996e2523cc
We already allow asynchronous removal of existing algorithm modules. By allowing the replacement of existing algorithms, we can replace algorithms without having to wait for for all existing users to complete. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
329 lines
6.4 KiB
C
329 lines
6.4 KiB
C
/*
|
|
* Scatterlist Cryptographic API.
|
|
*
|
|
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
|
|
* Copyright (c) 2002 David S. Miller (davem@redhat.com)
|
|
* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
|
|
* and Nettle, by Niels Möller.
|
|
*
|
|
* 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/compiler.h>
|
|
#include <linux/init.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kmod.h>
|
|
#include <linux/rwsem.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include "internal.h"
|
|
|
|
LIST_HEAD(crypto_alg_list);
|
|
DECLARE_RWSEM(crypto_alg_sem);
|
|
|
|
static inline int crypto_alg_get(struct crypto_alg *alg)
|
|
{
|
|
return try_module_get(alg->cra_module);
|
|
}
|
|
|
|
static inline void crypto_alg_put(struct crypto_alg *alg)
|
|
{
|
|
module_put(alg->cra_module);
|
|
}
|
|
|
|
static struct crypto_alg *crypto_alg_lookup(const char *name)
|
|
{
|
|
struct crypto_alg *q, *alg = NULL;
|
|
int best = -1;
|
|
|
|
if (!name)
|
|
return NULL;
|
|
|
|
down_read(&crypto_alg_sem);
|
|
|
|
list_for_each_entry(q, &crypto_alg_list, cra_list) {
|
|
int exact, fuzzy;
|
|
|
|
exact = !strcmp(q->cra_driver_name, name);
|
|
fuzzy = !strcmp(q->cra_name, name);
|
|
if (!exact && !(fuzzy && q->cra_priority > best))
|
|
continue;
|
|
|
|
if (unlikely(!crypto_alg_get(q)))
|
|
continue;
|
|
|
|
best = q->cra_priority;
|
|
if (alg)
|
|
crypto_alg_put(alg);
|
|
alg = q;
|
|
|
|
if (exact)
|
|
break;
|
|
}
|
|
|
|
up_read(&crypto_alg_sem);
|
|
return alg;
|
|
}
|
|
|
|
/* A far more intelligent version of this is planned. For now, just
|
|
* try an exact match on the name of the algorithm. */
|
|
static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
|
|
{
|
|
return try_then_request_module(crypto_alg_lookup(name), name);
|
|
}
|
|
|
|
static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
|
|
{
|
|
tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
|
|
flags &= ~CRYPTO_TFM_REQ_MASK;
|
|
|
|
switch (crypto_tfm_alg_type(tfm)) {
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
return crypto_init_cipher_flags(tfm, flags);
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
return crypto_init_digest_flags(tfm, flags);
|
|
|
|
case CRYPTO_ALG_TYPE_COMPRESS:
|
|
return crypto_init_compress_flags(tfm, flags);
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
BUG();
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int crypto_init_ops(struct crypto_tfm *tfm)
|
|
{
|
|
switch (crypto_tfm_alg_type(tfm)) {
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
return crypto_init_cipher_ops(tfm);
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
return crypto_init_digest_ops(tfm);
|
|
|
|
case CRYPTO_ALG_TYPE_COMPRESS:
|
|
return crypto_init_compress_ops(tfm);
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
BUG();
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void crypto_exit_ops(struct crypto_tfm *tfm)
|
|
{
|
|
switch (crypto_tfm_alg_type(tfm)) {
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
crypto_exit_cipher_ops(tfm);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
crypto_exit_digest_ops(tfm);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_COMPRESS:
|
|
crypto_exit_compress_ops(tfm);
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
|
|
}
|
|
}
|
|
|
|
static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
|
|
{
|
|
unsigned int len;
|
|
|
|
switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
|
|
default:
|
|
BUG();
|
|
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
len = crypto_cipher_ctxsize(alg, flags);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
len = crypto_digest_ctxsize(alg, flags);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_COMPRESS:
|
|
len = crypto_compress_ctxsize(alg, flags);
|
|
break;
|
|
}
|
|
|
|
return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
|
|
}
|
|
|
|
struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
|
|
{
|
|
struct crypto_tfm *tfm = NULL;
|
|
struct crypto_alg *alg;
|
|
unsigned int tfm_size;
|
|
|
|
alg = crypto_alg_mod_lookup(name);
|
|
if (alg == NULL)
|
|
goto out;
|
|
|
|
tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
|
|
tfm = kzalloc(tfm_size, GFP_KERNEL);
|
|
if (tfm == NULL)
|
|
goto out_put;
|
|
|
|
tfm->__crt_alg = alg;
|
|
|
|
if (crypto_init_flags(tfm, flags))
|
|
goto out_free_tfm;
|
|
|
|
if (crypto_init_ops(tfm))
|
|
goto out_free_tfm;
|
|
|
|
if (alg->cra_init && alg->cra_init(tfm))
|
|
goto cra_init_failed;
|
|
|
|
goto out;
|
|
|
|
cra_init_failed:
|
|
crypto_exit_ops(tfm);
|
|
out_free_tfm:
|
|
kfree(tfm);
|
|
tfm = NULL;
|
|
out_put:
|
|
crypto_alg_put(alg);
|
|
out:
|
|
return tfm;
|
|
}
|
|
|
|
void crypto_free_tfm(struct crypto_tfm *tfm)
|
|
{
|
|
struct crypto_alg *alg;
|
|
int size;
|
|
|
|
if (unlikely(!tfm))
|
|
return;
|
|
|
|
alg = tfm->__crt_alg;
|
|
size = sizeof(*tfm) + alg->cra_ctxsize;
|
|
|
|
if (alg->cra_exit)
|
|
alg->cra_exit(tfm);
|
|
crypto_exit_ops(tfm);
|
|
crypto_alg_put(alg);
|
|
memset(tfm, 0, size);
|
|
kfree(tfm);
|
|
}
|
|
|
|
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);
|
|
out:
|
|
up_write(&crypto_alg_sem);
|
|
return ret;
|
|
}
|
|
|
|
int crypto_unregister_alg(struct crypto_alg *alg)
|
|
{
|
|
int ret = -ENOENT;
|
|
struct crypto_alg *q;
|
|
|
|
BUG_ON(!alg->cra_module);
|
|
|
|
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);
|
|
return ret;
|
|
}
|
|
|
|
int crypto_alg_available(const char *name, u32 flags)
|
|
{
|
|
int ret = 0;
|
|
struct crypto_alg *alg = crypto_alg_mod_lookup(name);
|
|
|
|
if (alg) {
|
|
crypto_alg_put(alg);
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __init init_crypto(void)
|
|
{
|
|
printk(KERN_INFO "Initializing Cryptographic API\n");
|
|
crypto_init_proc();
|
|
return 0;
|
|
}
|
|
|
|
__initcall(init_crypto);
|
|
|
|
EXPORT_SYMBOL_GPL(crypto_register_alg);
|
|
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
|
|
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
|
|
EXPORT_SYMBOL_GPL(crypto_free_tfm);
|
|
EXPORT_SYMBOL_GPL(crypto_alg_available);
|