Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
17f0f4a4 NH |
2 | /* |
3 | * Cryptographic API. | |
4 | * | |
5 | * RNG operations. | |
6 | * | |
7 | * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com> | |
94f1bb15 | 8 | * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> |
17f0f4a4 NH |
9 | */ |
10 | ||
17f0f4a4 | 11 | #include <crypto/internal/rng.h> |
9807e49b HX |
12 | #include <linux/atomic.h> |
13 | #include <linux/cryptouser.h> | |
17f0f4a4 | 14 | #include <linux/err.h> |
9807e49b | 15 | #include <linux/kernel.h> |
17f0f4a4 NH |
16 | #include <linux/module.h> |
17 | #include <linux/mutex.h> | |
18 | #include <linux/random.h> | |
19 | #include <linux/seq_file.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
17f0f4a4 | 21 | #include <linux/string.h> |
792608e9 | 22 | #include <net/netlink.h> |
17f0f4a4 | 23 | |
d0e83059 HX |
24 | #include "internal.h" |
25 | ||
17f0f4a4 NH |
26 | static DEFINE_MUTEX(crypto_default_rng_lock); |
27 | struct crypto_rng *crypto_default_rng; | |
28 | EXPORT_SYMBOL_GPL(crypto_default_rng); | |
29 | static int crypto_default_rng_refcnt; | |
30 | ||
3c5d8fa9 | 31 | int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) |
17f0f4a4 NH |
32 | { |
33 | u8 *buf = NULL; | |
34 | int err; | |
35 | ||
36 | if (!seed && slen) { | |
37 | buf = kmalloc(slen, GFP_KERNEL); | |
30d0f6a9 | 38 | if (!buf) |
29ce50e0 | 39 | return -ENOMEM; |
17f0f4a4 | 40 | |
c2176f00 | 41 | err = get_random_bytes_wait(buf, slen); |
30d0f6a9 | 42 | if (err) |
29ce50e0 | 43 | goto out; |
17f0f4a4 NH |
44 | seed = buf; |
45 | } | |
46 | ||
29ce50e0 | 47 | err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); |
9807e49b | 48 | out: |
29ce50e0 EB |
49 | kfree_sensitive(buf); |
50 | return err; | |
17f0f4a4 | 51 | } |
3c5d8fa9 | 52 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
17f0f4a4 | 53 | |
d0e83059 | 54 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
17f0f4a4 | 55 | { |
17f0f4a4 NH |
56 | return 0; |
57 | } | |
58 | ||
acec27ff HX |
59 | static unsigned int seedsize(struct crypto_alg *alg) |
60 | { | |
61 | struct rng_alg *ralg = container_of(alg, struct rng_alg, base); | |
62 | ||
94f1bb15 | 63 | return ralg->seedsize; |
acec27ff HX |
64 | } |
65 | ||
c0f9e01d HX |
66 | static int __maybe_unused crypto_rng_report( |
67 | struct sk_buff *skb, struct crypto_alg *alg) | |
792608e9 SK |
68 | { |
69 | struct crypto_report_rng rrng; | |
70 | ||
37db69e0 | 71 | memset(&rrng, 0, sizeof(rrng)); |
792608e9 | 72 | |
37db69e0 | 73 | strscpy(rrng.type, "rng", sizeof(rrng.type)); |
792608e9 | 74 | |
37db69e0 | 75 | rrng.seedsize = seedsize(alg); |
792608e9 | 76 | |
37db69e0 | 77 | return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng); |
792608e9 SK |
78 | } |
79 | ||
17f0f4a4 | 80 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
d8c34b94 | 81 | __maybe_unused; |
17f0f4a4 NH |
82 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
83 | { | |
84 | seq_printf(m, "type : rng\n"); | |
acec27ff | 85 | seq_printf(m, "seedsize : %u\n", seedsize(alg)); |
17f0f4a4 NH |
86 | } |
87 | ||
94f1bb15 | 88 | static const struct crypto_type crypto_rng_type = { |
d0e83059 HX |
89 | .extsize = crypto_alg_extsize, |
90 | .init_tfm = crypto_rng_init_tfm, | |
17f0f4a4 NH |
91 | #ifdef CONFIG_PROC_FS |
92 | .show = crypto_rng_show, | |
93 | #endif | |
b8969a1b | 94 | #if IS_ENABLED(CONFIG_CRYPTO_USER) |
792608e9 | 95 | .report = crypto_rng_report, |
9807e49b | 96 | #endif |
d0e83059 HX |
97 | .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
98 | .maskset = CRYPTO_ALG_TYPE_MASK, | |
