providers/implementations/rands/drbg_hmac.c

   1 /*
   2  * Copyright 2011-2023 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 <stdlib.h>
  11 #include <string.h>
  12 #include <openssl/crypto.h>
  13 #include <openssl/err.h>
  14 #include <openssl/rand.h>
  15 #include <openssl/proverr.h>
  16 #include "internal/thread_once.h"
  17 #include "prov/providercommon.h"
  18 #include "prov/implementations.h"
  19 #include "prov/provider_ctx.h"
  20 #include "prov/hmac_drbg.h"
  21 #include "drbg_local.h"
  22
  23 static OSSL_FUNC_rand_newctx_fn drbg_hmac_new_wrapper;
  24 static OSSL_FUNC_rand_freectx_fn drbg_hmac_free;
  25 static OSSL_FUNC_rand_instantiate_fn drbg_hmac_instantiate_wrapper;
  26 static OSSL_FUNC_rand_uninstantiate_fn drbg_hmac_uninstantiate_wrapper;
  27 static OSSL_FUNC_rand_generate_fn drbg_hmac_generate_wrapper;
  28 static OSSL_FUNC_rand_reseed_fn drbg_hmac_reseed_wrapper;
  29 static OSSL_FUNC_rand_settable_ctx_params_fn drbg_hmac_settable_ctx_params;
  30 static OSSL_FUNC_rand_set_ctx_params_fn drbg_hmac_set_ctx_params;
  31 static OSSL_FUNC_rand_gettable_ctx_params_fn drbg_hmac_gettable_ctx_params;
  32 static OSSL_FUNC_rand_get_ctx_params_fn drbg_hmac_get_ctx_params;
  33 static OSSL_FUNC_rand_verify_zeroization_fn drbg_hmac_verify_zeroization;
  34
  35 static int drbg_hmac_set_ctx_params_locked(void *vctx, const OSSL_PARAM params[]);
  36
  37 /*
  38  * Called twice by SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process.
  39  *
  40  * hmac is an object that holds the input/output Key and Value (K and V).
  41  * inbyte is 0x00 on the first call and 0x01 on the second call.
  42  * in1, in2, in3 are optional inputs that can be NULL.
  43  * in1len, in2len, in3len are the lengths of the input buffers.
  44  *
  45  * The returned K,V is:
  46  *   hmac->K = HMAC(hmac->K, hmac->V || inbyte || [in1] || [in2] || [in3])
  47  *   hmac->V = HMAC(hmac->K, hmac->V)
  48  *
  49  * Returns zero if an error occurs otherwise it returns 1.
  50  */
  51 static int do_hmac(PROV_DRBG_HMAC *hmac, unsigned char inbyte,
  52                    const unsigned char *in1, size_t in1len,
  53                    const unsigned char *in2, size_t in2len,
  54                    const unsigned char *in3, size_t in3len)
  55 {
  56     EVP_MAC_CTX *ctx = hmac->ctx;
  57
  58     if (!EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
  59             /* K = HMAC(K, V || inbyte || [in1] || [in2] || [in3]) */
  60             || !EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  61             || !EVP_MAC_update(ctx, &inbyte, 1)
  62             || !(in1 == NULL || in1len == 0 || EVP_MAC_update(ctx, in1, in1len))
  63             || !(in2 == NULL || in2len == 0 || EVP_MAC_update(ctx, in2, in2len))
  64             || !(in3 == NULL || in3len == 0 || EVP_MAC_update(ctx, in3, in3len))
  65             || !EVP_MAC_final(ctx, hmac->K, NULL, sizeof(hmac->K)))
  66         return 0;
  67
  68    /* V = HMAC(K, V) */
  69     return EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
  70            && EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  71            && EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V));
  72 }
  73
  74 /*
  75  * SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process
  76  *
  77  *
  78  * Updates the drbg objects Key(K) and Value(V) using the following algorithm:
  79  *   K,V = do_hmac(hmac, 0, in1, in2, in3)
  80  *   if (any input is not NULL)
  81  *     K,V = do_hmac(hmac, 1, in1, in2, in3)
  82  *
  83  * where in1, in2, in3 are optional input buffers that can be NULL.
  84  *       in1len, in2len, in3len are the lengths of the input buffers.
  85  *
  86  * Returns zero if an error occurs otherwise it returns 1.
