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crypto: lrw - split gf128mul table initialization from setkey

Split gf128mul initialization from setkey so that it can be used outside
lrw-module.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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1 parent 4660720 commit 171c02048f50d7187991f251ddeed2d7e5de104f @jkivilin jkivilin committed with herbertx Oct 18, 2011
Showing with 40 additions and 21 deletions.
  1. +40 −21 crypto/lrw.c
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@@ -29,8 +29,7 @@
#define LRW_BLOCK_SIZE 16
-struct priv {
- struct crypto_cipher *child;
+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
@@ -45,6 +44,11 @@ struct priv {
be128 mulinc[128];
};
+struct priv {
+ struct crypto_cipher *child;
+ struct lrw_table_ctx table;
+};
+
static inline void setbit128_bbe(void *b, int bit)
{
__set_bit(bit ^ (0x80 -
@@ -56,28 +60,16 @@ static inline void setbit128_bbe(void *b, int bit)
), b);
}
-static int setkey(struct crypto_tfm *parent, const u8 *key,
- unsigned int keylen)
+static int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
{
- struct priv *ctx = crypto_tfm_ctx(parent);
- struct crypto_cipher *child = ctx->child;
- int err, i;
be128 tmp = { 0 };
- int bsize = LRW_BLOCK_SIZE;
-
- crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
- crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
- CRYPTO_TFM_REQ_MASK);
- if ((err = crypto_cipher_setkey(child, key, keylen - bsize)))
- return err;
- crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
- CRYPTO_TFM_RES_MASK);
+ int i;
if (ctx->table)
gf128mul_free_64k(ctx->table);
/* initialize multiplication table for Key2 */
- ctx->table = gf128mul_init_64k_bbe((be128 *)(key + keylen - bsize));
+ ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
if (!ctx->table)
return -ENOMEM;
@@ -91,6 +83,32 @@ static int setkey(struct crypto_tfm *parent, const u8 *key,
return 0;
}
+static void lrw_free_table(struct lrw_table_ctx *ctx)
+{
+ if (ctx->table)
+ gf128mul_free_64k(ctx->table);
+}
+
+static int setkey(struct crypto_tfm *parent, const u8 *key,
+ unsigned int keylen)
+{
+ struct priv *ctx = crypto_tfm_ctx(parent);
+ struct crypto_cipher *child = ctx->child;
+ int err, bsize = LRW_BLOCK_SIZE;
+ const u8 *tweak = key + keylen - bsize;
+
+ crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_cipher_setkey(child, key, keylen - bsize);
+ if (err)
+ return err;
+ crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
+ CRYPTO_TFM_RES_MASK);
+
+ return lrw_init_table(&ctx->table, tweak);
+}
+
struct sinfo {
be128 t;
struct crypto_tfm *tfm;
@@ -157,15 +175,16 @@ static int crypt(struct blkcipher_desc *d,
s.t = *iv;
/* T <- I*Key2 */
- gf128mul_64k_bbe(&s.t, ctx->table);
+ gf128mul_64k_bbe(&s.t, ctx->table.table);
goto first;
for (;;) {
do {
/* T <- I*Key2, using the optimization
* discussed in the specification */
- be128_xor(&s.t, &s.t, &ctx->mulinc[get_index128(iv)]);
+ be128_xor(&s.t, &s.t,
+ &ctx->table.mulinc[get_index128(iv)]);
inc(iv);
first:
@@ -233,8 +252,8 @@ static int init_tfm(struct crypto_tfm *tfm)
static void exit_tfm(struct crypto_tfm *tfm)
{
struct priv *ctx = crypto_tfm_ctx(tfm);
- if (ctx->table)
- gf128mul_free_64k(ctx->table);
+
+ lrw_free_table(&ctx->table);
crypto_free_cipher(ctx->child);
}

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