On Wed, Dec 21, 2022 at 11:41:07PM +0100, Vladis Dronov wrote:
> xts_check_key() is obsoleted by xts_verify_key(). Over time XTS crypto
> drivers adopted the newer xts_verify_key() variant, but xts_check_key()
> is still used by a number of drivers. Switch drivers to use the newer
> xts_verify_key() and make a couple of cleanups. This allows us to drop
> xts_check_key() completely and avoid redundancy.
>
> Signed-off-by: Vladis Dronov <vdronov@redhat.com>
> ---
> arch/s390/crypto/paes_s390.c | 2 +-
> drivers/crypto/atmel-aes.c | 2 +-
> drivers/crypto/axis/artpec6_crypto.c | 2 +-
> drivers/crypto/cavium/cpt/cptvf_algs.c | 8 +++----
> .../crypto/cavium/nitrox/nitrox_skcipher.c | 8 +++----
> drivers/crypto/ccree/cc_cipher.c | 2 +-
> .../crypto/marvell/octeontx/otx_cptvf_algs.c | 2 +-
> .../marvell/octeontx2/otx2_cptvf_algs.c | 2 +-
> include/crypto/xts.h | 21 +++----------------
> 9 files changed, 15 insertions(+), 34 deletions(-)
Reviewed-by: Eric Biggers <ebiggers@google.com>
but one comment below:
> static inline int xts_verify_key(struct crypto_skcipher *tfm,
> const u8 *key, unsigned int keylen)
> {
> @@ -42,7 +25,9 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
> if (fips_enabled && keylen != 32 && keylen != 64)
> return -EINVAL;
>
> - /* ensure that the AES and tweak key are not identical */
> + /* ensure that the AES and tweak key are not identical
> + * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
> + */
> if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
> CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
> !crypto_memneq(key, key + (keylen / 2), keylen / 2))
Please use the kernel style for block comments:
/*
* Ensure that the AES and tweak key are not identical when in FIPS mode
* or the FORBID_WEAK_KEYS flag is set.
*/
- Eric
Hi,
On Thu, Dec 22, 2022 at 12:33 AM Eric Biggers <ebiggers@kernel.org> wrote:
>
> On Wed, Dec 21, 2022 at 11:41:07PM +0100, Vladis Dronov wrote:
> ...skip...
> > - /* ensure that the AES and tweak key are not identical */
> > + /* ensure that the AES and tweak key are not identical
> > + * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
> > + */
> > if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
> > CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
> > !crypto_memneq(key, key + (keylen / 2), keylen / 2))
>
> Please use the kernel style for block comments:
>
> /*
> * Ensure that the AES and tweak key are not identical when in FIPS mode
> * or the FORBID_WEAK_KEYS flag is set.
> */
Thanks Eric, I will wait a bit for more review notes and I will resend
the patchset.
