include/crypto/lrw.h

   1 #ifndef _CRYPTO_LRW_H
   2 #define _CRYPTO_LRW_H
   3
   4 #include <crypto/b128ops.h>
   5
   6 struct scatterlist;
   7 struct gf128mul_64k;
   8 struct blkcipher_desc;
   9
  10 #define LRW_BLOCK_SIZE 16
  11
  12 struct lrw_table_ctx {
  13         /* optimizes multiplying a random (non incrementing, as at the
  14          * start of a new sector) value with key2, we could also have
  15          * used 4k optimization tables or no optimization at all. In the
  16          * latter case we would have to store key2 here */
  17         struct gf128mul_64k *table;
  18         /* stores:
  19          *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
  20          *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
  21          *  key2*{ 0,0,...1,1,1,1,1 }, etc
  22          * needed for optimized multiplication of incrementing values
  23          * with key2 */
  24         be128 mulinc[128];
  25 };
  26
  27 int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak);
  28 void lrw_free_table(struct lrw_table_ctx *ctx);
  29
  30 struct lrw_crypt_req {
  31         be128 *tbuf;
  32         unsigned int tbuflen;
  33
  34         struct lrw_table_ctx *table_ctx;
  35         void *crypt_ctx;
  36         void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
  37 };
  38
  39 int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  40               struct scatterlist *src, unsigned int nbytes,
  41               struct lrw_crypt_req *req);
  42
  43 #endif  /* _CRYPTO_LRW_H */