From 985e4c4154dcf1e45f66ed649bfaa3737c5c99bd Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Wed, 28 Jun 2006 08:52:16 +0000
Subject: [PATCH] Mitigate the hazard of cache-collision timing attack on last
 round. The only chance for T[ed]4 to get evicted in this module is when its
 cache "overlaps" with last 128 bits of key schedule.

---
 crypto/aes/asm/aes-sparcv9.pl | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/crypto/aes/asm/aes-sparcv9.pl b/crypto/aes/asm/aes-sparcv9.pl
index c04125e28b..095711ca71 100755
--- a/crypto/aes/asm/aes-sparcv9.pl
+++ b/crypto/aes/asm/aes-sparcv9.pl
@@ -6,7 +6,7 @@
 # forms are granted according to the OpenSSL license.
 # ====================================================================
 #
-# Version 1.0
+# Version 1.1
 #
 # The major reason for undertaken effort was to mitigate the hazard of
 # cache-timing attack. This is [currently and initially!] addressed in
@@ -16,6 +16,9 @@
 # is an initial draft and one should expect more countermeasures to
 # be implemented...
 #
+# Version 1.1 prefetches T[ed]4 in order to mitigate attack on last
+# round.
+#
 # Even though performance was not the primary goal [on the contrary,
 # extra shifts "induced" by compressed S-box and longer loop epilogue
 # "induced" by scheduling for L2 have negative effect on performance],
@@ -78,7 +81,7 @@ ___
 $code.=<<___;
 .section	".text",#alloc,#execinstr
 
-.align	64
+.align	256
 AES_Te:
 ___
 &_data_word(
@@ -364,20 +367,28 @@ _sparcv9_AES_encrypt:
 	ld	[$key+28],$t3			!
 		srlx	$acc9,8,$acc9
 		xor	$acc5,$s1,$s1
+	ldx	[$tbl+2048+0],%g0		! prefetch te4
 		srlx	$acc10,16,$acc10
 		xor	$acc6,$s1,$s1
+	ldx	[$tbl+2048+32],%g0		! prefetch te4
 		srlx	$acc11,24,$acc11
 		xor	$acc7,$s1,$s1
+	ldx	[$tbl+2048+64],%g0		! prefetch te4
 		srlx	$acc13,8,$acc13
 		xor	$acc8,$s2,$s2
+	ldx	[$tbl+2048+96],%g0		! prefetch te4
 		srlx	$acc14,16,$acc14	!
 		xor	$acc9,$s2,$s2
+	ldx	[$tbl+2048+128],%g0		! prefetch te4
 		srlx	$acc15,24,$acc15
 		xor	$acc10,$s2,$s2
+	ldx	[$tbl+2048+160],%g0		! prefetch te4
 	srl	$s0,21,$acc0
 		xor	$acc11,$s2,$s2
+	ldx	[$tbl+2048+192],%g0		! prefetch te4
 		xor	$acc12,$acc14,$acc14
 		xor	$acc13,$s3,$s3
+	ldx	[$tbl+2048+224],%g0		! prefetch te4
 	srl	$s1,13,$acc1			!
 		xor	$acc14,$s3,$s3
 		xor	$acc15,$s3,$s3
@@ -616,7 +627,7 @@ AES_encrypt:
 ___
 
 $code.=<<___;
-.align	64
+.align	256
 AES_Td:
 ___
 &_data_word(
@@ -902,20 +913,28 @@ _sparcv9_AES_decrypt:
 	ld	[$key+28],$t3			!
 		srlx	$acc9,8,$acc9
 		xor	$acc5,$s1,$s1
+	ldx	[$tbl+2048+0],%g0		! prefetch td4
 		srlx	$acc10,16,$acc10
 		xor	$acc6,$s1,$s1
+	ldx	[$tbl+2048+32],%g0		! prefetch td4
 		srlx	$acc11,24,$acc11
 		xor	$acc7,$s1,$s1
+	ldx	[$tbl+2048+64],%g0		! prefetch td4
 		srlx	$acc13,8,$acc13
 		xor	$acc8,$s2,$s2
+	ldx	[$tbl+2048+96],%g0		! prefetch td4
 		srlx	$acc14,16,$acc14	!
 		xor	$acc9,$s2,$s2
+	ldx	[$tbl+2048+128],%g0		! prefetch td4
 		srlx	$acc15,24,$acc15
 		xor	$acc10,$s2,$s2
+	ldx	[$tbl+2048+160],%g0		! prefetch td4
 	srl	$s0,21,$acc0
 		xor	$acc11,$s2,$s2
+	ldx	[$tbl+2048+192],%g0		! prefetch td4
 		xor	$acc12,$acc14,$acc14
 		xor	$acc13,$s3,$s3
+	ldx	[$tbl+2048+224],%g0		! prefetch td4
 	and	$acc0,2040,$acc0		!
 		xor	$acc14,$s3,$s3
 		xor	$acc15,$s3,$s3
-- 
2.40.0