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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cryptographic API.
4 *
5 * RNG operations.
6 *
7 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
8 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
9 */
10
11#include <crypto/internal/rng.h>
12#include <linux/atomic.h>
13#include <linux/cryptouser.h>
14#include <linux/err.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mutex.h>
18#include <linux/random.h>
19#include <linux/seq_file.h>
20#include <linux/slab.h>
21#include <linux/string.h>
22#include <net/netlink.h>
23
24#include "internal.h"
25
26static DEFINE_MUTEX(crypto_default_rng_lock);
27struct crypto_rng *crypto_default_rng;
28EXPORT_SYMBOL_GPL(crypto_default_rng);
29static int crypto_default_rng_refcnt;
30
31int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
32{
33 struct rng_alg *alg = crypto_rng_alg(tfm);
34 u8 *buf = NULL;
35 int err;
36
37 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
38 atomic64_inc(&rng_get_stat(alg)->seed_cnt);
39
40 if (!seed && slen) {
41 buf = kmalloc(slen, GFP_KERNEL);
42 err = -ENOMEM;
43 if (!buf)
44 goto out;
45
46 err = get_random_bytes_wait(buf, slen);
47 if (err)
48 goto free_buf;
49 seed = buf;
50 }
51
52 err = alg->seed(tfm, seed, slen);
53free_buf:
54 kfree_sensitive(buf);
55out:
56 return crypto_rng_errstat(alg, err);
57}
58EXPORT_SYMBOL_GPL(crypto_rng_reset);
59
60static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
61{
62 return 0;
63}
64
65static unsigned int seedsize(struct crypto_alg *alg)
66{
67 struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
68
69 return ralg->seedsize;
70}
71
72static int __maybe_unused crypto_rng_report(
73 struct sk_buff *skb, struct crypto_alg *alg)
74{
75 struct crypto_report_rng rrng;
76
77 memset(&rrng, 0, sizeof(rrng));
78
79 strscpy(rrng.type, "rng", sizeof(rrng.type));
80
81 rrng.seedsize = seedsize(alg);
82
83 return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);
84}
85
86static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
87 __maybe_unused;
88static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
89{
90 seq_printf(m, "type : rng\n");
91 seq_printf(m, "seedsize : %u\n", seedsize(alg));
92}
93
94static 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
115static const struct crypto_type crypto_rng_type = {
116 .extsize = crypto_alg_extsize,
117 .init_tfm = crypto_rng_init_tfm,
118#ifdef CONFIG_PROC_FS
119 .show = crypto_rng_show,
120#endif
121#if IS_ENABLED(CONFIG_CRYPTO_USER)
122 .report = crypto_rng_report,
123#endif
124#ifdef CONFIG_CRYPTO_STATS
125 .report_stat = crypto_rng_report_stat,
126#endif
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),
131};
132
133struct 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}
137EXPORT_SYMBOL_GPL(crypto_alloc_rng);
138
139int 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
163unlock:
164 mutex_unlock(&crypto_default_rng_lock);
165
166 return err;
167}
168EXPORT_SYMBOL_GPL(crypto_get_default_rng);
169
170void crypto_put_default_rng(void)
171{
172 mutex_lock(&crypto_default_rng_lock);
173 crypto_default_rng_refcnt--;
174 mutex_unlock(&crypto_default_rng_lock);
175}
176EXPORT_SYMBOL_GPL(crypto_put_default_rng);
177
178#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
179int 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
192out:
193 mutex_unlock(&crypto_default_rng_lock);
194
195 return err;
196}
197EXPORT_SYMBOL_GPL(crypto_del_default_rng);
198#endif
199
200int crypto_register_rng(struct rng_alg *alg)
201{
202 struct crypto_istat_rng *istat = rng_get_stat(alg);
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
212 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
213 memset(istat, 0, sizeof(*istat));
214
215 return crypto_register_alg(base);
216}
217EXPORT_SYMBOL_GPL(crypto_register_rng);
218
219void crypto_unregister_rng(struct rng_alg *alg)
220{
221 crypto_unregister_alg(&alg->base);
222}
223EXPORT_SYMBOL_GPL(crypto_unregister_rng);
224
225int 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
237err:
238 for (--i; i >= 0; --i)
239 crypto_unregister_rng(algs + i);
240
241 return ret;
242}
243EXPORT_SYMBOL_GPL(crypto_register_rngs);
244
245void 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}
252EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
253
254MODULE_LICENSE("GPL");
255MODULE_DESCRIPTION("Random Number Generator");
1/*
2 * Cryptographic API.
