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 <linux/compiler.h>
 27#include <net/netlink.h>
 28
 29#include "internal.h"
 30
 31static DEFINE_MUTEX(crypto_default_rng_lock);
 32struct crypto_rng *crypto_default_rng;
 33EXPORT_SYMBOL_GPL(crypto_default_rng);
 34static int crypto_default_rng_refcnt;
 35
 36int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
 37{
 38	u8 *buf = NULL;
 39	int err;
 40
 41	if (!seed && slen) {
 42		buf = kmalloc(slen, GFP_KERNEL);
 43		if (!buf)
 44			return -ENOMEM;
 45
 46		err = get_random_bytes_wait(buf, slen);
 47		if (err)
 48			goto out;
 49		seed = buf;
 50	}
 51
 52	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
 53out:
 54	kzfree(buf);
 55	return err;
 56}
 57EXPORT_SYMBOL_GPL(crypto_rng_reset);
 58
 59static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
 60{
 61	return 0;
 62}
 63
 64static unsigned int seedsize(struct crypto_alg *alg)
 65{
 66	struct rng_alg *ralg = container_of(alg, struct rng_alg, base);
 67
 68	return ralg->seedsize;
 69}
 70
 71#ifdef CONFIG_NET
 72static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
 73{
 74	struct crypto_report_rng rrng;
 
 75
 76	strncpy(rrng.type, "rng", sizeof(rrng.type));
 
 77
 78	rrng.seedsize = seedsize(alg);
 79
 80	if (nla_put(skb, CRYPTOCFGA_REPORT_RNG,
 81		    sizeof(struct crypto_report_rng), &rrng))
 82		goto nla_put_failure;
 83	return 0;
 84
 85nla_put_failure:
 86	return -EMSGSIZE;
 87}
 88#else
 89static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
 90{
 91	return -ENOSYS;
 92}
 93#endif
 94
 95static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 96	__maybe_unused;
 97static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
 98{
 99	seq_printf(m, "type         : rng\n");
100	seq_printf(m, "seedsize     : %u\n", seedsize(alg));
101}
102
103static const struct crypto_type crypto_rng_type = {
104	.extsize = crypto_alg_extsize,
105	.init_tfm = crypto_rng_init_tfm,
 
 
 
 
 
 
106#ifdef CONFIG_PROC_FS
107	.show = crypto_rng_show,
108#endif
109	.report = crypto_rng_report,
110	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
111	.maskset = CRYPTO_ALG_TYPE_MASK,
112	.type = CRYPTO_ALG_TYPE_RNG,
113	.tfmsize = offsetof(struct crypto_rng, base),
114};
115
116struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask)
117{
118	return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask);
119}
120EXPORT_SYMBOL_GPL(crypto_alloc_rng);
121
122int crypto_get_default_rng(void)
123{
124	struct crypto_rng *rng;
125	int err;
126
127	mutex_lock(&crypto_default_rng_lock);
128	if (!crypto_default_rng) {
129		rng = crypto_alloc_rng("stdrng", 0, 0);
130		err = PTR_ERR(rng);
131		if (IS_ERR(rng))
132			goto unlock;
133
134		err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
135		if (err) {
136			crypto_free_rng(rng);
137			goto unlock;
138		}
139
140		crypto_default_rng = rng;
141	}
142
143	crypto_default_rng_refcnt++;
144	err = 0;
145
146unlock:
147	mutex_unlock(&crypto_default_rng_lock);
148
149	return err;
150}
151EXPORT_SYMBOL_GPL(crypto_get_default_rng);
152
153void crypto_put_default_rng(void)
154{
155	mutex_lock(&crypto_default_rng_lock);
156	crypto_default_rng_refcnt--;
 
 
 
157	mutex_unlock(&crypto_default_rng_lock);
158}
159EXPORT_SYMBOL_GPL(crypto_put_default_rng);
160
161#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
162int crypto_del_default_rng(void)
163{
164	int err = -EBUSY;
165
166	mutex_lock(&crypto_default_rng_lock);
167	if (crypto_default_rng_refcnt)
168		goto out;
169
170	crypto_free_rng(crypto_default_rng);
171	crypto_default_rng = NULL;
172
173	err = 0;
174
175out:
176	mutex_unlock(&crypto_default_rng_lock);
177
178	return err;
179}
180EXPORT_SYMBOL_GPL(crypto_del_default_rng);
181#endif
182
183int crypto_register_rng(struct rng_alg *alg)
184{
185	struct crypto_alg *base = &alg->base;
186
187	if (alg->seedsize > PAGE_SIZE / 8)
188		return -EINVAL;
189
190	base->cra_type = &crypto_rng_type;
191	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
192	base->cra_flags |= CRYPTO_ALG_TYPE_RNG;
193
194	return crypto_register_alg(base);
195}
196EXPORT_SYMBOL_GPL(crypto_register_rng);
197
198void crypto_unregister_rng(struct rng_alg *alg)
199{
200	crypto_unregister_alg(&alg->base);
201}
202EXPORT_SYMBOL_GPL(crypto_unregister_rng);
203
204int crypto_register_rngs(struct rng_alg *algs, int count)
205{
206	int i, ret;
207
208	for (i = 0; i < count; i++) {
209		ret = crypto_register_rng(algs + i);
210		if (ret)
211			goto err;
212	}
213
214	return 0;
215
216err:
217	for (--i; i >= 0; --i)
218		crypto_unregister_rng(algs + i);
219
220	return ret;
221}
222EXPORT_SYMBOL_GPL(crypto_register_rngs);
223
224void crypto_unregister_rngs(struct rng_alg *algs, int count)
225{
226	int i;
227
228	for (i = count - 1; i >= 0; --i)
229		crypto_unregister_rng(algs + i);
230}
231EXPORT_SYMBOL_GPL(crypto_unregister_rngs);
232
233MODULE_LICENSE("GPL");
234MODULE_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");