crypto/dsa/dsa_lib.c

   1 /*
   2  * Copyright 1995-2016 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 <openssl/bn.h>
  15 #include "dsa_locl.h"
  16 #include <openssl/asn1.h>
  17 #include <openssl/engine.h>
  18 #include <openssl/dh.h>
  19
  20 static const DSA_METHOD *default_DSA_method = NULL;
  21
  22 void DSA_set_default_method(const DSA_METHOD *meth)
  23 {
  24     default_DSA_method = meth;
  25 }
  26
  27 const DSA_METHOD *DSA_get_default_method(void)
  28 {
  29     if (!default_DSA_method)
  30         default_DSA_method = DSA_OpenSSL();
  31     return default_DSA_method;
  32 }
  33
  34 DSA *DSA_new(void)
  35 {
  36     return DSA_new_method(NULL);
  37 }
  38
  39 int DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
  40 {
  41     /*
  42      * NB: The caller is specifically setting a method, so it's not up to us
  43      * to deal with which ENGINE it comes from.
  44      */
  45     const DSA_METHOD *mtmp;
  46     mtmp = dsa->meth;
  47     if (mtmp->finish)
  48         mtmp->finish(dsa);
  49 #ifndef OPENSSL_NO_ENGINE
  50     ENGINE_finish(dsa->engine);
  51     dsa->engine = NULL;
  52 #endif
  53     dsa->meth = meth;
  54     if (meth->init)
  55         meth->init(dsa);
  56     return 1;
  57 }
  58
  59 const DSA_METHOD *DSA_get_method(DSA *d)
  60 {
  61     return d->meth;
  62 }
  63
  64 DSA *DSA_new_method(ENGINE *engine)
  65 {
  66     DSA *ret = OPENSSL_zalloc(sizeof(*ret));
  67
  68     if (ret == NULL) {
  69         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
  70         return NULL;
  71     }
  72
  73     ret->references = 1;
  74     ret->lock = CRYPTO_THREAD_lock_new();
  75     if (ret->lock == NULL) {
  76         OPENSSL_free(ret);
  77         return NULL;
  78     }
  79
  80     ret->meth = DSA_get_default_method();
  81 #ifndef OPENSSL_NO_ENGINE
  82     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW; /* early default init */
  83     if (engine) {
  84         if (!ENGINE_init(engine)) {
  85             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  86             goto err;
  87         }
  88         ret->engine = engine;
  89     } else
  90         ret->engine = ENGINE_get_default_DSA();
  91     if (ret->engine) {
  92         ret->meth = ENGINE_get_DSA(ret->engine);
  93         if (ret->meth == NULL) {
  94             DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_ENGINE_LIB);
  95             goto err;
  96         }
  97     }
  98 #endif
  99
 100     ret->flags = ret->meth->flags & ~DSA_FLAG_NON_FIPS_ALLOW;
 101
 102     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data))
 103         goto err;
 104
 105     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 106         DSAerr(DSA_F_DSA_NEW_METHOD, ERR_R_INIT_FAIL);
 107 err:
 108         DSA_free(ret);
 109         ret = NULL;
 110     }
 111
 112     return ret;
 113 }
 114
 115 void DSA_free(DSA *r)
 116 {
 117     int i;
 118
 119     if (r == NULL)
 120         return;
 121
 122     CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
 123     REF_PRINT_COUNT("DSA", r);
 124     if (i > 0)
 125         return;
 126     REF_ASSERT_ISNT(i < 0);
 127
 128     if (r->meth->finish)
 129         r->meth->finish(r);
 130 #ifndef OPENSSL_NO_ENGINE
 131     ENGINE_finish(r->engine);
 132 #endif
 133
 134     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);
 135
 136     CRYPTO_THREAD_lock_free(r->lock);
 137
 138     BN_clear_free(r->p);
 139     BN_clear_free(r->q);
 140     BN_clear_free(r->g);
 141     BN_clear_free(r->pub_key);
 142     BN_clear_free(r->priv_key);
 143     OPENSSL_free(r);
 144 }
 145
 146 int DSA_up_ref(DSA *r)
 147 {
 148     int i;
 149
 150     if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
 151         return 0;
 152
 153     REF_PRINT_COUNT("DSA", r);
 154     REF_ASSERT_ISNT(i < 2);
 155     return ((i > 1) ? 1 : 0);
 156 }
 157
 158 int DSA_size(const DSA *r)
 159 {
 160     int ret, i;
 161     ASN1_INTEGER bs;
 162     unsigned char buf[4];       /* 4 bytes looks really small. However,
 163                                  * i2d_ASN1_INTEGER() will not look beyond
 164                                  * the first byte, as long as the second
 165                                  * parameter is NULL. */
 166
 167     i = BN_num_bits(r->q);
 168     bs.length = (i + 7) / 8;
 169     bs.data = buf;
 170     bs.type = V_ASN1_INTEGER;
 171     /* If the top bit is set the asn1 encoding is 1 larger. */
 172     buf[0] = 0xff;
 173
 174     i = i2d_ASN1_INTEGER(&bs, NULL);
 175     i += i;                     /* r and s */
 176     ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);
 177     return (ret);
 178 }
 179
 180 int DSA_set_ex_data(DSA *d, int idx, void *arg)
 181 {
 182     return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
 183 }
 184
 185 void *DSA_get_ex_data(DSA *d, int idx)
 186 {
 187     return (CRYPTO_get_ex_data(&d->ex_data, idx));
 188 }
 189
 190 int DSA_security_bits(const DSA *d)
 191 {
 192     if (d->p && d->q)
 193         return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
 194     return -1;
 195 }
 196
 197 #ifndef OPENSSL_NO_DH
 198 DH *DSA_dup_DH(const DSA *r)
 199 {
 200     /*
 201      * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
 202      * optional length, g, optional pub_key, optional priv_key, optional q.
