crypto/evp/exchange.c

   1 /*
   2  * Copyright 2019-2022 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/crypto.h>
  11 #include <openssl/evp.h>
  12 #include <openssl/err.h>
  13 #include "internal/cryptlib.h"
  14 #include "internal/refcount.h"
  15 #include "internal/provider.h"
  16 #include "internal/core.h"
  17 #include "internal/numbers.h"   /* includes SIZE_MAX */
  18 #include "crypto/evp.h"
  19 #include "evp_local.h"
  20
  21 static EVP_KEYEXCH *evp_keyexch_new(OSSL_PROVIDER *prov)
  22 {
  23     EVP_KEYEXCH *exchange = OPENSSL_zalloc(sizeof(EVP_KEYEXCH));
  24
  25     if (exchange == NULL)
  26         return NULL;
  27
  28     exchange->lock = CRYPTO_THREAD_lock_new();
  29     if (exchange->lock == NULL) {
  30         ERR_raise(ERR_LIB_EVP, ERR_R_CRYPTO_LIB);
  31         OPENSSL_free(exchange);
  32         return NULL;
  33     }
  34     exchange->prov = prov;
  35     ossl_provider_up_ref(prov);
  36     exchange->refcnt = 1;
  37
  38     return exchange;
  39 }
  40
  41 static void *evp_keyexch_from_algorithm(int name_id,
  42                                         const OSSL_ALGORITHM *algodef,
  43                                         OSSL_PROVIDER *prov)
  44 {
  45     const OSSL_DISPATCH *fns = algodef->implementation;
  46     EVP_KEYEXCH *exchange = NULL;
  47     int fncnt = 0, sparamfncnt = 0, gparamfncnt = 0;
  48
  49     if ((exchange = evp_keyexch_new(prov)) == NULL) {
  50         ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
  51         goto err;
  52     }
  53
  54     exchange->name_id = name_id;
  55     if ((exchange->type_name = ossl_algorithm_get1_first_name(algodef)) == NULL)
  56         goto err;
  57     exchange->description = algodef->algorithm_description;
  58
  59     for (; fns->function_id != 0; fns++) {
  60         switch (fns->function_id) {
  61         case OSSL_FUNC_KEYEXCH_NEWCTX:
  62             if (exchange->newctx != NULL)
  63                 break;
  64             exchange->newctx = OSSL_FUNC_keyexch_newctx(fns);
  65             fncnt++;
  66             break;
  67         case OSSL_FUNC_KEYEXCH_INIT:
  68             if (exchange->init != NULL)
  69                 break;
  70             exchange->init = OSSL_FUNC_keyexch_init(fns);
  71             fncnt++;
  72             break;
  73         case OSSL_FUNC_KEYEXCH_SET_PEER:
  74             if (exchange->set_peer != NULL)
  75                 break;
  76             exchange->set_peer = OSSL_FUNC_keyexch_set_peer(fns);
  77             break;
  78         case OSSL_FUNC_KEYEXCH_DERIVE:
  79             if (exchange->derive != NULL)
  80                 break;
  81             exchange->derive = OSSL_FUNC_keyexch_derive(fns);
  82             fncnt++;
  83             break;
  84         case OSSL_FUNC_KEYEXCH_FREECTX:
  85             if (exchange->freectx != NULL)
  86                 break;
  87             exchange->freectx = OSSL_FUNC_keyexch_freectx(fns);
  88             fncnt++;
  89             break;
  90         case OSSL_FUNC_KEYEXCH_DUPCTX:
  91             if (exchange->dupctx != NULL)
  92                 break;
  93             exchange->dupctx = OSSL_FUNC_keyexch_dupctx(fns);
  94             break;
  95         case OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS:
  96             if (exchange->get_ctx_params != NULL)
  97                 break;
  98             exchange->get_ctx_params = OSSL_FUNC_keyexch_get_ctx_params(fns);
  99             gparamfncnt++;
 100             break;
 101         case OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS:
 102             if (exchange->gettable_ctx_params != NULL)
 103                 break;
 104             exchange->gettable_ctx_params
 105                 = OSSL_FUNC_keyexch_gettable_ctx_params(fns);
 106             gparamfncnt++;
 107             break;
 108         case OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS:
 109             if (exchange->set_ctx_params != NULL)
 110                 break;