Best regards,
Vladis
@@ -474,7 +474,7 @@ static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
return rc;
/*
- * xts_check_key verifies the key length is not odd and makes
+ * xts_verify_key verifies the key length is not odd and makes
* sure that the two keys are not the same. This can be done
* on the two protected keys as well
*/
@@ -1879,7 +1879,7 @@ static int atmel_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
struct atmel_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
int err;
- err = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+ err = xts_verify_key(tfm, key, keylen);
if (err)
return err;
@@ -1621,7 +1621,7 @@ artpec6_crypto_xts_set_key(struct crypto_skcipher *cipher, const u8 *key,
crypto_skcipher_ctx(cipher);
int ret;
- ret = xts_check_key(&cipher->base, key, keylen);
+ ret = xts_verify_key(cipher, key, keylen);
if (ret)
return ret;
@@ -232,13 +232,12 @@ static int cvm_decrypt(struct skcipher_request *req)
static int cvm_xts_setkey(struct crypto_skcipher *cipher, const u8 *key,
u32 keylen)
{
- struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
- struct cvm_enc_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct cvm_enc_ctx *ctx = crypto_skcipher_ctx(cipher);
int err;
const u8 *key1 = key;
const u8 *key2 = key + (keylen / 2);
- err = xts_check_key(tfm, key, keylen);
+ err = xts_verify_key(cipher, key, keylen);
if (err)
return err;
ctx->key_len = keylen;
@@ -289,8 +288,7 @@ static int cvm_validate_keylen(struct cvm_enc_ctx *ctx, u32 keylen)
static int cvm_setkey(struct crypto_skcipher *cipher, const u8 *key,
u32 keylen, u8 cipher_type)
{
- struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
- struct cvm_enc_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct cvm_enc_ctx *ctx = crypto_skcipher_ctx(cipher);
ctx->cipher_type = cipher_type;
if (!cvm_validate_keylen(ctx, keylen)) {
@@ -337,12 +337,11 @@ static int nitrox_3des_decrypt(struct skcipher_request *skreq)
static int nitrox_aes_xts_setkey(struct crypto_skcipher *cipher,
const u8 *key, unsigned int keylen)
{
- struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
- struct nitrox_crypto_ctx *nctx = crypto_tfm_ctx(tfm);
+ struct nitrox_crypto_ctx *nctx = crypto_skcipher_ctx(cipher);
struct flexi_crypto_context *fctx;
int aes_keylen, ret;
- ret = xts_check_key(tfm, key, keylen);
+ ret = xts_verify_key(cipher, key, keylen);
if (ret)
return ret;
@@ -362,8 +361,7 @@ static int nitrox_aes_xts_setkey(struct crypto_skcipher *cipher,
static int nitrox_aes_ctr_rfc3686_setkey(struct crypto_skcipher *cipher,
const u8 *key, unsigned int keylen)
{
- struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
- struct nitrox_crypto_ctx *nctx = crypto_tfm_ctx(tfm);
+ struct nitrox_crypto_ctx *nctx = crypto_skcipher_ctx(cipher);
struct flexi_crypto_context *fctx;
int aes_keylen;
@@ -460,7 +460,7 @@ static int cc_cipher_setkey(struct crypto_skcipher *sktfm, const u8 *key,
}
if (ctx_p->cipher_mode == DRV_CIPHER_XTS &&
- xts_check_key(tfm, key, keylen)) {
+ xts_verify_key(sktfm, key, keylen)) {
dev_dbg(dev, "weak XTS key");
return -EINVAL;
}
@@ -398,7 +398,7 @@ static int otx_cpt_skcipher_xts_setkey(struct crypto_skcipher *tfm,
const u8 *key1 = key;
int ret;
- ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+ ret = xts_verify_key(tfm, key, keylen);
if (ret)
return ret;
ctx->key_len = keylen;
@@ -412,7 +412,7 @@ static int otx2_cpt_skcipher_xts_setkey(struct crypto_skcipher *tfm,
const u8 *key1 = key;
int ret;
- ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+ ret = xts_verify_key(tfm, key, keylen);
if (ret)
return ret;
ctx->key_len = keylen;
@@ -8,23 +8,6 @@
#define XTS_BLOCK_SIZE 16
-static inline int xts_check_key(struct crypto_tfm *tfm,
- const u8 *key, unsigned int keylen)
-{
- /*
- * key consists of keys of equal size concatenated, therefore
- * the length must be even.
- */
- if (keylen % 2)
- return -EINVAL;
-
- /* ensure that the AES and tweak key are not identical */
- if (fips_enabled && !crypto_memneq(key, key + (keylen / 2), keylen / 2))
- return -EINVAL;
-
- return 0;
-}
-
static inline int xts_verify_key(struct crypto_skcipher *tfm,
const u8 *key, unsigned int keylen)
{
@@ -42,7 +25,9 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
if (fips_enabled && keylen != 32 && keylen != 64)
return -EINVAL;
- /* ensure that the AES and tweak key are not identical */
+ /* ensure that the AES and tweak key are not identical
+ * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
+ */
if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
!crypto_memneq(key, key + (keylen / 2), keylen / 2))