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