linux/crypto/algapi.c

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/*
* 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/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/string.h>
#include "internal.h"
static LIST_HEAD(crypto_template_list);
void crypto_larval_error(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);
if (alg) {
if (crypto_is_larval(alg)) {
struct crypto_larval *larval = (void *)alg;
complete(&larval->completion);
}
crypto_mod_put(alg);
}
}
EXPORT_SYMBOL_GPL(crypto_larval_error);
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;
}
static int crypto_check_alg(struct crypto_alg *alg)
{
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;
return crypto_set_driver_name(alg);
}
static void crypto_destroy_instance(struct crypto_alg *alg)
{
struct crypto_instance *inst = (void *)alg;
struct crypto_template *tmpl = inst->tmpl;
tmpl->free(inst);
crypto_tmpl_put(tmpl);
}
static void crypto_remove_spawns(struct list_head *spawns,
struct list_head *list)
{
struct crypto_spawn *spawn, *n;
list_for_each_entry_safe(spawn, n, spawns, list) {
struct crypto_instance *inst = spawn->inst;
struct crypto_template *tmpl = inst->tmpl;
list_del_init(&spawn->list);
spawn->alg = NULL;
if (crypto_is_dead(&inst->alg))
continue;
inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
if (!tmpl || !crypto_tmpl_get(tmpl))
continue;
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
list_move(&inst->alg.cra_list, list);
hlist_del(&inst->list);
inst->alg.cra_destroy = crypto_destroy_instance;
if (!list_empty(&inst->alg.cra_users)) {
if (&n->list == spawns)
n = list_entry(inst->alg.cra_users.next,
typeof(*n), list);
__list_splice(&inst->alg.cra_users, spawns->prev);
}
}
}
static int __crypto_register_alg(struct crypto_alg *alg,
struct list_head *list)
{
struct crypto_alg *q;
int ret = -EAGAIN;
if (crypto_is_dead(alg))
goto out;
INIT_LIST_HEAD(&alg->cra_users);
ret = -EEXIST;
atomic_set(&alg->cra_refcnt, 1);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg)
goto out;
if (crypto_is_moribund(q))
continue;
if (crypto_is_larval(q)) {
struct crypto_larval *larval = (void *)q;
if (strcmp(alg->cra_name, q->cra_name) &&
strcmp(alg->cra_driver_name, q->cra_name))
continue;
if (larval->adult)
continue;
if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
continue;
if (!crypto_mod_get(alg))
continue;
larval->adult = alg;
complete(&larval->completion);
continue;
}
if (strcmp(alg->cra_name, q->cra_name))
continue;
if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
q->cra_priority > alg->cra_priority)
continue;
crypto_remove_spawns(&q->cra_users, list);
}
list_add(&alg->cra_list, &crypto_alg_list);
crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
ret = 0;
out:
return ret;
}
static void crypto_remove_final(struct list_head *list)
{
struct crypto_alg *alg;
struct crypto_alg *n;
list_for_each_entry_safe(alg, n, list, cra_list) {
list_del_init(&alg->cra_list);
crypto_alg_put(alg);
}
}
int crypto_register_alg(struct crypto_alg *alg)
{
LIST_HEAD(list);
int err;
err = crypto_check_alg(alg);
if (err)
return err;
down_write(&crypto_alg_sem);
err = __crypto_register_alg(alg, &list);
up_write(&crypto_alg_sem);
crypto_remove_final(&list);
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);
static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
if (unlikely(list_empty(&alg->cra_list)))
return -ENOENT;
alg->cra_flags |= CRYPTO_ALG_DEAD;
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
list_del_init(&alg->cra_list);
crypto_remove_spawns(&alg->cra_users, list);
return 0;
}
int crypto_unregister_alg(struct crypto_alg *alg)
{
int ret;
LIST_HEAD(list);
down_write(&crypto_alg_sem);
ret = crypto_remove_alg(alg, &list);
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);
crypto_remove_final(&list);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
int crypto_register_template(struct crypto_template *tmpl)
{
struct crypto_template *q;
int err = -EEXIST;
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_template_list, list) {
if (q == tmpl)
goto out;
}
list_add(&tmpl->list, &crypto_template_list);
crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
err = 0;
out:
up_write(&crypto_alg_sem);
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);
void crypto_unregister_template(struct crypto_template *tmpl)
