mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Herbert Xu](/assets/img/avatar_default.png)
This patch reintroduces a completely revamped crypto_alloc_tfm. The biggest change is that we now take two crypto_type objects when allocating a tfm, a frontend and a backend. In fact this simply formalises what we've been doing behind the API's back. For example, as it stands crypto_alloc_ahash may use an actual ahash algorithm or a crypto_hash algorithm. Putting this in the API allows us to do this much more cleanly. The existing types will be converted across gradually. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
604 lines
13 KiB
C
604 lines
13 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/err.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kmod.h>
|
|
#include <linux/module.h>
|
|
#include <linux/param.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include "internal.h"
|
|
|
|
LIST_HEAD(crypto_alg_list);
|
|
EXPORT_SYMBOL_GPL(crypto_alg_list);
|
|
DECLARE_RWSEM(crypto_alg_sem);
|
|
EXPORT_SYMBOL_GPL(crypto_alg_sem);
|
|
|
|
BLOCKING_NOTIFIER_HEAD(crypto_chain);
|
|
EXPORT_SYMBOL_GPL(crypto_chain);
|
|
|
|
static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
|
|
{
|
|
atomic_inc(&alg->cra_refcnt);
|
|
return alg;
|
|
}
|
|
|
|
struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
|
|
{
|
|
return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_mod_get);
|
|
|
|
void crypto_mod_put(struct crypto_alg *alg)
|
|
{
|
|
struct module *module = alg->cra_module;
|
|
|
|
crypto_alg_put(alg);
|
|
module_put(module);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_mod_put);
|
|
|
|
static inline int crypto_is_test_larval(struct crypto_larval *larval)
|
|
{
|
|
return larval->alg.cra_driver_name[0];
|
|
}
|
|
|
|
static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
|
|
u32 mask)
|
|
{
|
|
struct crypto_alg *q, *alg = NULL;
|
|
int best = -2;
|
|
|
|
list_for_each_entry(q, &crypto_alg_list, cra_list) {
|
|
int exact, fuzzy;
|
|
|
|
if (crypto_is_moribund(q))
|
|
continue;
|
|
|
|
if ((q->cra_flags ^ type) & mask)
|
|
continue;
|
|
|
|
if (crypto_is_larval(q) &&
|
|
!crypto_is_test_larval((struct crypto_larval *)q) &&
|
|
((struct crypto_larval *)q)->mask != mask)
|
|
continue;
|
|
|
|
exact = !strcmp(q->cra_driver_name, name);
|
|
fuzzy = !strcmp(q->cra_name, name);
|
|
if (!exact && !(fuzzy && q->cra_priority > best))
|
|
continue;
|
|
|
|
if (unlikely(!crypto_mod_get(q)))
|
|
continue;
|
|
|
|
best = q->cra_priority;
|
|
if (alg)
|
|
crypto_mod_put(alg);
|
|
alg = q;
|
|
|
|
if (exact)
|
|
break;
|
|
}
|
|
|
|
return alg;
|
|
}
|
|
|
|
static void crypto_larval_destroy(struct crypto_alg *alg)
|
|
{
|
|
struct crypto_larval *larval = (void *)alg;
|
|
|
|
BUG_ON(!crypto_is_larval(alg));
|
|
if (larval->adult)
|
|
crypto_mod_put(larval->adult);
|
|
kfree(larval);
|
|
}
|
|
|
|
struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
|
|
{
|
|
struct crypto_larval *larval;
|
|
|
|
larval = kzalloc(sizeof(*larval), GFP_KERNEL);
|
|
if (!larval)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
larval->mask = mask;
|
|
larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
|
|
larval->alg.cra_priority = -1;
|
|
larval->alg.cra_destroy = crypto_larval_destroy;
|
|
|
|
strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
|
|
init_completion(&larval->completion);
|
|
|
|
return larval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_larval_alloc);
