providers/implementations/rands/drbg_local.h

   1 /*
   2  * Copyright 1995-2023 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 #ifndef OSSL_CRYPTO_PROV_LOCAL_H
  11 # define OSSL_CRYPTO_PROV_LOCAL_H
  12
  13 # include <openssl/evp.h>
  14 # include <openssl/core_dispatch.h>
  15 # include <openssl/core_names.h>
  16 # include <openssl/params.h>
  17 # include "internal/tsan_assist.h"
  18 # include "internal/nelem.h"
  19 # include "internal/numbers.h"
  20 # include "prov/provider_ctx.h"
  21
  22 /* How many times to read the TSC as a randomness source. */
  23 # define TSC_READ_COUNT                 4
  24
  25 /* Maximum reseed intervals */
  26 # define MAX_RESEED_INTERVAL                     (1 << 24)
  27 # define MAX_RESEED_TIME_INTERVAL                (1 << 20) /* approx. 12 days */
  28
  29 /* Default reseed intervals */
  30 # define RESEED_INTERVAL                         (1 << 8)
  31 # define TIME_INTERVAL                           (60*60)   /* 1 hour */
  32
  33 /*
  34  * The number of bytes that constitutes an atomic lump of entropy with respect
  35  * to the FIPS 140-2 section 4.9.2 Conditional Tests.  The size is somewhat
  36  * arbitrary, the smaller the value, the less entropy is consumed on first
  37  * read but the higher the probability of the test failing by accident.
  38  *
  39  * The value is in bytes.
  40  */
  41 #define CRNGT_BUFSIZ    16
  42
  43 /*
  44  * Maximum input size for the DRBG (entropy, nonce, personalization string)
  45  *
  46  * NIST SP800 90Ar1 allows a maximum of (1 << 35) bits i.e., (1 << 32) bytes.
  47  *
  48  * We lower it to 'only' INT32_MAX bytes, which is equivalent to 2 gigabytes.
  49  */
  50 # define DRBG_MAX_LENGTH                         INT32_MAX
  51
  52 /* The default nonce */
  53 /* ASCII: "OpenSSL NIST SP 800-90A DRBG", in hex for EBCDIC compatibility */
  54 #define DRBG_DEFAULT_PERS_STRING "\x4f\x70\x65\x6e\x53\x53\x4c\x20\x4e\x49\x53\x54\x20\x53\x50\x20\x38\x30\x30\x2d\x39\x30\x41\x20\x44\x52\x42\x47"
  55
  56 typedef struct prov_drbg_st PROV_DRBG;
  57
  58 /* DRBG status values */
  59 typedef enum drbg_status_e {
  60     DRBG_UNINITIALISED,
  61     DRBG_READY,
  62     DRBG_ERROR
  63 } DRBG_STATUS;
  64
  65 /*
  66  * The state of all types of DRBGs.
  67  */
  68 struct prov_drbg_st {
  69     CRYPTO_RWLOCK *lock;
  70     PROV_CTX *provctx;
  71
  72     /* Virtual functions are cache here */
  73     int (*instantiate)(PROV_DRBG *drbg,
  74                        const unsigned char *entropy, size_t entropylen,
  75                        const unsigned char *nonce, size_t noncelen,
  76                        const unsigned char *pers, size_t perslen);
  77     int (*uninstantiate)(PROV_DRBG *ctx);
  78     int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
  79                   const unsigned char *adin, size_t adin_len);
  80     int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
  81                     const unsigned char *adin, size_t adin_len);
  82
  83     /* Parent PROV_RAND and its dispatch table functions */
  84     void *parent;
  85     OSSL_FUNC_rand_enable_locking_fn *parent_enable_locking;
  86     OSSL_FUNC_rand_lock_fn *parent_lock;
  87     OSSL_FUNC_rand_unlock_fn *parent_unlock;
  88     OSSL_FUNC_rand_get_ctx_params_fn *parent_get_ctx_params;
  89     OSSL_FUNC_rand_nonce_fn *parent_nonce;
  90     OSSL_FUNC_rand_get_seed_fn *parent_get_seed;
  91     OSSL_FUNC_rand_clear_seed_fn *parent_clear_seed;
  92
  93     const OSSL_DISPATCH *parent_dispatch;
  94
  95     /*
  96      * Stores the return value of openssl_get_fork_id() as of when we last
  97      * reseeded.  The DRBG reseeds automatically whenever drbg->fork_id !=
  98      * openssl_get_fork_id().  Used to provide fork-safety and reseed this
  99      * DRBG in the child process.
