providers/implementations/rands/drbg_hmac.c

   1 /*
   2  * Copyright 2011-2020 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 #include <stdlib.h>
  11 #include <string.h>
  12 #include <openssl/crypto.h>
  13 #include <openssl/err.h>
  14 #include <openssl/rand.h>
  15 #include "prov/provider_util.h"
  16 #include "internal/thread_once.h"
  17 #include "prov/providercommon.h"
  18 #include "prov/providercommonerr.h"
  19 #include "prov/implementations.h"
  20 #include "prov/provider_ctx.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 typedef struct rand_drbg_hmac_st {
  36     EVP_MAC_CTX *ctx;            /* H(x) = HMAC_hash OR H(x) = KMAC */
  37     PROV_DIGEST digest;          /* H(x) = hash(x) */
  38     size_t blocklen;
  39     unsigned char K[EVP_MAX_MD_SIZE];
  40     unsigned char V[EVP_MAX_MD_SIZE];
  41 } PROV_DRBG_HMAC;
  42
  43 /*
  44  * Called twice by SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process.
  45  *
  46  * hmac is an object that holds the input/output Key and Value (K and V).
  47  * inbyte is 0x00 on the first call and 0x01 on the second call.
  48  * in1, in2, in3 are optional inputs that can be NULL.
  49  * in1len, in2len, in3len are the lengths of the input buffers.
  50  *
  51  * The returned K,V is:
  52  *   hmac->K = HMAC(hmac->K, hmac->V || inbyte || [in1] || [in2] || [in3])
  53  *   hmac->V = HMAC(hmac->K, hmac->V)
  54  *
  55  * Returns zero if an error occurs otherwise it returns 1.
  56  */
  57 static int do_hmac(PROV_DRBG_HMAC *hmac, unsigned char inbyte,
  58                    const unsigned char *in1, size_t in1len,
  59                    const unsigned char *in2, size_t in2len,
  60                    const unsigned char *in3, size_t in3len)
  61 {
  62     EVP_MAC_CTX *ctx = hmac->ctx;
  63     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
  64
  65     *params = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, hmac->K,
  66                                                 hmac->blocklen);
  67     if (!EVP_MAC_CTX_set_params(ctx, params)
  68             || !EVP_MAC_init(ctx)
  69             /* K = HMAC(K, V || inbyte || [in1] || [in2] || [in3]) */
  70             || !EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  71             || !EVP_MAC_update(ctx, &inbyte, 1)
  72             || !(in1 == NULL || in1len == 0 || EVP_MAC_update(ctx, in1, in1len))
  73             || !(in2 == NULL || in2len == 0 || EVP_MAC_update(ctx, in2, in2len))
  74             || !(in3 == NULL || in3len == 0 || EVP_MAC_update(ctx, in3, in3len))
  75             || !EVP_MAC_final(ctx, hmac->K, NULL, sizeof(hmac->K)))
  76         return 0;
  77
  78    /* V = HMAC(K, V) */
  79     *params = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, hmac->K,
  80                                                 hmac->blocklen);
  81     return EVP_MAC_CTX_set_params(ctx, params)
  82            && EVP_MAC_init(ctx)
  83            && EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  84            && EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V));
  85 }
  86
  87 /*
  88  * SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process
  89  *
  90  *
  91  * Updates the drbg objects Key(K) and Value(V) using the following algorithm:
  92  *   K,V = do_hmac(hmac, 0, in1, in2, in3)
  93  *   if (any input is not NULL)
  94  *     K,V = do_hmac(hmac, 1, in1, in2, in3)
  95  *
  96  * where in1, in2, in3 are optional input buffers that can be NULL.
  97  *       in1len, in2len, in3len are the lengths of the input buffers.
  98  *
  99  * Returns zero if an error occurs otherwise it returns 1.
 100  */
 101 static int drbg_hmac_update(PROV_DRBG *drbg,
 102                             const unsigned char *in1, size_t in1len,
 103                             const unsigned char *in2, size_t in2len,
 104                             const unsigned char *in3, size_t in3len)
 105 {
 106     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 107
 108     /* (Steps 1-2) K = HMAC(K, V||0x00||provided_data). V = HMAC(K,V) */
 109     if (!do_hmac(hmac, 0x00, in1, in1len, in2, in2len, in3, in3len))
 110         return 0;
 111     /* (Step 3) If provided_data == NULL then return (K,V) */
 112     if (in1len == 0 && in2len == 0 && in3len == 0)
 113         return 1;
 114     /* (Steps 4-5) K = HMAC(K, V||0x01||provided_data). V = HMAC(K,V) */
 115     return do_hmac(hmac, 0x01, in1, in1len, in2, in2len, in3, in3len);
 116 }
 117
 118 /*
 119  * SP800-90Ar1 10.1.2.3 HMAC_DRBG_Instantiate_Process:
 120  *
 121  * This sets the drbg Key (K) to all zeros, and Value (V) to all 1's.
