crypto/dh/dh_lib.c

   1 /*
   2  * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 /*
  11  * DH low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <stdio.h>
  17 #include <openssl/bn.h>
  18 #include <openssl/engine.h>
  19 #include <openssl/obj_mac.h>
  20 #include <openssl/core_names.h>
  21 #include "internal/cryptlib.h"
  22 #include "internal/refcount.h"
  23 #include "crypto/evp.h"
  24 #include "crypto/dh.h"
  25 #include "dh_local.h"
  26
  27 static DH *dh_new_intern(ENGINE *engine, OPENSSL_CTX *libctx);
  28
  29 #ifndef FIPS_MODE
  30 int DH_set_method(DH *dh, const DH_METHOD *meth)
  31 {
  32     /*
  33      * NB: The caller is specifically setting a method, so it's not up to us
  34      * to deal with which ENGINE it comes from.
  35      */
  36     const DH_METHOD *mtmp;
  37     mtmp = dh->meth;
  38     if (mtmp->finish)
  39         mtmp->finish(dh);
  40 #ifndef OPENSSL_NO_ENGINE
  41     ENGINE_finish(dh->engine);
  42     dh->engine = NULL;
  43 #endif
  44     dh->meth = meth;
  45     if (meth->init)
  46         meth->init(dh);
  47     return 1;
  48 }
  49
  50 const DH_METHOD *dh_get_method(const DH *dh)
  51 {
  52     return dh->meth;
  53 }
  54
  55 DH *DH_new(void)
  56 {
  57     return dh_new_intern(NULL, NULL);
  58 }
  59
  60 DH *DH_new_method(ENGINE *engine)
  61 {
  62     return dh_new_intern(engine, NULL);
  63 }
  64 #endif /* !FIPS_MODE */
  65
  66 DH *dh_new_with_libctx(OPENSSL_CTX *libctx)
  67 {
  68     return dh_new_intern(NULL, libctx);
  69 }
  70
  71 static DH *dh_new_intern(ENGINE *engine, OPENSSL_CTX *libctx)
  72 {
  73     DH *ret = OPENSSL_zalloc(sizeof(*ret));
  74
  75     if (ret == NULL) {
  76         DHerr(0, ERR_R_MALLOC_FAILURE);
  77         return NULL;
  78     }
  79
  80     ret->references = 1;
  81     ret->lock = CRYPTO_THREAD_lock_new();
  82     if (ret->lock == NULL) {
  83         DHerr(0, ERR_R_MALLOC_FAILURE);
  84         OPENSSL_free(ret);
  85         return NULL;
  86     }
  87
  88     ret->libctx = libctx;
  89     ret->meth = DH_get_default_method();
  90 #if !defined(FIPS_MODE) && !defined(OPENSSL_NO_ENGINE)
  91     ret->flags = ret->meth->flags;  /* early default init */
  92     if (engine) {
  93         if (!ENGINE_init(engine)) {
  94             DHerr(0, ERR_R_ENGINE_LIB);
  95             goto err;
  96         }
  97         ret->engine = engine;
  98     } else
  99         ret->engine = ENGINE_get_default_DH();
 100     if (ret->engine) {
 101         ret->meth = ENGINE_get_DH(ret->engine);
 102         if (ret->meth == NULL) {
 103             DHerr(0, ERR_R_ENGINE_LIB);
 104             goto err;
 105         }
 106     }
 107 #endif
 108
 109     ret->flags = ret->meth->flags;
 110
 111 #ifndef FIPS_MODE
 112     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data))
 113         goto err;
 114 #endif /* FIPS_MODE */
 115
 116     if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
 117         DHerr(0, ERR_R_INIT_FAIL);
 118         goto err;
 119     }
 120
 121     return ret;
 122
 123  err:
 124     DH_free(ret);
 125     return NULL;
 126 }
 127
 128 void DH_free(DH *r)
 129 {
 130     int i;
 131
 132     if (r == NULL)
 133         return;
 134
 135     CRYPTO_DOWN_REF(&r->references, &i, r->lock);
 136     REF_PRINT_COUNT("DH", r);
 137     if (i > 0)
 138         return;
 139     REF_ASSERT_ISNT(i < 0);
 140
 141     if (r->meth != NULL && r->meth->finish != NULL)
 142         r->meth->finish(r);
 143 #if !defined(FIPS_MODE)
 144 # if !defined(OPENSSL_NO_ENGINE)
 145     ENGINE_finish(r->engine);
 146 # endif
 147     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
 148 #endif
 149
 150     CRYPTO_THREAD_lock_free(r->lock);
 151
 152     ffc_params_cleanup(&r->params);
 153     BN_clear_free(r->pub_key);
 154     BN_clear_free(r->priv_key);
