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");

 
  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#include <linux/cryptouser.h>
 
 25#include <net/netlink.h>
 26
 
 
 27static DEFINE_MUTEX(crypto_default_rng_lock);
 28struct crypto_rng *crypto_default_rng;
 29EXPORT_SYMBOL_GPL(crypto_default_rng);
 30static int crypto_default_rng_refcnt;
 31
 32static int rngapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
 33{
 
 34	u8 *buf = NULL;
 35	int err;
 36
 
 37	if (!seed && slen) {
 38		buf = kmalloc(slen, GFP_KERNEL);
 39		if (!buf)
 
 40			return -ENOMEM;
 
 41
 42		get_random_bytes(buf, slen);
 
 
 
 
 43		seed = buf;
 44	}
 45
 46	err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);
 47
 48	kfree(buf);
 
 49	return err;
 50}
 
 51
 52static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 53{
 54	struct rng_alg *alg = &tfm->__crt_alg->cra_rng;
 55	struct rng_tfm *ops = &tfm->crt_rng;
 56
 57	ops->rng_gen_random = alg->rng_make_random;
 58	ops->rng_reset = rngapi_reset;
 
 59
 60	return 0;
 61}
 62
 63#ifdef CONFIG_NET
 64static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
 65{
 66	struct crypto_report_rng rrng;
 67
 68	strncpy(rrng.type, "rng", sizeof(rrng.type));
 69
 70	rrng.seedsize = alg->cra_rng.seedsize;
 71
 72	if (nla_put(skb, CRYPTOCFGA_REPORT_RNG,
 73		    sizeof(struct crypto_report_rng), &rrng))
 74		goto nla_put_failure;
 75	return 0;
 76
 77nla_put_failure:
 78	return -EMSGSIZE;
 79}
 80#else
 81static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
 82{
 83	return -ENOSYS;
 84}
 85#endif
 86
 87static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 88	__attribute__ ((unused));
 89static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 90{
 91	seq_printf(m, "type         : rng\n");
 92	seq_printf(m, "seedsize     : %u\n", alg->cra_rng.seedsize);
 93}
 94
 95static unsigned int crypto_rng_ctxsize(struct crypto_alg *alg, u32 type,
 96				       u32 mask)
 97{
 98	return alg->cra_ctxsize;
 99}
100
101const struct crypto_type crypto_rng_type = {
102	.ctxsize = crypto_rng_ctxsize,
103	.init = crypto_init_rng_ops,
104#ifdef CONFIG_PROC_FS
105	.show = crypto_rng_show,
106#endif
107	.report = crypto_rng_report,
 
 
 
 
108};
109EXPORT_SYMBOL_GPL(crypto_rng_type);
 
 
 
 
 
110
111int crypto_get_default_rng(void)
112{
113	struct crypto_rng *rng;
114	int err;
115
116	mutex_lock(&crypto_default_rng_lock);
117	if (!crypto_default_rng) {
118		rng = crypto_alloc_rng("stdrng", 0, 0);
119		err = PTR_ERR(rng);
120		if (IS_ERR(rng))
121			goto unlock;
122
123		err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
124		if (err) {
125			crypto_free_rng(rng);
126			goto unlock;
127		}
128
129		crypto_default_rng = rng;
130	}
131
132	crypto_default_rng_refcnt++;
133	err = 0;
134
135unlock:
136	mutex_unlock(&crypto_default_rng_lock);
137
138	return err;
139}
140EXPORT_SYMBOL_GPL(crypto_get_default_rng);
141
142void crypto_put_default_rng(void)
143{
144	mutex_lock(&crypto_default_rng_lock);
145	if (!--crypto_default_rng_refcnt) {
146		crypto_free_rng(crypto_default_rng);
147		crypto_default_rng = NULL;
148	}
149	mutex_unlock(&crypto_default_rng_lock);
150}
151EXPORT_SYMBOL_GPL(crypto_put_default_rng);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
152
153MODULE_LICENSE("GPL");
154MODULE_DESCRIPTION("Random Number Generator");