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/*
* 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 = crypto_alg_lookup(name, type, mask);
if (!alg) {
request_module("%s", name);
if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
CRYPTO_ALG_NEED_FALLBACK))
request_module("%s-all", name);
alg = crypto_alg_lookup(name, type, mask);
}
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 (!((type | 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_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_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_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);
void *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);
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);
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:
mem = ERR_PTR(err);
out:
return mem;
}
EXPORT_SYMBOL_GPL(crypto_create_tfm);
struct crypto_alg *crypto_find_alg(const char *alg_name,
const struct crypto_type *frontend,
u32 type, u32 mask)
{
struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
crypto_alg_mod_lookup;
if (frontend) {
type &= frontend->maskclear;
mask &= frontend->maskclear;
type |= frontend->type;
mask |= frontend->maskset;
if (frontend->lookup)
lookup = frontend->lookup;
}
return lookup(alg_name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_find_alg);
/*
* 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.
*/
void *crypto_alloc_tfm(const char *alg_name,
const struct crypto_type *frontend, u32 type, u32 mask)
{
void *tfm;
int err;
for (;;) {
struct crypto_alg *alg;
alg = crypto_find_alg(alg_name, frontend, 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_destroy_tfm - Free crypto transform
* @mem: Start of tfm slab
* @tfm: Transform to free
*
* This function frees up the transform and any associated resources,
* then drops the refcount on the associated algorithm.
*/
void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
{
struct crypto_alg *alg;
if (unlikely(!mem))
return;
alg = tfm->__crt_alg;
if (!tfm->exit && alg->cra_exit)
alg->cra_exit(tfm);
crypto_exit_ops(tfm);
crypto_mod_put(alg);
kzfree(mem);
}
EXPORT_SYMBOL_GPL(crypto_destroy_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");
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