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 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
  11
  12 #include <stdio.h>
  13 #include "internal/cryptlib.h"
  14 #include "internal/refcount.h"
  15 #include <openssl/bn.h>
  16 #include "dsa_locl.h"
  17 #include <openssl/asn1.h>
  18 #include <openssl/engine.h>
  19 #include <openssl/dh.h>
  20
  21 DSA *DSA_new(void)
  22 {
  23     return DSA_new_method(NULL);
  24 }
  25
  26 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
  27 {
  28     /*
  29      * NB: The caller is specifically setting a method, so it's not up to us
  30      * to deal with which ENGINE it comes from.
  31      */
  32     const DSA_METHOD *mtmp;
  33     mtmp = dsa->meth;
  34     if (mtmp->finish)
  35         mtmp->finish(dsa);
  36 #ifndef OPENSSL_NO_ENGINE
  37     ENGINE_finish(dsa->engine);
  38     dsa->engine = NULL;
  39 #endif
  40     dsa->meth = meth;
  41     if (meth->init)
  42         meth->init(dsa);
  43     return 1;
  44 }
  45
  46 const DSA_METHOD *DSA_get_method(DSA *d)
  47 {
  48     return d->meth;
  49 }
  50
  51 DSA *DSA_new_method(ENGINE *engine)
  52 {
  53     DSA *ret = OPENSSL_zalloc(sizeof(*ret));
  54
  55     if (ret == NULL) {
  56         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  57         return NULL;
  58     }
  59
  60     ret->references = 1;
  61     ret->lock = CRYPTO_THREAD_lock_new();
  62     if (ret->lock == NULL) {
  63         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  64         OPENSSL_free(ret);
  65         return NULL;
  66     }
  67
  68     ret->meth = DSA_get_default_method();
  69 #ifndef OPENSSL_NO_ENGINE
  70     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW; /* early default init */
  71     if (engine) {
  72         if (!ENGINE_init(engine)) {
  73             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  74             goto err;
  75         }
  76         ret->engine = engine;
  77     } else
  78         ret->engine = ENGINE_get_default_DSA();
  79     if (ret->engine) {
  80         ret->meth = ENGINE_get_DSA(ret->engine);
  81         if (ret->meth == NULL) {
  82             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  83             goto err;
  84         }
  85     }
  86 #endif
  87
  88     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
  89
  90     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data))
  91         goto err;
  92
  93     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
  94         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_INIT_FAIL);
  95 err:
  96         DSA_free(ret);
  97         ret = NULL;
  98     }
  99
 100     return ret;
 101 }
 102
 103 void DSA_free(DSA *r)
 104 {
 105     int i;
 106
 107     if (r == NULL)
 108         return;
 109
 110     CRYPTO_DOWN_REF(&r->references, &i, r->lock);
 111     REF_PRINT_COUNT("DSA", r);
 112     if (i > 0)
 113         return;
 114     REF_ASSERT_ISNT(i < 0);
 115
 116     if (r->meth->finish)
 117         r->meth->finish(r);
 118 #ifndef OPENSSL_NO_ENGINE
 119     ENGINE_finish(r->engine);
 120 #endif
 121
 122     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 123
 124     CRYPTO_THREAD_lock_free(r->lock);
 125
 126     BN_clear_free(r->p);
 127     BN_clear_free(r->q);
 128     BN_clear_free(r->g);
 129     BN_clear_free(r->pub_key);
 130     BN_clear_free(r->priv_key);
 131     OPENSSL_free(r);
 132 }
 133
 134 int DSA_up_ref(DSA *r)
 135 {
 136     int i;
 137
 138     if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
 139         return 0;
 140
 141     REF_PRINT_COUNT("DSA", r);
 142     REF_ASSERT_ISNT(i < 2);
 143     return ((i > 1) ? 1 : 0);
 144 }
 145
 146 int DSA_size(const DSA *r)
 147 {
 148     int ret, i;
 149     ASN1_INTEGER bs;
 150     unsigned char buf[4];       /* 4 bytes looks really small. However,
 151                                  * i2d_ASN1_INTEGER() will not look beyond
 152                                  * the first byte, as long as the second
 153                                  * parameter is NULL. */
 154
 155     i = BN_num_bits(r->q);
 156     bs.length = (i + 7) / 8;
 157     bs.data = buf;
 158     bs.type = V_ASN1_INTEGER;
 159     /* If the top bit is set the asn1 encoding is 1 larger. */
 160     buf[0] = 0xff;
 161
 162     i = i2d_ASN1_INTEGER(&bs, NULL);
 163     i += i;                     /* r and s */
 164     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 165     return (ret);
 166 }
 167
 168 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 169 {
 170     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 171 }
 172
 173 void *DSA_get_ex_data(DSA *d, int idx)
 174 {
 175     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 176 }
 177
 178 int DSA_security_bits(const DSA *d)
 179 {
 180     if (d->p && d->q)
 181         return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
 182     return -1;
 183 }
 184
 185 #ifndef OPENSSL_NO_DH
 186 DH *DSA_dup_DH(const DSA *r)
 187 {
 188     /*
 189      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
 190      * optional length, g, optional pub_key, optional priv_key, optional q.
