6 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
15 #include <linux/atomic.h>
16 #include <crypto/internal/rng.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/random.h>
21 #include <linux/seq_file.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/cryptouser.h>
25 #include <net/netlink.h>
29 static DEFINE_MUTEX(crypto_default_rng_lock
);
30 struct crypto_rng
*crypto_default_rng
;
31 EXPORT_SYMBOL_GPL(crypto_default_rng
);
32 static int crypto_default_rng_refcnt
;
34 static inline struct crypto_rng
*__crypto_rng_cast(struct crypto_tfm
*tfm
)
36 return container_of(tfm
, struct crypto_rng
, base
);
39 static int rngapi_reset(struct crypto_rng
*tfm
, u8
*seed
, unsigned int slen
)
45 buf
= kmalloc(slen
, GFP_KERNEL
);
49 get_random_bytes(buf
, slen
);
53 err
= crypto_rng_alg(tfm
)->rng_reset(tfm
, seed
, slen
);
59 static int crypto_rng_init_tfm(struct crypto_tfm
*tfm
)
61 struct crypto_rng
*rng
= __crypto_rng_cast(tfm
);
62 struct rng_alg
*alg
= &tfm
->__crt_alg
->cra_rng
;
64 rng
->generate
= alg
->rng_make_random
;
65 rng
->seed
= rngapi_reset
;
71 static int crypto_rng_report(struct sk_buff
*skb
, struct crypto_alg
*alg
)
73 struct crypto_report_rng rrng
;
75 strncpy(rrng
.type
, "rng", sizeof(rrng
.type
));
77 rrng
.seedsize
= alg
->cra_rng
.seedsize
;
79 if (nla_put(skb
, CRYPTOCFGA_REPORT_RNG
,
80 sizeof(struct crypto_report_rng
), &rrng
))
88 static int crypto_rng_report(struct sk_buff
*skb
, struct crypto_alg
*alg
)
94 static void crypto_rng_show(struct seq_file
*m
, struct crypto_alg
*alg
)
95 __attribute__ ((unused
));
96 static void crypto_rng_show(struct seq_file
*m
, struct crypto_alg
*alg
)
98 seq_printf(m
, "type : rng\n");
99 seq_printf(m
, "seedsize : %u\n", alg
->cra_rng
.seedsize
);
102 const struct crypto_type crypto_rng_type
= {
103 .extsize
= crypto_alg_extsize
,
104 .init_tfm
= crypto_rng_init_tfm
,
105 #ifdef CONFIG_PROC_FS
106 .show
= crypto_rng_show
,
108 .report
= crypto_rng_report
,
109 .maskclear
= ~CRYPTO_ALG_TYPE_MASK
,
110 .maskset
= CRYPTO_ALG_TYPE_MASK
,
111 .type
= CRYPTO_ALG_TYPE_RNG
,
112 .tfmsize
= offsetof(struct crypto_rng
, base
),
114 EXPORT_SYMBOL_GPL(crypto_rng_type
);
116 struct crypto_rng
*crypto_alloc_rng(const char *alg_name
, u32 type
, u32 mask
)
118 return crypto_alloc_tfm(alg_name
, &crypto_rng_type
, type
, mask
);
120 EXPORT_SYMBOL_GPL(crypto_alloc_rng
);
122 int crypto_get_default_rng(void)
124 struct crypto_rng
*rng
;
127 mutex_lock(&crypto_default_rng_lock
);
128 if (!crypto_default_rng
) {
129 rng
= crypto_alloc_rng("stdrng", 0, 0);
134 err
= crypto_rng_reset(rng
, NULL
, crypto_rng_seedsize(rng
));
136 crypto_free_rng(rng
);
140 crypto_default_rng
= rng
;
143 crypto_default_rng_refcnt
++;
147 mutex_unlock(&crypto_default_rng_lock
);
151 EXPORT_SYMBOL_GPL(crypto_get_default_rng
);
153 void crypto_put_default_rng(void)
155 mutex_lock(&crypto_default_rng_lock
);
156 if (!--crypto_default_rng_refcnt
) {
157 crypto_free_rng(crypto_default_rng
);
158 crypto_default_rng
= NULL
;
160 mutex_unlock(&crypto_default_rng_lock
);
162 EXPORT_SYMBOL_GPL(crypto_put_default_rng
);
164 MODULE_LICENSE("GPL");
165 MODULE_DESCRIPTION("Random Number Generator");