| /* 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 |
| |
| 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) |
| return -EINVAL; |
| |
| /* |
| * In FIPS mode only a combined key length of either 256 or |
| * 512 bits is allowed, c.f. FIPS 140-3 IG C.I. |
| */ |
| if (fips_enabled && keylen != 32 && keylen != 64) |
| return -EINVAL; |
| |
| /* |
| * 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)) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| #endif /* _CRYPTO_XTS_H */ |
