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#include <openssl/cpu.h>
20
21#include "../../internal.h"
22#include "../modes/internal.h"
23
24#if defined(__cplusplus)
25extern "C" {
26#endif
27
28
29// RAND_bytes_with_additional_data samples from the RNG after mixing 32 bytes
30// from |user_additional_data| in.
31void RAND_bytes_with_additional_data(uint8_t *out, size_t out_len,
32 const uint8_t user_additional_data[32]);
33
34// CRYPTO_sysrand fills |len| bytes at |buf| with entropy from the operating
35// system.
36void CRYPTO_sysrand(uint8_t *buf, size_t len);
37
38// rand_fork_unsafe_buffering_enabled returns whether fork-unsafe buffering has
39// been enabled via |RAND_enable_fork_unsafe_buffering|.
40int rand_fork_unsafe_buffering_enabled(void);
41
42// CTR_DRBG_STATE contains the state of a CTR_DRBG based on AES-256. See SP
43// 800-90Ar1.
44typedef struct {
45 AES_KEY ks;
46 block128_f block;
47 ctr128_f ctr;
48 union {
49 uint8_t bytes[16];
50 uint32_t words[4];
51 } counter;
52 uint64_t reseed_counter;
53} CTR_DRBG_STATE;
54
55// See SP 800-90Ar1, table 3.
56#define CTR_DRBG_ENTROPY_LEN 48
57#define CTR_DRBG_MAX_GENERATE_LENGTH 65536
58
59// CTR_DRBG_init initialises |*drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of
60// entropy in |entropy| and, optionally, a personalization string up to
61// |CTR_DRBG_ENTROPY_LEN| bytes in length. It returns one on success and zero
62// on error.
63OPENSSL_EXPORT int CTR_DRBG_init(CTR_DRBG_STATE *drbg,
64 const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
65 const uint8_t *personalization,
66 size_t personalization_len);
67
68// CTR_DRBG_reseed reseeds |drbg| given |CTR_DRBG_ENTROPY_LEN| bytes of entropy
69// in |entropy| and, optionally, up to |CTR_DRBG_ENTROPY_LEN| bytes of
70// additional data. It returns one on success or zero on error.
71OPENSSL_EXPORT int CTR_DRBG_reseed(CTR_DRBG_STATE *drbg,
72 const uint8_t entropy[CTR_DRBG_ENTROPY_LEN],
73 const uint8_t *additional_data,
74 size_t additional_data_len);
75
76// CTR_DRBG_generate processes to up |CTR_DRBG_ENTROPY_LEN| bytes of additional
77// data (if any) and then writes |out_len| random bytes to |out|, where
78// |out_len| <= |CTR_DRBG_MAX_GENERATE_LENGTH|. It returns one on success or
79// zero on error.
80OPENSSL_EXPORT int CTR_DRBG_generate(CTR_DRBG_STATE *drbg, uint8_t *out,
81 size_t out_len,
82 const uint8_t *additional_data,
83 size_t additional_data_len);
84
85// CTR_DRBG_clear zeroises the state of |drbg|.
86OPENSSL_EXPORT void CTR_DRBG_clear(CTR_DRBG_STATE *drbg);
87
88
89#if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM)
90OPENSSL_INLINE int have_rdrand(void) {
91 return (OPENSSL_ia32cap_get()[1] & (1u << 30)) != 0;
92}
93
94// CRYPTO_rdrand writes eight bytes of random data from the hardware RNG to
95// |out|. It returns one on success or zero on hardware failure.
96int CRYPTO_rdrand(uint8_t out[8]);
97
98// CRYPTO_rdrand_multiple8_buf fills |len| bytes at |buf| with random data from
99// the hardware RNG. The |len| argument must be a multiple of eight. It returns
100// one on success and zero on hardware failure.
101int CRYPTO_rdrand_multiple8_buf(uint8_t *buf, size_t len);
102#endif // OPENSSL_X86_64 && !OPENSSL_NO_ASM
103
104
105#if defined(__cplusplus)
106} // extern C
107#endif
108
109#endif // OPENSSL_HEADER_CRYPTO_RAND_INTERNAL_H
110