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>

1 files changed, 40 insertions, 21 deletions

diff --git a/crypto/lrw.c b/crypto/lrw.c
index bee60226f723..91c17fa18374 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -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;
@@ -157,7 +175,7 @@ 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;
 
@@ -165,7 +183,8 @@ static int crypt(struct blkcipher_desc *d,
                 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);
 }