|
|
|
|
static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
|
|
u32 mask)
|
|
{
|
|
struct crypto_alg *alg;
|
|
struct crypto_larval *larval;
|
|
|
|
larval = crypto_larval_alloc(name, type, mask);
|
|
if (IS_ERR(larval))
|
|
return ERR_CAST(larval);
|
|
|
|
atomic_set(&larval->alg.cra_refcnt, 2);
|
|
|
|
down_write(&crypto_alg_sem);
|
|
alg = __crypto_alg_lookup(name, type, mask);
|
|
if (!alg) {
|
|
alg = &larval->alg;
|
|
list_add(&alg->cra_list, &crypto_alg_list);
|
|
}
|
|
up_write(&crypto_alg_sem);
|
|
|
|
if (alg != &larval->alg)
|
|
kfree(larval);
|
|
|
|
return alg;
|
|
}
|
|
|
|
void crypto_larval_kill(struct crypto_alg *alg)
|
|
{
|
|
struct crypto_larval *larval = (void *)alg;
|
|
|
|
down_write(&crypto_alg_sem);
|
|
list_del(&alg->cra_list);
|
|
up_write(&crypto_alg_sem);
|
|
complete_all(&larval->completion);
|
|
crypto_alg_put(alg);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_larval_kill);
|
|
|
|
static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
|
|
{
|
|
struct crypto_larval *larval = (void *)alg;
|
|
long timeout;
|
|
|
|
timeout = wait_for_completion_interruptible_timeout(
|
|
&larval->completion, 60 * HZ);
|
|
|
|
alg = larval->adult;
|
|
if (timeout < 0)
|
|
alg = ERR_PTR(-EINTR);
|
|
else if (!timeout)
|
|
alg = ERR_PTR(-ETIMEDOUT);
|
|
else if (!alg)
|
|
alg = ERR_PTR(-ENOENT);
|
|
else if (crypto_is_test_larval(larval) &&
|
|
!(alg->cra_flags & CRYPTO_ALG_TESTED))
|
|
alg = ERR_PTR(-EAGAIN);
|
|
else if (!crypto_mod_get(alg))
|
|
alg = ERR_PTR(-EAGAIN);
|
|
crypto_mod_put(&larval->alg);
|
|
|
|
return alg;
|
|
}
|
|
|
|
struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
|
|
{
|
|
struct crypto_alg *alg;
|
|
|
|
down_read(&crypto_alg_sem);
|
|
alg = __crypto_alg_lookup(name, type, mask);
|
|
up_read(&crypto_alg_sem);
|
|
|
|
return alg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_alg_lookup);
|
|
|
|
struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
|
|
{
|
|
struct crypto_alg *alg;
|
|
|
|
if (!name)
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
|
|
type &= mask;
|
|
|
|
alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
|
|
name);
|
|
if (alg)
|
|
return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
|
|
|
|
return crypto_larval_add(name, type, mask);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_larval_lookup);
|
|
|
|
int crypto_probing_notify(unsigned long val, void *v)
|
|
{
|
|
int ok;
|
|
|
|
ok = blocking_notifier_call_chain(&crypto_chain, val, v);
|
|
if (ok == NOTIFY_DONE) {
|
|
request_module("cryptomgr");
|
|
ok = blocking_notifier_call_chain(&crypto_chain, val, v);
|
|
}
|
|
|
|
return ok;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_probing_notify);
|
|
|
|
struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
|
|
{
|
|
struct crypto_alg *alg;
|
|
struct crypto_alg *larval;
|
|
int ok;
|
|
|
|
if (!(mask & CRYPTO_ALG_TESTED)) {
|
|
type |= CRYPTO_ALG_TESTED;
|
|
mask |= CRYPTO_ALG_TESTED;
|
|
}
|
|
|
|
larval = crypto_larval_lookup(name, type, mask);
|
|
if (IS_ERR(larval) || !crypto_is_larval(larval))
|
|
return larval;
|
|
|
|
ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
|
|
|
|
if (ok == NOTIFY_STOP)
|
|
alg = crypto_larval_wait(larval);
|
|
else {
|
|
crypto_mod_put(larval);
|
|
alg = ERR_PTR(-ENOENT);
|
|
}
|
|
crypto_larval_kill(larval);
|
|
return alg;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