  87  */
  88 static int drbg_hmac_update(PROV_DRBG_HMAC *hmac,
  89                             const unsigned char *in1, size_t in1len,
  90                             const unsigned char *in2, size_t in2len,
  91                             const unsigned char *in3, size_t in3len)
  92 {
  93     /* (Steps 1-2) K = HMAC(K, V||0x00||provided_data). V = HMAC(K,V) */
  94     if (!do_hmac(hmac, 0x00, in1, in1len, in2, in2len, in3, in3len))
  95         return 0;
  96     /* (Step 3) If provided_data == NULL then return (K,V) */
  97     if (in1len == 0 && in2len == 0 && in3len == 0)
  98         return 1;
  99     /* (Steps 4-5) K = HMAC(K, V||0x01||provided_data). V = HMAC(K,V) */
 100     return do_hmac(hmac, 0x01, in1, in1len, in2, in2len, in3, in3len);
 101 }
 102
 103 /*
 104  * SP800-90Ar1 10.1.2.3 HMAC_DRBG_Instantiate_Process:
 105  *
 106  * This sets the drbg Key (K) to all zeros, and Value (V) to all 1's.
 107  * and then calls (K,V) = drbg_hmac_update() with input parameters:
 108  *   ent = entropy data (Can be NULL) of length ent_len.
 109  *   nonce = nonce data (Can be NULL) of length nonce_len.
 110  *   pstr = personalization data (Can be NULL) of length pstr_len.
 111  *
 112  * Returns zero if an error occurs otherwise it returns 1.
 113  */
 114 int ossl_drbg_hmac_init(PROV_DRBG_HMAC *hmac,
 115                         const unsigned char *ent, size_t ent_len,
 116                         const unsigned char *nonce, size_t nonce_len,
 117                         const unsigned char *pstr, size_t pstr_len)
 118 {
 119     if (hmac->ctx == NULL) {
 120         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
 121         return 0;
 122     }
 123
 124     /* (Step 2) Key = 0x00 00...00 */
 125     memset(hmac->K, 0x00, hmac->blocklen);
 126     /* (Step 3) V = 0x01 01...01 */
 127     memset(hmac->V, 0x01, hmac->blocklen);
 128     /* (Step 4) (K,V) = HMAC_DRBG_Update(entropy||nonce||pers string, K, V) */
 129     return drbg_hmac_update(hmac, ent, ent_len, nonce, nonce_len, pstr,
 130                             pstr_len);
 131 }
 132 static int drbg_hmac_instantiate(PROV_DRBG *drbg,
 133                                  const unsigned char *ent, size_t ent_len,
 134                                  const unsigned char *nonce, size_t nonce_len,
 135                                  const unsigned char *pstr, size_t pstr_len)
 136 {
 137     return ossl_drbg_hmac_init((PROV_DRBG_HMAC *)drbg->data, ent, ent_len,
 138                                nonce, nonce_len, pstr, pstr_len);
 139 }
 140
 141 static int drbg_hmac_instantiate_wrapper(void *vdrbg, unsigned int strength,
 142                                          int prediction_resistance,
 143                                          const unsigned char *pstr,
 144                                          size_t pstr_len,
 145                                          const OSSL_PARAM params[])
 146 {
 147     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 148     int ret = 0;
 149
 150     if (drbg->lock != NULL && !CRYPTO_THREAD_write_lock(drbg->lock))
 151         return 0;
 152
 153     if (!ossl_prov_is_running()
 154             || !drbg_hmac_set_ctx_params_locked(drbg, params))
 155         goto err;
 156     ret = ossl_prov_drbg_instantiate(drbg, strength, prediction_resistance,
 157                                      pstr, pstr_len);
 158  err:
 159     if (drbg->lock != NULL)
 160         CRYPTO_THREAD_unlock(drbg->lock);
 161     return ret;
 162 }
 163
 164
 165 /*
 166  * SP800-90Ar1 10.1.2.4 HMAC_DRBG_Reseed_Process:
 167  *
 168  * Reseeds the drbg's Key (K) and Value (V) by calling
 169  * (K,V) = drbg_hmac_update() with the following input parameters:
 170  *   ent = entropy input data (Can be NULL) of length ent_len.
 171  *   adin = additional input data (Can be NULL) of length adin_len.
 172  *
 173  * Returns zero if an error occurs otherwise it returns 1.
