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 static inline int xts_check_key(struct crypto_tfm *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 */ 18 if (keylen % 2) 19 return -EINVAL; 20 21 /* ensure that the AES and tweak key are not identical */ 22 if (fips_enabled && !crypto_memneq(key, key + (keylen / 2), keylen / 2)) 23 return -EINVAL; 24 25 return 0; 26 } 27 28 static inline int xts_verify_key(struct crypto_skcipher *tfm, 29 const u8 *key, unsigned int keylen) 30 { 31 /* 32 * key consists of keys of equal size concatenated, therefore 33 * the length must be even. 34 */ 35 if (keylen % 2) 36 return -EINVAL; 37 38 /* ensure that the AES and tweak key are not identical */ 39 if ((fips_enabled || (crypto_skcipher_get_flags(tfm) & 40 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) && 41 !crypto_memneq(key, key + (keylen / 2), keylen / 2)) 42 return -EINVAL; 43 44 return 0; 45 } 46 47 #endif /* _CRYPTO_XTS_H */ 48