Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

607 lines (491 sloc) 13.683 kb
/*
* 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");
Jump to Line
Something went wrong with that request. Please try again.