 174  */
 175 static int drbg_hmac_reseed(PROV_DRBG *drbg,
 176                             const unsigned char *ent, size_t ent_len,
 177                             const unsigned char *adin, size_t adin_len)
 178 {
 179     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 180
 181     /* (Step 2) (K,V) = HMAC_DRBG_Update(entropy||additional_input, K, V) */
 182     return drbg_hmac_update(hmac, ent, ent_len, adin, adin_len, NULL, 0);
 183 }
 184
 185 static int drbg_hmac_reseed_wrapper(void *vdrbg, int prediction_resistance,
 186                                     const unsigned char *ent, size_t ent_len,
 187                                     const unsigned char *adin, size_t adin_len)
 188 {
 189     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 190
 191     return ossl_prov_drbg_reseed(drbg, prediction_resistance, ent, ent_len,
 192                                  adin, adin_len);
 193 }
 194
 195 /*
 196  * SP800-90Ar1 10.1.2.5 HMAC_DRBG_Generate_Process:
 197  *
 198  * Generates pseudo random bytes and updates the internal K,V for the drbg.
 199  * out is a buffer to fill with outlen bytes of pseudo random data.
 200  * adin is an additional_input string of size adin_len that may be NULL.
 201  *
 202  * Returns zero if an error occurs otherwise it returns 1.
 203  */
 204 int ossl_drbg_hmac_generate(PROV_DRBG_HMAC *hmac,
 205                             unsigned char *out, size_t outlen,
 206                             const unsigned char *adin, size_t adin_len)
 207 {
 208     EVP_MAC_CTX *ctx = hmac->ctx;
 209     const unsigned char *temp = hmac->V;
 210
 211     /* (Step 2) if adin != NULL then (K,V) = HMAC_DRBG_Update(adin, K, V) */
 212     if (adin != NULL
 213             && adin_len > 0
 214             && !drbg_hmac_update(hmac, adin, adin_len, NULL, 0, NULL, 0))
 215         return 0;
 216
 217     /*
 218      * (Steps 3-5) temp = NULL
 219      *             while (len(temp) < outlen) {
 220      *                 V = HMAC(K, V)
 221      *                 temp = temp || V
 222      *             }
 223      */
 224     for (;;) {
 225         if (!EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
 226             || !EVP_MAC_update(ctx, temp, hmac->blocklen))
 227             return 0;
 228
 229         if (outlen > hmac->blocklen) {
 230             if (!EVP_MAC_final(ctx, out, NULL, outlen))
 231                 return 0;
 232             temp = out;
 233         } else {
 234             if (!EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V)))
 235                 return 0;
 236             memcpy(out, hmac->V, outlen);
 237             break;
 238         }
 239         out += hmac->blocklen;
 240         outlen -= hmac->blocklen;
 241     }
 242     /* (Step 6) (K,V) = HMAC_DRBG_Update(adin, K, V) */
 243     if (!drbg_hmac_update(hmac, adin, adin_len, NULL, 0, NULL, 0))
 244         return 0;
 245
 246     return 1;
 247 }
 248
 249 static int drbg_hmac_generate(PROV_DRBG *drbg,
 250                               unsigned char *out, size_t outlen,
 251                               const unsigned char *adin, size_t adin_len)
 252 {
 253     return ossl_drbg_hmac_generate((PROV_DRBG_HMAC *)drbg->data, out, outlen,
 254                                     adin, adin_len);
 255 }
 256
 257 static int drbg_hmac_generate_wrapper(void *vdrbg,
 258      unsigned char *out, size_t outlen, unsigned int strength,
 259      int prediction_resistance, const unsigned char *adin, size_t adin_len)
 260 {
 261     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 262
 263     return ossl_prov_drbg_generate(drbg, out, outlen, strength,
 264                                    prediction_resistance, adin, adin_len);
 265 }
 266
 267 static int drbg_hmac_uninstantiate(PROV_DRBG *drbg)
 268 {
 269     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 270
 271     OPENSSL_cleanse(hmac->K, sizeof(hmac->K));
 272     OPENSSL_cleanse(hmac->V, sizeof(hmac->V));
 273     return ossl_prov_drbg_uninstantiate(drbg);
 274 }
 275
 276 static int drbg_hmac_uninstantiate_wrapper(void *vdrbg)
 277 {
