crypto/dsa/dsa_lib.c

   1 /*
   2  * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include "internal/refcount.h"
  13 #include <openssl/bn.h>
  14 #include "dsa_locl.h"
  15 #include <openssl/asn1.h>
  16 #include <openssl/engine.h>
  17 #include <openssl/dh.h>
  18
  19 DSA *DSA_new(void)
  20 {
  21     return DSA_new_method(NULL);
  22 }
  23
  24 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
  25 {
  26     /*
  27      * NB: The caller is specifically setting a method, so it's not up to us
  28      * to deal with which ENGINE it comes from.
  29      */
  30     const DSA_METHOD *mtmp;
  31     mtmp = dsa->meth;
  32     if (mtmp->finish)
  33         mtmp->finish(dsa);
  34 #ifndef OPENSSL_NO_ENGINE
  35     ENGINE_finish(dsa->engine);
  36     dsa->engine = NULL;
  37 #endif
  38     dsa->meth = meth;
  39     if (meth->init)
  40         meth->init(dsa);
  41     return 1;
  42 }
  43
  44 const DSA_METHOD *DSA_get_method(DSA *d)
  45 {
  46     return d->meth;
  47 }
  48
  49 DSA *DSA_new_method(ENGINE *engine)
  50 {
  51     DSA *ret = OPENSSL_zalloc(sizeof(*ret));
  52
  53     if (ret == NULL) {
  54         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  55         return NULL;
  56     }
  57
  58     ret->references = 1;
  59     ret->lock = CRYPTO_THREAD_lock_new();
  60     if (ret->lock == NULL) {
  61         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  62         OPENSSL_free(ret);
  63         return NULL;
  64     }
  65
  66     ret->meth = DSA_get_default_method();
  67 #ifndef OPENSSL_NO_ENGINE
  68     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW; /* early default init */
  69     if (engine) {
  70         if (!ENGINE_init(engine)) {
  71             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  72             goto err;
  73         }
  74         ret->engine = engine;
  75     } else
  76         ret->engine = ENGINE_get_default_DSA();
  77     if (ret->engine) {
  78         ret->meth = ENGINE_get_DSA(ret->engine);
  79         if (ret->meth == NULL) {
  80             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  81             goto err;
  82         }
  83     }
  84 #endif
  85
  86     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
  87
  88     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data))
  89         goto err;
  90
  91     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
  92         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_INIT_FAIL);
  93 err:
  94         DSA_free(ret);
  95         ret = NULL;
  96     }
  97
  98     return ret;
  99 }
 100
 101 void DSA_free(DSA *r)
 102 {
 103     int i;
 104
 105     if (r == NULL)
 106         return;
 107
 108     CRYPTO_DOWN_REF(&r->references, &i, r->lock);
 109     REF_PRINT_COUNT("DSA", r);
 110     if (i > 0)
 111         return;
 112     REF_ASSERT_ISNT(i < 0);
 113
 114     if (r->meth->finish)
 115         r->meth->finish(r);
 116 #ifndef OPENSSL_NO_ENGINE
 117     ENGINE_finish(r->engine);
 118 #endif
 119
 120     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 121
 122     CRYPTO_THREAD_lock_free(r->lock);
 123
 124     BN_clear_free(r->p);
 125     BN_clear_free(r->q);
 126     BN_clear_free(r->g);
 127     BN_clear_free(r->pub_key);
 128     BN_clear_free(r->priv_key);
 129     OPENSSL_free(r);
 130 }
 131
 132 int DSA_up_ref(DSA *r)
 133 {
 134     int i;
 135
 136     if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
 137         return 0;
 138
 139     REF_PRINT_COUNT("DSA", r);
 140     REF_ASSERT_ISNT(i < 2);
 141     return ((i > 1) ? 1 : 0);
 142 }
 143
 144 int DSA_size(const DSA *r)
 145 {
 146     int ret, i;
 147     ASN1_INTEGER bs;
 148     unsigned char buf[4];       /* 4 bytes looks really small. However,
 149                                  * i2d_ASN1_INTEGER() will not look beyond
 150                                  * the first byte, as long as the second
 151                                  * parameter is NULL. */
 152
 153     i = BN_num_bits(r->q);
 154     bs.length = (i + 7) / 8;
 155     bs.data = buf;
 156     bs.type = V_ASN1_INTEGER;
 157     /* If the top bit is set the asn1 encoding is 1 larger. */
 158     buf[0] = 0xff;
 159
 160     i = i2d_ASN1_INTEGER(&bs, NULL);
 161     i += i;                     /* r and s */
 162     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 163     return ret;
 164 }
 165
 166 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 167 {
 168     return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 169 }
 170
 171 void *DSA_get_ex_data(DSA *d, int idx)
 172 {
 173     return CRYPTO_get_ex_data(&d->ex_data, idx);
 174 }
 175
 176 int DSA_security_bits(const DSA *d)
 177 {
 178     if (d->p && d->q)
 179         return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
 180     return -1;
 181 }
 182
 183 #ifndef OPENSSL_NO_DH
 184 DH *DSA_dup_DH(const DSA *r)
 185 {
 186     /*
 187      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
 188      * optional length, g, optional pub_key, optional priv_key, optional q.
