crypto/evp/keymgmt_lib.c

   1 /*
   2  * Copyright 2019-2024 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 #include <openssl/core_names.h>
  11 #include "internal/cryptlib.h"
  12 #include "internal/nelem.h"
  13 #include "crypto/evp.h"
  14 #include "internal/core.h"
  15 #include "internal/provider.h"
  16 #include "evp_local.h"
  17
  18 /*
  19  * match_type() checks if two EVP_KEYMGMT are matching key types.  This
  20  * function assumes that the caller has made all the necessary NULL checks.
  21  */
  22 static int match_type(const EVP_KEYMGMT *keymgmt1, const EVP_KEYMGMT *keymgmt2)
  23 {
  24     const char *name2 = EVP_KEYMGMT_get0_name(keymgmt2);
  25
  26     return EVP_KEYMGMT_is_a(keymgmt1, name2);
  27 }
  28
  29 int evp_keymgmt_util_try_import(const OSSL_PARAM params[], void *arg)
  30 {
  31     struct evp_keymgmt_util_try_import_data_st *data = arg;
  32     int delete_on_error = 0;
  33
  34     /* Just in time creation of keydata */
  35     if (data->keydata == NULL) {
  36         if ((data->keydata = evp_keymgmt_newdata(data->keymgmt)) == NULL) {
  37             ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
  38             return 0;
  39         }
  40         delete_on_error = 1;
  41     }
  42
  43     /*
  44      * It's fine if there was no data to transfer, we just end up with an
  45      * empty destination key.
  46      */
  47     if (params[0].key == NULL)
  48         return 1;
  49
  50     if (evp_keymgmt_import(data->keymgmt, data->keydata, data->selection,
  51                            params))
  52         return 1;
  53     if (delete_on_error) {
  54         evp_keymgmt_freedata(data->keymgmt, data->keydata);
  55         data->keydata = NULL;
  56     }
  57     return 0;
  58 }
  59
  60 int evp_keymgmt_util_assign_pkey(EVP_PKEY *pkey, EVP_KEYMGMT *keymgmt,
  61                                  void *keydata)
  62 {
  63     if (pkey == NULL || keymgmt == NULL || keydata == NULL
  64         || !EVP_PKEY_set_type_by_keymgmt(pkey, keymgmt)) {
  65         ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
  66         return 0;
  67     }
  68     pkey->keydata = keydata;
  69     evp_keymgmt_util_cache_keyinfo(pkey);
  70     return 1;
  71 }
  72
  73 EVP_PKEY *evp_keymgmt_util_make_pkey(EVP_KEYMGMT *keymgmt, void *keydata)
  74 {
  75     EVP_PKEY *pkey = NULL;
  76
  77     if (keymgmt == NULL
  78         || keydata == NULL
  79         || (pkey = EVP_PKEY_new()) == NULL
  80         || !evp_keymgmt_util_assign_pkey(pkey, keymgmt, keydata)) {
  81         EVP_PKEY_free(pkey);
  82         return NULL;
  83     }
  84     return pkey;
  85 }
  86
  87 int evp_keymgmt_util_export(const EVP_PKEY *pk, int selection,
  88                             OSSL_CALLBACK *export_cb, void *export_cbarg)
  89 {
  90     if (pk == NULL || export_cb == NULL)
  91         return 0;
  92     return evp_keymgmt_export(pk->keymgmt, pk->keydata, selection,
  93                               export_cb, export_cbarg);
  94 }
  95
  96 void *evp_keymgmt_util_export_to_provider(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
  97                                           int selection)
  98 {
  99     struct evp_keymgmt_util_try_import_data_st import_data;
 100     OP_CACHE_ELEM *op;
 101
 102     /* Export to where? */
 103     if (keymgmt == NULL)
 104         return NULL;
 105
 106     /* If we have an unassigned key, give up */
 107     if (pk->keydata == NULL)
 108         return NULL;
 109
 110     /*
 111      * If |keymgmt| matches the "origin" |keymgmt|, there is no more to do.
 112      * The "origin" is determined by the |keymgmt| pointers being identical
 113      * or when the provider and the name ID match.  The latter case handles the
 114      * situation where the fetch cache is flushed and a "new" key manager is
 115      * created.
 116      */
 117     if (pk->keymgmt == keymgmt
 118         || (pk->keymgmt->name_id == keymgmt->name_id
 119             && pk->keymgmt->prov == keymgmt->prov))
 120         return pk->keydata;
 121
 122     if (!CRYPTO_THREAD_read_lock(pk->lock))
 123         return NULL;
 124     /*
 125      * If the provider native "origin" hasn't changed since last time, we
 126      * try to find our keymgmt in the operation cache.  If it has changed
 127      * and our keymgmt isn't found, we will clear the cache further down.
