Commit | Line | Data |
---|---|---|
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 | 32 | { |
9807e49b | 33 | struct rng_alg *alg = crypto_rng_alg(tfm); |
17f0f4a4 NH |
34 | u8 *buf = NULL; |
35 | int err; | |
36 | ||
9807e49b HX |
37 | if (IS_ENABLED(CONFIG_CRYPTO_STATS)) |
38 | atomic64_inc(&rng_get_stat(alg)->seed_cnt); | |
39 | ||
17f0f4a4 NH |
40 | if (!seed && slen) { |
41 | buf = kmalloc(slen, GFP_KERNEL); | |
9807e49b | 42 | err = -ENOMEM; |
30d0f6a9 | 43 | if (!buf) |
9807e49b | 44 | goto out; |
17f0f4a4 | 45 | |
c2176f00 | 46 | err = get_random_bytes_wait(buf, slen); |
30d0f6a9 | 47 | if (err) |
9807e49b | 48 | goto free_buf; |
17f0f4a4 NH |
49 | seed = buf; |
50 | } | |
51 | ||
9807e49b HX |
52 | err = alg->seed(tfm, seed, slen); |
53 | free_buf: | |
453431a5 | 54 | kfree_sensitive(buf); |
9807e49b HX |
55 | out: |
56 | return crypto_rng_errstat(alg, err); | |
17f0f4a4 | 57 | } |
3c5d8fa9 | 58 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
17f0f4a4 | 59 | |
d0e83059 | 60 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
17f0f4a4 | 61 | { |
17f0f4a4 NH |
62 | return 0; |
63 | } | |
64 | ||
acec27ff HX |
65 | static unsigned int seedsize(struct crypto_alg *alg) |
66 | { | |
67 | struct rng_alg *ralg = container_of(alg, struct rng_alg, base); | |
68 | ||
94f1bb15 | 69 | return ralg->seedsize; |
acec27ff HX |
70 | } |
71 | ||
c0f9e01d HX |
72 | static int __maybe_unused crypto_rng_report( |
73 | struct sk_buff *skb, struct crypto_alg *alg) | |
792608e9 SK |
74 | { |
75 | struct crypto_report_rng rrng; | |
76 | ||
37db69e0 | 77 | memset(&rrng, 0, sizeof(rrng)); |
792608e9 | 78 | |
37db69e0 | 79 | strscpy(rrng.type, "rng", sizeof(rrng.type)); |
792608e9 | 80 | |
37db69e0 | 81 | rrng.seedsize = seedsize(alg); |
792608e9 | 82 | |
37db69e0 | 83 | return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng); |
792608e9 SK |
84 | } |
85 | ||
17f0f4a4 | 86 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
d8c34b94 | 87 | __maybe_unused; |
17f0f4a4 NH |
88 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
89 | { | |
90 | seq_printf(m, "type : rng\n"); | |
acec27ff | 91 | seq_printf(m, "seedsize : %u\n", seedsize(alg)); |
17f0f4a4 NH |
92 | } |
93 | ||
9807e49b HX |
94 | static int __maybe_unused crypto_rng_report_stat( |
95 | struct sk_buff *skb, struct crypto_alg *alg) | |
96 | { | |
97 | struct rng_alg *rng = __crypto_rng_alg(alg); | |
98 | struct crypto_istat_rng *istat; | |
99 | struct crypto_stat_rng rrng; | |
100 | ||
101 | istat = rng_get_stat(rng); | |
102 | ||
103 | memset(&rrng, 0, sizeof(rrng)); | |
104 | ||
105 | strscpy(rrng.type, "rng", sizeof(rrng.type)); | |
106 | ||
107 | rrng.stat_generate_cnt = atomic64_read(&istat->generate_cnt); | |
108 | rrng.stat_generate_tlen = atomic64_read(&istat->generate_tlen); | |
109 | rrng.stat_seed_cnt = atomic64_read(&istat->seed_cnt); | |
110 | rrng.stat_err_cnt = atomic64_read(&istat->err_cnt); | |
111 | ||
112 | return nla_put(skb, CRYPTOCFGA_STAT_RNG, sizeof(rrng), &rrng); | |
113 | } | |
114 | ||
94f1bb15 | 115 | static const struct crypto_type crypto_rng_type = { |
d0e83059 HX |
116 | .extsize = crypto_alg_extsize, |
117 | .init_tfm = crypto_rng_init_tfm, | |
17f0f4a4 NH |
118 | #ifdef CONFIG_PROC_FS |
119 | .show = crypto_rng_show, | |
120 | #endif | |
b8969a1b | 121 | #if IS_ENABLED(CONFIG_CRYPTO_USER) |
792608e9 | 122 | .report = crypto_rng_report, |
c0f9e01d | 123 | #endif |
9807e49b HX |
124 | #ifdef CONFIG_CRYPTO_STATS |
125 | .report_stat = crypto_rng_report_stat, | |
126 | #endif | |
d0e83059 HX |
127 | .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
128 | .maskset = CRYPTO_ALG_TYPE_MASK, | |
129 | .type = CRYPTO_ALG_TYPE_RNG, | |
130 | .tfmsize = offsetof(struct crypto_rng, base), | |
