Commit | Line | Data |
---|---|---|
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 | 25 | #include <linux/cryptouser.h> |
d8c34b94 | 26 | #include <linux/compiler.h> |
792608e9 | 27 | #include <net/netlink.h> |
17f0f4a4 | 28 | |
d0e83059 HX |
29 | #include "internal.h" |
30 | ||
17f0f4a4 NH |
31 | static DEFINE_MUTEX(crypto_default_rng_lock); |
32 | struct crypto_rng *crypto_default_rng; | |
33 | EXPORT_SYMBOL_GPL(crypto_default_rng); | |
34 | static int crypto_default_rng_refcnt; | |
35 | ||
3c5d8fa9 | 36 | int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) |
17f0f4a4 NH |
37 | { |
38 | u8 *buf = NULL; | |
39 | int err; | |
40 | ||
41 | if (!seed && slen) { | |
42 | buf = kmalloc(slen, GFP_KERNEL); | |
43 | if (!buf) | |
44 | return -ENOMEM; | |
45 | ||
46 | get_random_bytes(buf, slen); | |
47 | seed = buf; | |
48 | } | |
49 | ||
94f1bb15 | 50 | err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); |
17f0f4a4 | 51 | |
b617b702 | 52 | kzfree(buf); |
17f0f4a4 NH |
53 | return err; |
54 | } | |
3c5d8fa9 | 55 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
17f0f4a4 | 56 | |
d0e83059 | 57 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
17f0f4a4 | 58 | { |
17f0f4a4 NH |
59 | return 0; |
60 | } | |
61 | ||
acec27ff HX |
62 | static unsigned int seedsize(struct crypto_alg *alg) |
63 | { | |
64 | struct rng_alg *ralg = container_of(alg, struct rng_alg, base); | |
65 | ||
94f1bb15 | 66 | return ralg->seedsize; |
acec27ff HX |
67 | } |
68 | ||
3acc8473 | 69 | #ifdef CONFIG_NET |
792608e9 SK |
70 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) |
71 | { | |
72 | struct crypto_report_rng rrng; | |
73 | ||
9a5467bf | 74 | strncpy(rrng.type, "rng", sizeof(rrng.type)); |
792608e9 | 75 | |
acec27ff | 76 | rrng.seedsize = seedsize(alg); |
792608e9 | 77 | |
6662df33 DM |
78 | if (nla_put(skb, CRYPTOCFGA_REPORT_RNG, |
79 | sizeof(struct crypto_report_rng), &rrng)) | |
80 | goto nla_put_failure; | |
792608e9 SK |
81 | return 0; |
82 | ||
83 | nla_put_failure: | |
84 | return -EMSGSIZE; | |
85 | } | |
3acc8473 HX |
86 | #else |
87 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) | |
88 | { | |
89 | return -ENOSYS; | |
90 | } | |
91 | #endif | |
792608e9 | 92 | |
17f0f4a4 | 93 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
d8c34b94 | 94 | __maybe_unused; |
17f0f4a4 NH |
95 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
96 | { | |
97 | seq_printf(m, "type : rng\n"); | |
acec27ff | 98 | seq_printf(m, "seedsize : %u\n", seedsize(alg)); |
17f0f4a4 NH |
99 | } |
100 | ||
94f1bb15 | 101 | static const struct crypto_type crypto_rng_type = { |
d0e83059 HX |
102 | .extsize = crypto_alg_extsize, |
103 | .init_tfm = crypto_rng_init_tfm, | |
17f0f4a4 NH |
104 | #ifdef CONFIG_PROC_FS |
105 | .show = crypto_rng_show, | |
106 | #endif | |
792608e9 | 107 | .report = crypto_rng_report, |
d0e83059 HX |
108 | .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
109 | .maskset = CRYPTO_ALG_TYPE_MASK, | |
110 | .type = CRYPTO_ALG_TYPE_RNG, | |
111 | .tfmsize = offsetof(struct crypto_rng, base), | |
17f0f4a4 | 112 | }; |
17f0f4a4 | 113 | |
d0e83059 HX |
114 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
115 | { | |
116 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); | |
117 | } | |
118 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); | |
