providers/implementations/rands/drbg_hmac.c

   1 /*
   2  * Copyright 2011-2021 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 "prov/provider_util.h"
  17 #include "internal/thread_once.h"
  18 #include "prov/providercommon.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
  64     if (!EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
  65             /* K = HMAC(K, V || inbyte || [in1] || [in2] || [in3]) */
  66             || !EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  67             || !EVP_MAC_update(ctx, &inbyte, 1)
  68             || !(in1 == NULL || in1len == 0 || EVP_MAC_update(ctx, in1, in1len))
  69             || !(in2 == NULL || in2len == 0 || EVP_MAC_update(ctx, in2, in2len))
  70             || !(in3 == NULL || in3len == 0 || EVP_MAC_update(ctx, in3, in3len))
  71             || !EVP_MAC_final(ctx, hmac->K, NULL, sizeof(hmac->K)))
  72         return 0;
  73
  74    /* V = HMAC(K, V) */
  75     return EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
  76            && EVP_MAC_update(ctx, hmac->V, hmac->blocklen)
  77            && EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V));
  78 }
  79
  80 /*
  81  * SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process
  82  *
  83  *
  84  * Updates the drbg objects Key(K) and Value(V) using the following algorithm:
  85  *   K,V = do_hmac(hmac, 0, in1, in2, in3)
  86  *   if (any input is not NULL)
  87  *     K,V = do_hmac(hmac, 1, in1, in2, in3)
  88  *
  89  * where in1, in2, in3 are optional input buffers that can be NULL.
  90  *       in1len, in2len, in3len are the lengths of the input buffers.
  91  *
  92  * Returns zero if an error occurs otherwise it returns 1.
  93  */
  94 static int drbg_hmac_update(PROV_DRBG *drbg,
  95                             const unsigned char *in1, size_t in1len,
  96                             const unsigned char *in2, size_t in2len,
  97                             const unsigned char *in3, size_t in3len)
  98 {
  99     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 100
 101     /* (Steps 1-2) K = HMAC(K, V||0x00||provided_data). V = HMAC(K,V) */
 102     if (!do_hmac(hmac, 0x00, in1, in1len, in2, in2len, in3, in3len))
 103         return 0;
 104     /* (Step 3) If provided_data == NULL then return (K,V) */
 105     if (in1len == 0 && in2len == 0 && in3len == 0)
 106         return 1;
 107     /* (Steps 4-5) K = HMAC(K, V||0x01||provided_data). V = HMAC(K,V) */
 108     return do_hmac(hmac, 0x01, in1, in1len, in2, in2len, in3, in3len);
 109 }
 110
 111 /*
 112  * SP800-90Ar1 10.1.2.3 HMAC_DRBG_Instantiate_Process:
 113  *
 114  * This sets the drbg Key (K) to all zeros, and Value (V) to all 1's.
 115  * and then calls (K,V) = drbg_hmac_update() with input parameters:
 116  *   ent = entropy data (Can be NULL) of length ent_len.
 117  *   nonce = nonce data (Can be NULL) of length nonce_len.
 118  *   pstr = personalization data (Can be NULL) of length pstr_len.
 119  *
 120  * Returns zero if an error occurs otherwise it returns 1.
 121  */
 122 static int drbg_hmac_instantiate(PROV_DRBG *drbg,
 123                                  const unsigned char *ent, size_t ent_len,
 124                                  const unsigned char *nonce, size_t nonce_len,
 125                                  const unsigned char *pstr, size_t pstr_len)
 126 {
 127     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 128
 129     if (hmac->ctx == NULL) {
 130         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
 131         return 0;
 132     }
 133
 134     /* (Step 2) Key = 0x00 00...00 */
 135     memset(hmac->K, 0x00, hmac->blocklen);
 136     /* (Step 3) V = 0x01 01...01 */
 137     memset(hmac->V, 0x01, hmac->blocklen);
 138     /* (Step 4) (K,V) = HMAC_DRBG_Update(entropy||nonce||pers string, K, V) */
 139     return drbg_hmac_update(drbg, ent, ent_len, nonce, nonce_len, pstr,
 140                             pstr_len);
 141 }
 142
 143 static int drbg_hmac_instantiate_wrapper(void *vdrbg, unsigned int strength,
 144                                          int prediction_resistance,
 145                                          const unsigned char *pstr,
 146                                          size_t pstr_len)
 147 {
 148     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 149
 150     return ossl_prov_drbg_instantiate(drbg, strength, prediction_resistance,
 151                                       pstr, pstr_len);
 152 }
 153
 154 /*
 155  * SP800-90Ar1 10.1.2.4 HMAC_DRBG_Reseed_Process:
 156  *
 157  * Reseeds the drbg's Key (K) and Value (V) by calling
 158  * (K,V) = drbg_hmac_update() with the following input parameters:
 159  *   ent = entropy input data (Can be NULL) of length ent_len.
