[PATCH 2/2] crypto: vmx - Adding support for XTS
Stephan Mueller
smueller at chronox.de
Tue Jul 12 06:10:39 AEST 2016
Am Montag, 11. Juli 2016, 16:07:40 CEST schrieb Paulo Flabiano Smorigo:
Hi Paulo,
> From: "Leonidas S. Barbosa" <leosilva at linux.vnet.ibm.com>
>
> This patch add XTS support using VMX-crypto driver.
>
> Signed-off-by: Leonidas S. Barbosa <leosilva at linux.vnet.ibm.com>
> Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo at linux.vnet.ibm.com>
> ---
> drivers/crypto/vmx/Makefile | 2 +-
> drivers/crypto/vmx/aes_xts.c | 187
> +++++++++++++++++++++++++++++++++++++++++++ drivers/crypto/vmx/vmx.c |
> 2 +
> 3 files changed, 190 insertions(+), 1 deletion(-)
> create mode 100644 drivers/crypto/vmx/aes_xts.c
>
> diff --git a/drivers/crypto/vmx/Makefile b/drivers/crypto/vmx/Makefile
> index d28ab96..de6e241 100644
> --- a/drivers/crypto/vmx/Makefile
> +++ b/drivers/crypto/vmx/Makefile
> @@ -1,5 +1,5 @@
> obj-$(CONFIG_CRYPTO_DEV_VMX_ENCRYPT) += vmx-crypto.o
> -vmx-crypto-objs := vmx.o aesp8-ppc.o ghashp8-ppc.o aes.o aes_cbc.o
> aes_ctr.o ghash.o +vmx-crypto-objs := vmx.o aesp8-ppc.o ghashp8-ppc.o aes.o
> aes_cbc.o aes_ctr.o aes_xts.o ghash.o
>
> ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
> TARGET := linux-ppc64le
> diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
> new file mode 100644
> index 0000000..62e698c
> --- /dev/null
> +++ b/drivers/crypto/vmx/aes_xts.c
> @@ -0,0 +1,187 @@
> +/**
> + * AES XTS routines supporting VMX In-core instructions on Power 8
> + *
> + * Copyright (C) 2015 International Business Machines Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundations; version 2 only.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY of FITNESS FOR A PARTICUPAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + *
> + * Author: Leonidas S. Barbosa <leosilva at linux.vnet.ibm.com>
> + */
> +
> +#include <linux/types.h>
> +#include <linux/err.h>
> +#include <linux/crypto.h>
> +#include <linux/delay.h>
> +#include <linux/hardirq.h>
> +#include <asm/switch_to.h>
> +#include <crypto/aes.h>
> +#include <crypto/scatterwalk.h>
> +
> +#include "aesp8-ppc.h"
> +
> +struct p8_aes_xts_ctx {
> + struct crypto_blkcipher *fallback;
> + struct aes_key enc_key;
> + struct aes_key dec_key;
> + struct aes_key tweak_key;
> +};
> +
> +static int p8_aes_xts_init(struct crypto_tfm *tfm)
> +{
> + const char *alg;
> + struct crypto_blkcipher *fallback;
> + struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
> +
> + if (!(alg = crypto_tfm_alg_name(tfm))) {
> + printk(KERN_ERR "Failed to get algorithm name.\n");
> + return -ENOENT;
> + }
> +
> + fallback =
> + crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
> + if (IS_ERR(fallback)) {
> + printk(KERN_ERR
> + "Failed to allocate transformation for '%s': %ld\n",
> + alg, PTR_ERR(fallback));
> + return PTR_ERR(fallback);
> + }
> + printk(KERN_INFO "Using '%s' as fallback implementation.\n",
> + crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));
> +
> + crypto_blkcipher_set_flags(
> + fallback,
> + crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
> + ctx->fallback = fallback;
> +
> + return 0;
> +}
> +
> +static void p8_aes_xts_exit(struct crypto_tfm *tfm)
> +{
> + struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
> +
> + if (ctx->fallback) {
> + crypto_free_blkcipher(ctx->fallback);
> + ctx->fallback = NULL;
> + }
> +}
> +
> +static int p8_aes_xts_setkey(struct crypto_tfm *tfm, const u8 *key,
> + unsigned int keylen)
> +{
> + int ret;
> + struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
> +
> + if (keylen % 2)
> + return -EINVAL;
Please use xts_check_key instead of this check.