 128      */
 129     if (pk->dirty_cnt == pk->dirty_cnt_copy) {
 130         /* If this key is already exported to |keymgmt|, no more to do */
 131         op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
 132         if (op != NULL && op->keymgmt != NULL) {
 133             void *ret = op->keydata;
 134
 135             CRYPTO_THREAD_unlock(pk->lock);
 136             return ret;
 137         }
 138     }
 139     CRYPTO_THREAD_unlock(pk->lock);
 140
 141     /* If the "origin" |keymgmt| doesn't support exporting, give up */
 142     if (pk->keymgmt->export == NULL)
 143         return NULL;
 144
 145     /*
 146      * Make sure that the type of the keymgmt to export to matches the type
 147      * of the "origin"
 148      */
 149     if (!ossl_assert(match_type(pk->keymgmt, keymgmt)))
 150         return NULL;
 151
 152     /*
 153      * We look at the already cached provider keys, and import from the
 154      * first that supports it (i.e. use its export function), and export
 155      * the imported data to the new provider.
 156      */
 157
 158     /* Setup for the export callback */
 159     import_data.keydata = NULL;  /* evp_keymgmt_util_try_import will create it */
 160     import_data.keymgmt = keymgmt;
 161     import_data.selection = selection;
 162
 163     /*
 164      * The export function calls the callback (evp_keymgmt_util_try_import),
 165      * which does the import for us.  If successful, we're done.
 166      */
 167     if (!evp_keymgmt_util_export(pk, selection,
 168                                  &evp_keymgmt_util_try_import, &import_data))
 169         /* If there was an error, bail out */
 170         return NULL;
 171
 172     if (!CRYPTO_THREAD_write_lock(pk->lock)) {
 173         evp_keymgmt_freedata(keymgmt, import_data.keydata);
 174         return NULL;
 175     }
 176     /* Check to make sure some other thread didn't get there first */
 177     op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
 178     if (op != NULL && op->keydata != NULL) {
 179         void *ret = op->keydata;
 180
 181         CRYPTO_THREAD_unlock(pk->lock);
 182
 183         /*
 184          * Another thread seemms to have already exported this so we abandon
 185          * all the work we just did.
 186          */
 187         evp_keymgmt_freedata(keymgmt, import_data.keydata);
 188
 189         return ret;
 190     }
 191
 192     /*
 193      * If the dirty counter changed since last time, then clear the
 194      * operation cache.  In that case, we know that |i| is zero.
 195      */
 196     if (pk->dirty_cnt != pk->dirty_cnt_copy)
 197         evp_keymgmt_util_clear_operation_cache(pk);
 198
 199     /* Add the new export to the operation cache */
 200     if (!evp_keymgmt_util_cache_keydata(pk, keymgmt, import_data.keydata,
 201                                         selection)) {
 202         CRYPTO_THREAD_unlock(pk->lock);
 203         evp_keymgmt_freedata(keymgmt, import_data.keydata);
 204         return NULL;
 205     }
 206
 207     /* Synchronize the dirty count */
 208     pk->dirty_cnt_copy = pk->dirty_cnt;
 209
 210     CRYPTO_THREAD_unlock(pk->lock);
 211
 212     return import_data.keydata;
 213 }
 214
 215 static void op_cache_free(OP_CACHE_ELEM *e)
 216 {
 217     evp_keymgmt_freedata(e->keymgmt, e->keydata);
 218     EVP_KEYMGMT_free(e->keymgmt);
 219     OPENSSL_free(e);
 220 }
 221
 222 int evp_keymgmt_util_clear_operation_cache(EVP_PKEY *pk)
 223 {
 224     if (pk != NULL) {
 225         sk_OP_CACHE_ELEM_pop_free(pk->operation_cache, op_cache_free);
 226         pk->operation_cache = NULL;
 227     }
 228
 229     return 1;
 230 }
 231
 232 OP_CACHE_ELEM *evp_keymgmt_util_find_operation_cache(EVP_PKEY *pk,
 233                                                      EVP_KEYMGMT *keymgmt,
 234                                                      int selection)
 235 {
 236     int i, end = sk_OP_CACHE_ELEM_num(pk->operation_cache);
 237     OP_CACHE_ELEM *p;
 238
 239     /*
 240      * A comparison and sk_P_CACHE_ELEM_find() are avoided to not cause
 241      * problems when we've only a read lock.