{
struct crypto_instance *inst;
struct hlist_node *p, *n;
struct hlist_head *list;
LIST_HEAD(users);
down_write(&crypto_alg_sem);
BUG_ON(list_empty(&tmpl->list));
list_del_init(&tmpl->list);
list = &tmpl->instances;
hlist_for_each_entry(inst, p, list, list) {
int err = crypto_remove_alg(&inst->alg, &users);
BUG_ON(err);
}
crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
up_write(&crypto_alg_sem);
hlist_for_each_entry_safe(inst, p, n, list, list) {
BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
tmpl->free(inst);
}
crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);
static struct crypto_template *__crypto_lookup_template(const char *name)
{
struct crypto_template *q, *tmpl = NULL;
down_read(&crypto_alg_sem);
list_for_each_entry(q, &crypto_template_list, list) {
if (strcmp(q->name, name))
continue;
if (unlikely(!crypto_tmpl_get(q)))
continue;
tmpl = q;
break;
}
up_read(&crypto_alg_sem);
return tmpl;
}
struct crypto_template *crypto_lookup_template(const char *name)
{
return try_then_request_module(__crypto_lookup_template(name), name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst)
{
LIST_HEAD(list);
int err = -EINVAL;
if (inst->alg.cra_destroy)
goto err;
err = crypto_check_alg(&inst->alg);
if (err)
goto err;
inst->alg.cra_module = tmpl->module;
down_write(&crypto_alg_sem);
err = __crypto_register_alg(&inst->alg, &list);
if (err)
goto unlock;
hlist_add_head(&inst->list, &tmpl->instances);
inst->tmpl = tmpl;
unlock:
up_write(&crypto_alg_sem);
crypto_remove_final(&list);
err:
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);
int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
struct crypto_instance *inst)
{
int err = -EAGAIN;
spawn->inst = inst;
down_write(&crypto_alg_sem);
if (!crypto_is_moribund(alg)) {
list_add(&spawn->list, &alg->cra_users);
spawn->alg = alg;
err = 0;
}
up_write(&crypto_alg_sem);
return err;
}
EXPORT_SYMBOL_GPL(crypto_init_spawn);
void crypto_drop_spawn(struct crypto_spawn *spawn)
{
down_write(&crypto_alg_sem);
list_del(&spawn->list);
up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);
struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
u32 mask)
{
struct crypto_alg *alg;
struct crypto_alg *alg2;
struct crypto_tfm *tfm;
down_read(&crypto_alg_sem);
alg = spawn->alg;
alg2 = alg;
if (alg2)
alg2 = crypto_mod_get(alg2);
up_read(&crypto_alg_sem);
if (!alg2) {
if (alg)
crypto_shoot_alg(alg);
return ERR_PTR(-EAGAIN);
}
tfm = ERR_PTR(-EINVAL);
if (unlikely((alg->cra_flags ^ type) & mask))
goto out_put_alg;
tfm = __crypto_alloc_tfm(alg, type, mask);
if (IS_ERR(tfm))
goto out_put_alg;
return tfm;
out_put_alg:
crypto_mod_put(alg);
return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
int crypto_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);
int crypto_unregister_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
{
struct rtattr *rta = tb[CRYPTOA_TYPE - 1];
struct crypto_attr_type *algt;
if (!rta)
return ERR_PTR(-ENOENT);
if (RTA_PAYLOAD(rta) < sizeof(*algt))
return ERR_PTR(-EINVAL);
algt = RTA_DATA(rta);
return algt;
}
EXPORT_SYMBOL_GPL(crypto_get_attr_type);
int crypto_check_attr_type(struct rtattr **tb, u32 type)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ type) & algt->mask)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(crypto_check_attr_type);
struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb, u32 type, u32 mask)
{
struct rtattr *rta = tb[CRYPTOA_ALG - 1];
struct crypto_attr_alg *alga;
if (!rta)
return ERR_PTR(-ENOENT);
if (RTA_PAYLOAD(rta) < sizeof(*alga))
return ERR_PTR(-EINVAL);
alga = RTA_DATA(rta);
alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
return crypto_alg_mod_lookup(alga->name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_get_attr_alg);
struct crypto_instance *crypto_alloc_instance(const char *name,
struct crypto_alg *alg)
{
struct crypto_instance *inst;
struct crypto_spawn *spawn;
int err;
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return ERR_PTR(-ENOMEM);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
spawn = crypto_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, inst);
if (err)
goto err_free_inst;
return inst;
err_free_inst:
kfree(inst);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_instance);
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");