 203      */
 204
 205     DH *ret = NULL;
 206     BIGNUM *p = NULL, *q = NULL, *g = NULL, *pub_key = NULL, *priv_key = NULL;
 207
 208     if (r == NULL)
 209         goto err;
 210     ret = DH_new();
 211     if (ret == NULL)
 212         goto err;
 213     if (r->p != NULL || r->g != NULL || r->q != NULL) {
 214         if (r->p == NULL || r->g == NULL || r->q == NULL) {
 215             /* Shouldn't happen */
 216             goto err;
 217         }
 218         p = BN_dup(r->p);
 219         g = BN_dup(r->g);
 220         q = BN_dup(r->q);
 221         if (p == NULL || g == NULL || q == NULL || !DH_set0_pqg(ret, p, q, g))
 222             goto err;
 223         p = g = q = NULL;
 224     }
 225
 226     if (r->pub_key != NULL) {
 227         pub_key = BN_dup(r->pub_key);
 228         if (pub_key == NULL)
 229             goto err;
 230         if (r->priv_key != NULL) {
 231             priv_key = BN_dup(r->priv_key);
 232             if (priv_key == NULL)
 233                 goto err;
 234         }
 235         if (!DH_set0_key(ret, pub_key, priv_key))
 236             goto err;
 237     } else if (r->priv_key != NULL) {
 238         /* Shouldn't happen */
 239         goto err;
 240     }
 241
 242     return ret;
 243
 244  err:
 245     BN_free(p);
 246     BN_free(g);
 247     BN_free(q);
 248     BN_free(pub_key);
 249     BN_free(priv_key);
 250     DH_free(ret);
 251     return NULL;
 252 }
 253 #endif
 254
 255 void DSA_get0_pqg(const DSA *d, BIGNUM **p, BIGNUM **q, BIGNUM **g)
 256 {
 257     if (p != NULL)
 258         *p = d->p;
 259     if (q != NULL)
 260         *q = d->q;
 261     if (g != NULL)
 262         *g = d->g;
 263 }
 264
 265 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 266 {
 267     /* If the fields in d are NULL, the corresponding input
 268      * parameters MUST be non-NULL.
 269      *
 270      * It is an error to give the results from get0 on d
 271      * as input parameters.
 272      */
 273     if (p == d->p || q == d->q || g == d->g)
 274         return 0;
 275
 276     if (p != NULL) {
 277         BN_free(d->p);
 278         d->p = p;
 279     }
 280     if (q != NULL) {
 281         BN_free(d->q);
 282         d->q = q;
 283     }
 284     if (g != NULL) {
 285         BN_free(d->g);
 286         d->g = g;
 287     }
 288
 289     return 1;
 290 }
 291
 292 void DSA_get0_key(const DSA *d, BIGNUM **pub_key, BIGNUM **priv_key)
 293 {
 294     if (pub_key != NULL)
 295         *pub_key = d->pub_key;
 296     if (priv_key != NULL)
 297         *priv_key = d->priv_key;
 298 }
 299
 300 int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 301 {
 302     /* If the pub_key in d is NULL, the corresponding input
 303      * parameters MUST be non-NULL.  The priv_key field may
 304      * be left NULL.
 305      *
 306      * It is an error to give the results from get0 on d
 307      * as input parameters.
 308      */
 309     if (d->pub_key == pub_key
 310         || (d->priv_key != NULL && priv_key == d->priv_key))
 311         return 0;
 312
 313     if (pub_key != NULL) {
 314         BN_free(d->pub_key);
 315         d->pub_key = pub_key;
 316     }
 317     if (priv_key != NULL) {
 318         BN_free(d->priv_key);
 319         d->priv_key = priv_key;
 320     }
 321
 322     return 1;
 323 }
 324
 325 void DSA_clear_flags(DSA *d, int flags)
 326 {
 327     d->flags &= ~flags;
 328 }
 329
 330 int DSA_test_flags(const DSA *d, int flags)
 331 {
 332     return d->flags & flags;
 333 }
 334
 335 void DSA_set_flags(DSA *d, int flags)
 336 {
 337     d->flags |= flags;
 338 }
 339
 340 ENGINE *DSA_get0_engine(DSA *d)
 341 {
 342     return d->engine;
 343 }