android_kernel_samsung_msm8976/crypto/ablkcipher.c
Herbert Xu b170a137f4 crypto: skcipher - Avoid infinite loop when cipher fails selftest
When an skcipher constructed through crypto_givcipher_default fails
its selftest, we'll loop forever trying to construct new skcipher
objects but failing because it already exists.

The crux of the issue is that once a givcipher fails the selftest,
we'll ignore it on the next run through crypto_skcipher_lookup and
attempt to construct a new givcipher.

We should instead return an error to the caller if we find a
givcipher that has failed the test.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18 21:20:06 +08:00

362 lines
9.3 KiB
C

/*
* Asynchronous block chaining cipher operations.
*
* This is the asynchronous version of blkcipher.c indicating completion
* via a callback.
*
* 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 <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include "internal.h"
static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cipher->setkey(tfm, alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
if ((unsigned long)key & alignmask)
return setkey_unaligned(tfm, key, keylen);
return cipher->setkey(tfm, key, keylen);
}
static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
return alg->cra_ctxsize;
}
int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
{
return crypto_ablkcipher_encrypt(&req->creq);
}
int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
{
return crypto_ablkcipher_decrypt(&req->creq);
}
static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
u32 mask)
{
struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
if (alg->ivsize > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
if (!alg->ivsize) {
crt->givencrypt = skcipher_null_givencrypt;
crt->givdecrypt = skcipher_null_givdecrypt;
}
crt->base = __crypto_ablkcipher_cast(tfm);
crt->ivsize = alg->ivsize;
return 0;
}
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
seq_printf(m, "type : ablkcipher\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
}
const struct crypto_type crypto_ablkcipher_type = {
.ctxsize = crypto_ablkcipher_ctxsize,
.init = crypto_init_ablkcipher_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_ablkcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
static int no_givdecrypt(struct skcipher_givcrypt_request *req)
{
return -ENOSYS;
}
static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
u32 mask)
{
struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
if (alg->ivsize > PAGE_SIZE / 8)
return -EINVAL;
crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
alg->setkey : setkey;
crt->encrypt = alg->encrypt;
crt->decrypt = alg->decrypt;
crt->givencrypt = alg->givencrypt;
crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
crt->base = __crypto_ablkcipher_cast(tfm);
crt->ivsize = alg->ivsize;
return 0;
}
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
seq_printf(m, "type : givcipher\n");
seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
"yes" : "no");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
}
const struct crypto_type crypto_givcipher_type = {
.ctxsize = crypto_ablkcipher_ctxsize,
.init = crypto_init_givcipher_ops,
#ifdef CONFIG_PROC_FS
.show = crypto_givcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_givcipher_type);
const char *crypto_default_geniv(const struct crypto_alg *alg)
{
return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";
}
static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
{
struct rtattr *tb[3];
struct {
struct rtattr attr;
struct crypto_attr_type data;
} ptype;
struct {
struct rtattr attr;
struct crypto_attr_alg data;
} palg;
struct crypto_template *tmpl;
struct crypto_instance *inst;
struct crypto_alg *larval;
const char *geniv;
int err;
larval = crypto_larval_lookup(alg->cra_driver_name,
CRYPTO_ALG_TYPE_GIVCIPHER,
CRYPTO_ALG_TYPE_MASK);
err = PTR_ERR(larval);
if (IS_ERR(larval))
goto out;
err = -EAGAIN;
if (!crypto_is_larval(larval))
goto drop_larval;
ptype.attr.rta_len = sizeof(ptype);
ptype.attr.rta_type = CRYPTOA_TYPE;
ptype.data.type = type | CRYPTO_ALG_GENIV;
/* GENIV tells the template that we're making a default geniv. */
ptype.data.mask = mask | CRYPTO_ALG_GENIV;
tb[0] = &ptype.attr;
palg.attr.rta_len = sizeof(palg);
palg.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
tb[1] = &palg.attr;
tb[2] = NULL;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
geniv = alg->cra_blkcipher.geniv;
else
geniv = alg->cra_ablkcipher.geniv;
if (!geniv)
geniv = crypto_default_geniv(alg);
tmpl = crypto_lookup_template(geniv);
err = -ENOENT;
if (!tmpl)
goto kill_larval;
inst = tmpl->alloc(tb);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto put_tmpl;
if ((err = crypto_register_instance(tmpl, inst))) {
tmpl->free(inst);
goto put_tmpl;
}
/* Redo the lookup to use the instance we just registered. */
err = -EAGAIN;
put_tmpl:
crypto_tmpl_put(tmpl);
kill_larval:
crypto_larval_kill(larval);
drop_larval:
crypto_mod_put(larval);
out:
crypto_mod_put(alg);
return err;
}
static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
u32 mask)
{
struct crypto_alg *alg;
alg = crypto_alg_mod_lookup(name, type, mask);
if (IS_ERR(alg))
return alg;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_GIVCIPHER)
return alg;
if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
alg->cra_ablkcipher.ivsize))
return alg;
crypto_mod_put(alg);
alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
mask & ~CRYPTO_ALG_TESTED);
if (IS_ERR(alg))
return alg;
if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_GIVCIPHER) {
if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
crypto_mod_put(alg);
alg = ERR_PTR(-ENOENT);
}
return alg;
}
BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
alg->cra_ablkcipher.ivsize));
return ERR_PTR(crypto_givcipher_default(alg, type, mask));
}
int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
u32 type, u32 mask)
{
struct crypto_alg *alg;
int err;
type = crypto_skcipher_type(type);
mask = crypto_skcipher_mask(mask);
alg = crypto_lookup_skcipher(name, type, mask);
if (IS_ERR(alg))
return PTR_ERR(alg);
err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
crypto_mod_put(alg);
return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
u32 type, u32 mask)
{
struct crypto_tfm *tfm;
int err;
type = crypto_skcipher_type(type);
mask = crypto_skcipher_mask(mask);
for (;;) {
struct crypto_alg *alg;
alg = crypto_lookup_skcipher(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 __crypto_ablkcipher_cast(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_ablkcipher);