linux/include/crypto/internal/rng.h
Herbert Xu 7cecadb7cc crypto: rng - Do not free default RNG when it becomes unused
Currently we free the default RNG when its use count hits zero.
This was OK when the IV generators would latch onto the RNG at
instance creation time and keep it until the instance is torn
down.

Now that IV generators only keep the RNG reference during init
time this scheme causes the default RNG to come and go at a high
frequencey.  This is highly undesirable as we want to keep a single
RNG in use unless the admin wants it to be removed.

This patch changes the scheme so that the system RNG once allocated
is never removed unless a specifically requested.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-22 15:49:18 +08:00

46 lines
1.2 KiB
C

/*
* RNG: Random Number Generator algorithms under the crypto API
*
* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
* Copyright (c) 2015 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 option)
* any later version.
*
*/
#ifndef _CRYPTO_INTERNAL_RNG_H
#define _CRYPTO_INTERNAL_RNG_H
#include <crypto/algapi.h>
#include <crypto/rng.h>
int crypto_register_rng(struct rng_alg *alg);
void crypto_unregister_rng(struct rng_alg *alg);
int crypto_register_rngs(struct rng_alg *algs, int count);
void crypto_unregister_rngs(struct rng_alg *algs, int count);
#if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE)
int crypto_del_default_rng(void);
#else
static inline int crypto_del_default_rng(void)
{
return 0;
}
#endif
static inline void *crypto_rng_ctx(struct crypto_rng *tfm)
{
return crypto_tfm_ctx(&tfm->base);
}
static inline void crypto_rng_set_entropy(struct crypto_rng *tfm,
const u8 *data, unsigned int len)
{
crypto_rng_alg(tfm)->set_ent(tfm, data, len);
}
#endif