1/* Copyright (c) 2015, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15#ifndef OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
16#define OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
17
18#include <openssl/aes.h>
19
20#include "../../internal.h"
21#include "../modes/internal.h"
22
23#if defined(__cplusplus)
24extern "C" {
25#endif
26
27
28// RAND_bytes_with_additional_data samples from the RNG after mixing 32 bytes
29// from |user_additional_data| in.
30void RAND_bytes_with_additional_data(uint8_t *out, size_t out_len,
31                                     const uint8_t user_additional_data[32]);
32
33// CRYPTO_sysrand fills |len| bytes at |buf| with entropy from the operating
34// system.
35void CRYPTO_sysrand(uint8_t *buf, size_t len);
36
37// rand_fork_unsafe_buffering_enabled returns whether fork-unsafe buffering has
38// been enabled via |RAND_enable_fork_unsafe_buffering|.
39int rand_fork_unsafe_buffering_enabled(void);
40
41// CTR_DRBG_STATE contains the state of a CTR_DRBG based on AES-256. See SP
42// 800-90Ar1.
43typedef struct {
44  AES_KEY ks;
45  block128_f block;
46  ctr128_f ctr;
47  union {
48    uint8_t bytes[16];
49    uint32_t words[4];
50  } counter;
51  uint64_t reseed_counter;
52} CTR_DRBG_STATE;
53
54// See SP 800-90Ar1, table 3.
55#define CTR_DRBG_ENTROPY_LEN 48
56#define CTR_DRBG_MAX_GENERATE_LENGTH 65536
57
58// CTR_DRBG_init initialises |*drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of
59// entropy in |entropy| and, optionally, a personalization string up to
60// |CTR_DRBG_ENTROPY_LEN| bytes in length. It returns one on success and zero
61// on error.
62OPENSSL_EXPORT int CTR_DRBG_init(CTR_DRBG_STATE *drbg,
63                                 const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
64                                 const uint8_t *personalization,
65                                 size_t personalization_len);
66
67// CTR_DRBG_reseed reseeds |drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of entropy
68// in |entropy| and, optionally, up to |CTR_DRBG_ENTROPY_LEN| bytes of
69// additional data. It returns one on success or zero on error.
70OPENSSL_EXPORT int CTR_DRBG_reseed(CTR_DRBG_STATE *drbg,
71                                   const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
72                                   const uint8_t *additional_data,
73                                   size_t additional_data_len);
74
75// CTR_DRBG_generate processes to up |CTR_DRBG_ENTROPY_LEN| bytes of additional
76// data (if any) and then writes |out_len| random bytes to |out|, where
77// |out_len| <= |CTR_DRBG_MAX_GENERATE_LENGTH|. It returns one on success or
78// zero on error.
79OPENSSL_EXPORT int CTR_DRBG_generate(CTR_DRBG_STATE *drbg, uint8_t *out,
80                                     size_t out_len,
81                                     const uint8_t *additional_data,
82                                     size_t additional_data_len);
83
84// CTR_DRBG_clear zeroises the state of |drbg|.
85OPENSSL_EXPORT void CTR_DRBG_clear(CTR_DRBG_STATE *drbg);
86
87
88#if defined(__cplusplus)
89}  // extern C
90#endif
91
92#endif  // OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
93