crypto/dsa/dsa_lib.c

   1 /* crypto/dsa/dsa_lib.c */
   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 #include "cryptlib.h"
  63 #include <openssl/bn.h>
  64 #include <openssl/dsa.h>
  65 #include <openssl/asn1.h>
  66 #ifndef OPENSSL_NO_ENGINE
  67 # include <openssl/engine.h>
  68 #endif
  69 #ifndef OPENSSL_NO_DH
  70 # include <openssl/dh.h>
  71 #endif
  72
  73 const char DSA_version[] = "DSA" OPENSSL_VERSION_PTEXT;
  74
  75 static const DSA_METHOD *default_DSA_method = NULL;
  76
  77 void DSA_set_default_method(const DSA_METHOD *meth)
  78 {
  79     default_DSA_method = meth;
  80 }
  81
  82 const DSA_METHOD *DSA_get_default_method(void)
  83 {
  84     if (!default_DSA_method)
  85         default_DSA_method = DSA_OpenSSL();
  86     return default_DSA_method;
  87 }
  88
  89 DSA *DSA_new(void)
  90 {
  91     return DSA_new_method(NULL);
  92 }
  93
  94 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
  95 {
  96     /*
  97      * NB: The caller is specifically setting a method, so it's not up to us
  98      * to deal with which ENGINE it comes from.
  99      */
 100     const DSA_METHOD *mtmp;
 101     mtmp = dsa->meth;
 102     if (mtmp->finish)
 103         mtmp->finish(dsa);
 104 #ifndef OPENSSL_NO_ENGINE
 105     if (dsa->engine) {
 106         ENGINE_finish(dsa->engine);
 107         dsa->engine = NULL;
 108     }
 109 #endif
 110     dsa->meth = meth;
 111     if (meth->init)
 112         meth->init(dsa);
 113     return 1;
 114 }
 115
 116 DSA *DSA_new_method(ENGINE *engine)
 117 {
 118     DSA *ret;
 119
 120     ret = (DSA *)OPENSSL_malloc(sizeof(DSA));
 121     if (ret == NULL) {
 122         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
 123         return (NULL);
 124     }
 125     ret->meth = DSA_get_default_method();
 126 #ifndef OPENSSL_NO_ENGINE
 127     if (engine) {
 128         if (!ENGINE_init(engine)) {
 129             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
 130             OPENSSL_free(ret);
 131             return NULL;
 132         }
 133         ret->engine = engine;
 134     } else
 135         ret->engine = ENGINE_get_default_DSA();
 136     if (ret->engine) {
 137         ret->meth = ENGINE_get_DSA(ret->engine);
 138         if (!ret->meth) {
 139             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
 140             ENGINE_finish(ret->engine);
 141             OPENSSL_free(ret);
 142             return NULL;
 143         }
 144     }
 145 #endif
 146
 147     ret->pad = 0;
 148     ret->version = 0;
 149     ret->write_params = 1;
 150     ret->p = NULL;
 151     ret->q = NULL;
 152     ret->g = NULL;
 153
 154     ret->pub_key = NULL;
 155     ret->priv_key = NULL;
 156
 157     ret->kinv = NULL;
 158     ret->r = NULL;
 159     ret->method_mont_p = NULL;
 160
 161     ret->references = 1;
 162     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
 163     CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 164     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 165 #ifndef OPENSSL_NO_ENGINE
 166         if (ret->engine)
 167             ENGINE_finish(ret->engine);
 168 #endif
 169         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
 170         OPENSSL_free(ret);
 171         ret = NULL;
 172     }
 173
 174     return (ret);
 175 }
 176
 177 void DSA_free(DSA *r)
 178 {
 179     int i;
 180
 181     if (r == NULL)
 182         return;
 183
 184     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DSA);
 185 #ifdef REF_PRINT
 186     REF_PRINT("DSA", r);
 187 #endif
 188     if (i > 0)
 189         return;
 190 #ifdef REF_CHECK
 191     if (i < 0) {
 192         fprintf(stderr, "DSA_free, bad reference count\n");
 193         abort();
 194     }
 195 #endif
 196