|
|
|
|
static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
|
|
{
|
|
const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
|
|
|
|
if (type_obj)
|
|
return type_obj->init(tfm, type, mask);
|
|
|
|
switch (crypto_tfm_alg_type(tfm)) {
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
return crypto_init_cipher_ops(tfm);
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) !=
|
|
CRYPTO_ALG_TYPE_HASH_MASK)
|
|
return crypto_init_digest_ops_async(tfm);
|
|
else
|
|
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)
|
|
{
|
|
const struct crypto_type *type = tfm->__crt_alg->cra_type;
|
|
|
|
if (type) {
|
|
if (tfm->exit)
|
|
tfm->exit(tfm);
|
|
return;
|
|
}
|
|
|
|
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, u32 type, u32 mask)
|
|
{
|
|
const struct crypto_type *type_obj = alg->cra_type;
|
|
unsigned int len;
|
|
|
|
len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
|
|
if (type_obj)
|
|
return len + type_obj->ctxsize(alg, type, mask);
|
|
|
|
switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
|
|
default:
|
|
BUG();
|
|
|
|
case CRYPTO_ALG_TYPE_CIPHER:
|
|
len += crypto_cipher_ctxsize(alg);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_DIGEST:
|
|
len += crypto_digest_ctxsize(alg);
|
|
break;
|
|
|
|
case CRYPTO_ALG_TYPE_COMPRESS:
|
|
len += crypto_compress_ctxsize(alg);
|
|
break;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
void crypto_shoot_alg(struct crypto_alg *alg)
|
|
{
|
|
down_write(&crypto_alg_sem);
|
|
alg->cra_flags |= CRYPTO_ALG_DYING;
|
|
up_write(&crypto_alg_sem);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_shoot_alg);
|
|
|
|
struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
|
|
u32 mask)
|
|
{
|
|
struct crypto_tfm *tfm = NULL;
|
|
unsigned int tfm_size;
|
|
int err = -ENOMEM;
|
|
|
|
tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
|
|
tfm = kzalloc(tfm_size, GFP_KERNEL);
|
|
if (tfm == NULL)
|
|
goto out_err;
|
|
|
|
tfm->__crt_alg = alg;
|
|
|
|
err = crypto_init_ops(tfm, type, mask);
|
|
if (err)
|
|
goto out_free_tfm;
|
|
|
|
if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
|
|
goto cra_init_failed;
|
|
|
|
goto out;
|
|
|
|
cra_init_failed:
|
|
crypto_exit_ops(tfm);
|
|
out_free_tfm:
|
|
if (err == -EAGAIN)
|
|
crypto_shoot_alg(alg);
|
|
kfree(tfm);
|
|
out_err:
|
|
tfm = ERR_PTR(err);
|
|
out:
|
|
return tfm;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
|
|
|
|
/*
|
|
* crypto_alloc_base - Locate algorithm and allocate transform
|
|
* @alg_name: Name of algorithm
|
|
* @type: Type of algorithm
|
|
* @mask: Mask for type comparison
|
|
*
|
|
* This function should not be used by new algorithm types.
|
|
* Plesae use crypto_alloc_tfm instead.
|
|
*
|
|
* crypto_alloc_base() will first attempt to locate an already loaded
|
|
* algorithm. If that fails and the kernel supports dynamically loadable
|
|
* modules, it will then attempt to load a module of the same name or
|
|
* alias. If that fails it will send a query to any loaded crypto manager
|
|
* to construct an algorithm on the fly. A refcount is grabbed on the
|
|
* algorithm which is then associated with the new transform.
|
|
*
|
|
* The returned transform is of a non-determinate type. Most people
|
|
* should use one of the more specific allocation functions such as
|
|
* crypto_alloc_blkcipher.
|
|
*
|
|
* In case of error the return value is an error pointer.
