Commit 8bab4e3c authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: x86/serpent-sse2 - remove XTS algorithm 



The XTS template now wraps an ECB mode algorithm rather than the block
cipher directly.  Therefore it is now redundant for crypto modules to
wrap their ECB code with generic XTS code themselves via xts_crypt().

Remove the xts-serpent-sse2 algorithm which did this.  Users who request
xts(serpent) and previously would have gotten xts-serpent-sse2 will now
get xts(ecb-serpent-sse2) instead, which is just as fast.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 2a05cfc3

arch/x86/crypto/serpent_sse2_glue.c

+0 −172
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include <crypto/cryptd.h>

#include <crypto/b128ops.h>

#include <crypto/ctr.h>

#include <crypto/xts.h>

#include <asm/crypto/serpent-sse2.h>

#include <asm/crypto/glue_helper.h>
@@ -170,134 +169,6 @@ static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, 
	return glue_ctr_crypt_128bit(&serpent_ctr, desc, dst, src, nbytes);

}



static inline bool serpent_fpu_begin(bool fpu_enabled, unsigned int nbytes)

{

	return glue_fpu_begin(SERPENT_BLOCK_SIZE, SERPENT_PARALLEL_BLOCKS,

			      NULL, fpu_enabled, nbytes);

}



static inline void serpent_fpu_end(bool fpu_enabled)

{

	glue_fpu_end(fpu_enabled);

}



struct crypt_priv {

	struct serpent_ctx *ctx;

	bool fpu_enabled;

};



static void encrypt_callback(void *priv, u8 *srcdst, unsigned int nbytes)

{

	const unsigned int bsize = SERPENT_BLOCK_SIZE;

	struct crypt_priv *ctx = priv;

	int i;



	ctx->fpu_enabled = serpent_fpu_begin(ctx->fpu_enabled, nbytes);



	if (nbytes == bsize * SERPENT_PARALLEL_BLOCKS) {

		serpent_enc_blk_xway(ctx->ctx, srcdst, srcdst);

		return;

	}



	for (i = 0; i < nbytes / bsize; i++, srcdst += bsize)

		__serpent_encrypt(ctx->ctx, srcdst, srcdst);

}



static void decrypt_callback(void *priv, u8 *srcdst, unsigned int nbytes)

{

	const unsigned int bsize = SERPENT_BLOCK_SIZE;

	struct crypt_priv *ctx = priv;

	int i;



	ctx->fpu_enabled = serpent_fpu_begin(ctx->fpu_enabled, nbytes);



	if (nbytes == bsize * SERPENT_PARALLEL_BLOCKS) {

		serpent_dec_blk_xway(ctx->ctx, srcdst, srcdst);

		return;

	}



	for (i = 0; i < nbytes / bsize; i++, srcdst += bsize)

		__serpent_decrypt(ctx->ctx, srcdst, srcdst);

}



struct serpent_xts_ctx {

	struct serpent_ctx tweak_ctx;

	struct serpent_ctx crypt_ctx;

};



static int xts_serpent_setkey(struct crypto_tfm *tfm, const u8 *key,

			      unsigned int keylen)

{

	struct serpent_xts_ctx *ctx = crypto_tfm_ctx(tfm);

	int err;



	err = xts_check_key(tfm, key, keylen);

	if (err)

		return err;



	/* first half of xts-key is for crypt */

	err = __serpent_setkey(&ctx->crypt_ctx, key, keylen / 2);

	if (err)

		return err;



	/* second half of xts-key is for tweak */

	return __serpent_setkey(&ctx->tweak_ctx, key + keylen / 2, keylen / 2);

}



static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,

		       struct scatterlist *src, unsigned int nbytes)

{

	struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);

	le128 buf[SERPENT_PARALLEL_BLOCKS];

	struct crypt_priv crypt_ctx = {

		.ctx = &ctx->crypt_ctx,

		.fpu_enabled = false,

	};

	struct xts_crypt_req req = {

		.tbuf = buf,

		.tbuflen = sizeof(buf),



		.tweak_ctx = &ctx->tweak_ctx,

		.tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),

		.crypt_ctx = &crypt_ctx,

		.crypt_fn = encrypt_callback,

	};

	int ret;



