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");