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");