 160  *   adin = additional input data (Can be NULL) of length adin_len.
 161  *
 162  * Returns zero if an error occurs otherwise it returns 1.
 163  */
 164 static int drbg_hmac_reseed(PROV_DRBG *drbg,
 165                             const unsigned char *ent, size_t ent_len,
 166                             const unsigned char *adin, size_t adin_len)
 167 {
 168     /* (Step 2) (K,V) = HMAC_DRBG_Update(entropy||additional_input, K, V) */
 169     return drbg_hmac_update(drbg, ent, ent_len, adin, adin_len, NULL, 0);
 170 }
 171
 172 static int drbg_hmac_reseed_wrapper(void *vdrbg, int prediction_resistance,
 173                                     const unsigned char *ent, size_t ent_len,
 174                                     const unsigned char *adin, size_t adin_len)
 175 {
 176     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 177
 178     return ossl_prov_drbg_reseed(drbg, prediction_resistance, ent, ent_len,
 179                                  adin, adin_len);
 180 }
 181
 182 /*
 183  * SP800-90Ar1 10.1.2.5 HMAC_DRBG_Generate_Process:
 184  *
 185  * Generates pseudo random bytes and updates the internal K,V for the drbg.
 186  * out is a buffer to fill with outlen bytes of pseudo random data.
 187  * adin is an additional_input string of size adin_len that may be NULL.
 188  *
 189  * Returns zero if an error occurs otherwise it returns 1.
 190  */
 191 static int drbg_hmac_generate(PROV_DRBG *drbg,
 192                               unsigned char *out, size_t outlen,
 193                               const unsigned char *adin, size_t adin_len)
 194 {
 195     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 196     EVP_MAC_CTX *ctx = hmac->ctx;
 197     const unsigned char *temp = hmac->V;
 198
 199     /* (Step 2) if adin != NULL then (K,V) = HMAC_DRBG_Update(adin, K, V) */
 200     if (adin != NULL
 201             && adin_len > 0
 202             && !drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
 203         return 0;
 204
 205     /*
 206      * (Steps 3-5) temp = NULL
 207      *             while (len(temp) < outlen) {
 208      *                 V = HMAC(K, V)
 209      *                 temp = temp || V
 210      *             }
 211      */
 212     for (;;) {
 213         if (!EVP_MAC_init(ctx, hmac->K, hmac->blocklen, NULL)
 214             || !EVP_MAC_update(ctx, temp, hmac->blocklen))
 215             return 0;
 216
 217         if (outlen > hmac->blocklen) {
 218             if (!EVP_MAC_final(ctx, out, NULL, outlen))
 219                 return 0;
 220             temp = out;
 221         } else {
 222             if (!EVP_MAC_final(ctx, hmac->V, NULL, sizeof(hmac->V)))
 223                 return 0;
 224             memcpy(out, hmac->V, outlen);
 225             break;
 226         }
 227         out += hmac->blocklen;
 228         outlen -= hmac->blocklen;
 229     }
 230     /* (Step 6) (K,V) = HMAC_DRBG_Update(adin, K, V) */
 231     if (!drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
 232         return 0;
 233
 234     return 1;
 235 }
 236
 237 static int drbg_hmac_generate_wrapper
 238     (void *vdrbg, unsigned char *out, size_t outlen, unsigned int strength,
 239      int prediction_resistance, const unsigned char *adin, size_t adin_len)
 240 {
 241     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 242
 243     return ossl_prov_drbg_generate(drbg, out, outlen, strength,
 244                                    prediction_resistance, adin, adin_len);
 245 }
 246
 247 static int drbg_hmac_uninstantiate(PROV_DRBG *drbg)
 248 {
 249     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 250
 251     OPENSSL_cleanse(hmac->K, sizeof(hmac->K));
 252     OPENSSL_cleanse(hmac->V, sizeof(hmac->V));
 253     return ossl_prov_drbg_uninstantiate(drbg);
 254 }
 255
 256 static int drbg_hmac_uninstantiate_wrapper(void *vdrbg)
 257 {
 258     return drbg_hmac_uninstantiate((PROV_DRBG *)vdrbg);
 259 }
 260
