[mirror_ubuntu-bionic-kernel.git] / include / crypto / xts.h

/* 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>

struct scatterlist;
struct blkcipher_desc;

#define XTS_BLOCK_SIZE 16

struct xts_crypt_req {
	le128 *tbuf;
	unsigned int tbuflen;

	void *tweak_ctx;
	void (*tweak_fn)(void *ctx, u8* dst, const u8* src);
	void *crypt_ctx;
	void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
};

#define XTS_TWEAK_CAST(x) ((void (*)(void *, u8*, const u8*))(x))

int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
	      struct scatterlist *src, unsigned int nbytes,
	      struct xts_crypt_req *req);

static inline int xts_check_key(struct crypto_tfm *tfm,
				const u8 *key, unsigned int keylen)
{
	u32 *flags = &tfm->crt_flags;

	/*
	 * key consists of keys of equal size concatenated, therefore
	 * the length must be even.
	 */
	if (keylen % 2) {
		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	/* ensure that the AES and tweak key are not identical */
	if (fips_enabled &&
	    !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
		*flags |= CRYPTO_TFM_RES_WEAK_KEY;
		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) {
		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	/* ensure that the AES and tweak key are not identical */
	if ((fips_enabled || crypto_skcipher_get_flags(tfm) &
			     CRYPTO_TFM_REQ_WEAK_KEY) &&
	    !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
		return -EINVAL;
	}

	return 0;
}

#endif  /* _CRYPTO_XTS_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
ce004556 JK	2	#ifndef _CRYPTO_XTS_H
	3	#define _CRYPTO_XTS_H
	4
	5	#include <crypto/b128ops.h>
f1c131b4	6	#include <crypto/internal/skcipher.h>
28856a9e	7	#include <linux/fips.h>
ce004556 JK	8
	9	struct scatterlist;
	10	struct blkcipher_desc;
	11
	12	#define XTS_BLOCK_SIZE 16
	13
	14	struct xts_crypt_req {
e55318c8	15	le128 *tbuf;
ce004556 JK	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
	26	int xts_crypt(struct blkcipher_desc desc, struct scatterlist dst,
	27	struct scatterlist *src, unsigned int nbytes,
	28	struct xts_crypt_req *req);
	29
28856a9e SM	30	static 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
f1c131b4 HX	54	static inline int xts_verify_key(struct crypto_skcipher *tfm,
	55	const u8 *key, unsigned int keylen)
	56	{
	57	/*
	58	* key consists of keys of equal size concatenated, therefore
	59	* the length must be even.
	60	*/
	61	if (keylen % 2) {
	62	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	63	return -EINVAL;
	64	}
	65
	66	/* ensure that the AES and tweak key are not identical */
	67	if ((fips_enabled \|\| crypto_skcipher_get_flags(tfm) &
	68	CRYPTO_TFM_REQ_WEAK_KEY) &&
	69	!crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
	70	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
	71	return -EINVAL;
	72	}
	73
	74	return 0;
	75	}
	76
ce004556	77	#endif /* _CRYPTO_XTS_H */