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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _CRYPTO_XTS_H
3#define _CRYPTO_XTS_H
4
5#include <crypto/b128ops.h>
6#include <crypto/internal/skcipher.h>
7#include <linux/fips.h>
8
9#define XTS_BLOCK_SIZE 16
10
11#define XTS_TWEAK_CAST(x) ((void (*)(void *, u8*, const u8*))(x))
12
13static inline int xts_check_key(struct crypto_tfm *tfm,
14 const u8 *key, unsigned int keylen)
15{
16 u32 *flags = &tfm->crt_flags;
17
18 /*
19 * key consists of keys of equal size concatenated, therefore
20 * the length must be even.
21 */
22 if (keylen % 2) {
23 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
24 return -EINVAL;
25 }
26
27 /* ensure that the AES and tweak key are not identical */
28 if (fips_enabled &&
29 !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
30 *flags |= CRYPTO_TFM_RES_WEAK_KEY;
31 return -EINVAL;
32 }
33
34 return 0;
35}
36
37static inline int xts_verify_key(struct crypto_skcipher *tfm,
38 const u8 *key, unsigned int keylen)
39{
40 /*
41 * key consists of keys of equal size concatenated, therefore
42 * the length must be even.
43 */
44 if (keylen % 2) {
45 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
46 return -EINVAL;
47 }
48
49 /* ensure that the AES and tweak key are not identical */
50 if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
51 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
52 !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
53 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
54 return -EINVAL;
55 }
56
57 return 0;
58}
59
60#endif /* _CRYPTO_XTS_H */
1#ifndef _CRYPTO_XTS_H
2#define _CRYPTO_XTS_H
3
4#include <crypto/b128ops.h>
5#include <linux/crypto.h>
6#include <crypto/algapi.h>
7#include <linux/fips.h>
8
9struct scatterlist;
10struct blkcipher_desc;
11
12#define XTS_BLOCK_SIZE 16
13
14struct xts_crypt_req {
15 be128 *tbuf;
16 unsigned int tbuflen;
17
18 void *tweak_ctx;
19 void (*tweak_fn)(void *ctx, u8* dst, const u8* src);
20 void *crypt_ctx;
21 void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
22};
23
24#define XTS_TWEAK_CAST(x) ((void (*)(void *, u8*, const u8*))(x))
25
26int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
27 struct scatterlist *src, unsigned int nbytes,
28 struct xts_crypt_req *req);
29
30static inline int xts_check_key(struct crypto_tfm *tfm,
31 const u8 *key, unsigned int keylen)
32{
33 u32 *flags = &tfm->crt_flags;
34
35 /*
36 * key consists of keys of equal size concatenated, therefore
37 * the length must be even.
38 */
39 if (keylen % 2) {
40 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
41 return -EINVAL;
42 }
43
44 /* ensure that the AES and tweak key are not identical */
45 if (fips_enabled &&
46 !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
47 *flags |= CRYPTO_TFM_RES_WEAK_KEY;
48 return -EINVAL;
49 }
50
51 return 0;
52}
53
54#endif /* _CRYPTO_XTS_H */