 155     OPENSSL_free(r);
 156 }
 157
 158 int DH_up_ref(DH *r)
 159 {
 160     int i;
 161
 162     if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
 163         return 0;
 164
 165     REF_PRINT_COUNT("DH", r);
 166     REF_ASSERT_ISNT(i < 2);
 167     return ((i > 1) ? 1 : 0);
 168 }
 169
 170 #ifndef FIPS_MODE
 171 int DH_set_ex_data(DH *d, int idx, void *arg)
 172 {
 173     return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
 174 }
 175
 176 void *DH_get_ex_data(const DH *d, int idx)
 177 {
 178     return CRYPTO_get_ex_data(&d->ex_data, idx);
 179 }
 180 #endif
 181
 182 int DH_bits(const DH *dh)
 183 {
 184     return BN_num_bits(dh->params.p);
 185 }
 186
 187 int DH_size(const DH *dh)
 188 {
 189     return BN_num_bytes(dh->params.p);
 190 }
 191
 192 int DH_security_bits(const DH *dh)
 193 {
 194     int N;
 195     if (dh->params.q != NULL)
 196         N = BN_num_bits(dh->params.q);
 197     else if (dh->length)
 198         N = dh->length;
 199     else
 200         N = -1;
 201     return BN_security_bits(BN_num_bits(dh->params.p), N);
 202 }
 203
 204 void DH_get0_pqg(const DH *dh,
 205                  const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 206 {
 207     ffc_params_get0_pqg(&dh->params, p, q, g);
 208 }
 209
 210 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
 211 {
 212     /*
 213      * If the fields p and g in d are NULL, the corresponding input
 214      * parameters MUST be non-NULL.  q may remain NULL.
 215      */
 216     if ((dh->params.p == NULL && p == NULL)
 217         || (dh->params.g == NULL && g == NULL))
 218         return 0;
 219
 220     ffc_params_set0_pqg(&dh->params, p, q, g);
 221     dh_cache_named_group(dh);
 222     if (q != NULL)
 223         dh->length = BN_num_bits(q);
 224     /*
 225      * Check if this is a named group. If it finds a named group then the
 226      * 'q' and 'length' value are either already set or are set by the
 227      * call.
 228      */
 229     if (DH_get_nid(dh) == NID_undef) {
 230         /* If its not a named group then set the 'length' if q is not NULL */
 231         if (q != NULL)
 232             dh->length = BN_num_bits(q);
 233     }
 234     dh->dirty_cnt++;
 235     return 1;
 236 }
 237
 238 long DH_get_length(const DH *dh)
 239 {
 240     return dh->length;
 241 }
 242
 243 int DH_set_length(DH *dh, long length)
 244 {
 245     dh->length = length;
 246     return 1;
 247 }
 248
 249 void DH_get0_key(const DH *dh, const BIGNUM **pub_key, const BIGNUM **priv_key)
 250 {
 251     if (pub_key != NULL)
 252         *pub_key = dh->pub_key;
 253     if (priv_key != NULL)
 254         *priv_key = dh->priv_key;
 255 }
 256
 257 int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)
 258 {
 259     if (pub_key != NULL) {
 260         BN_clear_free(dh->pub_key);
 261         dh->pub_key = pub_key;
 262     }
 263     if (priv_key != NULL) {
 264         BN_clear_free(dh->priv_key);
 265         dh->priv_key = priv_key;
 266         dh->length = BN_num_bits(priv_key);
 267     }
 268
 269     dh->dirty_cnt++;
 270     return 1;
 271 }
 272
 273 const BIGNUM *DH_get0_p(const DH *dh)
 274 {
 275     return dh->params.p;
 276 }
 277
 278 const BIGNUM *DH_get0_q(const DH *dh)
 279 {
 280     return dh->params.q;
 281 }
 282
 283 const BIGNUM *DH_get0_g(const DH *dh)
 284 {
 285     return dh->params.g;
 286 }
 287
 288 const BIGNUM *DH_get0_priv_key(const DH *dh)
 289 {
 290     return dh->priv_key;
 291 }
 292
 293 const BIGNUM *DH_get0_pub_key(const DH *dh)
 294 {
 295     return dh->pub_key;
 296 }
 297
 298 void DH_clear_flags(DH *dh, int flags)
 299 {
 300     dh->flags &= ~flags;
 301 }
 302
 303 int DH_test_flags(const DH *dh, int flags)
 304 {
 305     return dh->flags & flags;
 306 }
 307
 308 void DH_set_flags(DH *dh, int flags)
 309 {
