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crypto: remove direct blkcipher_walk dependency on transform
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In order to allow other uses of the blkcipher walk API than the blkcipher
algos themselves, this patch copies some of the transform data members to the
walk struct so the transform is only accessed at walk init time.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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@jpa468
Ard Biesheuvel authored and jpa468 committed Aug 28, 2014
1 parent 9ed7265 commit 29c0c76
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Showing 2 changed files with 37 additions and 35 deletions.
67 changes: 33 additions & 34 deletions crypto/blkcipher.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,14 +70,12 @@ static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
return max(start, end_page);
}

static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
struct blkcipher_walk *walk,
static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
unsigned int bsize)
{
u8 *addr;
unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
addr = blkcipher_get_spot(addr, bsize);
scatterwalk_copychunks(addr, &walk->out, bsize, 1);
return bsize;
Expand Down Expand Up @@ -105,7 +103,6 @@ static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
int blkcipher_walk_done(struct blkcipher_desc *desc,
struct blkcipher_walk *walk, int err)
{
struct crypto_blkcipher *tfm = desc->tfm;
unsigned int nbytes = 0;

if (likely(err >= 0)) {
Expand All @@ -117,7 +114,7 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
err = -EINVAL;
goto err;
} else
n = blkcipher_done_slow(tfm, walk, n);
n = blkcipher_done_slow(walk, n);

nbytes = walk->total - n;
err = 0;
Expand All @@ -136,7 +133,7 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
}

if (walk->iv != desc->info)
memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
memcpy(desc->info, walk->iv, walk->ivsize);
if (walk->buffer != walk->page)
kfree(walk->buffer);
if (walk->page)
Expand Down Expand Up @@ -226,22 +223,20 @@ static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
static int blkcipher_walk_next(struct blkcipher_desc *desc,
struct blkcipher_walk *walk)
{
struct crypto_blkcipher *tfm = desc->tfm;
unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
unsigned int bsize;
unsigned int n;
int err;

n = walk->total;
if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
if (unlikely(n < walk->cipher_blocksize)) {
desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
return blkcipher_walk_done(desc, walk, -EINVAL);
}

walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
BLKCIPHER_WALK_DIFF);
if (!scatterwalk_aligned(&walk->in, alignmask) ||
!scatterwalk_aligned(&walk->out, alignmask)) {
if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
!scatterwalk_aligned(&walk->out, walk->alignmask)) {
walk->flags |= BLKCIPHER_WALK_COPY;
if (!walk->page) {
walk->page = (void *)__get_free_page(GFP_ATOMIC);
Expand All @@ -250,12 +245,12 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
}
}

bsize = min(walk->blocksize, n);
bsize = min(walk->walk_blocksize, n);
n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n);

if (unlikely(n < bsize)) {
err = blkcipher_next_slow(desc, walk, bsize, alignmask);
err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
goto set_phys_lowmem;
}

Expand All @@ -277,36 +272,37 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
return err;
}

static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
struct crypto_blkcipher *tfm,
unsigned int alignmask)
static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
{
unsigned bs = walk->blocksize;
unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
unsigned aligned_bs = ALIGN(bs, alignmask + 1);
unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
(alignmask + 1);
unsigned bs = walk->walk_blocksize;
unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
unsigned int size = aligned_bs * 2 +
walk->ivsize + max(aligned_bs, walk->ivsize) -
(walk->alignmask + 1);
u8 *iv;

size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
walk->buffer = kmalloc(size, GFP_ATOMIC);
if (!walk->buffer)
return -ENOMEM;

iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
iv = blkcipher_get_spot(iv, bs) + aligned_bs;
iv = blkcipher_get_spot(iv, bs) + aligned_bs;
iv = blkcipher_get_spot(iv, ivsize);
iv = blkcipher_get_spot(iv, walk->ivsize);

walk->iv = memcpy(iv, walk->iv, ivsize);
walk->iv = memcpy(iv, walk->iv, walk->ivsize);
return 0;
}

int blkcipher_walk_virt(struct blkcipher_desc *desc,
struct blkcipher_walk *walk)
{
walk->flags &= ~BLKCIPHER_WALK_PHYS;
walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
walk->cipher_blocksize = walk->walk_blocksize;
walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
Expand All @@ -315,17 +311,17 @@ int blkcipher_walk_phys(struct blkcipher_desc *desc,
struct blkcipher_walk *walk)
{
walk->flags |= BLKCIPHER_WALK_PHYS;
walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
walk->cipher_blocksize = walk->walk_blocksize;
walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_phys);

static int blkcipher_walk_first(struct blkcipher_desc *desc,
struct blkcipher_walk *walk)
{
struct crypto_blkcipher *tfm = desc->tfm;
unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

if (WARN_ON_ONCE(in_irq()))
return -EDEADLK;

Expand All @@ -335,8 +331,8 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,

walk->buffer = NULL;
walk->iv = desc->info;
if (unlikely(((unsigned long)walk->iv & alignmask))) {
int err = blkcipher_copy_iv(walk, tfm, alignmask);
if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
int err = blkcipher_copy_iv(walk);
if (err)
return err;
}
Expand All @@ -353,7 +349,10 @@ int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
unsigned int blocksize)
{
walk->flags &= ~BLKCIPHER_WALK_PHYS;
walk->blocksize = blocksize;
walk->walk_blocksize = blocksize;
walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
Expand Down
5 changes: 4 additions & 1 deletion include/crypto/algapi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,9 +100,12 @@ struct blkcipher_walk {
void *page;
u8 *buffer;
u8 *iv;
unsigned int ivsize;

int flags;
unsigned int blocksize;
unsigned int walk_blocksize;
unsigned int cipher_blocksize;
unsigned int alignmask;
};

struct ablkcipher_walk {
Expand Down

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