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: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/lrw.c b/crypto/lrw.c
index 91c17fa..ba42acc 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -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 @@
), 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 @@
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 @@
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;