 111             exchange->set_ctx_params = OSSL_FUNC_keyexch_set_ctx_params(fns);
 112             sparamfncnt++;
 113             break;
 114         case OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS:
 115             if (exchange->settable_ctx_params != NULL)
 116                 break;
 117             exchange->settable_ctx_params
 118                 = OSSL_FUNC_keyexch_settable_ctx_params(fns);
 119             sparamfncnt++;
 120             break;
 121         }
 122     }
 123     if (fncnt != 4
 124             || (gparamfncnt != 0 && gparamfncnt != 2)
 125             || (sparamfncnt != 0 && sparamfncnt != 2)) {
 126         /*
 127          * In order to be a consistent set of functions we must have at least
 128          * a complete set of "exchange" functions: init, derive, newctx,
 129          * and freectx. The set_ctx_params and settable_ctx_params functions are
 130          * optional, but if one of them is present then the other one must also
 131          * be present. Same goes for get_ctx_params and gettable_ctx_params.
 132          * The dupctx and set_peer functions are optional.
 133          */
 134         ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
 135         goto err;
 136     }
 137
 138     return exchange;
 139
 140  err:
 141     EVP_KEYEXCH_free(exchange);
 142     return NULL;
 143 }
 144
 145 void EVP_KEYEXCH_free(EVP_KEYEXCH *exchange)
 146 {
 147     int i;
 148
 149     if (exchange == NULL)
 150         return;
 151     CRYPTO_DOWN_REF(&exchange->refcnt, &i, exchange->lock);
 152     if (i > 0)
 153         return;
 154     OPENSSL_free(exchange->type_name);
 155     ossl_provider_free(exchange->prov);
 156     CRYPTO_THREAD_lock_free(exchange->lock);
 157     OPENSSL_free(exchange);
 158 }
 159
 160 int EVP_KEYEXCH_up_ref(EVP_KEYEXCH *exchange)
 161 {
 162     int ref = 0;
 163
 164     CRYPTO_UP_REF(&exchange->refcnt, &ref, exchange->lock);
 165     return 1;
 166 }
 167
 168 OSSL_PROVIDER *EVP_KEYEXCH_get0_provider(const EVP_KEYEXCH *exchange)
 169 {
 170     return exchange->prov;
 171 }
 172
 173 EVP_KEYEXCH *EVP_KEYEXCH_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
 174                                const char *properties)
 175 {
 176     return evp_generic_fetch(ctx, OSSL_OP_KEYEXCH, algorithm, properties,
 177                              evp_keyexch_from_algorithm,
 178                              (int (*)(void *))EVP_KEYEXCH_up_ref,
 179                              (void (*)(void *))EVP_KEYEXCH_free);
 180 }
 181
 182 EVP_KEYEXCH *evp_keyexch_fetch_from_prov(OSSL_PROVIDER *prov,
 183                                          const char *algorithm,
 184                                          const char *properties)
 185 {
 186     return evp_generic_fetch_from_prov(prov, OSSL_OP_KEYEXCH,
 187                                        algorithm, properties,
 188                                        evp_keyexch_from_algorithm,
 189                                        (int (*)(void *))EVP_KEYEXCH_up_ref,
 190                                        (void (*)(void *))EVP_KEYEXCH_free);
 191 }
 192
 193 int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx)
 194 {
 195     return EVP_PKEY_derive_init_ex(ctx, NULL);
 196 }
 197
 198 int EVP_PKEY_derive_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])
 199 {
 200     int ret;
 201     void *provkey = NULL;
 202     EVP_KEYEXCH *exchange = NULL;
 203     EVP_KEYMGMT *tmp_keymgmt = NULL;
 204     const OSSL_PROVIDER *tmp_prov = NULL;
 205     const char *supported_exch = NULL;
 206     int iter;
 207
 208     if (ctx == NULL) {
 209         ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
 210         return -2;
 211     }
 212
 213     evp_pkey_ctx_free_old_ops(ctx);
 214     ctx->operation = EVP_PKEY_OP_DERIVE;
 215
 216     ERR_set_mark();
 217
 218     if (evp_pkey_ctx_is_legacy(ctx))
 219         goto legacy;
 220
 221     /*
 222      * Some algorithms (e.g. legacy KDFs) don't have a pkey - so we create
 223      * a blank one.