 197     if (r->meth->finish)
 198         r->meth->finish(r);
 199 #ifndef OPENSSL_NO_ENGINE
 200     if (r->engine)
 201         ENGINE_finish(r->engine);
 202 #endif
 203
 204     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 205
 206     if (r->p != NULL)
 207         BN_clear_free(r->p);
 208     if (r->q != NULL)
 209         BN_clear_free(r->q);
 210     if (r->g != NULL)
 211         BN_clear_free(r->g);
 212     if (r->pub_key != NULL)
 213         BN_clear_free(r->pub_key);
 214     if (r->priv_key != NULL)
 215         BN_clear_free(r->priv_key);
 216     if (r->kinv != NULL)
 217         BN_clear_free(r->kinv);
 218     if (r->r != NULL)
 219         BN_clear_free(r->r);
 220     OPENSSL_free(r);
 221 }
 222
 223 int DSA_up_ref(DSA *r)
 224 {
 225     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DSA);
 226 #ifdef REF_PRINT
 227     REF_PRINT("DSA", r);
 228 #endif
 229 #ifdef REF_CHECK
 230     if (i < 2) {
 231         fprintf(stderr, "DSA_up_ref, bad reference count\n");
 232         abort();
 233     }
 234 #endif
 235     return ((i > 1) ? 1 : 0);
 236 }
 237
 238 int DSA_size(const DSA *r)
 239 {
 240     int ret, i;
 241     ASN1_INTEGER bs;
 242     unsigned char buf[4];       /* 4 bytes looks really small. However,
 243                                  * i2d_ASN1_INTEGER() will not look beyond
 244                                  * the first byte, as long as the second
 245                                  * parameter is NULL. */
 246
 247     i = BN_num_bits(r->q);
 248     bs.length = (i + 7) / 8;
 249     bs.data = buf;
 250     bs.type = V_ASN1_INTEGER;
 251     /* If the top bit is set the asn1 encoding is 1 larger. */
 252     buf[0] = 0xff;
 253
 254     i = i2d_ASN1_INTEGER(&bs, NULL);
 255     i += i;                     /* r and s */
 256     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 257     return (ret);
 258 }
 259
 260 int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
 261                          CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
 262 {
 263     return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DSA, argl, argp,
 264                                    new_func, dup_func, free_func);
 265 }
 266
 267 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 268 {
 269     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 270 }
 271
 272 void *DSA_get_ex_data(DSA *d, int idx)
 273 {
 274     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 275 }
 276
 277 int DSA_security_bits(const DSA *d)
 278 {
 279     return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
 280 }
 281
 282 #ifndef OPENSSL_NO_DH
 283 DH *DSA_dup_DH(const DSA *r)
 284 {
 285     /*
 286      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
 287      * optional length, g, optional pub_key, optional priv_key, optional q.
 288      */
 289
 290     DH *ret = NULL;
 291
 292     if (r == NULL)
 293         goto err;
 294     ret = DH_new();
 295     if (ret == NULL)
 296         goto err;
 297     if (r->p != NULL)
 298         if ((ret->p = BN_dup(r->p)) == NULL)
 299             goto err;
 300     if (r->q != NULL) {
 301         ret->length = BN_num_bits(r->q);
 302         if ((ret->q = BN_dup(r->q)) == NULL)
 303             goto err;
 304     }
 305     if (r->g != NULL)
 306         if ((ret->g = BN_dup(r->g)) == NULL)
 307             goto err;
 308     if (r->pub_key != NULL)
 309         if ((ret->pub_key = BN_dup(r->pub_key)) == NULL)
 310             goto err;
 311     if (r->priv_key != NULL)
 312         if ((ret->priv_key = BN_dup(r->priv_key)) == NULL)
 313             goto err;
 314
 315     return ret;
 316
 317  err:
 318     if (ret != NULL)
 319         DH_free(ret);
 320     return NULL;
 321 }
 322 #endif