[deliverable/linux.git] / crypto / rng.c

/*
 * Cryptographic API.
 *
 * RNG operations.
 *
 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <linux/atomic.h>
#include <crypto/internal/rng.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/random.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>

static DEFINE_MUTEX(crypto_default_rng_lock);
struct crypto_rng *crypto_default_rng;
EXPORT_SYMBOL_GPL(crypto_default_rng);
static int crypto_default_rng_refcnt;

static int rngapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
{
	u8 *buf = NULL;
	int err;

	if (!seed && slen) {
		buf = kmalloc(slen, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;

		get_random_bytes(buf, slen);
		seed = buf;
	}

	err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);

	kfree(buf);
	return err;
}

static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct rng_alg *alg = &tfm->__crt_alg->cra_rng;
	struct rng_tfm *ops = &tfm->crt_rng;

	ops->rng_gen_random = alg->rng_make_random;
	ops->rng_reset = rngapi_reset;

	return 0;
}

static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_rng rrng;

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

	rrng.seedsize = alg->cra_rng.seedsize;

	NLA_PUT(skb, CRYPTOCFGA_REPORT_RNG,
		sizeof(struct crypto_report_rng), &rrng);

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
{
	seq_printf(m, "type         : rng\n");
	seq_printf(m, "seedsize     : %u\n", alg->cra_rng.seedsize);
}

static unsigned int crypto_rng_ctxsize(struct crypto_alg *alg, u32 type,
				       u32 mask)
{
	return alg->cra_ctxsize;
}

const struct crypto_type crypto_rng_type = {
	.ctxsize = crypto_rng_ctxsize,
	.init = crypto_init_rng_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_rng_show,
#endif
	.report = crypto_rng_report,
};
EXPORT_SYMBOL_GPL(crypto_rng_type);

int crypto_get_default_rng(void)
{
	struct crypto_rng *rng;
	int err;

	mutex_lock(&crypto_default_rng_lock);
	if (!crypto_default_rng) {
		rng = crypto_alloc_rng("stdrng", 0, 0);
		err = PTR_ERR(rng);
		if (IS_ERR(rng))
			goto unlock;

		err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
		if (err) {
			crypto_free_rng(rng);
			goto unlock;
		}

		crypto_default_rng = rng;
	}

	crypto_default_rng_refcnt++;
	err = 0;

unlock:
	mutex_unlock(&crypto_default_rng_lock);

	return err;
}
EXPORT_SYMBOL_GPL(crypto_get_default_rng);

void crypto_put_default_rng(void)
{
	mutex_lock(&crypto_default_rng_lock);
	if (!--crypto_default_rng_refcnt) {
		crypto_free_rng(crypto_default_rng);
		crypto_default_rng = NULL;
	}
	mutex_unlock(&crypto_default_rng_lock);
}
EXPORT_SYMBOL_GPL(crypto_put_default_rng);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Random Number Generator");
Commit	Line	Data
17f0f4a4 NH	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
60063497	15	#include <linux/atomic.h>
17f0f4a4 NH	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>
5a0e3ad6	22	#include <linux/slab.h>
17f0f4a4	23	#include <linux/string.h>
792608e9 SK	24	#include <linux/cryptouser.h>
792608e9 SK	25	#include <net/netlink.h>
17f0f4a4 NH	26
	27	static DEFINE_MUTEX(crypto_default_rng_lock);
	28	struct crypto_rng *crypto_default_rng;
	29	EXPORT_SYMBOL_GPL(crypto_default_rng);
	30	static int crypto_default_rng_refcnt;
	31
	32	static 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
	52	static 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
792608e9 SK	63	static int crypto_rng_report(struct sk_buff skb, struct crypto_alg alg)
	64	{
	65	struct crypto_report_rng rrng;
	66
	67	snprintf(rrng.type, CRYPTO_MAX_ALG_NAME, "%s", "rng");
	68
	69	rrng.seedsize = alg->cra_rng.seedsize;
	70
	71	NLA_PUT(skb, CRYPTOCFGA_REPORT_RNG,
	72	sizeof(struct crypto_report_rng), &rrng);
	73
	74	return 0;
	75
	76	nla_put_failure:
	77	return -EMSGSIZE;
	78	}
	79
17f0f4a4 NH	80	static void crypto_rng_show(struct seq_file m, struct crypto_alg alg)
	81	__attribute__ ((unused));
	82	static 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", alg->cra_rng.seedsize);
	86	}
	87
	88	static unsigned int crypto_rng_ctxsize(struct crypto_alg *alg, u32 type,
	89	u32 mask)
	90	{
	91	return alg->cra_ctxsize;
	92	}
	93
	94	const struct crypto_type crypto_rng_type = {
	95	.ctxsize = crypto_rng_ctxsize,
	96	.init = crypto_init_rng_ops,
	97	#ifdef CONFIG_PROC_FS
	98	.show = crypto_rng_show,
	99	#endif
792608e9	100	.report = crypto_rng_report,
17f0f4a4 NH	101	};
	102	EXPORT_SYMBOL_GPL(crypto_rng_type);
	103
	104	int crypto_get_default_rng(void)
	105	{
	106	struct crypto_rng *rng;
	107	int err;
	108
	109	mutex_lock(&crypto_default_rng_lock);
	110	if (!crypto_default_rng) {
	111	rng = crypto_alloc_rng("stdrng", 0, 0);
	112	err = PTR_ERR(rng);
	113	if (IS_ERR(rng))
	114	goto unlock;
	115
	116	err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
	117	if (err) {
	118	crypto_free_rng(rng);
	119	goto unlock;
	120	}
	121
	122	crypto_default_rng = rng;
	123	}
	124
	125	crypto_default_rng_refcnt++;
	126	err = 0;
	127
	128	unlock:
	129	mutex_unlock(&crypto_default_rng_lock);
	130
	131	return err;
	132	}
	133	EXPORT_SYMBOL_GPL(crypto_get_default_rng);
	134
	135	void crypto_put_default_rng(void)
	136	{
	137	mutex_lock(&crypto_default_rng_lock);
	138	if (!--crypto_default_rng_refcnt) {
	139	crypto_free_rng(crypto_default_rng);
	140	crypto_default_rng = NULL;
	141	}
	142	mutex_unlock(&crypto_default_rng_lock);
	143	}
	144	EXPORT_SYMBOL_GPL(crypto_put_default_rng);
	145
	146	MODULE_LICENSE("GPL");
a8ccc393	147	MODULE_DESCRIPTION("Random Number Generator");