17f0f4a4 | 131 | }; |
17f0f4a4 | 132 | |
d0e83059 HX |
133 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
134 | { | |
135 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); | |
138 | ||
17f0f4a4 NH |
139 | int crypto_get_default_rng(void) |
140 | { | |
141 | struct crypto_rng *rng; | |
142 | int err; | |
143 | ||
144 | mutex_lock(&crypto_default_rng_lock); | |
145 | if (!crypto_default_rng) { | |
146 | rng = crypto_alloc_rng("stdrng", 0, 0); | |
147 | err = PTR_ERR(rng); | |
148 | if (IS_ERR(rng)) | |
149 | goto unlock; | |
150 | ||
151 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); | |
152 | if (err) { | |
153 | crypto_free_rng(rng); | |
154 | goto unlock; | |
155 | } | |
156 | ||
157 | crypto_default_rng = rng; | |
158 | } | |
159 | ||
160 | crypto_default_rng_refcnt++; | |
161 | err = 0; | |
162 | ||
163 | unlock: | |
164 | mutex_unlock(&crypto_default_rng_lock); | |
165 | ||
166 | return err; | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); | |
169 | ||
170 | void crypto_put_default_rng(void) | |
171 | { | |
172 | mutex_lock(&crypto_default_rng_lock); | |
7cecadb7 | 173 | crypto_default_rng_refcnt--; |
17f0f4a4 NH |
174 | mutex_unlock(&crypto_default_rng_lock); |
175 | } | |
176 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); | |
177 | ||
7cecadb7 HX |
178 | #if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE) |
179 | int crypto_del_default_rng(void) | |
180 | { | |
181 | int err = -EBUSY; | |
182 | ||
183 | mutex_lock(&crypto_default_rng_lock); | |
184 | if (crypto_default_rng_refcnt) | |
185 | goto out; | |
186 | ||
187 | crypto_free_rng(crypto_default_rng); | |
188 | crypto_default_rng = NULL; | |
189 | ||
190 | err = 0; | |
191 | ||
192 | out: | |
193 | mutex_unlock(&crypto_default_rng_lock); | |
194 | ||
195 | return err; | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(crypto_del_default_rng); | |
198 | #endif | |
199 | ||
acec27ff HX |
200 | int crypto_register_rng(struct rng_alg *alg) |
201 | { | |
9807e49b | 202 | struct crypto_istat_rng *istat = rng_get_stat(alg); |
acec27ff HX |
203 | struct crypto_alg *base = &alg->base; |
204 | ||
205 | if (alg->seedsize > PAGE_SIZE / 8) | |
206 | return -EINVAL; | |
207 | ||
208 | base->cra_type = &crypto_rng_type; | |
209 | base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; | |
210 | base->cra_flags |= CRYPTO_ALG_TYPE_RNG; | |
211 | ||
9807e49b HX |
212 | if (IS_ENABLED(CONFIG_CRYPTO_STATS)) |
213 | memset(istat, 0, sizeof(*istat)); | |
214 | ||
acec27ff HX |
215 | return crypto_register_alg(base); |
216 | } | |
217 | EXPORT_SYMBOL_GPL(crypto_register_rng); | |
218 | ||
219 | void crypto_unregister_rng(struct rng_alg *alg) | |
220 | { | |
221 | crypto_unregister_alg(&alg->base); | |
222 | } | |
223 | EXPORT_SYMBOL_GPL(crypto_unregister_rng); | |
224 | ||
881cd6c5 HX |
225 | int crypto_register_rngs(struct rng_alg *algs, int count) |
226 | { | |
227 | int i, ret; | |
228 | ||
229 | for (i = 0; i < count; i++) { | |
230 | ret = crypto_register_rng(algs + i); | |
231 | if (ret) | |
232 | goto err; | |
233 | } | |
234 | ||
235 | return 0; | |
236 | ||
237 | err: | |
238 | for (--i; i >= 0; --i) | |
239 | crypto_unregister_rng(algs + i); | |
240 | ||
241 | return ret; | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(crypto_register_rngs); | |
244 | ||
245 | void crypto_unregister_rngs(struct rng_alg *algs, int count) | |
246 | { | |
247 | int i; | |
248 | ||
249 | for (i = count - 1; i >= 0; --i) | |
250 | crypto_unregister_rng(algs + i); | |
251 | } | |
252 | EXPORT_SYMBOL_GPL(crypto_unregister_rngs); | |
253 | ||
17f0f4a4 | 254 | MODULE_LICENSE("GPL"); |
a8ccc393 | 255 | MODULE_DESCRIPTION("Random Number Generator"); |