Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

127 lines (104 sloc) 2.821 kb
/*
* 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 <asm/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/string.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 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
};
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");
Jump to Line
Something went wrong with that request. Please try again.