diff options
| author | Andy Polyakov <appro@openssl.org> | 2015-12-01 09:00:32 +0100 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2015-12-03 13:12:01 +0000 |
| commit | 29851264f11ccc70c6c0140d7e3d8d93ef5c9b11 (patch) | |
| tree | 55e5ad3e76c2a869b25ef0f0ad438262f633e6ff /crypto/bn | |
| parent | b5516cfbd65de9331d827012fc5bdace1953613e (diff) | |
bn/asm/x86_64-mont5.pl: fix carry propagating bug (CVE-2015-3193).
Reviewed-by: Richard Levitte <levitte@openssl.org>
Diffstat (limited to 'crypto/bn')
| -rwxr-xr-x | crypto/bn/asm/x86_64-mont5.pl | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/crypto/bn/asm/x86_64-mont5.pl b/crypto/bn/asm/x86_64-mont5.pl index 388e3c6911..64e668f140 100755 --- a/crypto/bn/asm/x86_64-mont5.pl +++ b/crypto/bn/asm/x86_64-mont5.pl @@ -1784,6 +1784,15 @@ sqr8x_reduction: .align 32 .L8x_tail_done: add (%rdx),%r8 # can this overflow? + adc \$0,%r9 + adc \$0,%r10 + adc \$0,%r11 + adc \$0,%r12 + adc \$0,%r13 + adc \$0,%r14 + adc \$0,%r15 # can't overflow, because we + # started with "overhung" part + # of multiplication xor %rax,%rax neg $carry @@ -3130,6 +3139,15 @@ sqrx8x_reduction: .align 32 .Lsqrx8x_tail_done: add 24+8(%rsp),%r8 # can this overflow? + adc \$0,%r9 + adc \$0,%r10 + adc \$0,%r11 + adc \$0,%r12 + adc \$0,%r13 + adc \$0,%r14 + adc \$0,%r15 # can't overflow, because we + # started with "overhung" part + # of multiplication mov $carry,%rax # xor %rax,%rax sub 16+8(%rsp),$carry # mov 16(%rsp),%cf @@ -3173,13 +3191,11 @@ my ($rptr,$nptr)=("%rdx","%rbp"); my @ri=map("%r$_",(10..13)); my @ni=map("%r$_",(14..15)); $code.=<<___; - xor %rbx,%rbx + xor %ebx,%ebx sub %r15,%rsi # compare top-most words adc %rbx,%rbx mov %rcx,%r10 # -$num - .byte 0x67 or %rbx,%rax - .byte 0x67 mov %rcx,%r9 # -$num xor \$1,%rax sar \$3+2,%rcx # cf=0 |