crypto/evp/exchange.c

   1 /*
   2  * Copyright 2019 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/refcount.h"
  14 #include "crypto/evp.h"
  15 #include "internal/provider.h"
  16 #include "internal/numbers.h"   /* includes SIZE_MAX */
  17 #include "evp_local.h"
  18
  19 static EVP_KEYEXCH *evp_keyexch_new(OSSL_PROVIDER *prov)
  20 {
  21     EVP_KEYEXCH *exchange = OPENSSL_zalloc(sizeof(EVP_KEYEXCH));
  22
  23     if (exchange == NULL) {
  24         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
  25         return NULL;
  26     }
  27
  28     exchange->lock = CRYPTO_THREAD_lock_new();
  29     if (exchange->lock == NULL) {
  30         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
  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_dispatch(int name_id,
  42                                        const OSSL_DISPATCH *fns,
  43                                        OSSL_PROVIDER *prov)
  44 {
  45     EVP_KEYEXCH *exchange = NULL;
  46     int fncnt = 0, paramfncnt = 0;
  47
  48     if ((exchange = evp_keyexch_new(prov)) == NULL) {
  49         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
  50         goto err;
  51     }
  52
  53     exchange->name_id = name_id;
  54
  55     for (; fns->function_id != 0; fns++) {
  56         switch (fns->function_id) {
  57         case OSSL_FUNC_KEYEXCH_NEWCTX:
  58             if (exchange->newctx != NULL)
  59                 break;
  60             exchange->newctx = OSSL_get_OP_keyexch_newctx(fns);
  61             fncnt++;
  62             break;
  63         case OSSL_FUNC_KEYEXCH_INIT:
  64             if (exchange->init != NULL)
  65                 break;
  66             exchange->init = OSSL_get_OP_keyexch_init(fns);
  67             fncnt++;
  68             break;
  69         case OSSL_FUNC_KEYEXCH_SET_PEER:
  70             if (exchange->set_peer != NULL)
  71                 break;
  72             exchange->set_peer = OSSL_get_OP_keyexch_set_peer(fns);
  73             break;
  74         case OSSL_FUNC_KEYEXCH_DERIVE:
  75             if (exchange->derive != NULL)
  76                 break;
  77             exchange->derive = OSSL_get_OP_keyexch_derive(fns);
  78             fncnt++;
  79             break;
  80         case OSSL_FUNC_KEYEXCH_FREECTX:
  81             if (exchange->freectx != NULL)
  82                 break;
  83             exchange->freectx = OSSL_get_OP_keyexch_freectx(fns);
  84             fncnt++;
  85             break;
  86         case OSSL_FUNC_KEYEXCH_DUPCTX:
  87             if (exchange->dupctx != NULL)
  88                 break;
  89             exchange->dupctx = OSSL_get_OP_keyexch_dupctx(fns);
  90             break;
  91         case OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS:
  92             if (exchange->set_ctx_params != NULL)
  93                 break;
  94             exchange->set_ctx_params = OSSL_get_OP_keyexch_set_ctx_params(fns);
  95             paramfncnt++;
  96             break;
  97         case OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS:
  98             if (exchange->settable_ctx_params != NULL)
  99                 break;
 100             exchange->settable_ctx_params
 101                 = OSSL_get_OP_keyexch_settable_ctx_params(fns);
 102             paramfncnt++;
 103             break;
 104         }
 105     }
 106     if (fncnt != 4 || (paramfncnt != 0 && paramfncnt != 2)) {
 107         /*
 108          * In order to be a consistent set of functions we must have at least
 109          * a complete set of "exchange" functions: init, derive, newctx,
 110          * and freectx. The set_ctx_params and settable_ctx_params functions are
 111          * optional, but if one of them is present then the other one must also
 112          * be present. The dupctx and set_peer functions are optional.
 113          */
 114         EVPerr(EVP_F_EVP_KEYEXCH_FROM_DISPATCH,
 115                EVP_R_INVALID_PROVIDER_FUNCTIONS);
 116         goto err;
 117     }
 118
 119     return exchange;
 120
 121  err:
 122     EVP_KEYEXCH_free(exchange);
 123     return NULL;
 124 }
 125
 126 void EVP_KEYEXCH_free(EVP_KEYEXCH *exchange)
 127 {
 128     if (exchange != NULL) {
 129         int i;
 130
 131         CRYPTO_DOWN_REF(&exchange->refcnt, &i, exchange->lock);
 132         if (i > 0)
 133             return;
 134         ossl_provider_free(exchange->prov);
 135         CRYPTO_THREAD_lock_free(exchange->lock);
 136         OPENSSL_free(exchange);
 137     }
 138 }
 139
 140 int EVP_KEYEXCH_up_ref(EVP_KEYEXCH *exchange)
 141 {
 142     int ref = 0;
 143
 144     CRYPTO_UP_REF(&exchange->refcnt, &ref, exchange->lock);
 145     return 1;
 146 }
 147
 148 OSSL_PROVIDER *EVP_KEYEXCH_provider(const EVP_KEYEXCH *exchange)
 149 {
 150     return exchange->prov;
 151 }
 152
 153 EVP_KEYEXCH *EVP_KEYEXCH_fetch(OPENSSL_CTX *ctx, const char *algorithm,
 154                                const char *properties)
 155 {
 156     return evp_generic_fetch(ctx, OSSL_OP_KEYEXCH, algorithm, properties,
 157                              evp_keyexch_from_dispatch,
 158                              (int (*)(void *))EVP_KEYEXCH_up_ref,
 159                              (void (*)(void *))EVP_KEYEXCH_free);
 160 }
 161
 162 int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx)
 163 {
 164     int ret;
 165     void *provkey = NULL;
 166     EVP_KEYEXCH *exchange = NULL;
 167     EVP_KEYMGMT *tmp_keymgmt = NULL;
 168     const char *supported_exch = NULL;
 169
 170     if (ctx == NULL) {
 171         EVPerr(0, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 172         return -2;
 173     }
 174
 175     evp_pkey_ctx_free_old_ops(ctx);
 176     ctx->operation = EVP_PKEY_OP_DERIVE;
 177
 178     /*
 179      * TODO when we stop falling back to legacy, this and the ERR_pop_to_mark()
 180      * calls can be removed.
