lib/libtcplay/generic_xts.h

   1 /*
   2  * Copyright (C) 2008, Damien Miller
   3  * Copyright (C) 2011, Alex Hornung
   4  *
   5  * Permission to use, copy, and modify this software with or without fee
   6  * is hereby granted, provided that this entire notice is included in
   7  * all copies of any software which is or includes a copy or
   8  * modification of this software.
   9  * You may use this code under the GNU public license if you so wish. Please
  10  * contribute changes back to the authors under this freer than GPL license
  11  * so that we may further the use of strong encryption without limitations to
  12  * all.
  13  *
  14  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
  16  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
  17  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
  18  * PURPOSE.
  19  */
  20
  21 #include <inttypes.h>
  22 #define XTS_MAX_BLOCKSIZE       16
  23 #define XTS_IVSIZE              8
  24 #define XTS_ALPHA               0x87    /* GF(2^128) generator polynomial */
  25
  26 typedef int (*encrypt_decrypt_fn)(void *, size_t, const uint8_t *, uint8_t *);
  27 typedef int (*set_key_fn)(void **, void *, void *, const uint8_t *, int);
  28 typedef int (*zero_key_fn)(void **);
  29
  30
  31 struct xts_ctx {
  32         encrypt_decrypt_fn      encrypt_fn;
  33         encrypt_decrypt_fn      decrypt_fn;
  34         set_key_fn              set_key_fn;
  35         zero_key_fn             zero_key_fn;
  36
  37         void            *ctx1;
  38         void            *ctx2;
  39         uint8_t         tweak[XTS_MAX_BLOCKSIZE];
  40         uint32_t        blk_sz;
  41 };
  42
  43 int xts_init(struct xts_ctx *ctxp, void *arg1, void *arg2, set_key_fn set_key_fn,
  44     zero_key_fn zero_key_fn, encrypt_decrypt_fn encrypt_fn,
  45     encrypt_decrypt_fn decrypt_fn, uint32_t blk_sz, uint8_t *key, int len);
  46 int xts_encrypt(struct xts_ctx *ctx, uint8_t *data, size_t len, uint8_t *iv);
  47 int xts_decrypt(struct xts_ctx *ctx, uint8_t *data, size_t len, uint8_t *iv);
  48 int xts_uninit(struct xts_ctx *ctxp);
  49