Commit f43dcaf2 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: x86/twofish - drop CTR mode implementation 



Twofish in CTR mode is never used by the kernel directly, and is highly
unlikely to be relied upon by dm-crypt or algif_skcipher. So let's drop
the accelerated CTR mode implementation, and instead, rely on the CTR
template and the bare cipher.

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 7a6623cc

arch/x86/crypto/twofish-avx-x86_64-asm_64.S

+0 −27
Original line number Diff line number Diff line
@@ -374,30 +374,3 @@ SYM_FUNC_START(twofish_cbc_dec_8way) 
	FRAME_END

	ret;

SYM_FUNC_END(twofish_cbc_dec_8way)
 


SYM_FUNC_START(twofish_ctr_8way)

	/* input:

	 *	%rdi: ctx, CTX

	 *	%rsi: dst

	 *	%rdx: src

	 *	%rcx: iv (little endian, 128bit)

	 */

	FRAME_BEGIN



	pushq %r12;



	movq %rsi, %r11;

	movq %rdx, %r12;



	load_ctr_8way(%rcx, .Lbswap128_mask, RA1, RB1, RC1, RD1, RA2, RB2, RC2,

		      RD2, RX0, RX1, RY0);



	call __twofish_enc_blk8;



	store_ctr_8way(%r12, %r11, RC1, RD1, RA1, RB1, RC2, RD2, RA2, RB2);



	popq %r12;



	FRAME_END

	ret;

SYM_FUNC_END(twofish_ctr_8way)

arch/x86/crypto/twofish_avx_glue.c

+0 −38
Original line number Diff line number Diff line
@@ -25,8 +25,6 @@ asmlinkage void twofish_ecb_enc_8way(const void *ctx, u8 *dst, const u8 *src); 
asmlinkage void twofish_ecb_dec_8way(const void *ctx, u8 *dst, const u8 *src);



asmlinkage void twofish_cbc_dec_8way(const void *ctx, u8 *dst, const u8 *src);

asmlinkage void twofish_ctr_8way(const void *ctx, u8 *dst, const u8 *src,

				 le128 *iv);



static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,

				   const u8 *key, unsigned int keylen)
@@ -55,22 +53,6 @@ static const struct common_glue_ctx twofish_enc = { 
	} }

};



static const struct common_glue_ctx twofish_ctr = {

	.num_funcs = 3,

	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,



	.funcs = { {

		.num_blocks = TWOFISH_PARALLEL_BLOCKS,

		.fn_u = { .ctr = twofish_ctr_8way }

	}, {

		.num_blocks = 3,

		.fn_u = { .ctr = twofish_enc_blk_ctr_3way }

	}, {

		.num_blocks = 1,

		.fn_u = { .ctr = twofish_enc_blk_ctr }

	} }

};



static const struct common_glue_ctx twofish_dec = {

	.num_funcs = 3,

	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
@@ -123,11 +105,6 @@ static int cbc_decrypt(struct skcipher_request *req) 
	return glue_cbc_decrypt_req_128bit(&twofish_dec_cbc, req);

}



static int ctr_crypt(struct skcipher_request *req)

{

	return glue_ctr_req_128bit(&twofish_ctr, req);

}



static struct skcipher_alg twofish_algs[] = {

	{

		.base.cra_name		= "__ecb(twofish)",
@@ -156,21 +133,6 @@ static struct skcipher_alg twofish_algs[] = { 
		.setkey			= twofish_setkey_skcipher,

		.encrypt		= cbc_encrypt,

		.decrypt		= cbc_decrypt,

	}, {

		.base.cra_name		= "__ctr(twofish)",

		.base.cra_driver_name	= "__ctr-twofish-avx",

		.base.cra_priority	= 400,

		.base.cra_flags		= CRYPTO_ALG_INTERNAL,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct twofish_ctx),

		.base.cra_module	= THIS_MODULE,

		.min_keysize		= TF_MIN_KEY_SIZE,

		.max_keysize		= TF_MAX_KEY_SIZE,

		.ivsize			= TF_BLOCK_SIZE,

		.chunksize		= TF_BLOCK_SIZE,

		.setkey			= twofish_setkey_skcipher,

		.encrypt		= ctr_crypt,

		.decrypt		= ctr_crypt,

	},

};

arch/x86/crypto/twofish_glue_3way.c

+0 −78
Original line number Diff line number Diff line
@@ -30,12 +30,6 @@ static inline void twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src) 
	__twofish_enc_blk_3way(ctx, dst, src, false);

}



static inline void twofish_enc_blk_xor_3way(const void *ctx, u8 *dst,

					    const u8 *src)

{

	__twofish_enc_blk_3way(ctx, dst, src, true);

}



void twofish_dec_blk_cbc_3way(const void *ctx, u8 *d, const u8 *s)

