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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 u8 *buf = NULL;
34 int err;
35
36 if (!seed && slen) {
37 buf = kmalloc(slen, GFP_KERNEL);
38 if (!buf)
39 return -ENOMEM;
40
41 err = get_random_bytes_wait(buf, slen);
42 if (err)
43 goto out;
44 seed = buf;
45 }
46
47 err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
48out:
49 kfree_sensitive(buf);
50 return err;
51}
52EXPORT_SYMBOL_GPL(crypto_rng_reset);
53
54static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
55{
56 return 0;
57}
58
59static unsigned int seedsize(struct crypto_alg *alg)
60{
61 struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
62
63 return ralg->seedsize;
64}
65
66static int __maybe_unused crypto_rng_report(
67 struct sk_buff *skb, struct crypto_alg *alg)
68{
69 struct crypto_report_rng rrng;
70
71 memset(&rrng, 0, sizeof(rrng));
72
73 strscpy(rrng.type, "rng", sizeof(rrng.type));
74
75 rrng.seedsize = seedsize(alg);
76
77 return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);
78}
79
80static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
81 __maybe_unused;
82static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
83{
84 seq_printf(m, "type : rng\n");
85 seq_printf(m, "seedsize : %u\n", seedsize(alg));
86}
87
88static const struct crypto_type crypto_rng_type = {
89 .extsize = crypto_alg_extsize,
90 .init_tfm = crypto_rng_init_tfm,
91#ifdef CONFIG_PROC_FS
92 .show = crypto_rng_show,
93#endif
94#if IS_ENABLED(CONFIG_CRYPTO_USER)
95 .report = crypto_rng_report,
96#endif
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),
101};
102
103struct 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}
107EXPORT_SYMBOL_GPL(crypto_alloc_rng);
108
109int 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
133unlock:
134 mutex_unlock(&crypto_default_rng_lock);
135
136 return err;
137}
138EXPORT_SYMBOL_GPL(crypto_get_default_rng);
139
140void crypto_put_default_rng(void)
141{
142 mutex_lock(&crypto_default_rng_lock);
143 crypto_default_rng_refcnt--;
144 mutex_unlock(&crypto_default_rng_lock);
145}
146EXPORT_SYMBOL_GPL(crypto_put_default_rng);
147
148#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
149int 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
162out:
163 mutex_unlock(&crypto_default_rng_lock);
164
165 return err;
166}
167EXPORT_SYMBOL_GPL(crypto_del_default_rng);
168#endif
169
170int 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}
183EXPORT_SYMBOL_GPL(crypto_register_rng);
184
185void crypto_unregister_rng(struct rng_alg *alg)
186{
187 crypto_unregister_alg(&alg->base);
188}
189EXPORT_SYMBOL_GPL(crypto_unregister_rng);
190
191int 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
203err:
204 for (--i; i >= 0; --i)
205 crypto_unregister_rng(algs + i);
206
207 return ret;
208}
209EXPORT_SYMBOL_GPL(crypto_register_rngs);
210
211void 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}
218EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
219
220MODULE_LICENSE("GPL");
221MODULE_DESCRIPTION("Random Number Generator");
1/*
2 * Cryptographic API.
3 *
4 * RNG operations.
5 *
6 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <linux/atomic.h>
16#include <crypto/internal/rng.h>
17#include <linux/err.h>
18#include <linux/module.h>
19#include <linux/mutex.h>
20#include <linux/random.h>
21#include <linux/seq_file.h>
22#include <linux/slab.h>
23#include <linux/string.h>
24
25static DEFINE_MUTEX(crypto_default_rng_lock);
26struct crypto_rng *crypto_default_rng;
27EXPORT_SYMBOL_GPL(crypto_default_rng);
28static int crypto_default_rng_refcnt;
29
30static int rngapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
31{
32 u8 *buf = NULL;
33 int err;
34
35 if (!seed && slen) {
36 buf = kmalloc(slen, GFP_KERNEL);
37 if (!buf)
38 return -ENOMEM;
39
40 get_random_bytes(buf, slen);
41 seed = buf;
42 }
43
44 err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);
45
46 kfree(buf);
47 return err;
48}
49
50static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
51{
52 struct rng_alg *alg = &tfm->__crt_alg->cra_rng;
53 struct rng_tfm *ops = &tfm->crt_rng;
54
55 ops->rng_gen_random = alg->rng_make_random;
56 ops->rng_reset = rngapi_reset;
57
58 return 0;
59}
60
61static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
62 __attribute__ ((unused));
63static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
64{
65 seq_printf(m, "type : rng\n");
66 seq_printf(m, "seedsize : %u\n", alg->cra_rng.seedsize);
67}
68
69static unsigned int crypto_rng_ctxsize(struct crypto_alg *alg, u32 type,
70 u32 mask)
71{
72 return alg->cra_ctxsize;
73}
74
75const struct crypto_type crypto_rng_type = {
76 .ctxsize = crypto_rng_ctxsize,
77 .init = crypto_init_rng_ops,
78#ifdef CONFIG_PROC_FS
79 .show = crypto_rng_show,
80#endif
81};
82EXPORT_SYMBOL_GPL(crypto_rng_type);
83
84int crypto_get_default_rng(void)
85{
86 struct crypto_rng *rng;
87 int err;
88
89 mutex_lock(&crypto_default_rng_lock);
90 if (!crypto_default_rng) {
91 rng = crypto_alloc_rng("stdrng", 0, 0);
92 err = PTR_ERR(rng);
93 if (IS_ERR(rng))
94 goto unlock;
95
96 err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
97 if (err) {
98 crypto_free_rng(rng);
99 goto unlock;
100 }
101
102 crypto_default_rng = rng;
103 }
104
105 crypto_default_rng_refcnt++;
106 err = 0;
107
108unlock:
109 mutex_unlock(&crypto_default_rng_lock);
110
111 return err;
112}
113EXPORT_SYMBOL_GPL(crypto_get_default_rng);
114
115void crypto_put_default_rng(void)
116{
117 mutex_lock(&crypto_default_rng_lock);
118 if (!--crypto_default_rng_refcnt) {
119 crypto_free_rng(crypto_default_rng);
120 crypto_default_rng = NULL;
121 }
122 mutex_unlock(&crypto_default_rng_lock);
123}
124EXPORT_SYMBOL_GPL(crypto_put_default_rng);
125
126MODULE_LICENSE("GPL");
127MODULE_DESCRIPTION("Random Number Generator");