From 8e7643e39fc0c539f55d85263e87f64dca52efea Mon Sep 17 00:00:00 2001

From: "Daniel P. Berrange" <berrange@redhat.com>

Date: Wed, 24 Apr 2019 09:56:39 +0100

Subject: [PATCH 5/9] crypto: convert xts_tweak_encdec to use xts_uint128 type

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RH-Author: Daniel P. Berrange <berrange@redhat.com>

Message-id: <20190424095643.796-6-berrange@redhat.com>

Patchwork-id: 85883

O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 5/9] crypto: convert xts_tweak_encdec to use xts_uint128 type

Bugzilla: 1680231

RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

RH-Acked-by: John Snow <jsnow@redhat.com>

RH-Acked-by: Eric Blake <eblake@redhat.com>

Using 64-bit arithmetic increases the performance for xts-aes-128

when built with gcrypt:

  Encrypt: 272 MB/s -> 355 MB/s

  Decrypt: 275 MB/s -> 362 MB/s

Reviewed-by: Alberto Garcia <berto@igalia.com>

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

(cherry picked from commit db217c69f0849add67cfa2cd6601c329398be12c)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 crypto/xts.c | 84 +++++++++++++++++++++++++++++++++++++++++-------------------

 1 file changed, 58 insertions(+), 26 deletions(-)

diff --git a/crypto/xts.c b/crypto/xts.c

index bee23f8..0ad231f 100644

--- a/crypto/xts.c

+++ b/crypto/xts.c

@@ -31,6 +31,13 @@ typedef union {

     uint64_t u[2];

 } xts_uint128;

+static inline void xts_uint128_xor(xts_uint128 *D,

+                                   const xts_uint128 *S1,

+                                   const xts_uint128 *S2)

+{

+    D->u[0] = S1->u[0] ^ S2->u[0];

+    D->u[1] = S1->u[1] ^ S2->u[1];

+}

 static void xts_mult_x(uint8_t *I)

 {

@@ -60,25 +67,19 @@ static void xts_mult_x(uint8_t *I)

  */

 static void xts_tweak_encdec(const void *ctx,

                              xts_cipher_func *func,

-                             const uint8_t *src,

-                             uint8_t *dst,

-                             uint8_t *iv)

+                             const xts_uint128 *src,

+                             xts_uint128 *dst,

+                             xts_uint128 *iv)

 {

-    unsigned long x;

-

     /* tweak encrypt block i */

-    for (x = 0; x < XTS_BLOCK_SIZE; x++) {

-        dst[x] = src[x] ^ iv[x];

-    }

+    xts_uint128_xor(dst, src, iv);

-    func(ctx, XTS_BLOCK_SIZE, dst, dst);

+    func(ctx, XTS_BLOCK_SIZE, dst->b, dst->b);

-    for (x = 0; x < XTS_BLOCK_SIZE; x++) {

-        dst[x] = dst[x] ^ iv[x];

-    }

+    xts_uint128_xor(dst, dst, iv);

     /* LFSR the tweak */

-    xts_mult_x(iv);

+    xts_mult_x(iv->b);

 }

@@ -110,20 +111,34 @@ void xts_decrypt(const void *datactx,

     /* encrypt the iv */

     encfunc(tweakctx, XTS_BLOCK_SIZE, T.b, iv);

-    for (i = 0; i < lim; i++) {

-        xts_tweak_encdec(datactx, decfunc, src, dst, T.b);

-

-        src += XTS_BLOCK_SIZE;

-        dst += XTS_BLOCK_SIZE;

+    if (QEMU_PTR_IS_ALIGNED(src, sizeof(uint64_t)) &&

+        QEMU_PTR_IS_ALIGNED(dst, sizeof(uint64_t))) {

+        xts_uint128 *S = (xts_uint128 *)src;

+        xts_uint128 *D = (xts_uint128 *)dst;

+        for (i = 0; i < lim; i++, S++, D++) {

+            xts_tweak_encdec(datactx, decfunc, S, D, &T);