99 | .type = CRYPTO_ALG_TYPE_RNG, | |
100 | .tfmsize = offsetof(struct crypto_rng, base), | |
17f0f4a4 | 101 | }; |
17f0f4a4 | 102 | |
d0e83059 HX |
103 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
104 | { | |
105 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); | |
108 | ||
17f0f4a4 NH |
109 | int crypto_get_default_rng(void) |
110 | { | |
111 | struct crypto_rng *rng; | |
112 | int err; | |
113 | ||
114 | mutex_lock(&crypto_default_rng_lock); | |
115 | if (!crypto_default_rng) { | |
116 | rng = crypto_alloc_rng("stdrng", 0, 0); | |
117 | err = PTR_ERR(rng); | |
118 | if (IS_ERR(rng)) | |
119 | goto unlock; | |
120 | ||
121 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); | |
122 | if (err) { | |
123 | crypto_free_rng(rng); | |
124 | goto unlock; | |
125 | } | |
126 | ||
127 | crypto_default_rng = rng; | |
128 | } | |
129 | ||
130 | crypto_default_rng_refcnt++; | |
131 | err = 0; | |
132 | ||
133 | unlock: | |
134 | mutex_unlock(&crypto_default_rng_lock); | |
135 | ||
136 | return err; | |
137 | } | |
138 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); | |
139 | ||
140 | void crypto_put_default_rng(void) | |
141 | { | |
142 | mutex_lock(&crypto_default_rng_lock); | |
7cecadb7 | 143 | crypto_default_rng_refcnt--; |
17f0f4a4 NH |
144 | mutex_unlock(&crypto_default_rng_lock); |
145 | } | |
146 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); | |
147 | ||
7cecadb7 HX |
148 | #if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE) |
149 | int crypto_del_default_rng(void) | |
150 | { | |
151 | int err = -EBUSY; | |
152 | ||
153 | mutex_lock(&crypto_default_rng_lock); | |
154 | if (crypto_default_rng_refcnt) | |
155 | goto out; | |
156 | ||
157 | crypto_free_rng(crypto_default_rng); | |
158 | crypto_default_rng = NULL; | |
159 | ||
160 | err = 0; | |
161 | ||
162 | out: | |
163 | mutex_unlock(&crypto_default_rng_lock); | |
164 | ||
165 | return err; | |
166 | } | |
167 | EXPORT_SYMBOL_GPL(crypto_del_default_rng); | |
168 | #endif | |
169 | ||
acec27ff HX |
170 | int crypto_register_rng(struct rng_alg *alg) |
171 | { | |
172 | struct crypto_alg *base = &alg->base; | |
173 | ||
174 | if (alg->seedsize > PAGE_SIZE / 8) | |
175 | return -EINVAL; | |
176 | ||
177 | base->cra_type = &crypto_rng_type; | |
178 | base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; | |
179 | base->cra_flags |= CRYPTO_ALG_TYPE_RNG; | |
180 | ||
181 | return crypto_register_alg(base); | |
182 | } | |
183 | EXPORT_SYMBOL_GPL(crypto_register_rng); | |
184 | ||
185 | void crypto_unregister_rng(struct rng_alg *alg) | |
186 | { | |
187 | crypto_unregister_alg(&alg->base); | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(crypto_unregister_rng); | |
190 | ||
881cd6c5 HX |
191 | int crypto_register_rngs(struct rng_alg *algs, int count) |
192 | { | |
193 | int i, ret; | |
194 | ||
195 | for (i = 0; i < count; i++) { | |
196 | ret = crypto_register_rng(algs + i); | |
197 | if (ret) | |
198 | goto err; | |
199 | } | |
200 | ||
201 | return 0; | |
202 | ||
203 | err: | |
204 | for (--i; i >= 0; --i) | |
205 | crypto_unregister_rng(algs + i); | |
206 | ||
207 | return ret; | |
208 | } | |
209 | EXPORT_SYMBOL_GPL(crypto_register_rngs); | |
210 | ||
211 | void crypto_unregister_rngs(struct rng_alg *algs, int count) | |
212 | { | |
213 | int i; | |
214 | ||
215 | for (i = count - 1; i >= 0; --i) | |
216 | crypto_unregister_rng(algs + i); | |
217 | } | |
218 | EXPORT_SYMBOL_GPL(crypto_unregister_rngs); | |
219 | ||
17f0f4a4 | 220 | MODULE_LICENSE("GPL"); |
a8ccc393 | 221 | MODULE_DESCRIPTION("Random Number Generator"); |