 181      */
 182     ERR_set_mark();
 183
 184     if (ctx->engine != NULL || ctx->keytype == NULL)
 185         goto legacy;
 186
 187     /* Ensure that the key is provided.  If not, go legacy */
 188     tmp_keymgmt = ctx->keymgmt;
 189     provkey = evp_pkey_make_provided(ctx->pkey, ctx->libctx,
 190                                      &tmp_keymgmt, ctx->propquery, 0);
 191     if (provkey == NULL)
 192         goto legacy;
 193     if (!EVP_KEYMGMT_up_ref(tmp_keymgmt)) {
 194         ERR_clear_last_mark();
 195         ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
 196         goto err;
 197     }
 198     EVP_KEYMGMT_free(ctx->keymgmt);
 199     ctx->keymgmt = tmp_keymgmt;
 200
 201     if (ctx->keymgmt->query_operation_name != NULL)
 202         supported_exch = ctx->keymgmt->query_operation_name(OSSL_OP_KEYEXCH);
 203
 204     /*
 205      * If we didn't get a supported exch, assume there is one with the
 206      * same name as the key type.
 207      */
 208     if (supported_exch == NULL)
 209         supported_exch = ctx->keytype;
 210
 211     /*
 212      * Because we cleared out old ops, we shouldn't need to worry about
 213      * checking if exchange is already there.
 214      */
 215     exchange = EVP_KEYEXCH_fetch(ctx->libctx, supported_exch, ctx->propquery);
 216
 217     if (exchange == NULL
 218         || (EVP_KEYMGMT_provider(ctx->keymgmt)
 219             != EVP_KEYEXCH_provider(exchange))) {
 220         /*
 221          * We don't need to free ctx->keymgmt here, as it's not necessarily
 222          * tied to this operation.  It will be freed by EVP_PKEY_CTX_free().
 223          */
 224         EVP_KEYEXCH_free(exchange);
 225         goto legacy;
 226     }
 227
 228     /*
 229      * TODO remove this when legacy is gone
 230      * If we don't have the full support we need with provided methods,
 231      * let's go see if legacy does.
 232      */
 233     ERR_pop_to_mark();
 234
 235     /* No more legacy from here down to legacy: */
 236
 237     ctx->op.kex.exchange = exchange;
 238     ctx->op.kex.exchprovctx = exchange->newctx(ossl_provider_ctx(exchange->prov));
 239     if (ctx->op.kex.exchprovctx == NULL) {
 240         /* The provider key can stay in the cache */
 241         EVPerr(0, EVP_R_INITIALIZATION_ERROR);
 242         goto err;
 243     }
 244     ret = exchange->init(ctx->op.kex.exchprovctx, provkey);
 245
 246     return ret ? 1 : 0;
 247  err:
 248     ctx->operation = EVP_PKEY_OP_UNDEFINED;
 249     return 0;
 250
 251  legacy:
 252     /*
 253      * TODO remove this when legacy is gone
 254      * If we don't have the full support we need with provided methods,
 255      * let's go see if legacy does.
