linux/crypto/krng.c

/*
 * RNG implementation using standard kernel RNG.
 *
 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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
 * any later version.
 *
 */

#include <crypto/internal/rng.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/random.h>

static int krng_generate(struct crypto_rng *tfm,
			 const u8 *src, unsigned int slen,
			 u8 *rdata, unsigned int dlen)
{
	get_random_bytes(rdata, dlen);
	return 0;
}

static int krng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
{
	return 0;
}

static struct rng_alg krng_alg = {
	.generate		= krng_generate,
	.seed			= krng_seed,
	.base			=	{
		.cra_name		= "stdrng",
		.cra_driver_name	= "krng",
		.cra_priority		= 200,
		.cra_module		= THIS_MODULE,
	}
};


/* Module initalization */
static int __init krng_mod_init(void)
{
	return crypto_register_rng(&krng_alg);
}

static void __exit krng_mod_fini(void)
{
	crypto_unregister_rng(&krng_alg);
}

module_init(krng_mod_init);
module_exit(krng_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Kernel Random Number Generator");
MODULE_ALIAS_CRYPTO("stdrng");
MODULE_ALIAS_CRYPTO("krng");