 224      */
 225     if (ctx->pkey == NULL) {
 226         EVP_PKEY *pkey = EVP_PKEY_new();
 227
 228         if (pkey == NULL
 229             || !EVP_PKEY_set_type_by_keymgmt(pkey, ctx->keymgmt)
 230             || (pkey->keydata = evp_keymgmt_newdata(ctx->keymgmt)) == NULL) {
 231             ERR_clear_last_mark();
 232             EVP_PKEY_free(pkey);
 233             ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
 234             goto err;
 235         }
 236         ctx->pkey = pkey;
 237     }
 238
 239     /*
 240      * Try to derive the supported exch from |ctx->keymgmt|.
 241      */
 242     if (!ossl_assert(ctx->pkey->keymgmt == NULL
 243                      || ctx->pkey->keymgmt == ctx->keymgmt)) {
 244         ERR_clear_last_mark();
 245         ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
 246         goto err;
 247     }
 248     supported_exch = evp_keymgmt_util_query_operation_name(ctx->keymgmt,
 249                                                            OSSL_OP_KEYEXCH);
 250     if (supported_exch == NULL) {
 251         ERR_clear_last_mark();
 252         ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
 253         goto err;
 254     }
 255
 256
 257     /*
 258      * We perform two iterations:
 259      *
 260      * 1.  Do the normal exchange fetch, using the fetching data given by
 261      *     the EVP_PKEY_CTX.
 262      * 2.  Do the provider specific exchange fetch, from the same provider
 263      *     as |ctx->keymgmt|
 264      *
 265      * We then try to fetch the keymgmt from the same provider as the
 266      * exchange, and try to export |ctx->pkey| to that keymgmt (when
 267      * this keymgmt happens to be the same as |ctx->keymgmt|, the export
 268      * is a no-op, but we call it anyway to not complicate the code even
 269      * more).
 270      * If the export call succeeds (returns a non-NULL provider key pointer),
 271      * we're done and can perform the operation itself.  If not, we perform
 272      * the second iteration, or jump to legacy.
 273      */
 274     for (iter = 1, provkey = NULL; iter < 3 && provkey == NULL; iter++) {
 275         EVP_KEYMGMT *tmp_keymgmt_tofree = NULL;
 276
 277         /*
 278          * If we're on the second iteration, free the results from the first.
 279          * They are NULL on the first iteration, so no need to check what
 280          * iteration we're on.
 281          */
 282         EVP_KEYEXCH_free(exchange);
 283         EVP_KEYMGMT_free(tmp_keymgmt);
 284
 285         switch (iter) {
 286         case 1:
 287             exchange =
 288                 EVP_KEYEXCH_fetch(ctx->libctx, supported_exch, ctx->propquery);
 289             if (exchange != NULL)
 290                 tmp_prov = EVP_KEYEXCH_get0_provider(exchange);
 291             break;
 292         case 2:
 293             tmp_prov = EVP_KEYMGMT_get0_provider(ctx->keymgmt);
 294             exchange =
 295                 evp_keyexch_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,
 296                                               supported_exch, ctx->propquery);
 297             if (exchange == NULL)
 298                 goto legacy;
 299             break;
 300         }
 301         if (exchange == NULL)
 302             continue;
 303
 304         /*
 305          * Ensure that the key is provided, either natively, or as a cached
 306          * export.  We start by fetching the keymgmt with the same name as
 307          * |ctx->keymgmt|, but from the provider of the exchange method, using
 308          * the same property query as when fetching the exchange method.
