blob: 15b16c4853d835a5e6d0cb65f593971d35611777 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Jussi Kivilinnace004552011-11-09 11:56:06 +08002#ifndef _CRYPTO_XTS_H
3#define _CRYPTO_XTS_H
4
5#include <crypto/b128ops.h>
Herbert Xuf1c131b2016-11-22 20:08:19 +08006#include <crypto/internal/skcipher.h>
Stephan Mueller28856a92016-02-09 15:37:47 +01007#include <linux/fips.h>
Jussi Kivilinnace004552011-11-09 11:56:06 +08008
Jussi Kivilinnace004552011-11-09 11:56:06 +08009#define XTS_BLOCK_SIZE 16
10
Herbert Xuf1c131b2016-11-22 20:08:19 +080011static 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 Biggers674f3682019-12-30 21:19:36 -060018 if (keylen % 2)
Herbert Xuf1c131b2016-11-22 20:08:19 +080019 return -EINVAL;
Herbert Xuf1c131b2016-11-22 20:08:19 +080020
Nicolai Stange1c4428b2022-12-29 22:17:05 +010021 /*
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 Dronov0ee43362022-12-29 22:17:06 +010028 /*
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 Biggers231baec2019-01-18 22:48:00 -080032 if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
33 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
Eric Biggersc4c4db02019-12-30 21:19:37 -060034 !crypto_memneq(key, key + (keylen / 2), keylen / 2))
Herbert Xuf1c131b2016-11-22 20:08:19 +080035 return -EINVAL;
Herbert Xuf1c131b2016-11-22 20:08:19 +080036
37 return 0;
38}
39
Jussi Kivilinnace004552011-11-09 11:56:06 +080040#endif /* _CRYPTO_XTS_H */