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Commit | Line | Data |
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17f0f4a4 NH |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
4 | * RNG operations. | |
5 | * | |
6 | * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com> | |
94f1bb15 | 7 | * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> |
17f0f4a4 NH |
8 | * |
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) | |
12 | * any later version. | |
13 | * | |
14 | */ | |
15 | ||
60063497 | 16 | #include <linux/atomic.h> |
17f0f4a4 NH |
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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
17f0f4a4 | 24 | #include <linux/string.h> |
792608e9 SK |
25 | #include <linux/cryptouser.h> |
26 | #include <net/netlink.h> | |
17f0f4a4 | 27 | |
d0e83059 HX |
28 | #include "internal.h" |
29 | ||
17f0f4a4 NH |
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; | |
34 | ||
d0e83059 HX |
35 | static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm) |
36 | { | |
37 | return container_of(tfm, struct crypto_rng, base); | |
38 | } | |
39 | ||
3c5d8fa9 | 40 | int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) |
17f0f4a4 NH |
41 | { |
42 | u8 *buf = NULL; | |
43 | int err; | |
44 | ||
45 | if (!seed && slen) { | |
46 | buf = kmalloc(slen, GFP_KERNEL); | |
47 | if (!buf) | |
48 | return -ENOMEM; | |
49 | ||
50 | get_random_bytes(buf, slen); | |
51 | seed = buf; | |
52 | } | |
53 | ||
94f1bb15 | 54 | err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); |
17f0f4a4 NH |
55 | |
56 | kfree(buf); | |
57 | return err; | |
58 | } | |
3c5d8fa9 | 59 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
17f0f4a4 | 60 | |
d0e83059 | 61 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
17f0f4a4 | 62 | { |
17f0f4a4 NH |
63 | return 0; |
64 | } | |
65 | ||
acec27ff HX |
66 | static unsigned int seedsize(struct crypto_alg *alg) |
67 | { | |
68 | struct rng_alg *ralg = container_of(alg, struct rng_alg, base); | |
69 | ||
94f1bb15 | 70 | return ralg->seedsize; |
acec27ff HX |
71 | } |
72 | ||
3acc8473 | 73 | #ifdef CONFIG_NET |
792608e9 SK |
74 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) |
75 | { | |
76 | struct crypto_report_rng rrng; | |
77 | ||
9a5467bf | 78 | strncpy(rrng.type, "rng", sizeof(rrng.type)); |
792608e9 | 79 | |
acec27ff | 80 | rrng.seedsize = seedsize(alg); |
792608e9 | 81 | |
6662df33 DM |
82 | if (nla_put(skb, CRYPTOCFGA_REPORT_RNG, |
83 | sizeof(struct crypto_report_rng), &rrng)) | |
84 | goto nla_put_failure; | |
792608e9 SK |
85 | return 0; |
86 | ||
87 | nla_put_failure: | |
88 | return -EMSGSIZE; | |
89 | } | |
3acc8473 HX |
90 | #else |
91 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) | |
92 | { | |
93 | return -ENOSYS; | |
94 | } | |
95 | #endif | |
792608e9 | 96 | |
17f0f4a4 NH |
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) | |
100 | { | |
101 | seq_printf(m, "type : rng\n"); | |
acec27ff | 102 | seq_printf(m, "seedsize : %u\n", seedsize(alg)); |
17f0f4a4 NH |
103 | } |
104 | ||
94f1bb15 | 105 | static const struct crypto_type crypto_rng_type = { |
d0e83059 HX |
106 | .extsize = crypto_alg_extsize, |
107 | .init_tfm = crypto_rng_init_tfm, | |
17f0f4a4 NH |
108 | #ifdef CONFIG_PROC_FS |
109 | .show = crypto_rng_show, | |
110 | #endif | |
792608e9 | 111 | .report = crypto_rng_report, |
d0e83059 HX |
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), | |
17f0f4a4 | 116 | }; |
17f0f4a4 | 117 | |
d0e83059 HX |
118 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
119 | { | |
120 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); | |
123 | ||
17f0f4a4 NH |
124 | int crypto_get_default_rng(void) |
125 | { | |
126 | struct crypto_rng *rng; | |
127 | int err; | |
128 | ||
129 | mutex_lock(&crypto_default_rng_lock); | |
130 | if (!crypto_default_rng) { | |
131 | rng = crypto_alloc_rng("stdrng", 0, 0); | |
132 | err = PTR_ERR(rng); | |
133 | if (IS_ERR(rng)) | |
134 | goto unlock; | |
135 | ||
136 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); | |
137 | if (err) { | |
138 | crypto_free_rng(rng); | |
139 | goto unlock; | |
140 | } | |
141 | ||
142 | crypto_default_rng = rng; | |
143 | } | |
144 | ||
145 | crypto_default_rng_refcnt++; | |
146 | err = 0; | |
147 | ||
148 | unlock: | |
149 | mutex_unlock(&crypto_default_rng_lock); | |
150 | ||
151 | return err; | |
152 | } | |
153 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); | |
154 | ||
155 | void crypto_put_default_rng(void) | |
156 | { | |
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; | |
161 | } | |
162 | mutex_unlock(&crypto_default_rng_lock); | |
163 | } | |
164 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); | |
165 | ||
acec27ff HX |
166 | int crypto_register_rng(struct rng_alg *alg) |
167 | { | |
168 | struct crypto_alg *base = &alg->base; | |
169 | ||
170 | if (alg->seedsize > PAGE_SIZE / 8) | |
171 | return -EINVAL; | |
172 | ||
173 | base->cra_type = &crypto_rng_type; | |
174 | base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; | |
175 | base->cra_flags |= CRYPTO_ALG_TYPE_RNG; | |
176 | ||
177 | return crypto_register_alg(base); | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(crypto_register_rng); | |
180 | ||
181 | void crypto_unregister_rng(struct rng_alg *alg) | |
182 | { | |
183 | crypto_unregister_alg(&alg->base); | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(crypto_unregister_rng); | |
186 | ||
881cd6c5 HX |
187 | int crypto_register_rngs(struct rng_alg *algs, int count) |
188 | { | |
189 | int i, ret; | |
190 | ||
191 | for (i = 0; i < count; i++) { | |
192 | ret = crypto_register_rng(algs + i); | |
193 | if (ret) | |
194 | goto err; | |
195 | } | |
196 | ||
197 | return 0; | |
198 | ||
199 | err: | |
200 | for (--i; i >= 0; --i) | |
201 | crypto_unregister_rng(algs + i); | |
202 | ||
203 | return ret; | |
204 | } | |
205 | EXPORT_SYMBOL_GPL(crypto_register_rngs); | |
206 | ||
207 | void crypto_unregister_rngs(struct rng_alg *algs, int count) | |
208 | { | |
209 | int i; | |
210 | ||
211 | for (i = count - 1; i >= 0; --i) | |
212 | crypto_unregister_rng(algs + i); | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(crypto_unregister_rngs); | |
215 | ||
17f0f4a4 | 216 | MODULE_LICENSE("GPL"); |
a8ccc393 | 217 | MODULE_DESCRIPTION("Random Number Generator"); |