 309          * With the keymgmt we found (if we did), we try to export |ctx->pkey|
 310          * to it (evp_pkey_export_to_provider() is smart enough to only actually
 311          * export it if |tmp_keymgmt| is different from |ctx->pkey|'s keymgmt)
 312          */
 313         tmp_keymgmt_tofree = tmp_keymgmt =
 314             evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,
 315                                         EVP_KEYMGMT_get0_name(ctx->keymgmt),
 316                                         ctx->propquery);
 317         if (tmp_keymgmt != NULL)
 318             provkey = evp_pkey_export_to_provider(ctx->pkey, ctx->libctx,
 319                                                   &tmp_keymgmt, ctx->propquery);
 320         if (tmp_keymgmt == NULL)
 321             EVP_KEYMGMT_free(tmp_keymgmt_tofree);
 322     }
 323
 324     if (provkey == NULL) {
 325         EVP_KEYEXCH_free(exchange);
 326         goto legacy;
 327     }
 328
 329     ERR_pop_to_mark();
 330
 331     /* No more legacy from here down to legacy: */
 332
 333     /* A Coverity false positive with up_ref/down_ref and free */
 334     /* coverity[use_after_free] */
 335     ctx->op.kex.exchange = exchange;
 336     /* A Coverity false positive with up_ref/down_ref and free */
 337     /* coverity[deref_arg] */
 338     ctx->op.kex.algctx = exchange->newctx(ossl_provider_ctx(exchange->prov));
 339     if (ctx->op.kex.algctx == NULL) {
 340         /* The provider key can stay in the cache */
 341         ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
 342         goto err;
 343     }
 344     ret = exchange->init(ctx->op.kex.algctx, provkey, params);
 345
 346     EVP_KEYMGMT_free(tmp_keymgmt);
 347     return ret ? 1 : 0;
 348  err:
 349     evp_pkey_ctx_free_old_ops(ctx);
 350     ctx->operation = EVP_PKEY_OP_UNDEFINED;
 351     EVP_KEYMGMT_free(tmp_keymgmt);
 352     return 0;
 353
 354  legacy:
 355     /*
 356      * If we don't have the full support we need with provided methods,
 357      * let's go see if legacy does.
 358      */
 359     ERR_pop_to_mark();
 360
 361 #ifdef FIPS_MODULE
 362     return 0;
 363 #else
 364     if (ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
 365         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 366         return -2;
 367     }
 368
 369     if (ctx->pmeth->derive_init == NULL)
 370         return 1;
 371     ret = ctx->pmeth->derive_init(ctx);
 372     if (ret <= 0)
 373         ctx->operation = EVP_PKEY_OP_UNDEFINED;
 374     EVP_KEYMGMT_free(tmp_keymgmt);
 375     return ret;
 376 #endif
 377 }
 378
 379 int EVP_PKEY_derive_set_peer_ex(EVP_PKEY_CTX *ctx, EVP_PKEY *peer,
 380                                 int validate_peer)
 381 {
 382     int ret = 0, check;
 383     void *provkey = NULL;
 384     EVP_PKEY_CTX *check_ctx = NULL;
 385     EVP_KEYMGMT *tmp_keymgmt = NULL, *tmp_keymgmt_tofree = NULL;
 386
 387     if (ctx == NULL) {
 388         ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
 389         return -1;
 390     }
 391
 392     if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx) || ctx->op.kex.algctx == NULL)
 393         goto legacy;
 394
 395     if (ctx->op.kex.exchange->set_peer == NULL) {
 396         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 397         return -2;
 398     }
 399
 400     if (validate_peer) {
 401         check_ctx = EVP_PKEY_CTX_new_from_pkey(ctx->libctx, peer, ctx->propquery);
 402         if (check_ctx == NULL)
 403             return -1;
 404         check = EVP_PKEY_public_check(check_ctx);
 405         EVP_PKEY_CTX_free(check_ctx);
 406         if (check <= 0)
 407             return -1;
 408     }
 409
 410     /*
 411      * Ensure that the |peer| is provided, either natively, or as a cached
 412      * export.  We start by fetching the keymgmt with the same name as
 413      * |ctx->keymgmt|, but from the provider of the exchange method, using
 414      * the same property query as when fetching the exchange method.
