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