> +
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> + ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8,
> &ctx->tweak_key); + ret += aes_p8_set_encrypt_key(key, (keylen/2) * 8,
> &ctx->enc_key); + ret += aes_p8_set_decrypt_key(key, (keylen/2) * 8,
> &ctx->dec_key); + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
> +
> + ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
> + return ret;
> +}
> +
> +static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
> + struct scatterlist *dst,
> + struct scatterlist *src,
> + unsigned int nbytes, int enc)
> +{
> + int ret;
> + u8 tweak[AES_BLOCK_SIZE];
> + u8 *iv;
> + struct blkcipher_walk walk;
> + struct p8_aes_xts_ctx *ctx =
> + crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
> + struct blkcipher_desc fallback_desc = {
> + .tfm = ctx->fallback,
> + .info = desc->info,
> + .flags = desc->flags
> + };
> +
> + if (in_interrupt()) {
> + ret = enc ? crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes)
:
> + crypto_blkcipher_decrypt(&fallback_desc, dst,
> src, nbytes); + } else {
> + preempt_disable();
> + pagefault_disable();
> + enable_kernel_vsx();
> +
> + blkcipher_walk_init(&walk, dst, src, nbytes);
> +
> + iv = (u8 *)walk.iv;
> + ret = blkcipher_walk_virt(desc, &walk);
> + aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
> +
> + while ((nbytes = walk.nbytes)) {
> + if (enc)
> + aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
> + nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
> + else
> + aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
> + nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
> +
> + nbytes &= AES_BLOCK_SIZE - 1;
> + ret = blkcipher_walk_done(desc, &walk, nbytes);
> + }
> +
> + disable_kernel_vsx();
> + pagefault_enable();
> + preempt_enable();
memzero_explicit(tweak) ?
> + }
> + return ret;
> +}
> +
> +static int p8_aes_xts_encrypt(struct blkcipher_desc *desc,
> + struct scatterlist *dst,
> + struct scatterlist *src, unsigned int nbytes)
> +{
> + return p8_aes_xts_crypt(desc, dst, src, nbytes, 1);
> +}
> +
> +static int p8_aes_xts_decrypt(struct blkcipher_desc *desc,
> + struct scatterlist *dst,
> + struct scatterlist *src, unsigned int nbytes)
> +{
> + return p8_aes_xts_crypt(desc, dst, src, nbytes, 0);
> +}
> +
> +struct crypto_alg p8_aes_xts_alg = {
> + .cra_name = "xts(aes)",
> + .cra_driver_name = "p8_aes_xts",
> + .cra_module = THIS_MODULE,
> + .cra_priority = 2000,
> + .cra_type = &crypto_blkcipher_type,
> + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
> + .cra_alignmask = 0,
> + .cra_blocksize = AES_BLOCK_SIZE,
> + .cra_ctxsize = sizeof(struct p8_aes_xts_ctx),
> + .cra_init = p8_aes_xts_init,
> + .cra_exit = p8_aes_xts_exit,
> + .cra_blkcipher = {
> + .ivsize = AES_BLOCK_SIZE,
> + .min_keysize = 2 * AES_MIN_KEY_SIZE,
> + .max_keysize = 2 * AES_MAX_KEY_SIZE,
> + .setkey = p8_aes_xts_setkey,
> + .encrypt = p8_aes_xts_encrypt,
> + .decrypt = p8_aes_xts_decrypt,
> + }
> +};
> diff --git a/drivers/crypto/vmx/vmx.c b/drivers/crypto/vmx/vmx.c
> index e163d57..f688c32 100644
> --- a/drivers/crypto/vmx/vmx.c
> +++ b/drivers/crypto/vmx/vmx.c
> @@ -31,10 +31,12 @@ extern struct shash_alg p8_ghash_alg;
> extern struct crypto_alg p8_aes_alg;
> extern struct crypto_alg p8_aes_cbc_alg;
> extern struct crypto_alg p8_aes_ctr_alg;
> +extern struct crypto_alg p8_aes_xts_alg;
> static struct crypto_alg *algs[] = {
> &p8_aes_alg,
> &p8_aes_cbc_alg,
> &p8_aes_ctr_alg,
> + &p8_aes_xts_alg,
> NULL,
> };
Ciao
Stephan
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