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crypto: algif_skcipher - Use chunksize instead of blocksize
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When algif_skcipher does a partial operation it always process data
that is a multiple of blocksize.  However, for algorithms such as
CTR this is wrong because even though it can process any number of
bytes overall, the partial block must come at the very end and not
in the middle.

This is exactly what chunksize is meant to describe so this patch
changes blocksize to chunksize.

Fixes: 8ff5909 ("crypto: algif_skcipher - User-space...")
Signed-off-by: Herbert Xu <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
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herbertx committed Oct 4, 2019
1 parent 7a627db commit 5b0fe95
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Showing 3 changed files with 31 additions and 31 deletions.
2 changes: 1 addition & 1 deletion crypto/algif_skcipher.c
Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
struct alg_sock *pask = alg_sk(psk);
struct af_alg_ctx *ctx = ask->private;
struct crypto_skcipher *tfm = pask->private;
unsigned int bs = crypto_skcipher_blocksize(tfm);
unsigned int bs = crypto_skcipher_chunksize(tfm);
struct af_alg_async_req *areq;
int err = 0;
size_t len = 0;
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30 changes: 0 additions & 30 deletions include/crypto/internal/skcipher.h
Original file line number Diff line number Diff line change
Expand Up @@ -205,19 +205,6 @@ static inline unsigned int crypto_skcipher_alg_max_keysize(
return alg->max_keysize;
}

static inline unsigned int crypto_skcipher_alg_chunksize(
struct skcipher_alg *alg)
{
if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
return alg->base.cra_blocksize;

if (alg->base.cra_ablkcipher.encrypt)
return alg->base.cra_blocksize;

return alg->chunksize;
}

static inline unsigned int crypto_skcipher_alg_walksize(
struct skcipher_alg *alg)
{
Expand All @@ -231,23 +218,6 @@ static inline unsigned int crypto_skcipher_alg_walksize(
return alg->walksize;
}

/**
* crypto_skcipher_chunksize() - obtain chunk size
* @tfm: cipher handle
*
* The block size is set to one for ciphers such as CTR. However,
* you still need to provide incremental updates in multiples of
* the underlying block size as the IV does not have sub-block
* granularity. This is known in this API as the chunk size.
*
* Return: chunk size in bytes
*/
static inline unsigned int crypto_skcipher_chunksize(
struct crypto_skcipher *tfm)
{
return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
}

/**
* crypto_skcipher_walksize() - obtain walk size
* @tfm: cipher handle
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30 changes: 30 additions & 0 deletions include/crypto/skcipher.h
Original file line number Diff line number Diff line change
Expand Up @@ -304,6 +304,36 @@ static inline unsigned int crypto_skcipher_blocksize(
return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
}

static inline unsigned int crypto_skcipher_alg_chunksize(
struct skcipher_alg *alg)
{
if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) ==
CRYPTO_ALG_TYPE_BLKCIPHER)
return alg->base.cra_blocksize;

if (alg->base.cra_ablkcipher.encrypt)
return alg->base.cra_blocksize;

return alg->chunksize;
}

/**
* crypto_skcipher_chunksize() - obtain chunk size
* @tfm: cipher handle
*
* The block size is set to one for ciphers such as CTR. However,
* you still need to provide incremental updates in multiples of
* the underlying block size as the IV does not have sub-block
* granularity. This is known in this API as the chunk size.
*
* Return: chunk size in bytes
*/
static inline unsigned int crypto_skcipher_chunksize(
struct crypto_skcipher *tfm)
{
return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm));
}

static inline unsigned int crypto_sync_skcipher_blocksize(
struct crypto_sync_skcipher *tfm)
{
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