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[CRYPTO] blkcipher: Added blkcipher_walk_virt_block

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This patch adds the helper blkcipher_walk_virt_block which is similar to
blkcipher_walk_virt but uses a supplied block size instead of the block
size of the block cipher.  This is useful for CTR where the block size is
1 but we still want to walk by the block size of the underlying cipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2007-10-04 15:24:05 +08:00 committed by David S. Miller
parent 2614de1b9a
commit 7607bd8ff0
2 changed files with 28 additions and 10 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

34
crypto/blkcipher.c
View file

@ -84,8 +84,6 @@ static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk, static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
unsigned int n) unsigned int n)
{ {
n = walk->nbytes - n;
if (walk->flags & BLKCIPHER_WALK_COPY) { if (walk->flags & BLKCIPHER_WALK_COPY) {
blkcipher_map_dst(walk); blkcipher_map_dst(walk);
memcpy(walk->dst.virt.addr, walk->page, n); memcpy(walk->dst.virt.addr, walk->page, n);
@ -109,13 +107,15 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
unsigned int nbytes = 0; unsigned int nbytes = 0;
if (likely(err >= 0)) { if (likely(err >= 0)) {
unsigned int bsize = crypto_blkcipher_blocksize(tfm); unsigned int n = walk->nbytes - err;
unsigned int n;
if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW))) if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
n = blkcipher_done_fast(walk, err); n = blkcipher_done_fast(walk, n);
else else if (WARN_ON(err)) {
n = blkcipher_done_slow(tfm, walk, bsize); err = -EINVAL;
goto err;
} else
n = blkcipher_done_slow(tfm, walk, n);
nbytes = walk->total - n; nbytes = walk->total - n;
err = 0; err = 0;
@ -132,6 +132,7 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
return blkcipher_walk_next(desc, walk); return blkcipher_walk_next(desc, walk);
} }
err:
if (walk->iv != desc->info) if (walk->iv != desc->info)
memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm)); memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
if (walk->buffer != walk->page) if (walk->buffer != walk->page)
@ -225,12 +226,12 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
{ {
struct crypto_blkcipher *tfm = desc->tfm; struct crypto_blkcipher *tfm = desc->tfm;
unsigned int alignmask = crypto_blkcipher_alignmask(tfm); unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
unsigned int bsize = crypto_blkcipher_blocksize(tfm); unsigned int bsize;
unsigned int n; unsigned int n;
int err; int err;
n = walk->total; n = walk->total;
if (unlikely(n < bsize)) { if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
return blkcipher_walk_done(desc, walk, -EINVAL); return blkcipher_walk_done(desc, walk, -EINVAL);
} }
@ -247,6 +248,7 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
} }
} }
bsize = min(walk->blocksize, n);
n = scatterwalk_clamp(&walk->in, n); n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n); n = scatterwalk_clamp(&walk->out, n);
@ -277,7 +279,7 @@ static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
struct crypto_blkcipher *tfm, struct crypto_blkcipher *tfm,
unsigned int alignmask) unsigned int alignmask)
{ {
unsigned bs = crypto_blkcipher_blocksize(tfm); unsigned bs = walk->blocksize;
unsigned int ivsize = crypto_blkcipher_ivsize(tfm); unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
unsigned aligned_bs = ALIGN(bs, alignmask + 1); unsigned aligned_bs = ALIGN(bs, alignmask + 1);
unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) - unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
@ -302,6 +304,7 @@ int blkcipher_walk_virt(struct blkcipher_desc *desc,
struct blkcipher_walk *walk) struct blkcipher_walk *walk)
{ {
walk->flags &= ~BLKCIPHER_WALK_PHYS; walk->flags &= ~BLKCIPHER_WALK_PHYS;
walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
return blkcipher_walk_first(desc, walk); return blkcipher_walk_first(desc, walk);
} }
EXPORT_SYMBOL_GPL(blkcipher_walk_virt); EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
@ -310,6 +313,7 @@ int blkcipher_walk_phys(struct blkcipher_desc *desc,
struct blkcipher_walk *walk) struct blkcipher_walk *walk)
{ {
walk->flags |= BLKCIPHER_WALK_PHYS; walk->flags |= BLKCIPHER_WALK_PHYS;
walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
return blkcipher_walk_first(desc, walk); return blkcipher_walk_first(desc, walk);
} }
EXPORT_SYMBOL_GPL(blkcipher_walk_phys); EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
@ -342,6 +346,16 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,
return blkcipher_walk_next(desc, walk); return blkcipher_walk_next(desc, walk);
} }
int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
unsigned int blocksize)
{
walk->flags &= ~BLKCIPHER_WALK_PHYS;
walk->blocksize = blocksize;
return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
unsigned int keylen) unsigned int keylen)
{ {

4
include/crypto/algapi.h
View file

@ -91,6 +91,7 @@ struct blkcipher_walk {
u8 *iv; u8 *iv;
int flags; int flags;
unsigned int blocksize;
}; };
extern const struct crypto_type crypto_ablkcipher_type; extern const struct crypto_type crypto_ablkcipher_type;
@ -129,6 +130,9 @@ int blkcipher_walk_virt(struct blkcipher_desc *desc,
struct blkcipher_walk *walk); struct blkcipher_walk *walk);
int blkcipher_walk_phys(struct blkcipher_desc *desc, int blkcipher_walk_phys(struct blkcipher_desc *desc,
struct blkcipher_walk *walk); struct blkcipher_walk *walk);
int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
unsigned int blocksize);
static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm) static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
{ {