openssl/include/internal/rand.h
Dr. Matthias St. Pierre 4917e91160 RAND_DRBG: add a function for setting the reseeding defaults
The introduction of thread local public and private DRBG instances (#5547)
makes it very cumbersome to change the reseeding (time) intervals for
those instances. This commit provides a function to set the default
values for all subsequently created DRBG instances.

 int RAND_DRBG_set_reseed_defaults(
                                   unsigned int master_reseed_interval,
                                   unsigned int slave_reseed_interval,
                                   time_t master_reseed_time_interval,
                                   time_t slave_reseed_time_interval
                                   );

The function is intended only to be used during application initialization,
before any threads are created and before any random bytes are generated.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5576)
2018-03-10 00:26:30 +01:00

134 lines
5.2 KiB
C

/*
* Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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 HEADER_DRBG_RAND_H
# define HEADER_DRBG_RAND_H
/* In CTR mode, disable derivation function ctr_df */
#define RAND_DRBG_FLAG_CTR_NO_DF 0x1
/*
* Default security strength (in the sense of [NIST SP 800-90Ar1])
*
* NIST SP 800-90Ar1 supports the strength of the DRBG being smaller than that
* of the cipher by collecting less entropy. The current DRBG implemantion does
* not take RAND_DRBG_STRENGTH into account and sets the strength of the DRBG
* to that of the cipher.
*
* RAND_DRBG_STRENGTH is currently only used for the legacy RAND
* implementation.
*
* Currently supported ciphers are: NID_aes_128_ctr, NID_aes_192_ctr and
* NID_aes_256_ctr
*
* TODO(DRBG): would be nice to have the NID and strength configurable
*/
# define RAND_DRBG_STRENGTH 256
# define RAND_DRBG_NID NID_aes_256_ctr
/*
* Object lifetime functions.
*/
RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent);
RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent);
int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
int RAND_DRBG_instantiate(RAND_DRBG *drbg,
const unsigned char *pers, size_t perslen);
int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
void RAND_DRBG_free(RAND_DRBG *drbg);
/*
* Object "use" functions.
*/
int RAND_DRBG_reseed(RAND_DRBG *drbg,
const unsigned char *adin, size_t adinlen);
int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
int prediction_resistance,
const unsigned char *adin, size_t adinlen);
int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen);
int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval);
int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval);
int RAND_DRBG_set_reseed_defaults(
unsigned int master_reseed_interval,
unsigned int slave_reseed_interval,
time_t master_reseed_time_interval,
time_t slave_reseed_time_interval
);
RAND_DRBG *RAND_DRBG_get0_master(void);
RAND_DRBG *RAND_DRBG_get0_public(void);
RAND_DRBG *RAND_DRBG_get0_private(void);
/*
* EXDATA
*/
#define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
/*
* Callback functions. See comments in drbg_lib.c
*/
typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
unsigned char **pout,
int entropy, size_t min_len,
size_t max_len);
typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
unsigned char *out, size_t outlen);
typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
int entropy, size_t min_len,
size_t max_len);
typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
unsigned char *out, size_t outlen);
int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
RAND_DRBG_get_entropy_fn get_entropy,
RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
RAND_DRBG_get_nonce_fn get_nonce,
RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
/*
* RAND_POOL functions
*/
RAND_POOL *RAND_POOL_new(int entropy_requested, size_t min_len, size_t max_len);
void RAND_POOL_free(RAND_POOL *pool);
const unsigned char *RAND_POOL_buffer(RAND_POOL *pool);
unsigned char *RAND_POOL_detach(RAND_POOL *pool);
size_t RAND_POOL_entropy(RAND_POOL *pool);
size_t RAND_POOL_length(RAND_POOL *pool);
size_t RAND_POOL_entropy_available(RAND_POOL *pool);
size_t RAND_POOL_entropy_needed(RAND_POOL *pool);
size_t RAND_POOL_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte);
size_t RAND_POOL_bytes_remaining(RAND_POOL *pool);
size_t RAND_POOL_add(RAND_POOL *pool,
const unsigned char *buffer, size_t len, size_t entropy);
unsigned char *RAND_POOL_add_begin(RAND_POOL *pool, size_t len);
size_t RAND_POOL_add_end(RAND_POOL *pool, size_t len, size_t entropy);
/*
* Add random bytes to the pool to acquire requested amount of entropy
*
* This function is platform specific and tries to acquire the requested
* amount of entropy by polling platform specific entropy sources.
*
* If the function succeeds in acquiring at least |entropy_requested| bits
* of entropy, the total entropy count is returned. If it fails, it returns
* an entropy count of 0.
*/
size_t RAND_POOL_acquire_entropy(RAND_POOL *pool);
#endif