linux/crypto/algapi.c
Herbert Xu cce9e06d10 [CRYPTO] api: Split out low-level API
The crypto API is made up of the part facing users such as IPsec and the
low-level part which is used by cryptographic entities such as algorithms.
This patch splits out the latter so that the two APIs are more clearly
delineated.  As a bonus the low-level API can now be modularised if all
algorithms are built as modules.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2006-09-21 11:16:30 +10:00

119 lines
2.4 KiB
C

/*
* Cryptographic API for algorithms (i.e., low-level API).
*
* Copyright (c) 2006 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/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include "internal.h"
static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
static const char suffix[] = "-generic";
char *driver_name = alg->cra_driver_name;
int len;
if (*driver_name)
return 0;
len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
memcpy(driver_name + len, suffix, sizeof(suffix));
return 0;
}
int crypto_register_alg(struct crypto_alg *alg)
{
int ret;
struct crypto_alg *q;
if (alg->cra_alignmask & (alg->cra_alignmask + 1))
return -EINVAL;
if (alg->cra_alignmask & alg->cra_blocksize)
return -EINVAL;
if (alg->cra_blocksize > PAGE_SIZE / 8)
return -EINVAL;
if (alg->cra_priority < 0)
return -EINVAL;
ret = crypto_set_driver_name(alg);
if (unlikely(ret))
return ret;
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg) {
ret = -EEXIST;
goto out;
}
}
list_add(&alg->cra_list, &crypto_alg_list);
atomic_set(&alg->cra_refcnt, 1);
out:
up_write(&crypto_alg_sem);
return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);
int crypto_unregister_alg(struct crypto_alg *alg)
{
int ret = -ENOENT;
struct crypto_alg *q;
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (alg == q) {
list_del(&alg->cra_list);
ret = 0;
goto out;
}
}
out:
up_write(&crypto_alg_sem);
if (ret)
return ret;
BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
if (alg->cra_destroy)
alg->cra_destroy(alg);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
static int __init crypto_algapi_init(void)
{
crypto_init_proc();
return 0;
}
static void __exit crypto_algapi_exit(void)
{
crypto_exit_proc();
}
module_init(crypto_algapi_init);
module_exit(crypto_algapi_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");