1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/*
* RNG: Random Number Generator algorithms under the crypto API
*
* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#ifndef _CRYPTO_RNG_H
#define _CRYPTO_RNG_H
#include <linux/crypto.h>
struct crypto_rng {
int (*generate)(struct crypto_rng *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int dlen);
int (*seed)(struct crypto_rng *tfm, u8 *seed, unsigned int slen);
struct crypto_tfm base;
};
extern struct crypto_rng *crypto_default_rng;
int crypto_get_default_rng(void);
void crypto_put_default_rng(void);
/**
* DOC: Random number generator API
*
* The random number generator API is used with the ciphers of type
* CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto)
*/
/**
* crypto_alloc_rng() -- allocate RNG handle
* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
* message digest cipher
* @type: specifies the type of the cipher
* @mask: specifies the mask for the cipher
*
* Allocate a cipher handle for a random number generator. The returned struct
* crypto_rng is the cipher handle that is required for any subsequent
* API invocation for that random number generator.
*
* For all random number generators, this call creates a new private copy of
* the random number generator that does not share a state with other
* instances. The only exception is the "krng" random number generator which
* is a kernel crypto API use case for the get_random_bytes() function of the
* /dev/random driver.
*
* Return: allocated cipher handle in case of success; IS_ERR() is true in case
* of an error, PTR_ERR() returns the error code.
*/
struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask);
static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
{
return &tfm->base;
}
/**
* crypto_rng_alg - obtain name of RNG
* @tfm: cipher handle
*
* Return the generic name (cra_name) of the initialized random number generator
*
* Return: generic name string
*/
static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
{
return &crypto_rng_tfm(tfm)->__crt_alg->cra_rng;
}
/**
* crypto_free_rng() - zeroize and free RNG handle
* @tfm: cipher handle to be freed
*/
static inline void crypto_free_rng(struct crypto_rng *tfm)
{
crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm));
}
/**
* crypto_rng_generate() - get random number
* @tfm: cipher handle
* @src: Input buffer holding additional data, may be NULL
* @slen: Length of additional data
* @dst: output buffer holding the random numbers
* @dlen: length of the output buffer
*
* This function fills the caller-allocated buffer with random
* numbers using the random number generator referenced by the
* cipher handle.
*
* Return: 0 function was successful; < 0 if an error occurred
*/
static inline int crypto_rng_generate(struct crypto_rng *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int dlen)
{
return tfm->generate(tfm, src, slen, dst, dlen);
}
/**
* crypto_rng_get_bytes() - get random number
* @tfm: cipher handle
* @rdata: output buffer holding the random numbers
* @dlen: length of the output buffer
*
* This function fills the caller-allocated buffer with random numbers using the
* random number generator referenced by the cipher handle.
*
* Return: 0 function was successful; < 0 if an error occurred
*/
static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
u8 *rdata, unsigned int dlen)
{
return crypto_rng_generate(tfm, NULL, 0, rdata, dlen);
}
/**
* crypto_rng_reset() - re-initialize the RNG
* @tfm: cipher handle
* @seed: seed input data
* @slen: length of the seed input data
*
* The reset function completely re-initializes the random number generator
* referenced by the cipher handle by clearing the current state. The new state
* is initialized with the caller provided seed or automatically, depending
* on the random number generator type (the ANSI X9.31 RNG requires
* caller-provided seed, the SP800-90A DRBGs perform an automatic seeding).
* The seed is provided as a parameter to this function call. The provided seed
* should have the length of the seed size defined for the random number
* generator as defined by crypto_rng_seedsize.
*
* Return: 0 if the setting of the key was successful; < 0 if an error occurred
*/
static inline int crypto_rng_reset(struct crypto_rng *tfm,
u8 *seed, unsigned int slen)
{
return tfm->seed(tfm, seed, slen);
}
/**
* crypto_rng_seedsize() - obtain seed size of RNG
* @tfm: cipher handle
*
* The function returns the seed size for the random number generator
* referenced by the cipher handle. This value may be zero if the random
* number generator does not implement or require a reseeding. For example,
* the SP800-90A DRBGs implement an automated reseeding after reaching a
* pre-defined threshold.
*
* Return: seed size for the random number generator
*/
static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
{
return crypto_rng_alg(tfm)->seedsize;
}
#endif
|