 261 static int drbg_hmac_verify_zeroization(void *vdrbg)
 262 {
 263     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 264     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 265
 266     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->K);
 267     PROV_DRBG_VERYIFY_ZEROIZATION(hmac->V);
 268     return 1;
 269 }
 270
 271 static int drbg_hmac_new(PROV_DRBG *drbg)
 272 {
 273     PROV_DRBG_HMAC *hmac;
 274
 275     hmac = OPENSSL_secure_zalloc(sizeof(*hmac));
 276     if (hmac == NULL) {
 277         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
 278         return 0;
 279     }
 280
 281     drbg->data = hmac;
 282     /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 283     drbg->max_entropylen = DRBG_MAX_LENGTH;
 284     drbg->max_noncelen = DRBG_MAX_LENGTH;
 285     drbg->max_perslen = DRBG_MAX_LENGTH;
 286     drbg->max_adinlen = DRBG_MAX_LENGTH;
 287
 288     /* Maximum number of bits per request = 2^19  = 2^16 bytes */
 289     drbg->max_request = 1 << 16;
 290     return 1;
 291 }
 292
 293 static void *drbg_hmac_new_wrapper(void *provctx, void *parent,
 294                                    const OSSL_DISPATCH *parent_dispatch)
 295 {
 296     return ossl_rand_drbg_new(provctx, parent, parent_dispatch, &drbg_hmac_new,
 297                               &drbg_hmac_instantiate, &drbg_hmac_uninstantiate,
 298                               &drbg_hmac_reseed, &drbg_hmac_generate);
 299 }
 300
 301 static void drbg_hmac_free(void *vdrbg)
 302 {
 303     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 304     PROV_DRBG_HMAC *hmac;
 305
 306     if (drbg != NULL && (hmac = (PROV_DRBG_HMAC *)drbg->data) != NULL) {
 307         EVP_MAC_CTX_free(hmac->ctx);
 308         ossl_prov_digest_reset(&hmac->digest);
 309         OPENSSL_secure_clear_free(hmac, sizeof(*hmac));
 310     }
 311     ossl_rand_drbg_free(drbg);
 312 }
 313
 314 static int drbg_hmac_get_ctx_params(void *vdrbg, OSSL_PARAM params[])
 315 {
 316     PROV_DRBG *drbg = (PROV_DRBG *)vdrbg;
 317     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)drbg->data;
 318     const char *name;
 319     const EVP_MD *md;
 320     OSSL_PARAM *p;
 321
 322     p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_MAC);
 323     if (p != NULL) {
 324         if (hmac->ctx == NULL)
 325             return 0;
 326         name = EVP_MAC_name(EVP_MAC_CTX_mac(hmac->ctx));
 327         if (!OSSL_PARAM_set_utf8_string(p, name))
 328             return 0;
 329     }
 330
 331     p = OSSL_PARAM_locate(params, OSSL_DRBG_PARAM_DIGEST);
 332     if (p != NULL) {
 333         md = ossl_prov_digest_md(&hmac->digest);
 334         if (md == NULL || !OSSL_PARAM_set_utf8_string(p, EVP_MD_name(md)))
 335             return 0;
 336     }
 337
 338     return ossl_drbg_get_ctx_params(drbg, params);
 339 }
 340
 341 static const OSSL_PARAM *drbg_hmac_gettable_ctx_params(ossl_unused void *vctx,
 342                                                        ossl_unused void *p_ctx)
 343 {
 344     static const OSSL_PARAM known_gettable_ctx_params[] = {
 345         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_MAC, NULL, 0),
 346         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
 347         OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON,
 348         OSSL_PARAM_END
 349     };
 350     return known_gettable_ctx_params;
 351 }
 352
 353 static int drbg_hmac_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 354 {
 355     PROV_DRBG *ctx = (PROV_DRBG *)vctx;
 356     PROV_DRBG_HMAC *hmac = (PROV_DRBG_HMAC *)ctx->data;
 357     OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
 358     const EVP_MD *md;
 359
 360     if (!ossl_prov_digest_load_from_params(&hmac->digest, params, libctx))
 361         return 0;
 362
 363     /*
 364      * Confirm digest is allowed. We allow all digests that are not XOF
 365      * (such as SHAKE).  In FIPS mode, the fetch will fail for non-approved
 366      * digests.
