From e485d0702e2acf9b83aaf42f4cc62d804c1c282a Mon Sep 17 00:00:00 2001

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

Date: Wed, 24 Apr 2019 09:56:38 +0100

Subject: [PATCH 4/9] crypto: introduce a xts_uint128 data type

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

Message-id: <20190424095643.796-5-berrange@redhat.com>

Patchwork-id: 85882

O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 4/9] crypto: introduce a xts_uint128 data 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>

The new type is designed to allow use of 64-bit arithmetic instead

of operating 1-byte at a time. The following patches will use this to

improve performance.

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

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

(cherry picked from commit cc36930e4077eb3dbee6cd30d2d826ec62b3490a)

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

---

 crypto/xts.c | 46 ++++++++++++++++++++++++++--------------------

 1 file changed, 26 insertions(+), 20 deletions(-)

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

index 3c1a92f..bee23f8 100644

--- a/crypto/xts.c

+++ b/crypto/xts.c

@@ -26,6 +26,12 @@

 #include "qemu/osdep.h"

 #include "crypto/xts.h"

+typedef union {

+    uint8_t b[XTS_BLOCK_SIZE];

+    uint64_t u[2];

+} xts_uint128;

+

+

 static void xts_mult_x(uint8_t *I)

 {

     int x;

@@ -85,7 +91,7 @@ void xts_decrypt(const void *datactx,

                  uint8_t *dst,

                  const uint8_t *src)

 {

-    uint8_t PP[XTS_BLOCK_SIZE], CC[XTS_BLOCK_SIZE], T[XTS_BLOCK_SIZE];

+    xts_uint128 PP, CC, T;

     unsigned long i, m, mo, lim;

     /* get number of blocks */

@@ -102,10 +108,10 @@ void xts_decrypt(const void *datactx,

     }

     /* encrypt the iv */

-    encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv);

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

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

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

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

         src += XTS_BLOCK_SIZE;

         dst += XTS_BLOCK_SIZE;

@@ -113,27 +119,27 @@ void xts_decrypt(const void *datactx,

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

     if (mo > 0) {

-        memcpy(CC, T, XTS_BLOCK_SIZE);

-        xts_mult_x(CC);

+        memcpy(&CC, &T, XTS_BLOCK_SIZE);

+        xts_mult_x(CC.b);

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

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

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

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

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

-            CC[i] = src[XTS_BLOCK_SIZE + i];

-            dst[XTS_BLOCK_SIZE + i] = PP[i];

+            CC.b[i] = src[XTS_BLOCK_SIZE + i];

+            dst[XTS_BLOCK_SIZE + i] = PP.b[i];

         }

         for (; i < XTS_BLOCK_SIZE; i++) {

-            CC[i] = PP[i];

+            CC.b[i] = PP.b[i];

         }

         /* Pm-1 = Tweak uncrypt CC */

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

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

     }

     /* Decrypt the iv back */

-    decfunc(tweakctx, XTS_BLOCK_SIZE, iv, T);

+    decfunc(tweakctx, XTS_BLOCK_SIZE, iv, T.b);

 }

@@ -146,7 +152,7 @@ void xts_encrypt(const void *datactx,

                  uint8_t *dst,

                  const uint8_t *src)

 {

-    uint8_t PP[XTS_BLOCK_SIZE], CC[XTS_BLOCK_SIZE], T[XTS_BLOCK_SIZE];

+    xts_uint128 PP, CC, T;

     unsigned long i, m, mo, lim;

     /* get number of blocks */

@@ -163,10 +169,10 @@ void xts_encrypt(const void *datactx,

     }

     /* encrypt the iv */

-    encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv);

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

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

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

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

         dst += XTS_BLOCK_SIZE;

         src += XTS_BLOCK_SIZE;

@@ -175,22 +181,22 @@ void xts_encrypt(const void *datactx,

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

     if (mo > 0) {

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

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

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

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

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

-            PP[i] = src[XTS_BLOCK_SIZE + i];

-            dst[XTS_BLOCK_SIZE + i] = CC[i];

+            PP.b[i] = src[XTS_BLOCK_SIZE + i];

+            dst[XTS_BLOCK_SIZE + i] = CC.b[i];

         }

         for (; i < XTS_BLOCK_SIZE; i++) {

-            PP[i] = CC[i];

+            PP.b[i] = CC.b[i];

         }

         /* Cm-1 = Tweak encrypt PP */

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

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

     }

     /* Decrypt the iv back */

-    decfunc(tweakctx, XTS_BLOCK_SIZE, iv, T);

+    decfunc(tweakctx, XTS_BLOCK_SIZE, iv, T.b);

 }

-- 

1.8.3.1