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Commit ec808bbe authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: arm64/aes-bs - implement non-SIMD fallback for AES-CTR 



Of the various chaining modes implemented by the bit sliced AES driver,
only CTR is exposed as a synchronous cipher, and requires a fallback in
order to remain usable once we update the kernel mode NEON handling logic
to disallow nested use. So wire up the existing CTR fallback C code.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 611d5324

arch/arm64/crypto/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -89,6 +89,7 @@ config CRYPTO_AES_ARM64_BS 
	depends on KERNEL_MODE_NEON

	depends on KERNEL_MODE_NEON

	select CRYPTO_BLKCIPHER

	select CRYPTO_BLKCIPHER

	select CRYPTO_AES_ARM64_NEON_BLK

	select CRYPTO_AES_ARM64_NEON_BLK

	select CRYPTO_AES_ARM64

	select CRYPTO_SIMD

	select CRYPTO_SIMD





endif
 
endif

arch/arm64/crypto/aes-neonbs-glue.c

+43 −5
Original line number Original line Diff line number Diff line 
/*

/*

 * Bit sliced AES using NEON instructions

 * Bit sliced AES using NEON instructions

 *

 *

 * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>

 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>

 *

 *

 * This program is free software; you can redistribute it and/or modify

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * it under the terms of the GNU General Public License version 2 as
@@ -9,12 +9,15 @@ 
 */

 */





#include <asm/neon.h>

#include <asm/neon.h>

#include <asm/simd.h>

#include <crypto/aes.h>

#include <crypto/aes.h>

#include <crypto/internal/simd.h>

#include <crypto/internal/simd.h>

#include <crypto/internal/skcipher.h>

#include <crypto/internal/skcipher.h>

#include <crypto/xts.h>

#include <crypto/xts.h>

#include <linux/module.h>

#include <linux/module.h>





#include "aes-ctr-fallback.h"



MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");

MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");

MODULE_LICENSE("GPL v2");

MODULE_LICENSE("GPL v2");
@@ -58,6 +61,11 @@ struct aesbs_cbc_ctx { 
	u32			enc[AES_MAX_KEYLENGTH_U32];

	u32			enc[AES_MAX_KEYLENGTH_U32];

};

};





struct aesbs_ctr_ctx {

	struct aesbs_ctx	key;		/* must be first member */

	struct crypto_aes_ctx	fallback;

};



struct aesbs_xts_ctx {

struct aesbs_xts_ctx {

	struct aesbs_ctx	key;

	struct aesbs_ctx	key;

	u32			twkey[AES_MAX_KEYLENGTH_U32];

	u32			twkey[AES_MAX_KEYLENGTH_U32];
@@ -196,6 +204,25 @@ static int cbc_decrypt(struct skcipher_request *req) 
	return err;

	return err;

}

}





static int aesbs_ctr_setkey_sync(struct crypto_skcipher *tfm, const u8 *in_key,

				 unsigned int key_len)

{

	struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);

	int err;



	err = crypto_aes_expand_key(&ctx->fallback, in_key, key_len);

	if (err)

		return err;



	ctx->key.rounds = 6 + key_len / 4;



	kernel_neon_begin();

	aesbs_convert_key(ctx->key.rk, ctx->fallback.key_enc, ctx->key.rounds);

	kernel_neon_end();



	return 0;

}



static int ctr_encrypt(struct skcipher_request *req)

static int ctr_encrypt(struct skcipher_request *req)

{

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
@@ -259,6 +286,17 @@ static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key, 
	return aesbs_setkey(tfm, in_key, key_len);

	return aesbs_setkey(tfm, in_key, key_len);

}

}





static int ctr_encrypt_sync(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);



	if (!may_use_simd())

		return aes_ctr_encrypt_fallback(&ctx->fallback, req);



	return ctr_encrypt(req);

}



static int __xts_crypt(struct skcipher_request *req,

static int __xts_crypt(struct skcipher_request *req,

		       void (*fn)(u8 out[], u8 const in[], u8 const rk[],

		       void (*fn)(u8 out[], u8 const in[], u8 const rk[],

				  int rounds, int blocks, u8 iv[]))

				  int rounds, int blocks, u8 iv[]))
@@ -355,7 +393,7 @@ static struct skcipher_alg aes_algs[] = { { 
	.base.cra_driver_name	= "ctr-aes-neonbs",

	.base.cra_driver_name	= "ctr-aes-neonbs",

	.base.cra_priority	= 250 - 1,

	.base.cra_priority	= 250 - 1,

	.base.cra_blocksize	= 1,

	.base.cra_blocksize	= 1,

	.base.cra_ctxsize	= sizeof(struct aesbs_ctx),

	.base.cra_ctxsize	= sizeof(struct aesbs_ctr_ctx),

	.base.cra_module	= THIS_MODULE,

	.base.cra_module	= THIS_MODULE,





	.min_keysize		= AES_MIN_KEY_SIZE,

	.min_keysize		= AES_MIN_KEY_SIZE,
@@ -363,9 +401,9 @@ static struct skcipher_alg aes_algs[] = { { 
	.chunksize		= AES_BLOCK_SIZE,

	.chunksize		= AES_BLOCK_SIZE,

	.walksize		= 8 * AES_BLOCK_SIZE,

	.walksize		= 8 * AES_BLOCK_SIZE,

	.ivsize			= AES_BLOCK_SIZE,

	.ivsize			= AES_BLOCK_SIZE,

	.setkey			= aesbs_setkey,

	.setkey			= aesbs_ctr_setkey_sync,

	.encrypt		= ctr_encrypt,

	.encrypt		= ctr_encrypt_sync,

	.decrypt		= ctr_encrypt,

	.decrypt		= ctr_encrypt_sync,

}, {

}, {

	.base.cra_name		= "__xts(aes)",

	.base.cra_name		= "__xts(aes)",

	.base.cra_driver_name	= "__xts-aes-neonbs",

	.base.cra_driver_name	= "__xts-aes-neonbs",