 122  * and then calls (K,V) = drbg_hmac_update() with input parameters:
 123  *   ent = entropy data (Can be NULL) of length ent_len.
 124  *   nonce = nonce data (Can be NULL) of length nonce_len.
 125  *   pstr = personalization data (Can be NULL) of length pstr_len.
 126  *
 127  * Returns zero if an error occurs otherwise it returns 1.
 128  */
 129 static int drbg_hmac_instantiate(PROV_DRBG *drbg,
 130                                  const unsigned char *ent, size_t ent_len,
 131                                  const unsigned char *nonce, size_t nonce_len,
 132                                  const unsigned char *pstr, size_t pstr_len)
 133 {
 134     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 135
 136     if (hmac->ctx == NULL) {
 137         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
 138         return 0;
 139     }
 140
 141     /* (Step 2) Key = 0x00 00...00 */
 142     memset(hmac->K, 0x00, hmac->blocklen);
 143     /* (Step 3) V = 0x01 01...01 */
 144     memset(hmac->V, 0x01, hmac->blocklen);
 145     /* (Step 4) (K,V) = HMAC_DRBG_Update(entropy||nonce||pers string, K, V) */
 146     return drbg_hmac_update(drbg, ent, ent_len, nonce, nonce_len, pstr,
 147                             pstr_len);
 148 }
 149
 150 static int drbg_hmac_instantiate_wrapper(void *vdrbg, unsigned int strength,
 151                                          int prediction_resistance,
 152                                          const unsigned char *pstr,
 153                                          size_t pstr_len)
 154 {
 155     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 156
 157     return PROV_DRBG_instantiate(drbg, strength, prediction_resistance,
 158                                  pstr, pstr_len);
 159 }
 160
 161 /*
 162  * SP800-90Ar1 10.1.2.4 HMAC_DRBG_Reseed_Process:
 163  *
 164  * Reseeds the drbg's Key (K) and Value (V) by calling
 165  * (K,V) = drbg_hmac_update() with the following input parameters:
 166  *   ent = entropy input data (Can be NULL) of length ent_len.
 167  *   adin = additional input data (Can be NULL) of length adin_len.
 168  *
 169  * Returns zero if an error occurs otherwise it returns 1.
 170  */
 171 static int drbg_hmac_reseed(PROV_DRBG *drbg,
 172                             const unsigned char *ent, size_t ent_len,
 173                             const unsigned char *adin, size_t adin_len)
 174 {
 175     /* (Step 2) (K,V) = HMAC_DRBG_Update(entropy||additional_input, K, V) */
 176     return drbg_hmac_update(drbg, ent, ent_len, adin, adin_len, NULL, 0);
 177 }
 178
 179 static int drbg_hmac_reseed_wrapper(void *vdrbg, int prediction_resistance,
 180                                     const unsigned char *ent, size_t ent_len,
 181                                     const unsigned char *adin, size_t adin_len)
 182 {
 183     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 184
 185     return PROV_DRBG_reseed(drbg, prediction_resistance, ent, ent_len,
 186                             adin, adin_len);
 187 }
 188
 189 /*
 190  * SP800-90Ar1 10.1.2.5 HMAC_DRBG_Generate_Process:
 191  *
 192  * Generates pseudo random bytes and updates the internal K,V for the drbg.
 193  * out is a buffer to fill with outlen bytes of pseudo random data.
 194  * adin is an additional_input string of size adin_len that may be NULL.
 195  *
 196  * Returns zero if an error occurs otherwise it returns 1.