 310     dh->flags |= flags;
 311 }
 312
 313 #ifndef FIPS_MODE
 314 ENGINE *DH_get0_engine(DH *dh)
 315 {
 316     return dh->engine;
 317 }
 318 #endif /*FIPS_MODE */
 319
 320 FFC_PARAMS *dh_get0_params(DH *dh)
 321 {
 322     return &dh->params;
 323 }
 324 int dh_get0_nid(const DH *dh)
 325 {
 326     return dh->params.nid;
 327 }
 328
 329 int dh_ffc_params_fromdata(DH *dh, const OSSL_PARAM params[])
 330 {
 331     int ret;
 332     FFC_PARAMS *ffc;
 333
 334     if (dh == NULL)
 335         return 0;
 336     ffc = dh_get0_params(dh);
 337     if (ffc == NULL)
 338         return 0;
 339
 340     ret = ffc_params_fromdata(ffc, params);
 341     if (ret) {
 342         dh_cache_named_group(dh);
 343         dh->dirty_cnt++;
 344     }
 345     return ret;
 346 }
 347
 348 static int dh_paramgen_check(EVP_PKEY_CTX *ctx)
 349 {
 350     if (ctx == NULL || !EVP_PKEY_CTX_IS_GEN_OP(ctx)) {
 351         ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
 352         /* Uses the same return values as EVP_PKEY_CTX_ctrl */
 353         return -2;
 354     }
 355     /* If key type not DH return error */
 356     if (ctx->pmeth != NULL
 357         && ctx->pmeth->pkey_id != EVP_PKEY_DH
 358         && ctx->pmeth->pkey_id != EVP_PKEY_DHX)
 359         return -1;
 360     return 1;
 361 }
 362
 363 int EVP_PKEY_CTX_set_dh_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex)
 364 {
 365     int ret;
 366     OSSL_PARAM params[2], *p = params;
 367
 368     if ((ret = dh_paramgen_check(ctx)) <= 0)
 369         return ret;
 370
 371     *p++ = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_FFC_GINDEX, &gindex);
 372     *p++ = OSSL_PARAM_construct_end();
 373
 374     return EVP_PKEY_CTX_set_params(ctx, params);
 375 }
 376
 377 int EVP_PKEY_CTX_set_dh_paramgen_seed(EVP_PKEY_CTX *ctx,
 378                                       const unsigned char *seed,
 379                                       size_t seedlen)
 380 {
 381     int ret;
 382     OSSL_PARAM params[2], *p = params;
 383
 384     if ((ret = dh_paramgen_check(ctx)) <= 0)
 385         return ret;
 386
 387     *p++ = OSSL_PARAM_construct_octet_string(OSSL_PKEY_PARAM_FFC_SEED,
 388                                              (void *)seed, seedlen);
 389     *p++ = OSSL_PARAM_construct_end();
 390
 391     return EVP_PKEY_CTX_set_params(ctx, params);
 392 }
 393
 394 int EVP_PKEY_CTX_set_dh_paramgen_type(EVP_PKEY_CTX *ctx, int typ)
 395 {
 396     int ret;
 397     OSSL_PARAM params[2], *p = params;
 398     const char *name;
 399
 400     if ((ret = dh_paramgen_check(ctx)) <= 0)
 401         return ret;
 402
 403 #if !defined(FIPS_MODE)
 404     /* TODO(3.0): Remove this eventually when no more legacy */
 405     if (ctx->op.keymgmt.genctx == NULL)
 406         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN,
 407                                  EVP_PKEY_CTRL_DH_PARAMGEN_TYPE, typ, NULL);
 408 #endif
 409
 410     name = dh_gen_type_id2name(typ);
 411     if (name == NULL)
 412         return 0;
 413     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE,
 414                                             (char *) name, 0);
 415     *p++ = OSSL_PARAM_construct_end();
 416
 417     return EVP_PKEY_CTX_set_params(ctx, params);
 418 }
 419
 420 int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int pbits)
 421 {
 422     int ret;
 423     OSSL_PARAM params[2], *p = params;
 424     size_t bits = pbits;
 425
 426     if ((ret = dh_paramgen_check(ctx)) <= 0)
 427         return ret;
 428
 429 #if !defined(FIPS_MODE)
 430     /* TODO(3.0): Remove this eventually when no more legacy */
 431     if (ctx->op.keymgmt.genctx == NULL)
 432         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN,
 433                                  EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN, pbits,