 100      */
 101     int fork_id;
 102     unsigned short flags; /* various external flags */
 103
 104     /*
 105      * The following parameters are setup by the per-type "init" function.
 106      *
 107      * The supported types and their init functions are:
 108      *    (1) CTR_DRBG:  drbg_ctr_init().
 109      *    (2) HMAC_DRBG: drbg_hmac_init().
 110      *    (3) HASH_DRBG: drbg_hash_init().
 111      *
 112      * The parameters are closely related to the ones described in
 113      * section '10.2.1 CTR_DRBG' of [NIST SP 800-90Ar1], with one
 114      * crucial difference: In the NIST standard, all counts are given
 115      * in bits, whereas in OpenSSL entropy counts are given in bits
 116      * and buffer lengths are given in bytes.
 117      *
 118      * Since this difference has lead to some confusion in the past,
 119      * (see [GitHub Issue #2443], formerly [rt.openssl.org #4055])
 120      * the 'len' suffix has been added to all buffer sizes for
 121      * clarification.
 122      */
 123
 124     unsigned int strength;
 125     size_t max_request;
 126     size_t min_entropylen, max_entropylen;
 127     size_t min_noncelen, max_noncelen;
 128     size_t max_perslen, max_adinlen;
 129
 130     /*
 131      * Counts the number of generate requests since the last reseed
 132      * (Starts at 1). This value is the reseed_counter as defined in
 133      * NIST SP 800-90Ar1
 134      */
 135     unsigned int generate_counter;
 136     /*
 137      * Maximum number of generate requests until a reseed is required.
 138      * This value is ignored if it is zero.
 139      */
 140     unsigned int reseed_interval;
 141     /* Stores the time when the last reseeding occurred */
 142     time_t reseed_time;
 143     /*
 144      * Specifies the maximum time interval (in seconds) between reseeds.
 145      * This value is ignored if it is zero.
 146      */
 147     time_t reseed_time_interval;
 148     /*
 149      * Counts the number of reseeds since instantiation.
 150      * This value is ignored if it is zero.
 151      *
 152      * This counter is used only for seed propagation from the <master> DRBG
 153      * to its two children, the <public> and <private> DRBG. This feature is
 154      * very special and its sole purpose is to ensure that any randomness which
 155      * is added by PROV_add() or PROV_seed() will have an immediate effect on
 156      * the output of PROV_bytes() resp. PROV_priv_bytes().