|
|
*/
|
|
struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
|
|
{
|
|
struct crypto_tfm *tfm;
|
|
int err;
|
|
|
|
for (;;) {
|
|
struct crypto_alg *alg;
|
|
|
|
alg = crypto_alg_mod_lookup(alg_name, type, mask);
|
|
if (IS_ERR(alg)) {
|
|
err = PTR_ERR(alg);
|
|
goto err;
|
|
}
|
|
|
|
tfm = __crypto_alloc_tfm(alg, type, mask);
|
|
if (!IS_ERR(tfm))
|
|
return tfm;
|
|
|
|
crypto_mod_put(alg);
|
|
err = PTR_ERR(tfm);
|
|
|
|
err:
|
|
if (err != -EAGAIN)
|
|
break;
|
|
if (signal_pending(current)) {
|
|
err = -EINTR;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_alloc_base);
|
|
|
|
struct crypto_tfm *crypto_create_tfm(struct crypto_alg *alg,
|
|
const struct crypto_type *frontend)
|
|
{
|
|
char *mem;
|
|
struct crypto_tfm *tfm = NULL;
|
|
unsigned int tfmsize;
|
|
unsigned int total;
|
|
int err = -ENOMEM;
|
|
|
|
tfmsize = frontend->tfmsize;
|
|
total = tfmsize + sizeof(*tfm) + frontend->extsize(alg, frontend);
|
|
|
|
mem = kzalloc(total, GFP_KERNEL);
|
|
if (mem == NULL)
|
|
goto out_err;
|
|
|
|
tfm = (struct crypto_tfm *)(mem + tfmsize);
|
|
tfm->__crt_alg = alg;
|
|
|
|
err = frontend->init_tfm(tfm, frontend);
|
|
if (err)
|
|
goto out_free_tfm;
|
|
|
|
if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
|
|
goto cra_init_failed;
|
|
|
|
goto out;
|
|
|
|
cra_init_failed:
|
|
crypto_exit_ops(tfm);
|
|
out_free_tfm:
|
|
if (err == -EAGAIN)
|
|
crypto_shoot_alg(alg);
|
|
kfree(mem);
|
|
out_err:
|
|
tfm = ERR_PTR(err);
|
|
out:
|
|
return tfm;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_create_tfm);
|
|
|
|
/*
|
|
* crypto_alloc_tfm - Locate algorithm and allocate transform
|
|
* @alg_name: Name of algorithm
|
|
* @frontend: Frontend algorithm type
|
|
* @type: Type of algorithm
|
|
* @mask: Mask for type comparison
|
|
*
|
|
* crypto_alloc_tfm() will first attempt to locate an already loaded
|
|
* algorithm. If that fails and the kernel supports dynamically loadable
|
|
* modules, it will then attempt to load a module of the same name or
|
|
* alias. If that fails it will send a query to any loaded crypto manager
|
|
* to construct an algorithm on the fly. A refcount is grabbed on the
|
|
* algorithm which is then associated with the new transform.
|
|
*
|
|
* The returned transform is of a non-determinate type. Most people
|
|
* should use one of the more specific allocation functions such as
|
|
* crypto_alloc_blkcipher.
|
|
*
|
|
* In case of error the return value is an error pointer.
|
|
*/
|
|
struct crypto_tfm *crypto_alloc_tfm(const char *alg_name,
|
|
const struct crypto_type *frontend,
|
|
u32 type, u32 mask)
|
|
{
|
|
struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask);
|
|
struct crypto_tfm *tfm;
|
|
int err;
|
|
|
|
type &= frontend->maskclear;
|
|
mask &= frontend->maskclear;
|
|
type |= frontend->type;
|
|
mask |= frontend->maskset;
|
|
|
|
lookup = frontend->lookup ?: crypto_alg_mod_lookup;
|
|
|
|
for (;;) {
|
|
struct crypto_alg *alg;
|
|
|
|
alg = lookup(alg_name, type, mask);
|
|
if (IS_ERR(alg)) {
|
|
err = PTR_ERR(alg);
|
|
goto err;
|
|
}
|
|
|
|
tfm = crypto_create_tfm(alg, frontend);
|
|
if (!IS_ERR(tfm))
|
|
return tfm;
|
|
|
|
crypto_mod_put(alg);
|
|
err = PTR_ERR(tfm);
|
|
|
|
err:
|
|
if (err != -EAGAIN)
|
|
break;
|
|
if (signal_pending(current)) {
|
|
err = -EINTR;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
|
|
|
|
/*
|
|
* crypto_free_tfm - Free crypto transform
|
|
* @tfm: Transform to free
|
|
*
|
|
* crypto_free_tfm() frees up the transform and any associated resources,
|
|
* then drops the refcount on the associated algorithm.
|
|
*/
|
|
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 (!tfm->exit && alg->cra_exit)
|
|
alg->cra_exit(tfm);
|
|
crypto_exit_ops(tfm);
|
|
crypto_mod_put(alg);
|
|
memset(tfm, 0, size);
|
|
kfree(tfm);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(crypto_free_tfm);
|
|
|
|
int crypto_has_alg(const char *name, u32 type, u32 mask)
|
|
{
|
|
int ret = 0;
|
|
struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
|
|
|
|
if (!IS_ERR(alg)) {
|
|
crypto_mod_put(alg);
|
|
ret = 1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_has_alg);
|
|
|
|
MODULE_DESCRIPTION("Cryptographic core API");
|
|
MODULE_LICENSE("GPL");
|