 367      */
 368     md = ossl_prov_digest_md(&hmac->digest);
 369     if (md != NULL && (EVP_MD_flags(md) & EVP_MD_FLAG_XOF) != 0) {
 370         ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
 371         return 0;
 372     }
 373
 374     if (!ossl_prov_macctx_load_from_params(&hmac->ctx, params,
 375                                            NULL, NULL, NULL, libctx))
 376         return 0;
 377
 378     if (hmac->ctx != NULL) {
 379         /* These are taken from SP 800-90 10.1 Table 2 */
 380         hmac->blocklen = EVP_MD_size(md);
 381         /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
 382         ctx->strength = 64 * (int)(hmac->blocklen >> 3);
 383         if (ctx->strength > 256)
 384             ctx->strength = 256;
 385         ctx->seedlen = hmac->blocklen;
 386         ctx->min_entropylen = ctx->strength / 8;
 387         ctx->min_noncelen = ctx->min_entropylen / 2;
 388     }
 389
 390     return ossl_drbg_set_ctx_params(ctx, params);
 391 }
 392
 393 static const OSSL_PARAM *drbg_hmac_settable_ctx_params(ossl_unused void *vctx,
 394                                                        ossl_unused void *p_ctx)
 395 {
 396     static const OSSL_PARAM known_settable_ctx_params[] = {
 397         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_PROPERTIES, NULL, 0),
 398         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST, NULL, 0),
 399         OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_MAC, NULL, 0),
 400         OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON,
 401         OSSL_PARAM_END
 402     };
 403     return known_settable_ctx_params;
 404 }
 405
 406 const OSSL_DISPATCH ossl_drbg_ossl_hmac_functions[] = {
 407     { OSSL_FUNC_RAND_NEWCTX, (void(*)(void))drbg_hmac_new_wrapper },
 408     { OSSL_FUNC_RAND_FREECTX, (void(*)(void))drbg_hmac_free },
 409     { OSSL_FUNC_RAND_INSTANTIATE,
 410       (void(*)(void))drbg_hmac_instantiate_wrapper },
 411     { OSSL_FUNC_RAND_UNINSTANTIATE,
 412       (void(*)(void))drbg_hmac_uninstantiate_wrapper },
 413     { OSSL_FUNC_RAND_GENERATE, (void(*)(void))drbg_hmac_generate_wrapper },
 414     { OSSL_FUNC_RAND_RESEED, (void(*)(void))drbg_hmac_reseed_wrapper },
 415     { OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))ossl_drbg_enable_locking },
 416     { OSSL_FUNC_RAND_LOCK, (void(*)(void))ossl_drbg_lock },
 417     { OSSL_FUNC_RAND_UNLOCK, (void(*)(void))ossl_drbg_unlock },
 418     { OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS,
 419       (void(*)(void))drbg_hmac_settable_ctx_params },
 420     { OSSL_FUNC_RAND_SET_CTX_PARAMS, (void(*)(void))drbg_hmac_set_ctx_params },
 421     { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
 422       (void(*)(void))drbg_hmac_gettable_ctx_params },
 423     { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))drbg_hmac_get_ctx_params },
 424     { OSSL_FUNC_RAND_VERIFY_ZEROIZATION,
 425       (void(*)(void))drbg_hmac_verify_zeroization },
 426     { OSSL_FUNC_RAND_GET_SEED, (void(*)(void))ossl_drbg_get_seed },
 427     { OSSL_FUNC_RAND_CLEAR_SEED, (void(*)(void))ossl_drbg_clear_seed },
 428     { 0, NULL }
 429 };