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

  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 <linux/atomic.h>
 12#include <crypto/internal/rng.h>
 13#include <linux/err.h>
 14#include <linux/module.h>
 15#include <linux/mutex.h>
 16#include <linux/random.h>
 17#include <linux/seq_file.h>
 18#include <linux/slab.h>
 19#include <linux/string.h>
 20#include <linux/cryptouser.h>
 21#include <linux/compiler.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 crypto_alg *alg = tfm->base.__crt_alg;
 34	u8 *buf = NULL;
 35	int err;
 36
 37	crypto_stats_get(alg);
 38	if (!seed && slen) {
 39		buf = kmalloc(slen, GFP_KERNEL);
 40		if (!buf) {
 41			crypto_alg_put(alg);
 42			return -ENOMEM;
 43		}
 44
 45		err = get_random_bytes_wait(buf, slen);
 46		if (err) {
 47			crypto_alg_put(alg);
 48			goto out;
 49		}
 50		seed = buf;
 51	}
 52
 53	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
 54	crypto_stats_rng_seed(alg, err);
 55out:
 56	kfree_sensitive(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	memset(&rrng, 0, sizeof(rrng));
 79
 80	strscpy(rrng.type, "rng", sizeof(rrng.type));
 81
 82	rrng.seedsize = seedsize(alg);
 83
 84	return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);
 85}
 86#else
 87static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
 88{
 89	return -ENOSYS;
 90}
 91#endif
 92
 93static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 94	__maybe_unused;
 95static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 96{
 97	seq_printf(m, "type         : rng\n");
 98	seq_printf(m, "seedsize     : %u\n", seedsize(alg));
 99}
100
101static const struct crypto_type crypto_rng_type = {
102	.extsize = crypto_alg_extsize,
103	.init_tfm = crypto_rng_init_tfm,
104#ifdef CONFIG_PROC_FS
105	.show = crypto_rng_show,
106#endif
107	.report = crypto_rng_report,
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),
112};
113
114struct 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}
118EXPORT_SYMBOL_GPL(crypto_alloc_rng);
119
120int 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
144unlock:
145	mutex_unlock(&crypto_default_rng_lock);
146
147	return err;
148}
149EXPORT_SYMBOL_GPL(crypto_get_default_rng);
150
151void crypto_put_default_rng(void)
152{
153	mutex_lock(&crypto_default_rng_lock);
154	crypto_default_rng_refcnt--;
155	mutex_unlock(&crypto_default_rng_lock);
156}
157EXPORT_SYMBOL_GPL(crypto_put_default_rng);
158
159#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
160int 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
173out:
174	mutex_unlock(&crypto_default_rng_lock);
175
176	return err;
177}
178EXPORT_SYMBOL_GPL(crypto_del_default_rng);
179#endif
180
181int 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}
194EXPORT_SYMBOL_GPL(crypto_register_rng);
195
196void crypto_unregister_rng(struct rng_alg *alg)
197{
198	crypto_unregister_alg(&alg->base);
199}
200EXPORT_SYMBOL_GPL(crypto_unregister_rng);
201
202int 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
214err:
215	for (--i; i >= 0; --i)
216		crypto_unregister_rng(algs + i);
217
218	return ret;
219}
220EXPORT_SYMBOL_GPL(crypto_register_rngs);
221
222void 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}
229EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
230
231MODULE_LICENSE("GPL");
232MODULE_DESCRIPTION("Random Number Generator");