3 *
4 * RNG operations.
5 *
6 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
7 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
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
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>
27
28#include "internal.h"
29
30static DEFINE_MUTEX(crypto_default_rng_lock);
31struct crypto_rng *crypto_default_rng;
32EXPORT_SYMBOL_GPL(crypto_default_rng);
33static int crypto_default_rng_refcnt;
34
35static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm)
36{
37 return container_of(tfm, struct crypto_rng, base);
38}
39
40int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
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
54 err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
55
56 kzfree(buf);
57 return err;
58}
59EXPORT_SYMBOL_GPL(crypto_rng_reset);
60
61static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
62{
63 return 0;
64}
65
66static unsigned int seedsize(struct crypto_alg *alg)
67{
68 struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
69
70 return ralg->seedsize;
71}
72
73#ifdef CONFIG_NET
74static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
75{
76 struct crypto_report_rng rrng;
77
78 strncpy(rrng.type, "rng", sizeof(rrng.type));
79
80 rrng.seedsize = seedsize(alg);
81
82 if (nla_put(skb, CRYPTOCFGA_REPORT_RNG,
83 sizeof(struct crypto_report_rng), &rrng))
84 goto nla_put_failure;
85 return 0;
86
87nla_put_failure:
88 return -EMSGSIZE;
89}
90#else
91static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
92{
93 return -ENOSYS;
94}
95#endif
96
97static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
98 __attribute__ ((unused));
99static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
100{
101 seq_printf(m, "type : rng\n");
102 seq_printf(m, "seedsize : %u\n", seedsize(alg));
103}
104
105static 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,
110#endif
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),
116};
117
118struct 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}
122EXPORT_SYMBOL_GPL(crypto_alloc_rng);
123
124int 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
148unlock:
149 mutex_unlock(&crypto_default_rng_lock);
150
151 return err;
152}
153EXPORT_SYMBOL_GPL(crypto_get_default_rng);
154
155void crypto_put_default_rng(void)
156{
157 mutex_lock(&crypto_default_rng_lock);
158 crypto_default_rng_refcnt--;
159 mutex_unlock(&crypto_default_rng_lock);
160}
161EXPORT_SYMBOL_GPL(crypto_put_default_rng);
162
163#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
164int crypto_del_default_rng(void)
165{
166 int err = -EBUSY;
167
168 mutex_lock(&crypto_default_rng_lock);
169 if (crypto_default_rng_refcnt)
170 goto out;
171
172 crypto_free_rng(crypto_default_rng);
173 crypto_default_rng = NULL;
174
175 err = 0;
176
177out:
178 mutex_unlock(&crypto_default_rng_lock);
179
180 return err;
181}
182EXPORT_SYMBOL_GPL(crypto_del_default_rng);
183#endif
184
185int crypto_register_rng(struct rng_alg *alg)
186{
187 struct crypto_alg *base = &alg->base;
188
189 if (alg->seedsize > PAGE_SIZE / 8)
190 return -EINVAL;
191
192 base->cra_type = &crypto_rng_type;
193 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
194 base->cra_flags |= CRYPTO_ALG_TYPE_RNG;
195
196 return crypto_register_alg(base);
197}
198EXPORT_SYMBOL_GPL(crypto_register_rng);
199
200void crypto_unregister_rng(struct rng_alg *alg)
201{
202 crypto_unregister_alg(&alg->base);
203}
204EXPORT_SYMBOL_GPL(crypto_unregister_rng);
205
206int crypto_register_rngs(struct rng_alg *algs, int count)
207{
208 int i, ret;
209
210 for (i = 0; i < count; i++) {
211 ret = crypto_register_rng(algs + i);
212 if (ret)
213 goto err;
214 }
215
216 return 0;
217
218err:
219 for (--i; i >= 0; --i)
220 crypto_unregister_rng(algs + i);
221
222 return ret;
223}
224EXPORT_SYMBOL_GPL(crypto_register_rngs);
225
226void crypto_unregister_rngs(struct rng_alg *algs, int count)
227{
228 int i;
229
230 for (i = count - 1; i >= 0; --i)
231 crypto_unregister_rng(algs + i);
232}
233EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
234
235MODULE_LICENSE("GPL");
236MODULE_DESCRIPTION("Random Number Generator");