 191      */
 192
 193     DH *ret = NULL;
 194     BIGNUM *p = NULL, *q = NULL, *g = NULL, *pub_key = NULL, *priv_key = NULL;
 195
 196     if (r == NULL)
 197         goto err;
 198     ret = DH_new();
 199     if (ret == NULL)
 200         goto err;
 201     if (r->p != NULL || r->g != NULL || r->q != NULL) {
 202         if (r->p == NULL || r->g == NULL || r->q == NULL) {
 203             /* Shouldn't happen */
 204             goto err;
 205         }
 206         p = BN_dup(r->p);
 207         g = BN_dup(r->g);
 208         q = BN_dup(r->q);
 209         if (p == NULL || g == NULL || q == NULL || !DH_set0_pqg(ret, p, q, g))
 210             goto err;
 211         p = g = q = NULL;
 212     }
 213
 214     if (r->pub_key != NULL) {
 215         pub_key = BN_dup(r->pub_key);
 216         if (pub_key == NULL)
 217             goto err;
 218         if (r->priv_key != NULL) {
 219             priv_key = BN_dup(r->priv_key);
 220             if (priv_key == NULL)
 221                 goto err;
 222         }
 223         if (!DH_set0_key(ret, pub_key, priv_key))
 224             goto err;
 225     } else if (r->priv_key != NULL) {
 226         /* Shouldn't happen */
 227         goto err;
 228     }
 229
 230     return ret;
 231
 232  err:
 233     BN_free(p);
 234     BN_free(g);
 235     BN_free(q);
 236     BN_free(pub_key);
 237     BN_free(priv_key);
 238     DH_free(ret);
 239     return NULL;
 240 }
 241 #endif
 242
 243 void DSA_get0_pqg(const DSA *d,
 244                   const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 245 {
 246     if (p != NULL)
 247         *p = d->p;
 248     if (q != NULL)
 249         *q = d->q;
 250     if (g != NULL)
 251         *g = d->g;
 252 }
 253
 254 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 255 {
 256     /* If the fields p, q and g in d are NULL, the corresponding input
 257      * parameters MUST be non-NULL.
 258      */
 259     if ((d->p == NULL && p == NULL)
 260         || (d->q == NULL && q == NULL)
 261         || (d->g == NULL && g == NULL))
 262         return 0;
 263
 264     if (p != NULL) {
 265         BN_free(d->p);
 266         d->p = p;
 267     }
 268     if (q != NULL) {
 269         BN_free(d->q);
 270         d->q = q;
 271     }
 272     if (g != NULL) {
 273         BN_free(d->g);
 274         d->g = g;
 275     }
 276
 277     return 1;
 278 }
 279
 280 void DSA_get0_key(const DSA *d,
 281                   const BIGNUM **pub_key, const BIGNUM **priv_key)
 282 {
 283     if (pub_key != NULL)
 284         *pub_key = d->pub_key;
 285     if (priv_key != NULL)
 286         *priv_key = d->priv_key;
 287 }
 288
 289 int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 290 {
 291     /* If the field pub_key in d is NULL, the corresponding input
 292      * parameters MUST be non-NULL.  The priv_key field may
 293      * be left NULL.
 294      */
 295     if (d->pub_key == NULL && pub_key == NULL)
 296         return 0;
 297
 298     if (pub_key != NULL) {
 299         BN_free(d->pub_key);
 300         d->pub_key = pub_key;
 301     }
 302     if (priv_key != NULL) {
 303         BN_free(d->priv_key);
 304         d->priv_key = priv_key;
 305     }
 306
 307     return 1;
 308 }
 309
 310 void DSA_clear_flags(DSA *d, int flags)
 311 {
 312     d->flags &= ~flags;
 313 }
 314
 315 int DSA_test_flags(const DSA *d, int flags)
 316 {
 317     return d->flags & flags;
 318 }
 319
 320 void DSA_set_flags(DSA *d, int flags)
 321 {
 322     d->flags |= flags;
 323 }
 324
 325 ENGINE *DSA_get0_engine(DSA *d)
 326 {
 327     return d->engine;
 328 }
 329
 330 int DSA_bits(const DSA *dsa)
 331 {
 332     return BN_num_bits(dsa->p);
 333 }