	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

	ret = xts_crypt(desc, dst, src, nbytes, &req);

	serpent_fpu_end(crypt_ctx.fpu_enabled);



	return ret;

}



static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,

		       struct scatterlist *src, unsigned int nbytes)

{

	struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);

	le128 buf[SERPENT_PARALLEL_BLOCKS];

	struct crypt_priv crypt_ctx = {

		.ctx = &ctx->crypt_ctx,

		.fpu_enabled = false,

	};

	struct xts_crypt_req req = {

		.tbuf = buf,

		.tbuflen = sizeof(buf),



		.tweak_ctx = &ctx->tweak_ctx,

		.tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),

		.crypt_ctx = &crypt_ctx,

		.crypt_fn = decrypt_callback,

	};

	int ret;



	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

	ret = xts_crypt(desc, dst, src, nbytes, &req);

	serpent_fpu_end(crypt_ctx.fpu_enabled);



	return ret;

}



static struct crypto_alg serpent_algs[] = { {

	.cra_name		= "__ecb-serpent-sse2",

	.cra_driver_name	= "__driver-ecb-serpent-sse2",
@@ -359,27 +230,6 @@ static struct crypto_alg serpent_algs[] = { { 
			.decrypt	= ctr_crypt,

		},

	},

}, {

	.cra_name		= "__xts-serpent-sse2",

	.cra_driver_name	= "__driver-xts-serpent-sse2",

	.cra_priority		= 0,

	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER |

				  CRYPTO_ALG_INTERNAL,

	.cra_blocksize		= SERPENT_BLOCK_SIZE,

	.cra_ctxsize		= sizeof(struct serpent_xts_ctx),

	.cra_alignmask		= 0,

	.cra_type		= &crypto_blkcipher_type,

	.cra_module		= THIS_MODULE,

	.cra_u = {

		.blkcipher = {

			.min_keysize	= SERPENT_MIN_KEY_SIZE * 2,

			.max_keysize	= SERPENT_MAX_KEY_SIZE * 2,

			.ivsize		= SERPENT_BLOCK_SIZE,

			.setkey		= xts_serpent_setkey,

			.encrypt	= xts_encrypt,

			.decrypt	= xts_decrypt,

		},

	},

}, {

	.cra_name		= "ecb(serpent)",

	.cra_driver_name	= "ecb-serpent-sse2",
@@ -446,28 +296,6 @@ static struct crypto_alg serpent_algs[] = { { 
			.geniv		= "chainiv",

		},

	},

}, {

	.cra_name		= "xts(serpent)",

	.cra_driver_name	= "xts-serpent-sse2",

	.cra_priority		= 400,

	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,

	.cra_blocksize		= SERPENT_BLOCK_SIZE,

	.cra_ctxsize		= sizeof(struct async_helper_ctx),

	.cra_alignmask		= 0,

	.cra_type		= &crypto_ablkcipher_type,

	.cra_module		= THIS_MODULE,

	.cra_init		= ablk_init,

	.cra_exit		= ablk_exit,

	.cra_u = {

		.ablkcipher = {

			.min_keysize	= SERPENT_MIN_KEY_SIZE * 2,

			.max_keysize	= SERPENT_MAX_KEY_SIZE * 2,

			.ivsize		= SERPENT_BLOCK_SIZE,

			.setkey		= ablk_set_key,

			.encrypt	= ablk_encrypt,

			.decrypt	= ablk_decrypt,

		},

	},

} };



static int __init serpent_sse2_init(void)

crypto/Kconfig

+0 −2
Original line number Diff line number Diff line
@@ -1427,7 +1427,6 @@ config CRYPTO_SERPENT_SSE2_X86_64 
	select CRYPTO_ABLK_HELPER

	select CRYPTO_GLUE_HELPER_X86

	select CRYPTO_SERPENT

	select CRYPTO_XTS

	help

	  Serpent cipher algorithm, by Anderson, Biham & Knudsen.
@@ -1448,7 +1447,6 @@ config CRYPTO_SERPENT_SSE2_586 
	select CRYPTO_ABLK_HELPER

	select CRYPTO_GLUE_HELPER_X86

	select CRYPTO_SERPENT

	select CRYPTO_XTS

	help

	  Serpent cipher algorithm, by Anderson, Biham & Knudsen.

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