linux-imx

/*

 * Cryptographic API.

 *

 * RNG operations.

 *

 * 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.

 *

 */

​

#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 <linux/compiler.h>

#include <net/netlink.h>

​

#include "internal.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;

​

int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)

{

    struct crypto_alg *alg = tfm->base.__crt_alg;

    u8 *buf = NULL;

    int err;

​

    crypto_stats_get(alg);

    if (!seed && slen) {

        buf = kmalloc(slen, GFP_KERNEL);

        if (!buf)

            return -ENOMEM;

​

        err = get_random_bytes_wait(buf, slen);

        if (err)

            goto out;

        seed = buf;

    }

​

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

    crypto_stats_rng_seed(alg, err);

out:

    kzfree(buf);

    return err;

}

EXPORT_SYMBOL_GPL(crypto_rng_reset);

​

static int crypto_rng_init_tfm(struct crypto_tfm *tfm)

{

    return 0;

}

​

static unsigned int seedsize(struct crypto_alg *alg)

{

    struct rng_alg *ralg = container_of(alg, struct rng_alg, base);

​

    return ralg->seedsize;

}

​

#ifdef CONFIG_NET

static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)

{

    struct crypto_report_rng rrng;

​

    memset(&rrng, 0, sizeof(rrng));

​

    strscpy(rrng.type, "rng", sizeof(rrng.type));

​

    rrng.seedsize = seedsize(alg);

​

    return nla_put(skb, CRYPTOCFGA_REPORT_RNG, sizeof(rrng), &rrng);

}

#else

static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)

{

    return -ENOSYS;

}

#endif