 242      * A keymgmt is a match if the |keymgmt| pointers are identical or if the
 243      * provider and the name ID match
 244      */
 245     for (i = 0; i < end; i++) {
 246         p = sk_OP_CACHE_ELEM_value(pk->operation_cache, i);
 247         if ((p->selection & selection) == selection
 248                 && (keymgmt == p->keymgmt
 249                     || (keymgmt->name_id == p->keymgmt->name_id
 250                         && keymgmt->prov == p->keymgmt->prov)))
 251             return p;
 252     }
 253     return NULL;
 254 }
 255
 256 int evp_keymgmt_util_cache_keydata(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
 257                                    void *keydata, int selection)
 258 {
 259     OP_CACHE_ELEM *p = NULL;
 260
 261     if (keydata != NULL) {
 262         if (pk->operation_cache == NULL) {
 263             pk->operation_cache = sk_OP_CACHE_ELEM_new_null();
 264             if (pk->operation_cache == NULL)
 265                 return 0;
 266         }
 267
 268         p = OPENSSL_malloc(sizeof(*p));
 269         if (p == NULL)
 270             return 0;
 271         p->keydata = keydata;
 272         p->keymgmt = keymgmt;
 273         p->selection = selection;
 274
 275         if (!EVP_KEYMGMT_up_ref(keymgmt)) {
 276             OPENSSL_free(p);
 277             return 0;
 278         }
 279
 280         if (!sk_OP_CACHE_ELEM_push(pk->operation_cache, p)) {
 281             EVP_KEYMGMT_free(keymgmt);
 282             OPENSSL_free(p);
 283             return 0;
 284         }
 285     }
 286     return 1;
 287 }
 288
 289 void evp_keymgmt_util_cache_keyinfo(EVP_PKEY *pk)
 290 {
 291     /*
 292      * Cache information about the provider "origin" key.
 293      *
 294      * This services functions like EVP_PKEY_get_size, EVP_PKEY_get_bits, etc
 295      */
 296     if (pk->keydata != NULL) {
 297         int bits = 0;
 298         int security_bits = 0;
 299         int size = 0;
 300         OSSL_PARAM params[4];
 301
 302         params[0] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_BITS, &bits);
 303         params[1] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_SECURITY_BITS,
 304                                              &security_bits);
 305         params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_MAX_SIZE, &size);
 306         params[3] = OSSL_PARAM_construct_end();
 307         if (evp_keymgmt_get_params(pk->keymgmt, pk->keydata, params)) {
 308             pk->cache.size = size;
 309             pk->cache.bits = bits;
 310             pk->cache.security_bits = security_bits;
 311         }
 312     }
 313 }
 314
 315 void *evp_keymgmt_util_fromdata(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
 316                                 int selection, const OSSL_PARAM params[])
 317 {
 318     void *keydata = NULL;
 319
 320     if ((keydata = evp_keymgmt_newdata(keymgmt)) == NULL
 321         || !evp_keymgmt_import(keymgmt, keydata, selection, params)
 322         || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
 323         evp_keymgmt_freedata(keymgmt, keydata);
 324         keydata = NULL;
 325     }
 326     return keydata;
 327 }
 328
 329 int evp_keymgmt_util_has(EVP_PKEY *pk, int selection)
 330 {
 331     /* Check if key is even assigned */
 332     if (pk->keymgmt == NULL)
 333         return 0;
 334
 335     return evp_keymgmt_has(pk->keymgmt, pk->keydata, selection);
 336 }
 337
 338 /*
 339  * evp_keymgmt_util_match() doesn't just look at the provider side "origin",
 340  * but also in the operation cache to see if there's any common keymgmt that
 341  * supplies OP_keymgmt_match.
 342  *
 343  * evp_keymgmt_util_match() adheres to the return values that EVP_PKEY_eq()
 344  * and EVP_PKEY_parameters_eq() return, i.e.:
 345  *
 346  *  1   same key
 347  *  0   not same key
 348  * -1   not same key type
 349  * -2   unsupported operation
 350  */
 351 int evp_keymgmt_util_match(EVP_PKEY *pk1, EVP_PKEY *pk2, int selection)
 352 {
 353     EVP_KEYMGMT *keymgmt1 = NULL, *keymgmt2 = NULL;
 354     void *keydata1 = NULL, *keydata2 = NULL;
 355
 356     if (pk1 == NULL || pk2 == NULL) {
 357         if (pk1 == NULL && pk2 == NULL)
 358             return 1;
 359         return 0;
 360     }
 361
 362     keymgmt1 = pk1->keymgmt;
 363     keydata1 = pk1->keydata;
 364     keymgmt2 = pk2->keymgmt;
 365     keydata2 = pk2->keydata;
 366
 367     if (keymgmt1 != keymgmt2) {
 368         /*
 369          * The condition for a successful cross export is that the
 370          * keydata to be exported is NULL (typed, but otherwise empty
 371          * EVP_PKEY), or that it was possible to export it with
 372          * evp_keymgmt_util_export_to_provider().
