Commit 065ce327 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: glue_helper - Add skcipher xts helpers 



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

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 043a4400

arch/x86/crypto/glue_helper.c

+73 −1
Original line number Diff line number Diff line
@@ -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)

{

arch/x86/include/asm/crypto/glue_helper.h

+38 −1
Original line number Diff line number Diff line
@@ -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);

crypto/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -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