2023-09-25 18:33:49

by Chang S. Bae

Subject: [PATCH 2/3] crypto: x86/aesni - Correct the data type in struct aesni_xts_ctx

Currently, every field in struct aesni_xts_ctx is defined as a byte
array of the same size as struct crypto_aes_ctx. This data type
is obscure and the choice lacks justification.

To rectify this, update the field type in struct aesni_xts_ctx to
match its actual structure.

Suggested-by: Eric Biggers <[email protected]>
Signed-off-by: Chang S. Bae <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/all/ZFWQ4sZEVu%[email protected]/
---
arch/x86/crypto/aesni-intel_glue.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 241d38ae1ed9..412a99e914a6 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -61,8 +61,8 @@ struct generic_gcmaes_ctx {
};

struct aesni_xts_ctx {
- u8 raw_tweak_ctx[sizeof(struct crypto_aes_ctx)] AESNI_ALIGN_ATTR;
- u8 raw_crypt_ctx[sizeof(struct crypto_aes_ctx)] AESNI_ALIGN_ATTR;
+ struct crypto_aes_ctx tweak_ctx AESNI_ALIGN_ATTR;
+ struct crypto_aes_ctx crypt_ctx AESNI_ALIGN_ATTR;
};

#define GCM_BLOCK_LEN 16
@@ -885,13 +885,12 @@ static int xts_aesni_setkey(struct crypto_skcipher *tfm, const u8 *key,
keylen /= 2;

/* first half of xts-key is for crypt */
- err = aes_set_key_common(aes_ctx(ctx->raw_crypt_ctx), key, keylen);
+ err = aes_set_key_common(aes_ctx(&ctx->crypt_ctx), key, keylen);
if (err)
return err;

/* second half of xts-key is for tweak */
- return aes_set_key_common(aes_ctx(ctx->raw_tweak_ctx), key + keylen,
- keylen);
+ return aes_set_key_common(aes_ctx(&ctx->tweak_ctx), key + keylen, keylen);
}

static int xts_crypt(struct skcipher_request *req, bool encrypt)
@@ -933,7 +932,7 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
kernel_fpu_begin();

/* calculate first value of T */
- aesni_enc(aes_ctx(ctx->raw_tweak_ctx), walk.iv, walk.iv);
+ aesni_enc(aes_ctx(&ctx->tweak_ctx), walk.iv, walk.iv);

while (walk.nbytes > 0) {
int nbytes = walk.nbytes;
@@ -942,11 +941,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
nbytes &= ~(AES_BLOCK_SIZE - 1);

if (encrypt)
- aesni_xts_encrypt(aes_ctx(ctx->raw_crypt_ctx),
+ aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
walk.dst.virt.addr, walk.src.virt.addr,
nbytes, walk.iv);
else
- aesni_xts_decrypt(aes_ctx(ctx->raw_crypt_ctx),
+ aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
walk.dst.virt.addr, walk.src.virt.addr,
nbytes, walk.iv);
kernel_fpu_end();
@@ -974,11 +973,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)

kernel_fpu_begin();
if (encrypt)
- aesni_xts_encrypt(aes_ctx(ctx->raw_crypt_ctx),
+ aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
walk.dst.virt.addr, walk.src.virt.addr,
walk.nbytes, walk.iv);
else
- aesni_xts_decrypt(aes_ctx(ctx->raw_crypt_ctx),
+ aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
walk.dst.virt.addr, walk.src.virt.addr,
walk.nbytes, walk.iv);
kernel_fpu_end();
--
2.34.1

2023-09-26 05:24:02

by Eric Biggers

Subject: Re: [PATCH 2/3] crypto: x86/aesni - Correct the data type in struct aesni_xts_ctx

On Mon, Sep 25, 2023 at 08:17:51AM -0700, Chang S. Bae wrote:
> Currently, every field in struct aesni_xts_ctx is defined as a byte
> array of the same size as struct crypto_aes_ctx. This data type
> is obscure and the choice lacks justification.
>
> To rectify this, update the field type in struct aesni_xts_ctx to
> match its actual structure.
>
> Suggested-by: Eric Biggers <[email protected]>
> Signed-off-by: Chang S. Bae <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Link: https://lore.kernel.org/all/ZFWQ4sZEVu%[email protected]/

Please put the "Link" directly after the Suggested-by to make it clear that the
link is for the suggestion. Thanks!

- Eric