119 | ||
17f0f4a4 NH |
120 | int crypto_get_default_rng(void) |
121 | { | |
122 | struct crypto_rng *rng; | |
123 | int err; | |
124 | ||
125 | mutex_lock(&crypto_default_rng_lock); | |
126 | if (!crypto_default_rng) { | |
127 | rng = crypto_alloc_rng("stdrng", 0, 0); | |
128 | err = PTR_ERR(rng); | |
129 | if (IS_ERR(rng)) | |
130 | goto unlock; | |
131 | ||
132 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); | |
133 | if (err) { | |
134 | crypto_free_rng(rng); | |
135 | goto unlock; | |
136 | } | |
137 | ||
138 | crypto_default_rng = rng; | |
139 | } | |
140 | ||
141 | crypto_default_rng_refcnt++; | |
142 | err = 0; | |
143 | ||
144 | unlock: | |
145 | mutex_unlock(&crypto_default_rng_lock); | |
146 | ||
147 | return err; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); | |
150 | ||
151 | void crypto_put_default_rng(void) | |
152 | { | |
153 | mutex_lock(&crypto_default_rng_lock); | |
7cecadb7 | 154 | crypto_default_rng_refcnt--; |
17f0f4a4 NH |
155 | mutex_unlock(&crypto_default_rng_lock); |
156 | } | |
157 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); | |
158 | ||
7cecadb7 HX |
159 | #if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE) |
160 | int crypto_del_default_rng(void) | |
161 | { | |
162 | int err = -EBUSY; | |
163 | ||
164 | mutex_lock(&crypto_default_rng_lock); | |
165 | if (crypto_default_rng_refcnt) | |
166 | goto out; | |
167 | ||
168 | crypto_free_rng(crypto_default_rng); | |
169 | crypto_default_rng = NULL; | |
170 | ||
171 | err = 0; | |
172 | ||
173 | out: | |
174 | mutex_unlock(&crypto_default_rng_lock); | |
175 | ||
176 | return err; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(crypto_del_default_rng); | |
179 | #endif | |
180 | ||
acec27ff HX |
181 | int crypto_register_rng(struct rng_alg *alg) |
182 | { | |
183 | struct crypto_alg *base = &alg->base; | |
184 | ||
185 | if (alg->seedsize > PAGE_SIZE / 8) | |
186 | return -EINVAL; | |
187 | ||
188 | base->cra_type = &crypto_rng_type; | |
189 | base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; | |
190 | base->cra_flags |= CRYPTO_ALG_TYPE_RNG; | |
191 | ||
192 | return crypto_register_alg(base); | |
193 | } | |
194 | EXPORT_SYMBOL_GPL(crypto_register_rng); | |
195 | ||
196 | void crypto_unregister_rng(struct rng_alg *alg) | |
197 | { | |
198 | crypto_unregister_alg(&alg->base); | |
199 | } | |
200 | EXPORT_SYMBOL_GPL(crypto_unregister_rng); | |
201 | ||
881cd6c5 HX |
202 | int crypto_register_rngs(struct rng_alg *algs, int count) |
203 | { | |
204 | int i, ret; | |
205 | ||
206 | for (i = 0; i < count; i++) { | |
207 | ret = crypto_register_rng(algs + i); | |
208 | if (ret) | |
209 | goto err; | |
210 | } | |
211 | ||
212 | return 0; | |
213 | ||
214 | err: | |
215 | for (--i; i >= 0; --i) | |
216 | crypto_unregister_rng(algs + i); | |
217 | ||
218 | return ret; | |
219 | } | |
220 | EXPORT_SYMBOL_GPL(crypto_register_rngs); | |
221 | ||
222 | void crypto_unregister_rngs(struct rng_alg *algs, int count) | |
223 | { | |
224 | int i; | |
225 | ||
226 | for (i = count - 1; i >= 0; --i) | |
227 | crypto_unregister_rng(algs + i); | |
228 | } | |
229 | EXPORT_SYMBOL_GPL(crypto_unregister_rngs); | |
230 | ||
17f0f4a4 | 231 | MODULE_LICENSE("GPL"); |
a8ccc393 | 232 | MODULE_DESCRIPTION("Random Number Generator"); |