drbg_local.h
/*
* Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#ifndef OSSL_CRYPTO_PROV_LOCAL_H
# define OSSL_CRYPTO_PROV_LOCAL_H
# include <openssl/evp.h>
# include <openssl/core_dispatch.h>
# include <openssl/core_names.h>
# include <openssl/params.h>
# include "internal/tsan_assist.h"
# include "internal/nelem.h"
# include "internal/numbers.h"
# include "prov/provider_ctx.h"
/* How many times to read the TSC as a randomness source. */
# define TSC_READ_COUNT 4
/* Maximum reseed intervals */
# define MAX_RESEED_INTERVAL (1 << 24)
# define MAX_RESEED_TIME_INTERVAL (1 << 20) /* approx. 12 days */
/* Default reseed intervals */
# define RESEED_INTERVAL (1 << 8)
# define TIME_INTERVAL (60*60) /* 1 hour */
/*
* The number of bytes that constitutes an atomic lump of entropy with respect
* to the FIPS 140-2 section 4.9.2 Conditional Tests. The size is somewhat
* arbitrary, the smaller the value, the less entropy is consumed on first
* read but the higher the probability of the test failing by accident.
*
* The value is in bytes.
*/
#define CRNGT_BUFSIZ 16
/*
* Maximum input size for the DRBG (entropy, nonce, personalization string)
*
* NIST SP800 90Ar1 allows a maximum of (1 << 35) bits i.e., (1 << 32) bytes.
*
* We lower it to 'only' INT32_MAX bytes, which is equivalent to 2 gigabytes.
*/
# define DRBG_MAX_LENGTH INT32_MAX
/* The default nonce */
/* ASCII: "OpenSSL NIST SP 800-90A DRBG", in hex for EBCDIC compatibility */
#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"
typedef struct prov_drbg_st PROV_DRBG;
/* DRBG status values */
typedef enum drbg_status_e {
DRBG_UNINITIALISED,
DRBG_READY,
DRBG_ERROR
} DRBG_STATUS;
/*
* The state of all types of DRBGs.
*/
struct prov_drbg_st {
CRYPTO_RWLOCK *lock;
PROV_CTX *provctx;
/* Virtual functions are cache here */
int (*instantiate)(PROV_DRBG *drbg,
const unsigned char *entropy, size_t entropylen,
const unsigned char *nonce, size_t noncelen,
const unsigned char *pers, size_t perslen);
int (*uninstantiate)(PROV_DRBG *ctx);
int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adin_len);
int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
const unsigned char *adin, size_t adin_len);
/* Parent PROV_RAND and its dispatch table functions */
void *parent;
OSSL_FUNC_rand_enable_locking_fn *parent_enable_locking;
OSSL_FUNC_rand_lock_fn *parent_lock;
OSSL_FUNC_rand_unlock_fn *parent_unlock;
OSSL_FUNC_rand_get_ctx_params_fn *parent_get_ctx_params;
OSSL_FUNC_rand_nonce_fn *parent_nonce;
OSSL_FUNC_rand_get_seed_fn *parent_get_seed;
OSSL_FUNC_rand_clear_seed_fn *parent_clear_seed;
const OSSL_DISPATCH *parent_dispatch;
/*
* Stores the return value of openssl_get_fork_id() as of when we last
* reseeded. The DRBG reseeds automatically whenever drbg->fork_id !=
* openssl_get_fork_id(). Used to provide fork-safety and reseed this
* DRBG in the child process.
*/
int fork_id;
unsigned short flags; /* various external flags */
/*
* The following parameters are setup by the per-type "init" function.
*
* The supported types and their init functions are:
* (1) CTR_DRBG: drbg_ctr_init().
* (2) HMAC_DRBG: drbg_hmac_init().
* (3) HASH_DRBG: drbg_hash_init().
*
* The parameters are closely related to the ones described in
* section '10.2.1 CTR_DRBG' of [NIST SP 800-90Ar1], with one
* crucial difference: In the NIST standard, all counts are given
* in bits, whereas in OpenSSL entropy counts are given in bits
* and buffer lengths are given in bytes.
*
* Since this difference has lead to some confusion in the past,
* (see [GitHub Issue #2443], formerly [rt.openssl.org #4055])
* the 'len' suffix has been added to all buffer sizes for
* clarification.
*/
unsigned int strength;
size_t max_request;
size_t min_entropylen, max_entropylen;
size_t min_noncelen, max_noncelen;
size_t max_perslen, max_adinlen;
/*
* Counts the number of generate requests since the last reseed
* (Starts at 1). This value is the reseed_counter as defined in
* NIST SP 800-90Ar1
*/
unsigned int generate_counter;
/*
* Maximum number of generate requests until a reseed is required.
