mirror of
https://github.com/torvalds/linux
synced 2024-10-03 01:43:05 +00:00
d0e83059a6
This patch converts the top-level crypto_rng to the "new" style. It was the last algorithm type added before we switched over to the new way of doing things exemplified by shash. All users will automatically switch over to the new interface. Note that this patch does not touch the low-level interface to rng implementations. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
166 lines
3.7 KiB
C
166 lines
3.7 KiB
C
/*
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* Cryptographic API.
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*
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* RNG operations.
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*
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* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <linux/atomic.h>
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#include <crypto/internal/rng.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/random.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/cryptouser.h>
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#include <net/netlink.h>
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#include "internal.h"
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static DEFINE_MUTEX(crypto_default_rng_lock);
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struct crypto_rng *crypto_default_rng;
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EXPORT_SYMBOL_GPL(crypto_default_rng);
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static int crypto_default_rng_refcnt;
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static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm)
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{
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return container_of(tfm, struct crypto_rng, base);
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}
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static int rngapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
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{
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u8 *buf = NULL;
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int err;
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if (!seed && slen) {
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buf = kmalloc(slen, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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get_random_bytes(buf, slen);
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seed = buf;
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}
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err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);
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kfree(buf);
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return err;
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}
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static int crypto_rng_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_rng *rng = __crypto_rng_cast(tfm);
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struct rng_alg *alg = &tfm->__crt_alg->cra_rng;
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rng->generate = alg->rng_make_random;
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rng->seed = rngapi_reset;
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return 0;
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}
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#ifdef CONFIG_NET
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static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_rng rrng;
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strncpy(rrng.type, "rng", sizeof(rrng.type));
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rrng.seedsize = alg->cra_rng.seedsize;
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if (nla_put(skb, CRYPTOCFGA_REPORT_RNG,
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sizeof(struct crypto_report_rng), &rrng))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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#else
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static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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return -ENOSYS;
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}
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#endif
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static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
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{
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seq_printf(m, "type : rng\n");
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seq_printf(m, "seedsize : %u\n", alg->cra_rng.seedsize);
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}
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const struct crypto_type crypto_rng_type = {
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.extsize = crypto_alg_extsize,
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.init_tfm = crypto_rng_init_tfm,
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#ifdef CONFIG_PROC_FS
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.show = crypto_rng_show,
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#endif
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.report = crypto_rng_report,
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.maskclear = ~CRYPTO_ALG_TYPE_MASK,
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.maskset = CRYPTO_ALG_TYPE_MASK,
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.type = CRYPTO_ALG_TYPE_RNG,
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.tfmsize = offsetof(struct crypto_rng, base),
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};
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EXPORT_SYMBOL_GPL(crypto_rng_type);
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struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask)
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{
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return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask);
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}
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EXPORT_SYMBOL_GPL(crypto_alloc_rng);
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int crypto_get_default_rng(void)
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{
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struct crypto_rng *rng;
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int err;
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mutex_lock(&crypto_default_rng_lock);
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if (!crypto_default_rng) {
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rng = crypto_alloc_rng("stdrng", 0, 0);
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err = PTR_ERR(rng);
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if (IS_ERR(rng))
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goto unlock;
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err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
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if (err) {
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crypto_free_rng(rng);
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goto unlock;
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}
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crypto_default_rng = rng;
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}
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crypto_default_rng_refcnt++;
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err = 0;
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unlock:
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mutex_unlock(&crypto_default_rng_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(crypto_get_default_rng);
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void crypto_put_default_rng(void)
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{
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mutex_lock(&crypto_default_rng_lock);
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if (!--crypto_default_rng_refcnt) {
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crypto_free_rng(crypto_default_rng);
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crypto_default_rng = NULL;
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}
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mutex_unlock(&crypto_default_rng_lock);
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}
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EXPORT_SYMBOL_GPL(crypto_put_default_rng);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Random Number Generator");
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