6 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
7 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
16 #include <linux/atomic.h>
17 #include <crypto/internal/rng.h>
18 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/random.h>
22 #include <linux/seq_file.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/cryptouser.h>
26 #include <net/netlink.h>
30 static DEFINE_MUTEX(crypto_default_rng_lock
);
31 struct crypto_rng
*crypto_default_rng
;
32 EXPORT_SYMBOL_GPL(crypto_default_rng
);
33 static int crypto_default_rng_refcnt
;
35 static inline struct crypto_rng
*__crypto_rng_cast(struct crypto_tfm
*tfm
)
37 return container_of(tfm
, struct crypto_rng
, base
);
40 int crypto_rng_reset(struct crypto_rng
*tfm
, const u8
*seed
, unsigned int slen
)
46 buf
= kmalloc(slen
, GFP_KERNEL
);
50 get_random_bytes(buf
, slen
);
54 err
= crypto_rng_alg(tfm
)->seed(tfm
, seed
, slen
);
59 EXPORT_SYMBOL_GPL(crypto_rng_reset
);
61 static int crypto_rng_init_tfm(struct crypto_tfm
*tfm
)
66 static unsigned int seedsize(struct crypto_alg
*alg
)
68 struct rng_alg
*ralg
= container_of(alg
, struct rng_alg
, base
);
70 return ralg
->seedsize
;
74 static int crypto_rng_report(struct sk_buff
*skb
, struct crypto_alg
*alg
)
76 struct crypto_report_rng rrng
;
78 strncpy(rrng
.type
, "rng", sizeof(rrng
.type
));
80 rrng
.seedsize
= seedsize(alg
);
82 if (nla_put(skb
, CRYPTOCFGA_REPORT_RNG
,
83 sizeof(struct crypto_report_rng
), &rrng
))
91 static int crypto_rng_report(struct sk_buff
*skb
, struct crypto_alg
*alg
)
97 static void crypto_rng_show(struct seq_file
*m
, struct crypto_alg
*alg
)
98 __attribute__ ((unused
));
99 static void crypto_rng_show(struct seq_file
*m
, struct crypto_alg
*alg
)
101 seq_printf(m
, "type : rng\n");
102 seq_printf(m
, "seedsize : %u\n", seedsize(alg
));
105 static const struct crypto_type crypto_rng_type
= {
106 .extsize
= crypto_alg_extsize
,
107 .init_tfm
= crypto_rng_init_tfm
,
108 #ifdef CONFIG_PROC_FS
109 .show
= crypto_rng_show
,
111 .report
= crypto_rng_report
,
112 .maskclear
= ~CRYPTO_ALG_TYPE_MASK
,
113 .maskset
= CRYPTO_ALG_TYPE_MASK
,
114 .type
= CRYPTO_ALG_TYPE_RNG
,
115 .tfmsize
= offsetof(struct crypto_rng
, base
),
118 struct crypto_rng
*crypto_alloc_rng(const char *alg_name
, u32 type
, u32 mask
)
120 return crypto_alloc_tfm(alg_name
, &crypto_rng_type
, type
, mask
);
122 EXPORT_SYMBOL_GPL(crypto_alloc_rng
);
124 int crypto_get_default_rng(void)
126 struct crypto_rng
*rng
;
129 mutex_lock(&crypto_default_rng_lock
);
130 if (!crypto_default_rng
) {
131 rng
= crypto_alloc_rng("stdrng", 0, 0);
136 err
= crypto_rng_reset(rng
, NULL
, crypto_rng_seedsize(rng
));
138 crypto_free_rng(rng
);
142 crypto_default_rng
= rng
;
145 crypto_default_rng_refcnt
++;
149 mutex_unlock(&crypto_default_rng_lock
);
153 EXPORT_SYMBOL_GPL(crypto_get_default_rng
);
155 void crypto_put_default_rng(void)
157 mutex_lock(&crypto_default_rng_lock
);
158 if (!--crypto_default_rng_refcnt
) {
159 crypto_free_rng(crypto_default_rng
);
160 crypto_default_rng
= NULL
;
162 mutex_unlock(&crypto_default_rng_lock
);
164 EXPORT_SYMBOL_GPL(crypto_put_default_rng
);
166 int crypto_register_rng(struct rng_alg
*alg
)
168 struct crypto_alg
*base
= &alg
->base
;
170 if (alg
->seedsize
> PAGE_SIZE
/ 8)
173 base
->cra_type
= &crypto_rng_type
;
174 base
->cra_flags
&= ~CRYPTO_ALG_TYPE_MASK
;
175 base
->cra_flags
|= CRYPTO_ALG_TYPE_RNG
;
177 return crypto_register_alg(base
);
179 EXPORT_SYMBOL_GPL(crypto_register_rng
);
181 void crypto_unregister_rng(struct rng_alg
*alg
)
183 crypto_unregister_alg(&alg
->base
);
185 EXPORT_SYMBOL_GPL(crypto_unregister_rng
);
187 int crypto_register_rngs(struct rng_alg
*algs
, int count
)
191 for (i
= 0; i
< count
; i
++) {
192 ret
= crypto_register_rng(algs
+ i
);
200 for (--i
; i
>= 0; --i
)
201 crypto_unregister_rng(algs
+ i
);
205 EXPORT_SYMBOL_GPL(crypto_register_rngs
);
207 void crypto_unregister_rngs(struct rng_alg
*algs
, int count
)
211 for (i
= count
- 1; i
>= 0; --i
)
212 crypto_unregister_rng(algs
+ i
);
214 EXPORT_SYMBOL_GPL(crypto_unregister_rngs
);
216 MODULE_LICENSE("GPL");
217 MODULE_DESCRIPTION("Random Number Generator");