* This value is ignored if it is zero.
*/
unsigned int reseed_interval;
/* Stores the time when the last reseeding occurred */
time_t reseed_time;
/*
* Specifies the maximum time interval (in seconds) between reseeds.
* This value is ignored if it is zero.
*/
time_t reseed_time_interval;
/*
* Counts the number of reseeds since instantiation.
* This value is ignored if it is zero.
*
* This counter is used only for seed propagation from the <master> DRBG
* to its two children, the <public> and <private> DRBG. This feature is
* very special and its sole purpose is to ensure that any randomness which
* is added by PROV_add() or PROV_seed() will have an immediate effect on
* the output of PROV_bytes() resp. PROV_priv_bytes().
*/
TSAN_QUALIFIER unsigned int reseed_counter;
unsigned int reseed_next_counter;
unsigned int parent_reseed_counter;
size_t seedlen;
DRBG_STATUS state;
/* DRBG specific data */
void *data;
/* Entropy and nonce gathering callbacks */
void *callback_arg;
OSSL_INOUT_CALLBACK *get_entropy_fn;
OSSL_CALLBACK *cleanup_entropy_fn;
OSSL_INOUT_CALLBACK *get_nonce_fn;
OSSL_CALLBACK *cleanup_nonce_fn;
};
PROV_DRBG *ossl_rand_drbg_new
(void *provctx, void *parent, const OSSL_DISPATCH *parent_dispatch,
int (*dnew)(PROV_DRBG *ctx),
int (*instantiate)(PROV_DRBG *drbg,
const unsigned char *entropy, size_t entropylen,
const unsigned char *nonce, size_t noncelen,
const unsigned char *pers, size_t perslen),
int (*uninstantiate)(PROV_DRBG *ctx),
int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adin_len),
int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
const unsigned char *adin, size_t adin_len));
void ossl_rand_drbg_free(PROV_DRBG *drbg);
int ossl_prov_drbg_instantiate(PROV_DRBG *drbg, unsigned int strength,
int prediction_resistance,
const unsigned char *pers, size_t perslen);
int ossl_prov_drbg_uninstantiate(PROV_DRBG *drbg);
int ossl_prov_drbg_reseed(PROV_DRBG *drbg, int prediction_resistance,
const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adinlen);
int ossl_prov_drbg_generate(PROV_DRBG *drbg, unsigned char *out, size_t outlen,
unsigned int strength, int prediction_resistance,
const unsigned char *adin, size_t adinlen);
/* Seeding api */
OSSL_FUNC_rand_get_seed_fn ossl_drbg_get_seed;
OSSL_FUNC_rand_clear_seed_fn ossl_drbg_clear_seed;
/* Verify that an array of numeric values is all zero */
#define PROV_DRBG_VERIFY_ZEROIZATION(v) \
{ \
size_t i; \
\
for (i = 0; i < OSSL_NELEM(v); i++) \
if ((v)[i] != 0) \
goto err; \
}
/* locking api */
OSSL_FUNC_rand_enable_locking_fn ossl_drbg_enable_locking;
OSSL_FUNC_rand_lock_fn ossl_drbg_lock;
OSSL_FUNC_rand_unlock_fn ossl_drbg_unlock;
/* Common parameters for all of our DRBGs */
int ossl_drbg_get_ctx_params(PROV_DRBG *drbg, OSSL_PARAM params[]);
int ossl_drbg_get_ctx_params_no_lock(PROV_DRBG *drbg, OSSL_PARAM params[],
int *complete);
int ossl_drbg_set_ctx_params(PROV_DRBG *drbg, const OSSL_PARAM params[]);
#define OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON \
OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL), \
OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
#define OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON \
OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL), \
OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL), \
OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_ENTROPYLEN, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ENTROPYLEN, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_NONCELEN, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_NONCELEN, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_PERSLEN, NULL), \
OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ADINLEN, NULL), \
OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_COUNTER, NULL), \
OSSL_PARAM_time_t(OSSL_DRBG_PARAM_RESEED_TIME, NULL), \
OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL), \
OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
/* Continuous test "entropy" calls */
size_t ossl_crngt_get_entropy(PROV_DRBG *drbg,
unsigned char **pout,
int entropy, size_t min_len, size_t max_len,
int prediction_resistance);
void ossl_crngt_cleanup_entropy(PROV_DRBG *drbg,
unsigned char *out, size_t outlen);
/* Confirm digest is allowed to be used with a DRBG */
int ossl_drbg_verify_digest(ossl_unused OSSL_LIB_CTX *libctx, const EVP_MD *md);
#endif
