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Commit 70613783 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
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[CRYPTO] blkcipher: Remove alignment restriction on block size 



Previously we assumed for convenience that the block size is a multiple of
the algorithm's required alignment.  With the pending addition of CTR this
will no longer be the case as the block size will be 1 due to it being a
stream cipher.  However, the alignment requirement will be that of the
underlying implementation which will most likely be greater than 1.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent e4c5c6c9

crypto/algapi.c

+0 −3
Original line number Diff line number Diff line
@@ -63,9 +63,6 @@ static int crypto_check_alg(struct crypto_alg *alg) 
	if (alg->cra_alignmask & (alg->cra_alignmask + 1))

		return -EINVAL;



	if (alg->cra_alignmask & alg->cra_blocksize)

		return -EINVAL;



	if (alg->cra_blocksize > PAGE_SIZE / 8)

		return -EINVAL;

crypto/blkcipher.c

+8 −5
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ static inline int blkcipher_next_slow(struct blkcipher_desc *desc, 
				      unsigned int alignmask)

{

	unsigned int n;

	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);



	if (walk->buffer)

		goto ok;
@@ -167,8 +168,8 @@ static inline int blkcipher_next_slow(struct blkcipher_desc *desc, 
	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,

					  alignmask + 1);

	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);

	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,

						 bsize);

	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +

						 aligned_bsize, bsize);



	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
@@ -278,7 +279,9 @@ static inline int blkcipher_copy_iv(struct blkcipher_walk *walk, 
{

	unsigned bs = crypto_blkcipher_blocksize(tfm);

	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);

	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);

	unsigned aligned_bs = ALIGN(bs, alignmask + 1);

	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -

			    (alignmask + 1);

	u8 *iv;



	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
@@ -287,8 +290,8 @@ static inline int blkcipher_copy_iv(struct blkcipher_walk *walk, 
		return -ENOMEM;



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

	iv = blkcipher_get_spot(iv, bs) + bs;

	iv = blkcipher_get_spot(iv, bs) + bs;

	iv = blkcipher_get_spot(iv, bs) + aligned_bs;

	iv = blkcipher_get_spot(iv, bs) + aligned_bs;

	iv = blkcipher_get_spot(iv, ivsize);



	walk->iv = memcpy(iv, walk->iv, ivsize);