 278     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 279     int ret;
 280
 281     if (drbg->lock != NULL && !CRYPTO_THREAD_write_lock(drbg->lock))
 282         return 0;
 283
 284     ret = drbg_hmac_uninstantiate(drbg);
 285
 286     if (drbg->lock != NULL)
 287         CRYPTO_THREAD_unlock(drbg->lock);
 288
 289     return ret;
 290 }
 291
 292 static int drbg_hmac_verify_zeroization(void *vdrbg)
 293 {
 294     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 295     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 296     int ret = 0;
 297
 298     if (drbg->lock != NULL && !CRYPTO_THREAD_read_lock(drbg->lock))
 299         return 0;
 300
 301     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->K);
 302     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->V);
 303
 304     ret = 1;
 305  err:
 306     if (drbg->lock != NULL)
 307         CRYPTO_THREAD_unlock(drbg->lock);
 308     return ret;
 309 }
 310
 311 static int drbg_hmac_new(PROV_DRBG *drbg)
 312 {
 313     PROV_DRBG_HMAC *hmac;
 314
 315     hmac = OPENSSL_secure_zalloc(sizeof(*hmac));
 316     if (hmac == NULL)
 317         return 0;
 318
 319     drbg->data = hmac;
 320     /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 321     drbg->max_entropylen = DRBG_MAX_LENGTH;
 322     drbg->max_noncelen = DRBG_MAX_LENGTH;
 323     drbg->max_perslen = DRBG_MAX_LENGTH;
 324     drbg->max_adinlen = DRBG_MAX_LENGTH;
 325
 326     /* Maximum number of bits per request = 2^19  = 2^16 bytes */
 327     drbg->max_request = 1 << 16;
 328     return 1;
 329 }
 330
 331 static void *drbg_hmac_new_wrapper(void *provctx, void *parent,
 332                                    const OSSL_DISPATCH *parent_dispatch)
 333 {
 334     return ossl_rand_drbg_new(provctx, parent, parent_dispatch, &drbg_hmac_new,
 335                               &drbg_hmac_instantiate, &drbg_hmac_uninstantiate,
 336                               &drbg_hmac_reseed, &drbg_hmac_generate);
 337 }
 338
 339 static void drbg_hmac_free(void *vdrbg)
 340 {
 341     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 342     PROV_DRBG_HMAC *hmac;
 343
 344     if (drbg != NULL && (hmac = (PROV_DRBG_HMAC *)drbg->data) != NULL) {
 345         EVP_MAC_CTX_free(hmac->ctx);
 346         ossl_prov_digest_reset(&hmac->digest);
 347         OPENSSL_secure_clear_free(hmac, sizeof(*hmac));
 348     }
 349     ossl_rand_drbg_free(drbg);
 350 }
 351
 352 static int drbg_hmac_get_ctx_params(void *vdrbg, OSSL_PARAM params[])
 353 {
 354     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 355     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 356     const char *name;
 357     const EVP_MD *md;
 358     OSSL_PARAM *p;
 359     int ret = 0, complete = 0;
 360
 361     if (!ossl_drbg_get_ctx_params_no_lock(drbg, params, &complete))
 362         return 0;
 363
 364     if (complete)
 365         return 1;
 366
 367     if (drbg->lock != NULL && !CRYPTO_THREAD_read_lock(drbg->lock))
 368         return 0;
 369
 370     p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAC);
 371     if (p != NULL) {
 372         if (hmac->ctx == NULL)
 373             goto err;
 374         name = EVP_MAC_get0_name(EVP_MAC_CTX_get0_mac(hmac->ctx));
 375         if (!OSSL_PARAM_set_utf8_string(p, name))
 376             goto err;
 377     }
 378
 379     p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_DIGEST);
 380     if (p != NULL) {
 381         md = ossl_prov_digest_md(&hmac->digest);
 382         if (md == NULL || !OSSL_PARAM_set_utf8_string(p, EVP_MD_get0_name(md)))
 383             goto err;
 384     }
 385
 386     ret = ossl_drbg_get_ctx_params(drbg, params);
 387  err:
 388     if (drbg->lock != NULL)
 389         CRYPTO_THREAD_unlock(drbg->lock);
 390
 391     return ret;
 392 }
 393
 394 static const OSSL_PARAM *drbg_hmac_gettable_ctx_params(ossl_unused void *vctx,
 395                                                        ossl_unused void *p_ctx)
 396 {
 397     static const OSSL_PARAM known_gettable_ctx_params[] = {
 398         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_MAC, NULL, 0),
 399         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
