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authorEric Biggers <ebiggers@google.com>2018-02-19 23:48:25 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2018-03-03 00:03:34 +0800
commit217afccf65064709fb032652ee17cc0a8f68b7b5 (patch)
treea23d950380c22371b64cddbfc5f05aef22db6756 /crypto/lrw.c
parenteb66ecd56107e563de65121866990ec07142245d (diff)
downloadlwn-217afccf65064709fb032652ee17cc0a8f68b7b5.tar.gz
lwn-217afccf65064709fb032652ee17cc0a8f68b7b5.zip
crypto: lrw - remove lrw_crypt()
Now that all users of lrw_crypt() have been removed in favor of the LRW template wrapping an ECB mode algorithm, remove lrw_crypt(). Also remove crypto/lrw.h as that is no longer needed either; and fold 'struct lrw_table_ctx' into 'struct priv', lrw_init_table() into setkey(), and lrw_free_table() into exit_tfm(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/lrw.c')
-rw-r--r--crypto/lrw.c152
1 files changed, 39 insertions, 113 deletions
diff --git a/crypto/lrw.c b/crypto/lrw.c
index cbbd7c50ad19..a09cdaa6ddf3 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -28,13 +28,31 @@
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
-#include <crypto/lrw.h>
#define LRW_BUFFER_SIZE 128u
+#define LRW_BLOCK_SIZE 16
+
struct priv {
struct crypto_skcipher *child;
- struct lrw_table_ctx table;
+
+ /*
+ * 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];
};
struct rctx {
@@ -65,11 +83,25 @@ static inline void setbit128_bbe(void *b, int bit)
), b);
}
-int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
+static int setkey(struct crypto_skcipher *parent, const u8 *key,
+ unsigned int keylen)
{
+ struct priv *ctx = crypto_skcipher_ctx(parent);
+ struct crypto_skcipher *child = ctx->child;
+ int err, bsize = LRW_BLOCK_SIZE;
+ const u8 *tweak = key + keylen - bsize;
be128 tmp = { 0 };
int i;
+ crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
+ CRYPTO_TFM_REQ_MASK);
+ err = crypto_skcipher_setkey(child, key, keylen - bsize);
+ crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
+ CRYPTO_TFM_RES_MASK);
+ if (err)
+ return err;
+
if (ctx->table)
gf128mul_free_64k(ctx->table);
@@ -87,34 +119,6 @@ int lrw_init_table(struct lrw_table_ctx *ctx, const u8 *tweak)
return 0;
}
-EXPORT_SYMBOL_GPL(lrw_init_table);
-
-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_skcipher *parent, const u8 *key,
- unsigned int keylen)
-{
- struct priv *ctx = crypto_skcipher_ctx(parent);
- struct crypto_skcipher *child = ctx->child;
- int err, bsize = LRW_BLOCK_SIZE;
- const u8 *tweak = key + keylen - bsize;
-
- crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
- crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
- CRYPTO_TFM_REQ_MASK);
- err = crypto_skcipher_setkey(child, key, keylen - bsize);
- crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
- CRYPTO_TFM_RES_MASK);
- if (err)
- return err;
-
- return lrw_init_table(&ctx->table, tweak);
-}
static inline void inc(be128 *iv)
{
@@ -238,7 +242,7 @@ static int pre_crypt(struct skcipher_request *req)
/* T <- I*Key2, using the optimization
* discussed in the specification */
be128_xor(&rctx->t, &rctx->t,
- &ctx->table.mulinc[get_index128(iv)]);
+ &ctx->mulinc[get_index128(iv)]);
inc(iv);
} while ((avail -= bs) >= bs);
@@ -301,7 +305,7 @@ static int init_crypt(struct skcipher_request *req, crypto_completion_t done)
memcpy(&rctx->t, req->iv, sizeof(rctx->t));
/* T <- I*Key2 */
- gf128mul_64k_bbe(&rctx->t, ctx->table.table);
+ gf128mul_64k_bbe(&rctx->t, ctx->table);
return 0;
}
@@ -416,85 +420,6 @@ static int decrypt(struct skcipher_request *req)
return do_decrypt(req, init_crypt(req, decrypt_done));
}
-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_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
@@ -518,7 +443,8 @@ static void exit_tfm(struct crypto_skcipher *tfm)
{
struct priv *ctx = crypto_skcipher_ctx(tfm);
- lrw_free_table(&ctx->table);
+ if (ctx->table)
+ gf128mul_free_64k(ctx->table);
crypto_free_skcipher(ctx->child);
}