 415      * With the keymgmt we found (if we did), we try to export |peer|
 416      * to it (evp_pkey_export_to_provider() is smart enough to only actually
 417      * export it if |tmp_keymgmt| is different from |peer|'s keymgmt)
 418      */
 419     tmp_keymgmt_tofree = tmp_keymgmt =
 420         evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)
 421                                     EVP_KEYEXCH_get0_provider(ctx->op.kex.exchange),
 422                                     EVP_KEYMGMT_get0_name(ctx->keymgmt),
 423                                     ctx->propquery);
 424     if (tmp_keymgmt != NULL)
 425         /* A Coverity issue with up_ref/down_ref and free */
 426         /* coverity[pass_freed_arg] */
 427         provkey = evp_pkey_export_to_provider(peer, ctx->libctx,
 428                                               &tmp_keymgmt, ctx->propquery);
 429     EVP_KEYMGMT_free(tmp_keymgmt_tofree);
 430
 431     /*
 432      * If making the key provided wasn't possible, legacy may be able to pick
 433      * it up
 434      */
 435     if (provkey == NULL)
 436         goto legacy;
 437     return ctx->op.kex.exchange->set_peer(ctx->op.kex.algctx, provkey);
 438
 439  legacy:
 440 #ifdef FIPS_MODULE
 441     return ret;
 442 #else
 443     if (ctx->pmeth == NULL
 444         || !(ctx->pmeth->derive != NULL
 445              || ctx->pmeth->encrypt != NULL
 446              || ctx->pmeth->decrypt != NULL)
 447         || ctx->pmeth->ctrl == NULL) {
 448         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 449         return -2;
 450     }
 451     if (ctx->operation != EVP_PKEY_OP_DERIVE
 452         && ctx->operation != EVP_PKEY_OP_ENCRYPT
 453         && ctx->operation != EVP_PKEY_OP_DECRYPT) {
 454         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
 455         return -1;
 456     }
 457
 458     ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 0, peer);
 459
 460     if (ret <= 0)
 461         return ret;
 462
 463     if (ret == 2)
 464         return 1;
 465
 466     if (ctx->pkey == NULL) {
 467         ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);
 468         return -1;
 469     }
 470
 471     if (ctx->pkey->type != peer->type) {
 472         ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
 473         return -1;
 474     }
 475
 476     /*
 477      * For clarity.  The error is if parameters in peer are
 478      * present (!missing) but don't match.  EVP_PKEY_parameters_eq may return
 479      * 1 (match), 0 (don't match) and -2 (comparison is not defined).  -1
 480      * (different key types) is impossible here because it is checked earlier.
 481      * -2 is OK for us here, as well as 1, so we can check for 0 only.