 373          *
 374          * We use |ok| to determine if it's ok to cross export one way,
 375          * but also to determine if we should attempt a cross export
 376          * the other way.  There's no point doing it both ways.
 377          */
 378         int ok = 0;
 379
 380         /* Complex case, where the keymgmt differ */
 381         if (keymgmt1 != NULL
 382             && keymgmt2 != NULL
 383             && !match_type(keymgmt1, keymgmt2)) {
 384             ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
 385             return -1;           /* Not the same type */
 386         }
 387
 388         /*
 389          * The key types are determined to match, so we try cross export,
 390          * but only to keymgmt's that supply a matching function.
 391          */
 392         if (keymgmt2 != NULL
 393             && keymgmt2->match != NULL) {
 394             void *tmp_keydata = NULL;
 395
 396             ok = 1;
 397             if (keydata1 != NULL) {
 398                 tmp_keydata =
 399                     evp_keymgmt_util_export_to_provider(pk1, keymgmt2,
 400                                                         selection);
 401                 ok = (tmp_keydata != NULL);
 402             }
 403             if (ok) {
 404                 keymgmt1 = keymgmt2;
 405                 keydata1 = tmp_keydata;
 406             }
 407         }
 408         /*
 409          * If we've successfully cross exported one way, there's no point
 410          * doing it the other way, hence the |!ok| check.
 411          */
 412         if (!ok
 413             && keymgmt1 != NULL
 414             && keymgmt1->match != NULL) {
 415             void *tmp_keydata = NULL;
 416
 417             ok = 1;
 418             if (keydata2 != NULL) {
 419                 tmp_keydata =
 420                     evp_keymgmt_util_export_to_provider(pk2, keymgmt1,
 421                                                         selection);
 422                 ok = (tmp_keydata != NULL);
 423             }
 424             if (ok) {
 425                 keymgmt2 = keymgmt1;
 426                 keydata2 = tmp_keydata;
 427             }
 428         }
 429     }
 430
 431     /* If we still don't have matching keymgmt implementations, we give up */
 432     if (keymgmt1 != keymgmt2)
 433         return -2;
 434
 435     /* If both keydata are NULL, then they're the same key */
 436     if (keydata1 == NULL && keydata2 == NULL)
 437         return 1;
 438     /* If only one of the keydata is NULL, then they're different keys */
 439     if (keydata1 == NULL || keydata2 == NULL)
 440         return 0;
 441     /* If both keydata are non-NULL, we let the backend decide */
 442     return evp_keymgmt_match(keymgmt1, keydata1, keydata2, selection);
 443 }
 444
 445 int evp_keymgmt_util_copy(EVP_PKEY *to, EVP_PKEY *from, int selection)
 446 {
 447     /* Save copies of pointers we want to play with without affecting |to| */
 448     EVP_KEYMGMT *to_keymgmt = to->keymgmt;
 449     void *to_keydata = to->keydata, *alloc_keydata = NULL;
 450
 451     /* An unassigned key can't be copied */
 452     if (from == NULL || from->keydata == NULL)
 453         return 0;
 454
 455     /*
 456      * If |to| is unassigned, ensure it gets the same KEYMGMT as |from|,
 457      * Note that the final setting of KEYMGMT is done further down, with
 458      * EVP_PKEY_set_type_by_keymgmt(); we don't want to do that prematurely.
