[v3 PATCH 9/16] crypto: glue_helper - Add skcipher xts helpers

Herbert Xu
2016-11-22T12:08:41Z

This patch adds xts helpers that use the skcipher interface rather
than blkcipher. This will be used by aesni_intel.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

arch/x86/crypto/glue_helper.c | 74 +++++++++++++++++++++++++++++-
arch/x86/include/asm/crypto/glue_helper.h | 39 +++++++++++++++
crypto/Kconfig | 2
3 files changed, 112 insertions(+), 3 deletions(-)

diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 6a85598..260a060 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -27,10 +27,10 @@

#include <linux/module.h>
#include <crypto/b128ops.h>
+#include <crypto/internal/skcipher.h>
#include <crypto/lrw.h>
#include <crypto/xts.h>
#include <asm/crypto/glue_helper.h>
-#include <crypto/scatterwalk.h>

static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
struct blkcipher_desc *desc,
@@ -339,6 +339,41 @@ static unsigned int __glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
return nbytes;
}

+static unsigned int __glue_xts_req_128bit(const struct common_glue_ctx *gctx,
+ void *ctx,
+ struct skcipher_walk *walk)
+{
+ const unsigned int bsize = 128 / 8;
+ unsigned int nbytes = walk->nbytes;
+ u128 *src = walk->src.virt.addr;
+ u128 *dst = walk->dst.virt.addr;
+ unsigned int num_blocks, func_bytes;
+ unsigned int i;
+
+ /* Process multi-block batch */
+ for (i = 0; i < gctx->num_funcs; i++) {
+ num_blocks = gctx->funcs[i].num_blocks;
+ func_bytes = bsize * num_blocks;
+
+ if (nbytes >= func_bytes) {
+ do {
+ gctx->funcs[i].fn_u.xts(ctx, dst, src,
+ walk->iv);
+
+ src += num_blocks;
+ dst += num_blocks;
+ nbytes -= func_bytes;
+ } while (nbytes >= func_bytes);
+
+ if (nbytes < bsize)
+ goto done;
+ }
+ }
+
+done:
+ return nbytes;
+}
+
/* for implementations implementing faster XTS IV generator */
int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
struct blkcipher_desc *desc, struct scatterlist *dst,
@@ -379,6 +414,43 @@ int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
}
EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);

+int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
+ struct skcipher_request *req,
+ common_glue_func_t tweak_fn, void *tweak_ctx,
+ void *crypt_ctx)
+{
+ const unsigned int bsize = 128 / 8;
+ struct skcipher_walk walk;
+ bool fpu_enabled = false;
+ unsigned int nbytes;
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+ nbytes = walk.nbytes;
+ if (!nbytes)
+ return err;
+
+ /* set minimum length to bsize, for tweak_fn */
+ fpu_enabled = glue_skwalk_fpu_begin(bsize, gctx->fpu_blocks_limit,
+ &walk, fpu_enabled,
+ nbytes < bsize ? bsize : nbytes);
+
+ /* calculate first value of T */
+ tweak_fn(tweak_ctx, walk.iv, walk.iv);
+
+ while (nbytes) {
+ nbytes = __glue_xts_req_128bit(gctx, crypt_ctx, &walk);
+
+ err = skcipher_walk_done(&walk, nbytes);
+ nbytes = walk.nbytes;
+ }
+
+ glue_fpu_end(fpu_enabled);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(glue_xts_req_128bit);
+
void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
common_glue_func_t fn)
{
diff --git a/arch/x86/include/asm/crypto/glue_helper.h b/arch/x86/include/asm/crypto/glue_helper.h
index 03bb106..29e53ea 100644
--- a/arch/x86/include/asm/crypto/glue_helper.h
+++ b/arch/x86/include/asm/crypto/glue_helper.h
@@ -5,8 +5,8 @@
#ifndef _CRYPTO_GLUE_HELPER_H
#define _CRYPTO_GLUE_HELPER_H

+#include <crypto/internal/skcipher.h>
#include <linux/kernel.h>
-#include <linux/crypto.h>
#include <asm/fpu/api.h>
#include <crypto/b128ops.h>

@@ -69,6 +69,31 @@ static inline bool glue_fpu_begin(unsigned int bsize, int fpu_blocks_limit,
return true;
}

+static inline bool glue_skwalk_fpu_begin(unsigned int bsize,
+ int fpu_blocks_limit,
+ struct skcipher_walk *walk,
+ bool fpu_enabled, unsigned int nbytes)
+{
+ if (likely(fpu_blocks_limit < 0))
+ return false;
+
+ if (fpu_enabled)
+ return true;
+
+ /*
+ * Vector-registers are only used when chunk to be processed is large
+ * enough, so do not enable FPU until it is necessary.
+ */
+ if (nbytes < bsize * (unsigned int)fpu_blocks_limit)
+ return false;
+
+ /* prevent sleeping if FPU is in use */
+ skcipher_walk_atomise(walk);
+
+ kernel_fpu_begin();
+ return true;
+}
+
static inline void glue_fpu_end(bool fpu_enabled)
{
if (fpu_enabled)
@@ -139,6 +164,18 @@ extern int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
common_glue_func_t tweak_fn, void *tweak_ctx,
void *crypt_ctx);

+extern int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
+ struct blkcipher_desc *desc,
+ struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes,
+ common_glue_func_t tweak_fn, void *tweak_ctx,
+ void *crypt_ctx);
+
+extern int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
+ struct skcipher_request *req,
+ common_glue_func_t tweak_fn, void *tweak_ctx,
+ void *crypt_ctx);
+
extern void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src,
le128 *iv, common_glue_func_t fn);

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 3d31181..87a09c7 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -253,7 +253,7 @@ config CRYPTO_SIMD
config CRYPTO_GLUE_HELPER_X86
tristate
depends on X86
- select CRYPTO_ALGAPI
+ select CRYPTO_BLKCIPHER

config CRYPTO_ENGINE
tristate