+        }

+    } else {

+        xts_uint128 D;

+

+        for (i = 0; i < lim; i++) {

+            memcpy(&D, src, XTS_BLOCK_SIZE);

+            xts_tweak_encdec(datactx, decfunc, &D, &D, &T);

+            memcpy(dst, &D, XTS_BLOCK_SIZE);

+            src += XTS_BLOCK_SIZE;

+            dst += XTS_BLOCK_SIZE;

+        }

     }

     /* if length is not a multiple of XTS_BLOCK_SIZE then */

     if (mo > 0) {

+        xts_uint128 S, D;

         memcpy(&CC, &T, XTS_BLOCK_SIZE);

         xts_mult_x(CC.b);

         /* PP = tweak decrypt block m-1 */

-        xts_tweak_encdec(datactx, decfunc, src, PP.b, CC.b);

+        memcpy(&S, src, XTS_BLOCK_SIZE);

+        xts_tweak_encdec(datactx, decfunc, &S, &PP, &CC;;

         /* Pm = first length % XTS_BLOCK_SIZE bytes of PP */

         for (i = 0; i < mo; i++) {

@@ -135,7 +150,8 @@ void xts_decrypt(const void *datactx,

         }

         /* Pm-1 = Tweak uncrypt CC */

-        xts_tweak_encdec(datactx, decfunc, CC.b, dst, T.b);

+        xts_tweak_encdec(datactx, decfunc, &CC, &D, &T);

+        memcpy(dst, &D, XTS_BLOCK_SIZE);

     }

     /* Decrypt the iv back */

@@ -171,17 +187,32 @@ void xts_encrypt(const void *datactx,

     /* encrypt the iv */

     encfunc(tweakctx, XTS_BLOCK_SIZE, T.b, iv);

-    for (i = 0; i < lim; i++) {

-        xts_tweak_encdec(datactx, encfunc, src, dst, T.b);

+    if (QEMU_PTR_IS_ALIGNED(src, sizeof(uint64_t)) &&

+        QEMU_PTR_IS_ALIGNED(dst, sizeof(uint64_t))) {

+        xts_uint128 *S = (xts_uint128 *)src;

+        xts_uint128 *D = (xts_uint128 *)dst;

+        for (i = 0; i < lim; i++, S++, D++) {

+            xts_tweak_encdec(datactx, encfunc, S, D, &T);

+        }

+    } else {

+        xts_uint128 D;

+

+        for (i = 0; i < lim; i++) {

+            memcpy(&D, src, XTS_BLOCK_SIZE);

+            xts_tweak_encdec(datactx, encfunc, &D, &D, &T);

+            memcpy(dst, &D, XTS_BLOCK_SIZE);

-        dst += XTS_BLOCK_SIZE;

-        src += XTS_BLOCK_SIZE;

+            dst += XTS_BLOCK_SIZE;

+            src += XTS_BLOCK_SIZE;

+        }

     }

     /* if length is not a multiple of XTS_BLOCK_SIZE then */

     if (mo > 0) {

+        xts_uint128 S, D;

         /* CC = tweak encrypt block m-1 */

-        xts_tweak_encdec(datactx, encfunc, src, CC.b, T.b);

+        memcpy(&S, src, XTS_BLOCK_SIZE);

+        xts_tweak_encdec(datactx, encfunc, &S, &CC, &T);

         /* Cm = first length % XTS_BLOCK_SIZE bytes of CC */

         for (i = 0; i < mo; i++) {

@@ -194,7 +225,8 @@ void xts_encrypt(const void *datactx,

         }

         /* Cm-1 = Tweak encrypt PP */

-        xts_tweak_encdec(datactx, encfunc, PP.b, dst, T.b);

+        xts_tweak_encdec(datactx, encfunc, &PP, &D, &T);

+        memcpy(dst, &D, XTS_BLOCK_SIZE);

     }

     /* Decrypt the iv back */

-- 

1.8.3.1