boringssl/crypto/rand/internal.h
Adam Langley 730d69e159 Add CTR-DRBG.
This isn't actually used yet, but implements CTR-DRBG from SP 800-90Ar1.
Specifically, it always uses AES-256 and no derivation function.

Change-Id: Ie82b829590226addd7c165eac410a5d584858bfd
Reviewed-on: https://boringssl-review.googlesource.com/14891
Reviewed-by: Adam Langley <agl@google.com>
2017-04-14 16:54:40 +00:00

84 lines
3.2 KiB
C

/* Copyright (c) 2015, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#ifndef OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
#define OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
#include <openssl/aes.h>
#include "../internal.h"
#include "../modes/internal.h"
#if defined(__cplusplus)
extern "C" {
#endif
/* CRYPTO_sysrand fills |len| bytes at |buf| with entropy from the operating
* system. */
void CRYPTO_sysrand(uint8_t *buf, size_t len);
/* CTR_DRBG_STATE contains the state of a CTR_DRBG based on AES-256. See SP
* 800-90Ar1. */
typedef struct {
alignas(16) AES_KEY ks;
block128_f block;
ctr128_f ctr;
union {
uint8_t bytes[16];
uint32_t words[4];
} counter;
uint64_t reseed_counter;
} CTR_DRBG_STATE;
/* See SP 800-90Ar1, table 3. */
#define CTR_DRBG_ENTROPY_LEN 48
#define CTR_DRBG_MAX_GENERATE_LENGTH 65536
/* CTR_DRBG_init initialises |*drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of
* entropy in |entropy| and, optionally, a personalization string up to
* |CTR_DRBG_ENTROPY_LEN| bytes in length. It returns one on success and zero
* on error. */
OPENSSL_EXPORT int CTR_DRBG_init(CTR_DRBG_STATE *drbg,
const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
const uint8_t *personalization,
size_t personalization_len);
/* CTR_DRBG_reseed reseeds |drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of entropy
* in |entropy| and, optionally, up to |CTR_DRBG_ENTROPY_LEN| bytes of
* additional data. It returns one on success or zero on error. */
OPENSSL_EXPORT int CTR_DRBG_reseed(CTR_DRBG_STATE *drbg,
const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
const uint8_t *additional_data,
size_t additional_data_len);
/* CTR_DRBG_generate processes to up |CTR_DRBG_ENTROPY_LEN| bytes of additional
* data (if any) and then writes |out_len| random bytes to |out|, where
* |out_len| <= |CTR_DRBG_MAX_GENERATE_LENGTH|. It returns one on success or
* zero on error. */
OPENSSL_EXPORT int CTR_DRBG_generate(CTR_DRBG_STATE *drbg, uint8_t *out,
size_t out_len,
const uint8_t *additional_data,
size_t additional_data_len);
/* CTR_DRBG_clear zeroises the state of |drbg|. */
OPENSSL_EXPORT void CTR_DRBG_clear(CTR_DRBG_STATE *drbg);
#if defined(__cplusplus)
} /* extern C */
#endif
#endif /* OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H */