crypto/dsa/dsa_lib.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
  59
  60 #include <stdio.h>
  61 #include "internal/cryptlib.h"
  62 #include <openssl/bn.h>
  63 #include "dsa_locl.h"
  64 #include <openssl/asn1.h>
  65 #include <openssl/engine.h>
  66 #include <openssl/dh.h>
  67
  68 static const DSA_METHOD *default_DSA_method = NULL;
  69
  70 void DSA_set_default_method(const DSA_METHOD *meth)
  71 {
  72     default_DSA_method = meth;
  73 }
  74
  75 const DSA_METHOD *DSA_get_default_method(void)
  76 {
  77     if (!default_DSA_method)
  78         default_DSA_method = DSA_OpenSSL();
  79     return default_DSA_method;
  80 }
  81
  82 DSA *DSA_new(void)
  83 {
  84     return DSA_new_method(NULL);
  85 }
  86
  87 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
  88 {
  89     /*
  90      * NB: The caller is specifically setting a method, so it's not up to us
  91      * to deal with which ENGINE it comes from.
  92      */
  93     const DSA_METHOD *mtmp;
  94     mtmp = dsa->meth;
  95     if (mtmp->finish)
  96         mtmp->finish(dsa);
  97 #ifndef OPENSSL_NO_ENGINE
  98     ENGINE_finish(dsa->engine);
  99     dsa->engine = NULL;
 100 #endif
 101     dsa->meth = meth;
 102     if (meth->init)
 103         meth->init(dsa);
 104     return 1;
 105 }
 106
 107 const DSA_METHOD *DSA_get_method(DSA *d)
 108 {
 109     return d->meth;
 110 }
 111
 112 DSA *DSA_new_method(ENGINE *engine)
 113 {
 114     DSA *ret;
 115
 116     ret = OPENSSL_zalloc(sizeof(*ret));
 117     if (ret == NULL) {
 118         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
 119         return NULL;
 120     }
 121     ret->meth = DSA_get_default_method();
 122 #ifndef OPENSSL_NO_ENGINE
 123     if (engine) {
 124         if (!ENGINE_init(engine)) {
 125             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
 126             OPENSSL_free(ret);
 127             return NULL;
 128         }
 129         ret->engine = engine;
 130     } else
 131         ret->engine = ENGINE_get_default_DSA();
 132     if (ret->engine) {
 133         ret->meth = ENGINE_get_DSA(ret->engine);
 134         if (ret->meth == NULL) {
 135             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
 136             ENGINE_finish(ret->engine);
 137             OPENSSL_free(ret);
 138             return NULL;
 139         }
 140     }
 141 #endif
 142
 143     ret->references = 1;
 144     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
 145
 146     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 147
 148     ret->lock = CRYPTO_THREAD_lock_new();
 149     if (ret->lock == NULL) {
 150 #ifndef OPENSSL_NO_ENGINE
 151         ENGINE_finish(ret->engine);
 152 #endif
 153         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 154         OPENSSL_free(ret);
 155         return NULL;
 156     }
 157
 158     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 159         DSA_free(ret);
 160         ret = NULL;
 161     }
 162
 163     return ret;
 164 }
 165
 166 void DSA_free(DSA *r)
 167 {
 168     int i;
 169
 170     if (r == NULL)
 171         return;
 172
 173     CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
 174     REF_PRINT_COUNT("DSA", r);
 175     if (i > 0)
 176         return;
 177     REF_ASSERT_ISNT(i < 0);
 178
 179     if (r->meth->finish)
 180         r->meth->finish(r);
 181 #ifndef OPENSSL_NO_ENGINE
 182     ENGINE_finish(r->engine);
 183 #endif
 184
 185     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 186
 187     CRYPTO_THREAD_lock_free(r->lock);
 188
 189     BN_clear_free(r->p);
 190     BN_clear_free(r->q);
 191     BN_clear_free(r->g);
 192     BN_clear_free(r->pub_key);
 193     BN_clear_free(r->priv_key);
 194     OPENSSL_free(r);
 195 }
 196
 197 int DSA_up_ref(DSA *r)
 198 {
 199     int i;
 200
 201     if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
 202         return 0;
 203
 204     REF_PRINT_COUNT("DSA", r);
 205     REF_ASSERT_ISNT(i < 2);
 206     return ((i > 1) ? 1 : 0);
 207 }
 208
 209 int DSA_size(const DSA *r)
 210 {
 211     int ret, i;
 212     ASN1_INTEGER bs;
 213     unsigned char buf[4];       /* 4 bytes looks really small. However,
 214                                  * i2d_ASN1_INTEGER() will not look beyond
 215                                  * the first byte, as long as the second
 216                                  * parameter is NULL. */
 217
 218     i = BN_num_bits(r->q);
 219     bs.length = (i + 7) / 8;
 220     bs.data = buf;
 221     bs.type = V_ASN1_INTEGER;
 222     /* If the top bit is set the asn1 encoding is 1 larger. */
 223     buf[0] = 0xff;
 224
 225     i = i2d_ASN1_INTEGER(&bs, NULL);
 226     i += i;                     /* r and s */
 227     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 228     return (ret);
 229 }
 230
 231 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 232 {
 233     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 234 }
 235
 236 void *DSA_get_ex_data(DSA *d, int idx)
 237 {
 238     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 239 }
 240
 241 int DSA_security_bits(const DSA *d)
 242 {
 243     if (d->p && d->q)
 244         return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
 245     return -1;
 246 }
 247
 248 #ifndef OPENSSL_NO_DH
 249 DH *DSA_dup_DH(const DSA *r)
 250 {
 251     /*
 252      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
 253      * optional length, g, optional pub_key, optional priv_key, optional q.
