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crypto: padlock - Use shash fallback for sha
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This patch changes padlock sha fallback to shash instead of hash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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herbertx committed Jul 11, 2009
1 parent f63559b commit 7d02460
Showing 1 changed file with 52 additions and 30 deletions.
82 changes: 52 additions & 30 deletions drivers/crypto/padlock-sha.c
Original file line number Diff line number Diff line change
Expand Up @@ -12,28 +12,24 @@
*
*/

#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/cryptohash.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <asm/i387.h>
#include "padlock.h"

#define SHA1_DEFAULT_FALLBACK "sha1-generic"
#define SHA256_DEFAULT_FALLBACK "sha256-generic"

struct padlock_sha_ctx {
char *data;
size_t used;
int bypass;
void (*f_sha_padlock)(const char *in, char *out, int count);
struct hash_desc fallback;
struct shash_desc *fallback;
};

static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
Expand All @@ -47,21 +43,26 @@ static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)

static struct crypto_alg sha1_alg, sha256_alg;

static void padlock_sha_bypass(struct crypto_tfm *tfm)
static int padlock_sha_bypass(struct crypto_tfm *tfm)
{
int err = 0;

if (ctx(tfm)->bypass)
return;
goto out;

crypto_hash_init(&ctx(tfm)->fallback);
if (ctx(tfm)->data && ctx(tfm)->used) {
struct scatterlist sg;
err = crypto_shash_init(ctx(tfm)->fallback);
if (err)
goto out;

sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
}
if (ctx(tfm)->data && ctx(tfm)->used)
err = crypto_shash_update(ctx(tfm)->fallback, ctx(tfm)->data,
ctx(tfm)->used);

ctx(tfm)->used = 0;
ctx(tfm)->bypass = 1;

out:
return err;
}

static void padlock_sha_init(struct crypto_tfm *tfm)
Expand All @@ -73,15 +74,18 @@ static void padlock_sha_init(struct crypto_tfm *tfm)
static void padlock_sha_update(struct crypto_tfm *tfm,
const uint8_t *data, unsigned int length)
{
int err;

/* Our buffer is always one page. */
if (unlikely(!ctx(tfm)->bypass &&
(ctx(tfm)->used + length > PAGE_SIZE)))
padlock_sha_bypass(tfm);
(ctx(tfm)->used + length > PAGE_SIZE))) {
err = padlock_sha_bypass(tfm);
BUG_ON(err);
}

if (unlikely(ctx(tfm)->bypass)) {
struct scatterlist sg;
sg_init_one(&sg, (uint8_t *)data, length);
crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
err = crypto_shash_update(ctx(tfm)->fallback, data, length);
BUG_ON(err);
return;
}

Expand Down Expand Up @@ -151,8 +155,11 @@ static void padlock_do_sha256(const char *in, char *out, int count)

static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
{
int err;

if (unlikely(ctx(tfm)->bypass)) {
crypto_hash_final(&ctx(tfm)->fallback, out);
err = crypto_shash_final(ctx(tfm)->fallback, out);
BUG_ON(err);
ctx(tfm)->bypass = 0;
return;
}
Expand All @@ -166,27 +173,41 @@ static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
static int padlock_cra_init(struct crypto_tfm *tfm)
{
const char *fallback_driver_name = tfm->__crt_alg->cra_name;
struct crypto_hash *fallback_tfm;
struct crypto_shash *fallback_tfm;
int err = -ENOMEM;

/* For now we'll allocate one page. This
* could eventually be configurable one day. */
ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
if (!ctx(tfm)->data)
return -ENOMEM;
goto out;

/* Allocate a fallback and abort if it failed. */
fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK);
fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
fallback_driver_name);
free_page((unsigned long)(ctx(tfm)->data));
return PTR_ERR(fallback_tfm);
err = PTR_ERR(fallback_tfm);
goto out_free_page;
}

ctx(tfm)->fallback.tfm = fallback_tfm;
ctx(tfm)->fallback = kmalloc(sizeof(struct shash_desc) +
crypto_shash_descsize(fallback_tfm),
GFP_KERNEL);
if (!ctx(tfm)->fallback)
goto out_free_tfm;

ctx(tfm)->fallback->tfm = fallback_tfm;
ctx(tfm)->fallback->flags = 0;
return 0;

out_free_tfm:
crypto_free_shash(fallback_tfm);
out_free_page:
free_page((unsigned long)(ctx(tfm)->data));
out:
return err;
}

static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
Expand All @@ -210,8 +231,9 @@ static void padlock_cra_exit(struct crypto_tfm *tfm)
ctx(tfm)->data = NULL;
}

crypto_free_hash(ctx(tfm)->fallback.tfm);
ctx(tfm)->fallback.tfm = NULL;
crypto_free_shash(ctx(tfm)->fallback->tfm);

kzfree(ctx(tfm)->fallback);
}

static struct crypto_alg sha1_alg = {
Expand Down

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