 400         OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON,
 401         OSSL_PARAM_END
 402     };
 403     return known_gettable_ctx_params;
 404 }
 405
 406 static int drbg_hmac_set_ctx_params_locked(void *vctx, const OSSL_PARAM params[])
 407 {
 408     PROV_DRBG *ctx = (PROV_DRBG *)vctx;
 409     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)ctx->data;
 410     OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
 411     const EVP_MD *md;
 412
 413     if (!ossl_prov_digest_load_from_params(&hmac->digest, params, libctx))
 414         return 0;
 415
 416     md = ossl_prov_digest_md(&hmac->digest);
 417     if (md != NULL && !ossl_drbg_verify_digest(libctx, md))
 418         return 0;   /* Error already raised for us */
 419
 420     if (!ossl_prov_macctx_load_from_params(&hmac->ctx, params,
 421                                            NULL, NULL, NULL, libctx))
 422         return 0;
 423
 424     if (md != NULL && hmac->ctx != NULL) {
 425         /* These are taken from SP 800-90 10.1 Table 2 */
 426         hmac->blocklen = EVP_MD_get_size(md);
 427         /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 428         ctx->strength = 64 * (int)(hmac->blocklen >> 3);
 429         if (ctx->strength > 256)
 430             ctx->strength = 256;
 431         ctx->seedlen = hmac->blocklen;
 432         ctx->min_entropylen = ctx->strength / 8;
 433         ctx->min_noncelen = ctx->min_entropylen / 2;
 434     }
 435
 436     return ossl_drbg_set_ctx_params(ctx, params);
 437 }
 438
 439 static int drbg_hmac_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 440 {
 441     PROV_DRBG *drbg = (PROV_DRBG *)vctx;
 442     int ret;
 443
 444     if (drbg->lock != NULL && !CRYPTO_THREAD_write_lock(drbg->lock))
 445         return 0;
 446
 447     ret = drbg_hmac_set_ctx_params_locked(vctx, params);
 448
 449     if (drbg->lock != NULL)
 450         CRYPTO_THREAD_unlock(drbg->lock);
 451
 452     return ret;
 453 }
 454
 455 static const OSSL_PARAM *drbg_hmac_settable_ctx_params(ossl_unused void *vctx,
 456                                                        ossl_unused void *p_ctx)
 457 {
 458     static const OSSL_PARAM known_settable_ctx_params[] = {
 459         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_PROPERTIES, NULL, 0),
 460         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
 461         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_MAC, NULL, 0),
 462         OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON,
 463         OSSL_PARAM_END
 464     };
 465     return known_settable_ctx_params;
 466 }
 467
 468 const OSSL_DISPATCH ossl_drbg_ossl_hmac_functions[] = {
 469     { OSSL_FUNC_RAND_NEWCTX, (void(*)(void))drbg_hmac_new_wrapper },
 470     { OSSL_FUNC_RAND_FREECTX, (void(*)(void))drbg_hmac_free },
 471     { OSSL_FUNC_RAND_INSTANTIATE,
 472       (void(*)(void))drbg_hmac_instantiate_wrapper },
 473     { OSSL_FUNC_RAND_UNINSTANTIATE,
 474       (void(*)(void))drbg_hmac_uninstantiate_wrapper },
 475     { OSSL_FUNC_RAND_GENERATE, (void(*)(void))drbg_hmac_generate_wrapper },
 476     { OSSL_FUNC_RAND_RESEED, (void(*)(void))drbg_hmac_reseed_wrapper },
 477     { OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))ossl_drbg_enable_locking },
 478     { OSSL_FUNC_RAND_LOCK, (void(*)(void))ossl_drbg_lock },
 479     { OSSL_FUNC_RAND_UNLOCK, (void(*)(void))ossl_drbg_unlock },
 480     { OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS,
 481       (void(*)(void))drbg_hmac_settable_ctx_params },
 482     { OSSL_FUNC_RAND_SET_CTX_PARAMS, (void(*)(void))drbg_hmac_set_ctx_params },
 483     { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
 484       (void(*)(void))drbg_hmac_gettable_ctx_params },
 485     { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))drbg_hmac_get_ctx_params },
 486     { OSSL_FUNC_RAND_VERIFY_ZEROIZATION,
 487       (void(*)(void))drbg_hmac_verify_zeroization },
 488     { OSSL_FUNC_RAND_GET_SEED, (void(*)(void))ossl_drbg_get_seed },
 489     { OSSL_FUNC_RAND_CLEAR_SEED, (void(*)(void))ossl_drbg_clear_seed },
 490     OSSL_DISPATCH_END
 491 };