 254      */
 255
 256     DH *ret = NULL;
 257     BIGNUM *p = NULL, *q = NULL, *g = NULL, *pub_key = NULL, *priv_key = NULL;
 258
 259     if (r == NULL)
 260         goto err;
 261     ret = DH_new();
 262     if (ret == NULL)
 263         goto err;
 264     if (r->p != NULL || r->g != NULL || r->q != NULL) {
 265         if (r->p == NULL || r->g == NULL || r->q == NULL) {
 266             /* Shouldn't happen */
 267             goto err;
 268         }
 269         p = BN_dup(r->p);
 270         g = BN_dup(r->g);
 271         q = BN_dup(r->q);
 272         if (p == NULL || g == NULL || q == NULL || !DH_set0_pqg(ret, p, q, g))
 273             goto err;
 274     }
 275
 276     if (r->pub_key != NULL) {
 277         pub_key = BN_dup(r->pub_key);
 278         if (pub_key == NULL)
 279             goto err;
 280         if (r->priv_key != NULL) {
 281             priv_key = BN_dup(r->priv_key);
 282             if (priv_key == NULL)
 283                 goto err;
 284         }
 285         if (!DH_set0_key(ret, pub_key, priv_key))
 286             goto err;
 287     } else if (r->priv_key != NULL) {
 288         /* Shouldn't happen */
 289         goto err;
 290     }
 291
 292     return ret;
 293
 294  err:
 295     BN_free(p);
 296     BN_free(g);
 297     BN_free(q);
 298     BN_free(pub_key);
 299     BN_free(priv_key);
 300     DH_free(ret);
 301     return NULL;
 302 }
 303 #endif
 304
 305 void DSA_get0_pqg(const DSA *d, BIGNUM **p, BIGNUM **q, BIGNUM **g)
 306 {
 307     if (p != NULL)
 308         *p = d->p;
 309     if (q != NULL)
 310         *q = d->q;
 311     if (g != NULL)
 312         *g = d->g;
 313 }
 314
 315 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 316 {
 317     if (p == NULL || q == NULL || g == NULL)
 318         return 0;
 319     BN_free(d->p);
 320     BN_free(d->q);
 321     BN_free(d->g);
 322     d->p = p;
 323     d->q = q;
 324     d->g = g;
 325
 326     return 1;
 327 }
 328
 329 void DSA_get0_key(const DSA *d, BIGNUM **pub_key, BIGNUM **priv_key)
 330 {
 331     if (pub_key != NULL)
 332         *pub_key = d->pub_key;
 333     if (priv_key != NULL)
 334         *priv_key = d->priv_key;
 335 }
 336
 337 int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 338 {
 339     /* Note that it is valid for priv_key to be NULL */
 340     if (pub_key == NULL)
 341         return 0;
 342
 343     BN_free(d->pub_key);
 344     BN_free(d->priv_key);
 345     d->pub_key = pub_key;
 346     d->priv_key = priv_key;
 347
 348     return 1;
 349 }
 350
 351 void DSA_clear_flags(DSA *d, int flags)
 352 {
 353     d->flags &= ~flags;
 354 }
 355
 356 int DSA_test_flags(const DSA *d, int flags)
 357 {
 358     return d->flags & flags;
 359 }
 360
 361 void DSA_set_flags(DSA *d, int flags)
 362 {
 363     d->flags |= flags;
 364 }
 365
 366 ENGINE *DSA_get0_engine(DSA *d)
 367 {
 368     return d->engine;
 369 }