 157      */
 158     TSAN_QUALIFIER unsigned int reseed_counter;
 159     unsigned int reseed_next_counter;
 160     unsigned int parent_reseed_counter;
 161
 162     size_t seedlen;
 163     DRBG_STATUS state;
 164
 165     /* DRBG specific data */
 166     void *data;
 167
 168     /* Entropy and nonce gathering callbacks */
 169     void *callback_arg;
 170     OSSL_INOUT_CALLBACK *get_entropy_fn;
 171     OSSL_CALLBACK *cleanup_entropy_fn;
 172     OSSL_INOUT_CALLBACK *get_nonce_fn;
 173     OSSL_CALLBACK *cleanup_nonce_fn;
 174 };
 175
 176 PROV_DRBG *ossl_rand_drbg_new
 177     (void *provctx, void *parent, const OSSL_DISPATCH *parent_dispatch,
 178      int (*dnew)(PROV_DRBG *ctx),
 179      void (*dfree)(void *vctx),
 180      int (*instantiate)(PROV_DRBG *drbg,
 181                         const unsigned char *entropy, size_t entropylen,
 182                         const unsigned char *nonce, size_t noncelen,
 183                         const unsigned char *pers, size_t perslen),
 184      int (*uninstantiate)(PROV_DRBG *ctx),
 185      int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
 186                    const unsigned char *adin, size_t adin_len),
 187      int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
 188                      const unsigned char *adin, size_t adin_len));
 189 void ossl_rand_drbg_free(PROV_DRBG *drbg);
 190
 191 int ossl_prov_drbg_instantiate(PROV_DRBG *drbg, unsigned int strength,
 192                                int prediction_resistance,
 193                                const unsigned char *pers, size_t perslen);
 194
 195 int ossl_prov_drbg_uninstantiate(PROV_DRBG *drbg);
 196
 197 int ossl_prov_drbg_reseed(PROV_DRBG *drbg, int prediction_resistance,
 198                           const unsigned char *ent, size_t ent_len,
 199                           const unsigned char *adin, size_t adinlen);
 200
 201 int ossl_prov_drbg_generate(PROV_DRBG *drbg, unsigned char *out, size_t outlen,
 202                             unsigned int strength, int prediction_resistance,
 203                             const unsigned char *adin, size_t adinlen);
 204
 205 /* Seeding api */
 206 OSSL_FUNC_rand_get_seed_fn ossl_drbg_get_seed;
 207 OSSL_FUNC_rand_clear_seed_fn ossl_drbg_clear_seed;
 208
 209 /* Verify that an array of numeric values is all zero */
 210 #define PROV_DRBG_VERIFY_ZEROIZATION(v)     \
 211     {                                       \
 212         size_t i;                           \
 213                                             \
 214         for (i = 0; i < OSSL_NELEM(v); i++) \
 215             if ((v)[i] != 0)                \
 216                 goto err;                   \
 217     }
 218
 219 /* locking api */
 220 OSSL_FUNC_rand_enable_locking_fn ossl_drbg_enable_locking;
 221 OSSL_FUNC_rand_lock_fn ossl_drbg_lock;
 222 OSSL_FUNC_rand_unlock_fn ossl_drbg_unlock;
 223
 224 /* Common parameters for all of our DRBGs */
 225 int ossl_drbg_get_ctx_params(PROV_DRBG *drbg, OSSL_PARAM params[]);
 226 int ossl_drbg_get_ctx_params_no_lock(PROV_DRBG *drbg, OSSL_PARAM params[],
 227                                      int *complete);
 228 int ossl_drbg_set_ctx_params(PROV_DRBG *drbg, const OSSL_PARAM params[]);
 229
 230 #define OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON                             \
 231     OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL),             \
 232     OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
 233
 234 #define OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON                             \
 235     OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL),                        \
 236     OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL),                    \
 237     OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL),               \
 238     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_ENTROPYLEN, NULL),            \
 239     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ENTROPYLEN, NULL),            \
 240     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_NONCELEN, NULL),              \
 241     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_NONCELEN, NULL),              \
 242     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_PERSLEN, NULL),               \
 243     OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ADINLEN, NULL),               \
 244     OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_COUNTER, NULL),              \
 245     OSSL_PARAM_time_t(OSSL_DRBG_PARAM_RESEED_TIME, NULL),               \
 246     OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL),             \
 247     OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
 248
 249 /* Continuous test "entropy" calls */
 250 size_t ossl_crngt_get_entropy(PROV_DRBG *drbg,
 251                               unsigned char **pout,
 252                               int entropy, size_t min_len, size_t max_len,
 253                               int prediction_resistance);
 254 void ossl_crngt_cleanup_entropy(PROV_DRBG *drbg,
 255                                 unsigned char *out, size_t outlen);
 256
 257 /* Confirm digest is allowed to be used with a DRBG */
 258 int ossl_drbg_verify_digest(ossl_unused OSSL_LIB_CTX *libctx, const EVP_MD *md);
 259
 260 #endif