 189      */
 190
 191     DH *ret = NULL;
 192     BIGNUM *p = NULL, *q = NULL, *g = NULL, *pub_key = NULL, *priv_key = NULL;
 193
 194     if (r == NULL)
 195         goto err;
 196     ret = DH_new();
 197     if (ret == NULL)
 198         goto err;
 199     if (r->p != NULL || r->g != NULL || r->q != NULL) {
 200         if (r->p == NULL || r->g == NULL || r->q == NULL) {
 201             /* Shouldn't happen */
 202             goto err;
 203         }
 204         p = BN_dup(r->p);
 205         g = BN_dup(r->g);
 206         q = BN_dup(r->q);
 207         if (p == NULL || g == NULL || q == NULL || !DH_set0_pqg(ret, p, q, g))
 208             goto err;
 209         p = g = q = NULL;
 210     }
 211
 212     if (r->pub_key != NULL) {
 213         pub_key = BN_dup(r->pub_key);
 214         if (pub_key == NULL)
 215             goto err;
 216         if (r->priv_key != NULL) {
 217             priv_key = BN_dup(r->priv_key);
 218             if (priv_key == NULL)
 219                 goto err;
 220         }
 221         if (!DH_set0_key(ret, pub_key, priv_key))
 222             goto err;
 223     } else if (r->priv_key != NULL) {
 224         /* Shouldn't happen */
 225         goto err;
 226     }
 227
 228     return ret;
 229
 230  err:
 231     BN_free(p);
 232     BN_free(g);
 233     BN_free(q);
 234     BN_free(pub_key);
 235     BN_free(priv_key);
 236     DH_free(ret);
 237     return NULL;
 238 }
 239 #endif
 240
 241 void DSA_get0_pqg(const DSA *d,
 242                   const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 243 {
 244     if (p != NULL)
 245         *p = d->p;
 246     if (q != NULL)
 247         *q = d->q;
 248     if (g != NULL)
 249         *g = d->g;
 250 }
 251
 252 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 253 {
 254     /* If the fields p, q and g in d are NULL, the corresponding input
 255      * parameters MUST be non-NULL.
 256      */
 257     if ((d->p == NULL && p == NULL)
 258         || (d->q == NULL && q == NULL)
 259         || (d->g == NULL && g == NULL))
 260         return 0;
 261
 262     if (p != NULL) {
 263         BN_free(d->p);
 264         d->p = p;
 265     }
 266     if (q != NULL) {
 267         BN_free(d->q);
 268         d->q = q;
 269     }
 270     if (g != NULL) {
 271         BN_free(d->g);
 272         d->g = g;
 273     }
 274
 275     return 1;
 276 }
 277
 278 void DSA_get0_key(const DSA *d,
 279                   const BIGNUM **pub_key, const BIGNUM **priv_key)
 280 {
 281     if (pub_key != NULL)
 282         *pub_key = d->pub_key;
 283     if (priv_key != NULL)
 284         *priv_key = d->priv_key;
 285 }
 286
 287 int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 288 {
 289     /* If the field pub_key in d is NULL, the corresponding input
 290      * parameters MUST be non-NULL.  The priv_key field may
 291      * be left NULL.
 292      */
 293     if (d->pub_key == NULL && pub_key == NULL)
 294         return 0;
 295
 296     if (pub_key != NULL) {
 297         BN_free(d->pub_key);
 298         d->pub_key = pub_key;
 299     }
 300     if (priv_key != NULL) {
 301         BN_free(d->priv_key);
 302         d->priv_key = priv_key;
 303     }
 304
 305     return 1;
 306 }
 307
 308 void DSA_clear_flags(DSA *d, int flags)
 309 {
 310     d->flags &= ~flags;
 311 }
 312
 313 int DSA_test_flags(const DSA *d, int flags)
 314 {
 315     return d->flags & flags;
 316 }
 317
 318 void DSA_set_flags(DSA *d, int flags)
 319 {
 320     d->flags |= flags;
 321 }
 322
 323 ENGINE *DSA_get0_engine(DSA *d)
 324 {
 325     return d->engine;
 326 }
 327
 328 int DSA_bits(const DSA *dsa)
 329 {
 330     return BN_num_bits(dsa->p);
 331 }