Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
Jussi Kivilinna | ce00455 | 2011-11-09 11:56:06 +0800 | [diff] [blame] | 2 | #ifndef _CRYPTO_XTS_H |
| 3 | #define _CRYPTO_XTS_H |
| 4 | |
| 5 | #include <crypto/b128ops.h> |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 6 | #include <crypto/internal/skcipher.h> |
Stephan Mueller | 28856a9 | 2016-02-09 15:37:47 +0100 | [diff] [blame] | 7 | #include <linux/fips.h> |
Jussi Kivilinna | ce00455 | 2011-11-09 11:56:06 +0800 | [diff] [blame] | 8 | |
Jussi Kivilinna | ce00455 | 2011-11-09 11:56:06 +0800 | [diff] [blame] | 9 | #define XTS_BLOCK_SIZE 16 |
| 10 | |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 11 | static inline int xts_verify_key(struct crypto_skcipher *tfm, |
| 12 | const u8 *key, unsigned int keylen) |
| 13 | { |
| 14 | /* |
| 15 | * key consists of keys of equal size concatenated, therefore |
| 16 | * the length must be even. |
| 17 | */ |
Eric Biggers | 674f368 | 2019-12-30 21:19:36 -0600 | [diff] [blame] | 18 | if (keylen % 2) |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 19 | return -EINVAL; |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 20 | |
Nicolai Stange | 1c4428b | 2022-12-29 22:17:05 +0100 | [diff] [blame] | 21 | /* |
| 22 | * In FIPS mode only a combined key length of either 256 or |
| 23 | * 512 bits is allowed, c.f. FIPS 140-3 IG C.I. |
| 24 | */ |
| 25 | if (fips_enabled && keylen != 32 && keylen != 64) |
| 26 | return -EINVAL; |
| 27 | |
Vladis Dronov | 0ee4336 | 2022-12-29 22:17:06 +0100 | [diff] [blame] | 28 | /* |
| 29 | * Ensure that the AES and tweak key are not identical when |
| 30 | * in FIPS mode or the FORBID_WEAK_KEYS flag is set. |
| 31 | */ |
Eric Biggers | 231baec | 2019-01-18 22:48:00 -0800 | [diff] [blame] | 32 | if ((fips_enabled || (crypto_skcipher_get_flags(tfm) & |
| 33 | CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) && |
Eric Biggers | c4c4db0 | 2019-12-30 21:19:37 -0600 | [diff] [blame] | 34 | !crypto_memneq(key, key + (keylen / 2), keylen / 2)) |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 35 | return -EINVAL; |
Herbert Xu | f1c131b | 2016-11-22 20:08:19 +0800 | [diff] [blame] | 36 | |
| 37 | return 0; |
| 38 | } |
| 39 | |
Jussi Kivilinna | ce00455 | 2011-11-09 11:56:06 +0800 | [diff] [blame] | 40 | #endif /* _CRYPTO_XTS_H */ |