{

	u128 ivs[2];
@@ -52,46 +46,6 @@ void twofish_dec_blk_cbc_3way(const void *ctx, u8 *d, const u8 *s) 
}

EXPORT_SYMBOL_GPL(twofish_dec_blk_cbc_3way);



void twofish_enc_blk_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)

{

	be128 ctrblk;

	u128 *dst = (u128 *)d;

	const u128 *src = (const u128 *)s;



	if (dst != src)

		*dst = *src;



	le128_to_be128(&ctrblk, iv);

	le128_inc(iv);



	twofish_enc_blk(ctx, (u8 *)&ctrblk, (u8 *)&ctrblk);

	u128_xor(dst, dst, (u128 *)&ctrblk);

}

EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr);



void twofish_enc_blk_ctr_3way(const void *ctx, u8 *d, const u8 *s, le128 *iv)

{

	be128 ctrblks[3];

	u128 *dst = (u128 *)d;

	const u128 *src = (const u128 *)s;



	if (dst != src) {

		dst[0] = src[0];

		dst[1] = src[1];

		dst[2] = src[2];

	}



	le128_to_be128(&ctrblks[0], iv);

	le128_inc(iv);

	le128_to_be128(&ctrblks[1], iv);

	le128_inc(iv);

	le128_to_be128(&ctrblks[2], iv);

	le128_inc(iv);



	twofish_enc_blk_xor_3way(ctx, (u8 *)dst, (u8 *)ctrblks);

}

EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr_3way);



static const struct common_glue_ctx twofish_enc = {

	.num_funcs = 2,

	.fpu_blocks_limit = -1,
@@ -105,19 +59,6 @@ static const struct common_glue_ctx twofish_enc = { 
	} }

};



static const struct common_glue_ctx twofish_ctr = {

	.num_funcs = 2,

	.fpu_blocks_limit = -1,



	.funcs = { {

		.num_blocks = 3,

		.fn_u = { .ctr = twofish_enc_blk_ctr_3way }

	}, {

		.num_blocks = 1,

		.fn_u = { .ctr = twofish_enc_blk_ctr }

	} }

};



static const struct common_glue_ctx twofish_dec = {

	.num_funcs = 2,

	.fpu_blocks_limit = -1,
@@ -164,11 +105,6 @@ static int cbc_decrypt(struct skcipher_request *req) 
	return glue_cbc_decrypt_req_128bit(&twofish_dec_cbc, req);

}



static int ctr_crypt(struct skcipher_request *req)

{

	return glue_ctr_req_128bit(&twofish_ctr, req);

}



static struct skcipher_alg tf_skciphers[] = {

	{

		.base.cra_name		= "ecb(twofish)",
@@ -195,20 +131,6 @@ static struct skcipher_alg tf_skciphers[] = { 
		.setkey			= twofish_setkey_skcipher,

		.encrypt		= cbc_encrypt,

		.decrypt		= cbc_decrypt,

	}, {

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

		.base.cra_driver_name	= "ctr-twofish-3way",

		.base.cra_priority	= 300,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct twofish_ctx),

		.base.cra_module	= THIS_MODULE,

		.min_keysize		= TF_MIN_KEY_SIZE,

		.max_keysize		= TF_MAX_KEY_SIZE,

		.ivsize			= TF_BLOCK_SIZE,

		.chunksize		= TF_BLOCK_SIZE,

		.setkey			= twofish_setkey_skcipher,

		.encrypt		= ctr_crypt,

		.decrypt		= ctr_crypt,

	},

};

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

+0 −4
Original line number Diff line number Diff line
@@ -17,9 +17,5 @@ asmlinkage void twofish_dec_blk_3way(const void *ctx, u8 *dst, const u8 *src); 


/* helpers from twofish_x86_64-3way module */

extern void twofish_dec_blk_cbc_3way(const void *ctx, u8 *dst, const u8 *src);

extern void twofish_enc_blk_ctr(const void *ctx, u8 *dst, const u8 *src,

				le128 *iv);

extern void twofish_enc_blk_ctr_3way(const void *ctx, u8 *dst, const u8 *src,

				     le128 *iv);



#endif /* ASM_X86_TWOFISH_H */

crypto/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -1680,6 +1680,7 @@ config CRYPTO_TWOFISH_586 
	depends on (X86 || UML_X86) && !64BIT

	select CRYPTO_ALGAPI

	select CRYPTO_TWOFISH_COMMON

	imply CRYPTO_CTR

	help

	  Twofish cipher algorithm.
@@ -1696,6 +1697,7 @@ config CRYPTO_TWOFISH_X86_64 
	depends on (X86 || UML_X86) && 64BIT

	select CRYPTO_ALGAPI

	select CRYPTO_TWOFISH_COMMON

	imply CRYPTO_CTR

	help

	  Twofish cipher algorithm (x86_64).