From 1c5bc7b85abf831beb58375ab2652cdcdf31a0fc Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Sun, 25 Aug 2019 03:45:31 +0200 Subject: [PATCH] Fix side channel in ecp_nistz256-armv4.pl Reviewed-by: Nicola Tuveri Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/9239) --- crypto/ec/asm/ecp_nistz256-armv4.pl | 79 ++++++++++++----------------- 1 file changed, 33 insertions(+), 46 deletions(-) diff --git a/crypto/ec/asm/ecp_nistz256-armv4.pl b/crypto/ec/asm/ecp_nistz256-armv4.pl index 4e6bfef4b5..4809360ac4 100755 --- a/crypto/ec/asm/ecp_nistz256-armv4.pl +++ b/crypto/ec/asm/ecp_nistz256-armv4.pl @@ -1398,7 +1398,7 @@ my ($Z1sqr, $Z2sqr) = ($Hsqr, $Rsqr); # 256-bit vectors on top. Then note that we push # starting from r0, which means that we have copy of # input arguments just below these temporary vectors. -# We use three of them for !in1infty, !in2intfy and +# We use three of them for ~in1infty, ~in2infty and # result of check for zero. $code.=<<___; @@ -1428,7 +1428,7 @@ ecp_nistz256_point_add: #endif movne r12,#-1 stmia r3,{r4-r11} - str r12,[sp,#32*18+8] @ !in2infty + str r12,[sp,#32*18+8] @ ~in2infty ldmia $a_ptr!,{r4-r11} @ copy in1_x add r3,sp,#$in1_x @@ -1449,7 +1449,7 @@ ecp_nistz256_point_add: #endif movne r12,#-1 stmia r3,{r4-r11} - str r12,[sp,#32*18+4] @ !in1infty + str r12,[sp,#32*18+4] @ ~in1infty add $a_ptr,sp,#$in2_z add $b_ptr,sp,#$in2_z @@ -1514,33 +1514,20 @@ ecp_nistz256_point_add: orr $a0,$a0,$a2 orr $a4,$a4,$a6 orr $a0,$a0,$a7 - orrs $a0,$a0,$a4 + orr $a0,$a0,$a4 @ ~is_equal(U1,U2) - bne .Ladd_proceed @ is_equal(U1,U2)? + ldr $t0,[sp,#32*18+4] @ ~in1infty + ldr $t1,[sp,#32*18+8] @ ~in2infty + ldr $t2,[sp,#32*18+12] @ ~is_equal(S1,S2) + mvn $t0,$t0 @ -1/0 -> 0/-1 + mvn $t1,$t1 @ -1/0 -> 0/-1 + orr $a0,$t0 + orr $a0,$t1 + orrs $a0,$t2 @ set flags - ldr $t0,[sp,#32*18+4] - ldr $t1,[sp,#32*18+8] - ldr $t2,[sp,#32*18+12] - tst $t0,$t1 - beq .Ladd_proceed @ (in1infty || in2infty)? - tst $t2,$t2 - beq .Ladd_double @ is_equal(S1,S2)? + @ if(~is_equal(U1,U2) | in1infty | in2infty | ~is_equal(S1,S2)) + bne .Ladd_proceed - ldr $r_ptr,[sp,#32*18+16] - eor r4,r4,r4 - eor r5,r5,r5 - eor r6,r6,r6 - eor r7,r7,r7 - eor r8,r8,r8 - eor r9,r9,r9 - eor r10,r10,r10 - eor r11,r11,r11 - stmia $r_ptr!,{r4-r11} - stmia $r_ptr!,{r4-r11} - stmia $r_ptr!,{r4-r11} - b .Ladd_done - -.align 4 .Ladd_double: ldr $a_ptr,[sp,#32*18+20] add sp,sp,#32*(18-5)+16 @ difference in frame sizes @@ -1605,15 +1592,15 @@ ecp_nistz256_point_add: add $b_ptr,sp,#$S2 bl __ecp_nistz256_sub_from @ p256_sub(res_y, res_y, S2); - ldr r11,[sp,#32*18+4] @ !in1intfy - ldr r12,[sp,#32*18+8] @ !in2intfy + ldr r11,[sp,#32*18+4] @ ~in1infty + ldr r12,[sp,#32*18+8] @ ~in2infty add r1,sp,#$res_x add r2,sp,#$in2_x - and r10,r11,r12 + and r10,r11,r12 @ ~in1infty & ~in2infty mvn r11,r11 add r3,sp,#$in1_x - and r11,r11,r12 - mvn r12,r12 + and r11,r11,r12 @ in1infty & ~in2infty + mvn r12,r12 @ in2infty ldr $r_ptr,[sp,#32*18+16] ___ for($i=0;$i<96;$i+=8) { # conditional moves @@ -1621,11 +1608,11 @@ $code.=<<___; ldmia r1!,{r4-r5} @ res_x ldmia r2!,{r6-r7} @ in2_x ldmia r3!,{r8-r9} @ in1_x - and r4,r4,r10 + and r4,r4,r10 @ ~in1infty & ~in2infty and r5,r5,r10 - and r6,r6,r11 + and r6,r6,r11 @ in1infty & ~in2infty and r7,r7,r11 - and r8,r8,r12 + and r8,r8,r12 @ in2infty and r9,r9,r12 orr r4,r4,r6 orr r5,r5,r7 @@ -1660,7 +1647,7 @@ my $Z1sqr = $S2; # 256-bit vectors on top. Then note that we push # starting from r0, which means that we have copy of # input arguments just below these temporary vectors. -# We use two of them for !in1infty, !in2intfy. +# We use two of them for ~in1infty, ~in2infty. my @ONE_mont=(1,0,0,-1,-1,-1,-2,0); @@ -1691,7 +1678,7 @@ ecp_nistz256_point_add_affine: #endif movne r12,#-1 stmia r3,{r4-r11} - str r12,[sp,#32*15+4] @ !in1infty + str r12,[sp,#32*15+4] @ ~in1infty ldmia $b_ptr!,{r4-r11} @ copy in2_x add r3,sp,#$in2_x @@ -1718,7 +1705,7 @@ ecp_nistz256_point_add_affine: it ne #endif movne r12,#-1 - str r12,[sp,#32*15+8] @ !in2infty + str r12,[sp,#32*15+8] @ ~in2infty add $a_ptr,sp,#$in1_z add $b_ptr,sp,#$in1_z @@ -1800,15 +1787,15 @@ ecp_nistz256_point_add_affine: add $b_ptr,sp,#$S2 bl __ecp_nistz256_sub_from @ p256_sub(res_y, res_y, S2); - ldr r11,[sp,#32*15+4] @ !in1intfy - ldr r12,[sp,#32*15+8] @ !in2intfy + ldr r11,[sp,#32*15+4] @ ~in1infty + ldr r12,[sp,#32*15+8] @ ~in2infty add r1,sp,#$res_x add r2,sp,#$in2_x - and r10,r11,r12 + and r10,r11,r12 @ ~in1infty & ~in2infty mvn r11,r11 add r3,sp,#$in1_x - and r11,r11,r12 - mvn r12,r12 + and r11,r11,r12 @ in1infty & ~in2infty + mvn r12,r12 @ in2infty ldr $r_ptr,[sp,#32*15] ___ for($i=0;$i<64;$i+=8) { # conditional moves @@ -1816,11 +1803,11 @@ $code.=<<___; ldmia r1!,{r4-r5} @ res_x ldmia r2!,{r6-r7} @ in2_x ldmia r3!,{r8-r9} @ in1_x - and r4,r4,r10 + and r4,r4,r10 @ ~in1infty & ~in2infty and r5,r5,r10 - and r6,r6,r11 + and r6,r6,r11 @ in1infty & ~in2infty and r7,r7,r11 - and r8,r8,r12 + and r8,r8,r12 @ in2infty and r9,r9,r12 orr r4,r4,r6 orr r5,r5,r7 -- 2.25.1