Commit 6c2205b8 authored by Jussi Kivilinna's avatar Jussi Kivilinna Committed by Herbert Xu

crypto: lrw - add interface for parallelized cipher implementions

Export gf128mul table initialization routines and add lrw_crypt() function
that can be used by cipher implementations that can benefit from parallelized
cipher operations.
Signed-off-by: 's avatarJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: 's avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 171c0204
......@@ -3,7 +3,7 @@
*
* Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
*
* Based om ecb.c
* Based on ecb.c
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
......@@ -16,6 +16,7 @@
* http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
*
* The test vectors are included in the testing module tcrypt.[ch] */
#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
......@@ -26,23 +27,7 @@
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
#define LRW_BLOCK_SIZE 16
struct lrw_table_ctx {
/* optimizes multiplying a random (non incrementing, as at the
* start of a new sector) value with key2, we could also have
* used 4k optimization tables or no optimization at all. In the
* latter case we would have to store key2 here */
struct gf128mul_64k *table;
/* stores:
* key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
* key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
* key2*{ 0,0,...1,1,1,1,1 }, etc
* needed for optimized multiplication of incrementing values
* with key2 */
be128 mulinc[128];
};
#include <crypto/lrw.h>
struct priv {
struct crypto_cipher *child;
......@@ -60,7 +45,7 @@ static inline void setbit128_bbe(void *b, int bit)
), b);
}
static int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
{
be128 tmp = { 0 };
int i;
......@@ -82,12 +67,14 @@ static int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
return 0;
}
EXPORT_SYMBOL_GPL(lrw_init_table);
static void lrw_free_table(struct lrw_table_ctx *ctx)
void lrw_free_table(struct lrw_table_ctx *ctx)
{
if (ctx->table)
gf128mul_free_64k(ctx->table);
}
EXPORT_SYMBOL_GPL(lrw_free_table);
static int setkey(struct crypto_tfm *parent, const u8 *key,
unsigned int keylen)
......@@ -227,6 +214,85 @@ static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
crypto_cipher_alg(ctx->child)->cia_decrypt);
}
int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
struct scatterlist *ssrc, unsigned int nbytes,
struct lrw_crypt_req *req)
{
const unsigned int bsize = LRW_BLOCK_SIZE;
const unsigned int max_blks = req->tbuflen / bsize;
struct lrw_table_ctx *ctx = req->table_ctx;
struct blkcipher_walk walk;
unsigned int nblocks;
be128 *iv, *src, *dst, *t;
be128 *t_buf = req->tbuf;
int err, i;
BUG_ON(max_blks < 1);
blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
err = blkcipher_walk_virt(desc, &walk);
nbytes = walk.nbytes;
if (!nbytes)
return err;
nblocks = min(walk.nbytes / bsize, max_blks);
src = (be128 *)walk.src.virt.addr;
dst = (be128 *)walk.dst.virt.addr;
/* calculate first value of T */
iv = (be128 *)walk.iv;
t_buf[0] = *iv;
/* T <- I*Key2 */
gf128mul_64k_bbe(&t_buf[0], ctx->table);
i = 0;
goto first;
for (;;) {
do {
for (i = 0; i < nblocks; i++) {
/* T <- I*Key2, using the optimization
* discussed in the specification */
be128_xor(&t_buf[i], t,
&ctx->mulinc[get_index128(iv)]);
inc(iv);
first:
t = &t_buf[i];
/* PP <- T xor P */
be128_xor(dst + i, t, src + i);
}
/* CC <- E(Key2,PP) */
req->crypt_fn(req->crypt_ctx, (u8 *)dst,
nblocks * bsize);
/* C <- T xor CC */
for (i = 0; i < nblocks; i++)
be128_xor(dst + i, dst + i, &t_buf[i]);
src += nblocks;
dst += nblocks;
nbytes -= nblocks * bsize;
nblocks = min(nbytes / bsize, max_blks);
} while (nblocks > 0);
err = blkcipher_walk_done(desc, &walk, nbytes);
nbytes = walk.nbytes;
if (!nbytes)
break;
nblocks = min(nbytes / bsize, max_blks);
src = (be128 *)walk.src.virt.addr;
dst = (be128 *)walk.dst.virt.addr;
}
return err;
}
EXPORT_SYMBOL_GPL(lrw_crypt);
static int init_tfm(struct crypto_tfm *tfm)
{
struct crypto_cipher *cipher;
......
#ifndef _CRYPTO_LRW_H
#define _CRYPTO_LRW_H
#include <crypto/b128ops.h>
struct scatterlist;
struct gf128mul_64k;
struct blkcipher_desc;
#define LRW_BLOCK_SIZE 16
struct lrw_table_ctx {
/* optimizes multiplying a random (non incrementing, as at the
* start of a new sector) value with key2, we could also have
* used 4k optimization tables or no optimization at all. In the
* latter case we would have to store key2 here */
struct gf128mul_64k *table;
/* stores:
* key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
* key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
* key2*{ 0,0,...1,1,1,1,1 }, etc
* needed for optimized multiplication of incrementing values
* with key2 */
be128 mulinc[128];
};
int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak);
void lrw_free_table(struct lrw_table_ctx *ctx);
struct lrw_crypt_req {
be128 *tbuf;
unsigned int tbuflen;
struct lrw_table_ctx *table_ctx;
void *crypt_ctx;
void (*crypt_fn)(void *ctx, u8 *blks, unsigned int nbytes);
};
int lrw_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes,
struct lrw_crypt_req *req);
#endif /* _CRYPTO_LRW_H */
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