231baecdef
CRYPTO_TFM_REQ_WEAK_KEY confuses newcomers to the crypto API because it sounds like it is requesting a weak key. Actually, it is requesting that weak keys be forbidden (for algorithms that have the notion of "weak keys"; currently only DES and XTS do). Also it is only one letter away from CRYPTO_TFM_RES_WEAK_KEY, with which it can be easily confused. (This in fact happened in the UX500 driver, though just in some debugging messages.) Therefore, make the intent clear by renaming it to CRYPTO_TFM_REQ_FORBID_WEAK_KEYS. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _CRYPTO_XTS_H
|
|
#define _CRYPTO_XTS_H
|
|
|
|
#include <crypto/b128ops.h>
|
|
#include <crypto/internal/skcipher.h>
|
|
#include <linux/fips.h>
|
|
|
|
#define XTS_BLOCK_SIZE 16
|
|
|
|
#define XTS_TWEAK_CAST(x) ((void (*)(void *, u8*, const u8*))(x))
|
|
|
|
static inline int xts_check_key(struct crypto_tfm *tfm,
|
|
const u8 *key, unsigned int keylen)
|
|
{
|
|
u32 *flags = &tfm->crt_flags;
|
|
|
|
/*
|
|
* key consists of keys of equal size concatenated, therefore
|
|
* the length must be even.
|
|
*/
|
|
if (keylen % 2) {
|
|
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* ensure that the AES and tweak key are not identical */
|
|
if (fips_enabled &&
|
|
!crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
|
|
*flags |= CRYPTO_TFM_RES_WEAK_KEY;
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int xts_verify_key(struct crypto_skcipher *tfm,
|
|
const u8 *key, unsigned int keylen)
|
|
{
|
|
/*
|
|
* key consists of keys of equal size concatenated, therefore
|
|
* the length must be even.
|
|
*/
|
|
if (keylen % 2) {
|
|
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* ensure that the AES and tweak key are not identical */
|
|
if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
|
|
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
|
|
!crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
|
|
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* _CRYPTO_XTS_H */
|