 197  */
 198 static int drbg_hmac_generate(PROV_DRBG *drbg,
 199                               unsigned char *out, size_t outlen,
 200                               const unsigned char *adin, size_t adin_len)
 201 {
 202     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 203     EVP_MAC_CTX *ctx = hmac->ctx;
 204     const unsigned char *temp = hmac->V;
 205     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 206
 207     /* (Step 2) if adin != NULL then (K,V) = HMAC_DRBG_Update(adin, K, V) */
 208     if (adin != NULL
 209             && adin_len > 0
 210             && !drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
 211         return 0;
 212
 213     /*
 214      * (Steps 3-5) temp = NULL
 215      *             while (len(temp) < outlen) {
 216      *                 V = HMAC(K, V)
 217      *                 temp = temp || V
 218      *             }
 219      */
 220     for (;;) {
 221         *params = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
 222                                                     hmac->K, hmac->blocklen);
 223         if (!EVP_MAC_CTX_set_params(ctx, params)
 224             || !EVP_MAC_init(ctx)
 225             || !EVP_MAC_update(ctx, temp, hmac->blocklen))
 226             return 0;
 227
 228         if (outlen > hmac->blocklen) {
 229             if (!EVP_MAC_final(ctx, out, NULL, outlen))
 230                 return 0;
 231             temp = out;
 232         } else {
 233             if (!EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V)))
 234                 return 0;
 235             memcpy(out, hmac->V, outlen);
 236             break;
 237         }
 238         out += hmac->blocklen;
 239         outlen -= hmac->blocklen;
 240     }
 241     /* (Step 6) (K,V) = HMAC_DRBG_Update(adin, K, V) */
 242     if (!drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
 243         return 0;
 244
 245     return 1;
 246 }
 247
 248 static int drbg_hmac_generate_wrapper
 249     (void *vdrbg, unsigned char *out, size_t outlen, unsigned int strength,
 250      int prediction_resistance, const unsigned char *adin, size_t adin_len)
 251 {
 252     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 253
 254     return PROV_DRBG_generate(drbg, out, outlen, strength,
 255                               prediction_resistance, adin, adin_len);
 256 }
 257
 258 static int drbg_hmac_uninstantiate(PROV_DRBG *drbg)
 259 {
 260     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 261
 262     OPENSSL_cleanse(hmac->K, sizeof(hmac->K));
 263     OPENSSL_cleanse(hmac->V, sizeof(hmac->V));
 264     return PROV_DRBG_uninstantiate(drbg);
 265 }
 266
 267 static int drbg_hmac_uninstantiate_wrapper(void *vdrbg)
 268 {
 269     return drbg_hmac_uninstantiate((PROV_DRBG *)vdrbg);
 270 }
 271
 272 static int drbg_hmac_verify_zeroization(void *vdrbg)
 273 {
 274     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 275     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 276
 277     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->K);
 278     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->V);
 279     return 1;
 280 }
 281
 282 static int drbg_hmac_new(PROV_DRBG *drbg)
 283 {
 284     PROV_DRBG_HMAC *hmac;
 285
 286     hmac = OPENSSL_secure_zalloc(sizeof(*hmac));
 287     if (hmac == NULL) {
 288         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
 289         return 0;
 290     }
 291
 292     drbg->data = hmac;
 293     /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 294     drbg->max_entropylen = DRBG_MAX_LENGTH;
 295     drbg->max_noncelen = DRBG_MAX_LENGTH;
 296     drbg->max_perslen = DRBG_MAX_LENGTH;
 297     drbg->max_adinlen = DRBG_MAX_LENGTH;
 298
 299     /* Maximum number of bits per request = 2^19  = 2^16 bytes */
 300     drbg->max_request = 1 << 16;
 301     return 1;
 302 }
 303
 304 static void *drbg_hmac_new_wrapper(void *provctx, void *parent,
 305                                    const OSSL_DISPATCH *parent_dispatch)
 306 {
 307     return prov_rand_drbg_new(provctx, parent, parent_dispatch, &drbg_hmac_new,
 308                               &drbg_hmac_instantiate, &drbg_hmac_uninstantiate,
 309                               &drbg_hmac_reseed, &drbg_hmac_generate);
 310 }
 311
 312 static void drbg_hmac_free(void *vdrbg)
 313 {
 314     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 315     PROV_DRBG_HMAC *hmac;
 316
 317     if (drbg != NULL && (hmac = (PROV_DRBG_HMAC *)drbg->data) != NULL) {
 318         EVP_MAC_CTX_free(hmac->ctx);
 319         ossl_prov_digest_reset(&hmac->digest);
 320         OPENSSL_secure_clear_free(hmac, sizeof(*hmac));
 321     }
 322     prov_rand_drbg_free(drbg);
 323 }
 324
 325 static int drbg_hmac_get_ctx_params(void *vdrbg, OSSL_PARAM params[])
 326 {
 327     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 328
 329     return drbg_get_ctx_params(drbg, params);
 330 }
 331
 332 static const OSSL_PARAM *drbg_hmac_gettable_ctx_params(void *provctx)
 333 {
 334     static const OSSL_PARAM known_gettable_ctx_params[] = {
 335         OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON,
 336         OSSL_PARAM_END
 337     };
 338     return known_gettable_ctx_params;
 339 }
 340
 341 static int drbg_hmac_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 342 {
 343     PROV_DRBG *ctx = (PROV_DRBG *)vctx;
 344     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)ctx->data;
 345     OPENSSL_CTX *libctx = PROV_LIBRARY_CONTEXT_OF(ctx->provctx);
 346     const EVP_MD *md;
 347
 348     if (!ossl_prov_digest_load_from_params(&hmac->digest, params, libctx))
 349         return 0;
 350
 351     /*
 352      * Confirm digest is allowed. We allow all digests that are not XOF
 353      * (such as SHAKE).  In FIPS mode, the fetch will fail for non-approved
 354      * digests.
