summaryrefslogtreecommitdiffstats
path: root/include/crypto/xts.h
blob: 0f8dba69feb462052500934e5bc1e75403dfced4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/* 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_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)
{
	/*
	 * 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_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 */