Commit 768db5fe authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: x86/des - drop CTR mode implementation 



DES or Triple DES in counter mode is never used in the kernel, so there
is no point in keeping an accelerated implementation around.

Acked-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 89b7ba5c

arch/x86/crypto/des3_ede_glue.c

+0 −104
Original line number Diff line number Diff line
@@ -6,8 +6,6 @@ 
 *

 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:

 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>

 * CTR part based on code (crypto/ctr.c) by:

 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>

 */



#include <crypto/algapi.h>
@@ -253,94 +251,6 @@ static int cbc_decrypt(struct skcipher_request *req) 
	return err;

}



static void ctr_crypt_final(struct des3_ede_x86_ctx *ctx,

			    struct skcipher_walk *walk)

{

	u8 *ctrblk = walk->iv;

	u8 keystream[DES3_EDE_BLOCK_SIZE];

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	unsigned int nbytes = walk->nbytes;



	des3_ede_enc_blk(ctx, keystream, ctrblk);

	crypto_xor_cpy(dst, keystream, src, nbytes);



	crypto_inc(ctrblk, DES3_EDE_BLOCK_SIZE);

}



static unsigned int __ctr_crypt(struct des3_ede_x86_ctx *ctx,

				struct skcipher_walk *walk)

{

	unsigned int bsize = DES3_EDE_BLOCK_SIZE;

	unsigned int nbytes = walk->nbytes;

	__be64 *src = (__be64 *)walk->src.virt.addr;

	__be64 *dst = (__be64 *)walk->dst.virt.addr;

	u64 ctrblk = be64_to_cpu(*(__be64 *)walk->iv);

	__be64 ctrblocks[3];



	/* Process four block batch */

	if (nbytes >= bsize * 3) {

		do {

			/* create ctrblks for parallel encrypt */

			ctrblocks[0] = cpu_to_be64(ctrblk++);

			ctrblocks[1] = cpu_to_be64(ctrblk++);

			ctrblocks[2] = cpu_to_be64(ctrblk++);



			des3_ede_enc_blk_3way(ctx, (u8 *)ctrblocks,

					      (u8 *)ctrblocks);



			dst[0] = src[0] ^ ctrblocks[0];

			dst[1] = src[1] ^ ctrblocks[1];

			dst[2] = src[2] ^ ctrblocks[2];



			src += 3;

			dst += 3;

		} while ((nbytes -= bsize * 3) >= bsize * 3);



		if (nbytes < bsize)

			goto done;

	}



	/* Handle leftovers */

	do {

		ctrblocks[0] = cpu_to_be64(ctrblk++);



		des3_ede_enc_blk(ctx, (u8 *)ctrblocks, (u8 *)ctrblocks);



		dst[0] = src[0] ^ ctrblocks[0];



		src += 1;

		dst += 1;

	} while ((nbytes -= bsize) >= bsize);



done:

	*(__be64 *)walk->iv = cpu_to_be64(ctrblk);

	return nbytes;

}



static int ctr_crypt(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);

	struct skcipher_walk walk;

	unsigned int nbytes;

	int err;



	err = skcipher_walk_virt(&walk, req, false);



	while ((nbytes = walk.nbytes) >= DES3_EDE_BLOCK_SIZE) {

		nbytes = __ctr_crypt(ctx, &walk);

		err = skcipher_walk_done(&walk, nbytes);

	}



	if (nbytes) {

		ctr_crypt_final(ctx, &walk);

		err = skcipher_walk_done(&walk, 0);

	}



	return err;

}



static int des3_ede_x86_setkey(struct crypto_tfm *tfm, const u8 *key,

			       unsigned int keylen)

{
@@ -428,20 +338,6 @@ static struct skcipher_alg des3_ede_skciphers[] = { 
		.setkey			= des3_ede_x86_setkey_skcipher,

		.encrypt		= cbc_encrypt,

		.decrypt		= cbc_decrypt,

	}, {

		.base.cra_name		= "ctr(des3_ede)",

		.base.cra_driver_name	= "ctr-des3_ede-asm",

		.base.cra_priority	= 300,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct des3_ede_x86_ctx),

		.base.cra_module	= THIS_MODULE,

		.min_keysize		= DES3_EDE_KEY_SIZE,

		.max_keysize		= DES3_EDE_KEY_SIZE,

		.ivsize			= DES3_EDE_BLOCK_SIZE,

		.chunksize		= DES3_EDE_BLOCK_SIZE,

		.setkey			= des3_ede_x86_setkey_skcipher,

		.encrypt		= ctr_crypt,

		.decrypt		= ctr_crypt,

	}

};

crypto/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1427,6 +1427,7 @@ config CRYPTO_DES3_EDE_X86_64 
	depends on X86 && 64BIT

	select CRYPTO_SKCIPHER

	select CRYPTO_LIB_DES

	imply CRYPTO_CTR

	help

	  Triple DES EDE (FIPS 46-3) algorithm.