 459      */
 460     if (to_keymgmt == NULL)
 461         to_keymgmt = from->keymgmt;
 462
 463     if (to_keymgmt == from->keymgmt && to_keymgmt->dup != NULL
 464         && to_keydata == NULL) {
 465         to_keydata = alloc_keydata = evp_keymgmt_dup(to_keymgmt,
 466                                                      from->keydata,
 467                                                      selection);
 468         if (to_keydata == NULL)
 469             return 0;
 470     } else if (match_type(to_keymgmt, from->keymgmt)) {
 471         struct evp_keymgmt_util_try_import_data_st import_data;
 472
 473         import_data.keymgmt = to_keymgmt;
 474         import_data.keydata = to_keydata;
 475         import_data.selection = selection;
 476
 477         if (!evp_keymgmt_util_export(from, selection,
 478                                      &evp_keymgmt_util_try_import,
 479                                      &import_data))
 480             return 0;
 481
 482         /*
 483          * In case to_keydata was previously unallocated,
 484          * evp_keymgmt_util_try_import() may have created it for us.
 485          */
 486         if (to_keydata == NULL)
 487             to_keydata = alloc_keydata = import_data.keydata;
 488     } else {
 489         ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
 490         return 0;
 491     }
 492
 493     /*
 494      * We only need to set the |to| type when its |keymgmt| isn't set.
 495      * We can then just set its |keydata| to what we have, which might
 496      * be exactly what it had when entering this function.
 497      * This is a bit different from using evp_keymgmt_util_assign_pkey(),
 498      * which isn't as careful with |to|'s original |keymgmt|, since it's
 499      * meant to forcibly reassign an EVP_PKEY no matter what, which is
 500      * why we don't use that one here.
 501      */
 502     if (to->keymgmt == NULL
 503         && !EVP_PKEY_set_type_by_keymgmt(to, to_keymgmt)) {
 504         evp_keymgmt_freedata(to_keymgmt, alloc_keydata);
 505         return 0;
 506     }
 507     to->keydata = to_keydata;
 508     evp_keymgmt_util_cache_keyinfo(to);
 509
 510     return 1;
 511 }
 512
 513 void *evp_keymgmt_util_gen(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
 514                            void *genctx, OSSL_CALLBACK *cb, void *cbarg)
 515 {
 516     void *keydata = NULL;
 517
 518     if ((keydata = evp_keymgmt_gen(keymgmt, genctx, cb, cbarg)) == NULL
 519         || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
 520         evp_keymgmt_freedata(keymgmt, keydata);
 521         keydata = NULL;
 522     }
 523
 524     return keydata;
 525 }
 526
 527 /*
 528  * Returns the same numbers as EVP_PKEY_get_default_digest_name()
 529  * When the string from the EVP_KEYMGMT implementation is "", we use
 530  * SN_undef, since that corresponds to what EVP_PKEY_get_default_nid()
 531  * returns for no digest.
 532  */
 533 int evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT *keymgmt,
 534                                            void *keydata,
 535                                            char *mdname, size_t mdname_sz)
 536 {
 537     OSSL_PARAM params[3];
 538     char mddefault[100] = "";
 539     char mdmandatory[100] = "";
 540     char *result = NULL;
 541     int rv = -2;
 542
 543     params[0] =
 544         OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST,
 545                                          mddefault, sizeof(mddefault));
 546     params[1] =
 547         OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_MANDATORY_DIGEST,
 548                                          mdmandatory,
 549                                          sizeof(mdmandatory));
 550     params[2] = OSSL_PARAM_construct_end();
 551
 552     if (!evp_keymgmt_get_params(keymgmt, keydata, params))
 553         return 0;
 554
 555     if (OSSL_PARAM_modified(params + 1)) {
 556         if (params[1].return_size <= 1) /* Only a NUL byte */
 557             result = SN_undef;
 558         else
 559             result = mdmandatory;
 560         rv = 2;
 561     } else if (OSSL_PARAM_modified(params)) {
 562         if (params[0].return_size <= 1) /* Only a NUL byte */
 563             result = SN_undef;
 564         else
 565             result = mddefault;
 566         rv = 1;
 567     }
 568     if (rv > 0)
 569         OPENSSL_strlcpy(mdname, result, mdname_sz);
 570     return rv;
 571 }
 572
 573 /*
 574  * If |keymgmt| has the method function |query_operation_name|, use it to get
 575  * the name of a supported operation identity.  Otherwise, return the keytype,
 576  * assuming that it works as a default operation name.
 577  */
 578 const char *evp_keymgmt_util_query_operation_name(EVP_KEYMGMT *keymgmt,
 579                                                   int op_id)
 580 {
 581     const char *name = NULL;
 582
 583     if (keymgmt != NULL) {
 584         if (keymgmt->query_operation_name != NULL)
 585             name = keymgmt->query_operation_name(op_id);
 586         if (name == NULL)
 587             name = EVP_KEYMGMT_get0_name(keymgmt);
 588     }
 589     return name;
 590 }