 355      */
 356     md = ossl_prov_digest_md(&hmac->digest);
 357     if (md != NULL && (EVP_MD_flags(md) & EVP_MD_FLAG_XOF) != 0) {
 358         ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
 359         return 0;
 360     }
 361
 362     if (!ossl_prov_macctx_load_from_params(&hmac->ctx, params,
 363                                            NULL, NULL, NULL, libctx))
 364         return 0;
 365
 366     if (hmac->ctx != NULL) {
 367         /* These are taken from SP 800-90 10.1 Table 2 */
 368         hmac->blocklen = EVP_MD_size(md);
 369         /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 370         ctx->strength = 64 * (int)(hmac->blocklen >> 3);
 371         if (ctx->strength > 256)
 372             ctx->strength = 256;
 373         ctx->seedlen = hmac->blocklen;
 374         ctx->min_entropylen = ctx->strength / 8;
 375         ctx->min_noncelen = ctx->min_entropylen / 2;
 376     }
 377
 378     return drbg_set_ctx_params(ctx, params);
 379 }
 380
 381 static const OSSL_PARAM *drbg_hmac_settable_ctx_params(void *provctx)
 382 {
 383     static const OSSL_PARAM known_settable_ctx_params[] = {
 384         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_PROPERTIES, NULL, 0),
 385         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
 386         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_MAC, NULL, 0),
 387         OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON,
 388         OSSL_PARAM_END
 389     };
 390     return known_settable_ctx_params;
 391 }
 392
 393 const OSSL_DISPATCH drbg_hmac_functions[] = {
 394     { OSSL_FUNC_RAND_NEWCTX, (void(*)(void))drbg_hmac_new_wrapper },
 395     { OSSL_FUNC_RAND_FREECTX, (void(*)(void))drbg_hmac_free },
 396     { OSSL_FUNC_RAND_INSTANTIATE,
 397       (void(*)(void))drbg_hmac_instantiate_wrapper },
 398     { OSSL_FUNC_RAND_UNINSTANTIATE,
 399       (void(*)(void))drbg_hmac_uninstantiate_wrapper },
 400     { OSSL_FUNC_RAND_GENERATE, (void(*)(void))drbg_hmac_generate_wrapper },
 401     { OSSL_FUNC_RAND_RESEED, (void(*)(void))drbg_hmac_reseed_wrapper },
 402     { OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))drbg_enable_locking },
 403     { OSSL_FUNC_RAND_LOCK, (void(*)(void))drbg_lock },
 404     { OSSL_FUNC_RAND_UNLOCK, (void(*)(void))drbg_unlock },
 405     { OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS,
 406       (void(*)(void))drbg_hmac_settable_ctx_params },
 407     { OSSL_FUNC_RAND_SET_CTX_PARAMS, (void(*)(void))drbg_hmac_set_ctx_params },
 408     { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
 409       (void(*)(void))drbg_hmac_gettable_ctx_params },
 410     { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))drbg_hmac_get_ctx_params },
 411     { OSSL_FUNC_RAND_VERIFY_ZEROIZATION,
 412       (void(*)(void))drbg_hmac_verify_zeroization },
 413     { 0, NULL }
 414 };