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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _CRYPTO_LRW_H
3 #define _CRYPTO_LRW_H
4 
5 #include <crypto/b128ops.h>
6 
7 struct scatterlist;
8 struct gf128mul_64k;
9 struct blkcipher_desc;
10 
11 #define LRW_BLOCK_SIZE 16
12 
13 struct lrw_table_ctx {
14 	/* optimizes multiplying a random (non incrementing, as at the
15 	 * start of a new sector) value with key2, we could also have
16 	 * used 4k optimization tables or no optimization at all. In the
17 	 * latter case we would have to store key2 here */
18 	struct gf128mul_64k *table;
19 	/* stores:
20 	 *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
21 	 *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
22 	 *  key2*{ 0,0,...1,1,1,1,1 }, etc
23 	 * needed for optimized multiplication of incrementing values
24 	 * with key2 */
25 	be128 mulinc[128];
26 };
27 
28 int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak);
29 void lrw_free_table(struct lrw_table_ctx *ctx);
30 
31 struct lrw_crypt_req {
32 	be128 *tbuf;
33 	unsigned int tbuflen;
34 
35 	struct lrw_table_ctx *table_ctx;
36 	void *crypt_ctx;
37 	void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
38 };
39 
40 int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
41 	      struct scatterlist *src, unsigned int nbytes,
42 	      struct lrw_crypt_req *req);
43 
44 #endif  /* _CRYPTO_LRW_H */
45