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");

  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	snprintf(rrng.type, CRYPTO_MAX_ALG_NAME, "%s", "rng");
 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");