 256      */
 257     ERR_pop_to_mark();
 258
 259 #ifdef FIPS_MODE
 260     return 0;
 261 #else
 262     if (ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
 263         EVPerr(0, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 264         return -2;
 265     }
 266
 267     if (ctx->pmeth->derive_init == NULL)
 268         return 1;
 269     ret = ctx->pmeth->derive_init(ctx);
 270     if (ret <= 0)
 271         ctx->operation = EVP_PKEY_OP_UNDEFINED;
 272     return ret;
 273 #endif
 274 }
 275
 276 int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer)
 277 {
 278     int ret = 0;
 279     void *provkey = NULL;
 280
 281     if (ctx == NULL) {
 282         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
 283                EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 284         return -2;
 285     }
 286
 287     if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx) || ctx->op.kex.exchprovctx == NULL)
 288         goto legacy;
 289
 290     if (ctx->op.kex.exchange->set_peer == NULL) {
 291         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
 292                EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 293         return -2;
 294     }
 295
 296     provkey = evp_keymgmt_util_export_to_provider(peer, ctx->keymgmt, 0);
 297     /* If export failed, legacy may be able to pick it up */
 298     if (provkey == NULL)
 299         goto legacy;
 300     return ctx->op.kex.exchange->set_peer(ctx->op.kex.exchprovctx, provkey);
 301
 302  legacy:
 303 #ifdef FIPS_MODE
 304     return ret;
 305 #else
 306     if (ctx->pmeth == NULL
 307         || !(ctx->pmeth->derive != NULL
 308              || ctx->pmeth->encrypt != NULL
 309              || ctx->pmeth->decrypt != NULL)
 310         || ctx->pmeth->ctrl == NULL) {
 311         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
 312                EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 313         return -2;
 314     }
 315     if (ctx->operation != EVP_PKEY_OP_DERIVE
 316         && ctx->operation != EVP_PKEY_OP_ENCRYPT
 317         && ctx->operation != EVP_PKEY_OP_DECRYPT) {
 318         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER,
 319                EVP_R_OPERATON_NOT_INITIALIZED);
 320         return -1;
 321     }
 322
 323     ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 0, peer);
 324
 325     if (ret <= 0)
 326         return ret;
 327
 328     if (ret == 2)
 329         return 1;
 330
 331     if (ctx->pkey == NULL) {
 332         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_NO_KEY_SET);
 333         return -1;
 334     }
 335
 336     if (ctx->pkey->type != peer->type) {
 337         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_DIFFERENT_KEY_TYPES);
 338         return -1;
 339     }
 340
 341     /*
 342      * For clarity.  The error is if parameters in peer are
 343      * present (!missing) but don't match.  EVP_PKEY_cmp_parameters may return
 344      * 1 (match), 0 (don't match) and -2 (comparison is not defined).  -1
 345      * (different key types) is impossible here because it is checked earlier.
 346      * -2 is OK for us here, as well as 1, so we can check for 0 only.
 347      */
 348     if (!EVP_PKEY_missing_parameters(peer) &&
 349         !EVP_PKEY_cmp_parameters(ctx->pkey, peer)) {
 350         EVPerr(EVP_F_EVP_PKEY_DERIVE_SET_PEER, EVP_R_DIFFERENT_PARAMETERS);
 351         return -1;
 352     }
 353
 354     EVP_PKEY_free(ctx->peerkey);
 355     ctx->peerkey = peer;
 356
 357     ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 1, peer);
 358
 359     if (ret <= 0) {
 360         ctx->peerkey = NULL;
 361         return ret;
 362     }
 363
 364     EVP_PKEY_up_ref(peer);
 365     return 1;
 366 #endif
 367 }
 368
 369 int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *pkeylen)
 370 {
 371     int ret;
 372
 373     if (ctx == NULL) {
 374         EVPerr(EVP_F_EVP_PKEY_DERIVE,
 375                EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 376         return -2;
 377     }
 378
 379     if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
 380         EVPerr(EVP_F_EVP_PKEY_DERIVE, EVP_R_OPERATON_NOT_INITIALIZED);
 381         return -1;
 382     }
 383
 384     if (ctx->op.kex.exchprovctx == NULL)
 385         goto legacy;
 386
 387     ret = ctx->op.kex.exchange->derive(ctx->op.kex.exchprovctx, key, pkeylen,
 388                                        SIZE_MAX);
 389
 390     return ret;
 391  legacy:
 392     if (ctx ==  NULL || ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
 393         EVPerr(EVP_F_EVP_PKEY_DERIVE,
 394                EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 395         return -2;
 396     }
 397
 398     M_check_autoarg(ctx, key, pkeylen, EVP_F_EVP_PKEY_DERIVE)
 399         return ctx->pmeth->derive(ctx, key, pkeylen);
 400 }
 401
 402 int EVP_KEYEXCH_number(const EVP_KEYEXCH *keyexch)
 403 {
 404     return keyexch->name_id;
 405 }
 406
 407 int EVP_KEYEXCH_is_a(const EVP_KEYEXCH *keyexch, const char *name)
 408 {
 409     return evp_is_a(keyexch->prov, keyexch->name_id, NULL, name);
 410 }
 411
 412 void EVP_KEYEXCH_do_all_provided(OPENSSL_CTX *libctx,
 413                                  void (*fn)(EVP_KEYEXCH *keyexch, void *arg),
 414                                  void *arg)
 415 {
 416     evp_generic_do_all(libctx, OSSL_OP_KEYEXCH,
 417                        (void (*)(void *, void *))fn, arg,
 418                        evp_keyexch_from_dispatch,
 419                        (void (*)(void *))EVP_KEYEXCH_free);
 420 }
 421
 422 void EVP_KEYEXCH_names_do_all(const EVP_KEYEXCH *keyexch,
 423                               void (*fn)(const char *name, void *data),
 424                               void *data)
 425 {
 426     if (keyexch->prov != NULL)
 427         evp_names_do_all(keyexch->prov, keyexch->name_id, fn, data);
 428 }