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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _CRYPTO_XTS_H3#define _CRYPTO_XTS_H4 5#include <crypto/b128ops.h>6#include <crypto/internal/skcipher.h>7#include <linux/fips.h>8 9#define XTS_BLOCK_SIZE 1610 11static 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, therefore16 * the length must be even.17 */18 if (keylen % 2)19 return -EINVAL;20 21 /*22 * In FIPS mode only a combined key length of either 256 or23 * 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 28 /*29 * Ensure that the AES and tweak key are not identical when30 * in FIPS mode or the FORBID_WEAK_KEYS flag is set.31 */32 if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &33 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&34 !crypto_memneq(key, key + (keylen / 2), keylen / 2))35 return -EINVAL;36 37 return 0;38}39 40#endif /* _CRYPTO_XTS_H */41