_free(r->g);
 204         BN_clear_free(r->pub_key);
 205         BN_clear_free(r->priv_key);
 206         BN_clear_free(r->kinv);
 207         BN_clear_free(r->r);
 208         free(r);
 209 }
 210
 211 int
 212 DSA_up_ref(DSA *r)
 213 {
 214         int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
 215         return i > 1 ? 1 : 0;
 216 }
 217
 218 int
 219 DSA_size(const DSA *r)
 220 {
 221         int ret, i;
 222         ASN1_INTEGER bs;
 223         unsigned char buf[4];   /* 4 bytes looks really small.
 224                                    However, i2d_ASN1_INTEGER() will not look
 225                                    beyond the first byte, as long as the second
 226                                    parameter is NULL. */
 227
 228         i = BN_num_bits(r->q);
 229         bs.length = (i + 7) / 8;
 230         bs.data = buf;
 231         bs.type = V_ASN1_INTEGER;
 232         /* If the top bit is set the asn1 encoding is 1 larger. */
 233         buf[0] = 0xff;
 234
 235         i = i2d_ASN1_INTEGER(&bs, NULL);
 236         i += i; /* r and s */
 237         ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 238         return ret;
 239 }
 240
 241 int
 242 DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 243     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 244 {
 245         return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
 246             new_func, dup_func, free_func);
 247 }
 248
 249 int
 250 DSA_set_ex_data(DSA *d, int idx, void *arg)
 251 {
 252         return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 253 }
 254
 255 void *
 256 DSA_get_ex_data(DSA *d, int idx)
 257 {
 258         return CRYPTO_get_ex_data(&d->ex_data, idx);
 259 }
 260
 261 #ifndef OPENSSL_NO_DH
 262 DH *
 263 DSA_dup_DH(const DSA *r)
 264 {
 265         /*
 266          * DSA has p, q, g, optional pub_key, optional priv_key.
 267          * DH has p, optional length, g, optional pub_key, optional priv_key,
 268          * optional q.
 269          */
 270         DH *ret = NULL;
 271
 272         if (r == NULL)
 273                 goto err;
 274         ret = DH_new();
 275         if (ret == NULL)
 276                 goto err;
 277         if (r->p != NULL)
 278                 if ((ret->p = BN_dup(r->p)) == NULL)
 279                         goto err;
 280         if (r->q != NULL) {
 281                 ret->length = BN_num_bits(r->q);
 282                 if ((ret->q = BN_dup(r->q)) == NULL)
 283                         goto err;
 284         }
 285         if (r->g != NULL)
 286                 if ((ret->g = BN_dup(r->g)) == NULL)
 287                         goto err;
 288         if (r->pub_key != NULL)
 289                 if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
 290                         goto err;
 291         if (r->priv_key != NULL)
 292                 if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
 293                         goto err;
 294
 295         return ret;
 296
 297 err:
 298         DH_free(ret);
 299         return NULL;
 300 }
 301 #endif
 302
 303 void
 304 DSA_get0_pqg(const DSA *d, const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 305 {
 306         if (p != NULL)
 307                 *p = d->p;
 308         if (q != NULL)
 309                 *q = d->q;
 310         if (g != NULL)
 311                 *g = d->g;
 312 }
 313
 314 int
 315 DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 316 {
 317         if ((d->p == NULL && p == NULL) || (d->q == NULL && q == NULL) ||
 318             (d->g == NULL && g == NULL))
 319                 return 0;
 320
 321         if (p != NULL) {
 322                 BN_free(d->p);
 323                 d->p = p;
 324         }
 325         if (q != NULL) {
 326                 BN_free(d->q);
 327                 d->q = q;
 328         }
 329         if (g != NULL) {
 330                 BN_free(d->g);
 331                 d->g = g;
 332         }
 333
 334         return 1;
 335 }
 336
 337 void
 338 DSA_get0_key(const DSA *d, const BIGNUM **pub_key, const BIGNUM **priv_key)
 339 {
 340         if (pub_key != NULL)
 341                 *pub_key = d->pub_key;
 342         if (priv_key != NULL)
 343                 *priv_key = d->priv_key;
 344 }
 345
 346 int
 347 DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 348 {
 349         if (d->pub_key == NULL && pub_key == NULL)
 350                 return 0;
 351
 352         if (pub_key != NULL) {
 353                 BN_free(d->pub_key);
 354                 d->pub_key = pub_key;
 355         }
 356         if (priv_key != NULL) {
 357                 BN_free(d->priv_key);
 358                 d->priv_key = priv_key;
 359         }
 360
 361         return 1;
 362 }
 363
 364 void
 365 DSA_clear_flags(DSA *d, int flags)
 366 {
 367         d->flags &= ~flags;
 368 }
 369
 370 int
 371 DSA_test_flags(const DSA *d, int flags)
 372 {
 373         return d->flags & flags;
 374 }
 375
 376 void
 377 DSA_set_flags(DSA *d, int flags)
 378 {
 379         d->flags |= flags;
 380 }
 381
 382 ENGINE *
 383 DSA_get0_engine(DSA *d)
 384 {
 385         return d->engine;
 386 }