 482      */
 483     if (!EVP_PKEY_missing_parameters(peer) &&
 484         !EVP_PKEY_parameters_eq(ctx->pkey, peer)) {
 485         ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_PARAMETERS);
 486         return -1;
 487     }
 488
 489     EVP_PKEY_free(ctx->peerkey);
 490     ctx->peerkey = peer;
 491
 492     ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 1, peer);
 493
 494     if (ret <= 0) {
 495         ctx->peerkey = NULL;
 496         return ret;
 497     }
 498
 499     EVP_PKEY_up_ref(peer);
 500     return 1;
 501 #endif
 502 }
 503
 504 int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer)
 505 {
 506     return EVP_PKEY_derive_set_peer_ex(ctx, peer, 1);
 507 }
 508
 509 int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *pkeylen)
 510 {
 511     int ret;
 512
 513     if (ctx == NULL || pkeylen == NULL) {
 514         ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
 515         return -1;
 516     }
 517
 518     if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
 519         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
 520         return -1;
 521     }
 522
 523     if (ctx->op.kex.algctx == NULL)
 524         goto legacy;
 525
 526     ret = ctx->op.kex.exchange->derive(ctx->op.kex.algctx, key, pkeylen,
 527                                        key != NULL ? *pkeylen : 0);
 528
 529     return ret;
 530  legacy:
 531     if (ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
 532         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 533         return -2;
 534     }
 535
 536     M_check_autoarg(ctx, key, pkeylen, EVP_F_EVP_PKEY_DERIVE)
 537         return ctx->pmeth->derive(ctx, key, pkeylen);
 538 }
 539
 540 int evp_keyexch_get_number(const EVP_KEYEXCH *keyexch)
 541 {
 542     return keyexch->name_id;
 543 }
 544
 545 const char *EVP_KEYEXCH_get0_name(const EVP_KEYEXCH *keyexch)
 546 {
 547     return keyexch->type_name;
 548 }
 549
 550 const char *EVP_KEYEXCH_get0_description(const EVP_KEYEXCH *keyexch)
 551 {
 552     return keyexch->description;
 553 }
 554
 555 int EVP_KEYEXCH_is_a(const EVP_KEYEXCH *keyexch, const char *name)
 556 {
 557     return keyexch != NULL
 558            && evp_is_a(keyexch->prov, keyexch->name_id, NULL, name);
 559 }
 560
 561 void EVP_KEYEXCH_do_all_provided(OSSL_LIB_CTX *libctx,
 562                                  void (*fn)(EVP_KEYEXCH *keyexch, void *arg),
 563                                  void *arg)
 564 {
 565     evp_generic_do_all(libctx, OSSL_OP_KEYEXCH,
 566                        (void (*)(void *, void *))fn, arg,
 567                        evp_keyexch_from_algorithm,
 568                        (int (*)(void *))EVP_KEYEXCH_up_ref,
 569                        (void (*)(void *))EVP_KEYEXCH_free);
 570 }
 571
 572 int EVP_KEYEXCH_names_do_all(const EVP_KEYEXCH *keyexch,
 573                              void (*fn)(const char *name, void *data),
 574                              void *data)
 575 {
 576     if (keyexch->prov != NULL)
 577         return evp_names_do_all(keyexch->prov, keyexch->name_id, fn, data);
 578
 579     return 1;
 580 }
 581
 582 const OSSL_PARAM *EVP_KEYEXCH_gettable_ctx_params(const EVP_KEYEXCH *keyexch)
 583 {
 584     void *provctx;
 585
 586     if (keyexch == NULL || keyexch->gettable_ctx_params == NULL)
 587         return NULL;
 588
 589     provctx = ossl_provider_ctx(EVP_KEYEXCH_get0_provider(keyexch));
 590     return keyexch->gettable_ctx_params(NULL, provctx);
 591 }
 592
 593 const OSSL_PARAM *EVP_KEYEXCH_settable_ctx_params(const EVP_KEYEXCH *keyexch)
 594 {
 595     void *provctx;
 596
 597     if (keyexch == NULL || keyexch->settable_ctx_params == NULL)
 598         return NULL;
 599     provctx = ossl_provider_ctx(EVP_KEYEXCH_get0_provider(keyexch));
 600     return keyexch->settable_ctx_params(NULL, provctx);
 601 }