 434                                  NULL);
 435 #endif
 436     *p++ = OSSL_PARAM_construct_size_t(OSSL_PKEY_PARAM_FFC_PBITS, &bits);
 437     *p++ = OSSL_PARAM_construct_end();
 438     return EVP_PKEY_CTX_set_params(ctx, params);
 439 }
 440
 441 int EVP_PKEY_CTX_set_dh_paramgen_subprime_len(EVP_PKEY_CTX *ctx, int qbits)
 442 {
 443     int ret;
 444     OSSL_PARAM params[2], *p = params;
 445     size_t bits2 = qbits;
 446
 447     if ((ret = dh_paramgen_check(ctx)) <= 0)
 448         return ret;
 449
 450 #if !defined(FIPS_MODE)
 451     /* TODO(3.0): Remove this eventually when no more legacy */
 452     if (ctx->op.keymgmt.genctx == NULL)
 453         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN,
 454                                  EVP_PKEY_CTRL_DH_PARAMGEN_SUBPRIME_LEN, qbits,
 455                                  NULL);
 456 #endif
 457     *p++ = OSSL_PARAM_construct_size_t(OSSL_PKEY_PARAM_FFC_QBITS, &bits2);
 458     *p++ = OSSL_PARAM_construct_end();
 459
 460     return EVP_PKEY_CTX_set_params(ctx, params);
 461 }
 462
 463 int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen)
 464 {
 465     int ret;
 466     OSSL_PARAM params[2], *p = params;
 467
 468     if ((ret = dh_paramgen_check(ctx)) <= 0)
 469         return ret;
 470
 471 #if !defined(FIPS_MODE)
 472     /* TODO(3.0): Remove this eventually when no more legacy */
 473     if (ctx->op.keymgmt.genctx == NULL)
 474         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN,
 475                                  EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR, gen, NULL);
 476 #endif
 477
 478     *p++ = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_FFC_GENERATOR, &gen);
 479     *p++ = OSSL_PARAM_construct_end();
 480
 481     return EVP_PKEY_CTX_set_params(ctx, params);
 482 }
 483
 484 int EVP_PKEY_CTX_set_dh_rfc5114(EVP_PKEY_CTX *ctx, int gen)
 485 {
 486     int ret;
 487     OSSL_PARAM params[2], *p = params;
 488     const char *name;
 489
 490     if ((ret = dh_paramgen_check(ctx)) <= 0)
 491         return ret;
 492
 493 #if !defined(FIPS_MODE)
 494     /* TODO(3.0): Remove this eventually when no more legacy */
 495     if (ctx->op.keymgmt.genctx == NULL)
 496         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DHX, EVP_PKEY_OP_PARAMGEN,
 497                                  EVP_PKEY_CTRL_DH_RFC5114, gen, NULL);
 498 #endif
 499     name = ffc_named_group_from_uid(gen);
 500     if (name == NULL)
 501         return 0;
 502
 503     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_GROUP,
 504                                             (void *)name, 0);
 505     *p++ = OSSL_PARAM_construct_end();
 506     return EVP_PKEY_CTX_set_params(ctx, params);
 507 }
 508
 509 int EVP_PKEY_CTX_set_dhx_rfc5114(EVP_PKEY_CTX *ctx, int gen)
 510 {
 511     return EVP_PKEY_CTX_set_dh_rfc5114(ctx, gen);
 512 }
 513
 514 int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid)
 515 {
 516     int ret;
 517     OSSL_PARAM params[2], *p = params;
 518     const char *name;
 519
 520     if ((ret = dh_paramgen_check(ctx)) <= 0)
 521         return ret;
 522
 523 #if !defined(FIPS_MODE)
 524     /* TODO(3.0): Remove this eventually when no more legacy */
 525     if (ctx->op.keymgmt.genctx == NULL)
 526         return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH,
 527                                  EVP_PKEY_OP_PARAMGEN | EVP_PKEY_OP_KEYGEN,
 528                                  EVP_PKEY_CTRL_DH_NID, nid, NULL);
 529 #endif
 530     name = ffc_named_group_from_uid(nid);
 531     if (name == NULL)
 532         return 0;
 533
 534     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_GROUP,
 535                                             (void *)name, 0);
 536     *p++ = OSSL_PARAM_construct_end();
 537     return EVP_PKEY_CTX_set_params(ctx, params);
 538 }