/* 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 */