#! /usr/bin/env perl
# Copyright 2010-2020 The OpenSSL Project Authors. All Rights Reserved.
#
# Licensed under the OpenSSL license (the "License"). You may not use
# this file except in compliance with the License. You can obtain a copy
# in the file LICENSE in the source distribution or at
# https://www.openssl.org/source/license.html
#
# ====================================================================
# Written by Andy Polyakov <appro@openssl.org> for the OpenSSL
# project. The module is, however, dual licensed under OpenSSL and
# CRYPTOGAMS licenses depending on where you obtain it. For further
# details see http://www.openssl.org/~appro/cryptogams/.
# ====================================================================
#
# April 2010
#
# The module implements "4-bit" GCM GHASH function and underlying
# single multiplication operation in GF(2^128). "4-bit" means that it
# uses 256 bytes per-key table [+32 bytes shared table]. There is no
# experimental performance data available yet. The only approximation
# that can be made at this point is based on code size. Inner loop is
# 32 instructions long and on single-issue core should execute in <40
# cycles. Having verified that gcc 3.4 didn't unroll corresponding
# loop, this assembler loop body was found to be ~3x smaller than
# compiler-generated one...
#
# July 2010
#
# Rescheduling for dual-issue pipeline resulted in 8.5% improvement on
# Cortex A8 core and ~25 cycles per processed byte (which was observed
# to be ~3 times faster than gcc-generated code:-)
#
# February 2011
#
# Profiler-assisted and platform-specific optimization resulted in 7%
# improvement on Cortex A8 core and ~23.5 cycles per byte.
#
# March 2011
#
# Add NEON implementation featuring polynomial multiplication, i.e. no
# lookup tables involved. On Cortex A8 it was measured to process one
# byte in 15 cycles or 55% faster than integer-only code.
#
# April 2014
#
# Switch to multiplication algorithm suggested in paper referred
# below and combine it with reduction algorithm from x86 module.
# Performance improvement over previous version varies from 65% on
# Snapdragon S4 to 110% on Cortex A9. In absolute terms Cortex A8
# processes one byte in 8.45 cycles, A9 - in 10.2, A15 - in 7.63,
# Snapdragon S4 - in 9.33.
#
# Câmara, D.; Gouvêa, C. P. L.; López, J. & Dahab, R.: Fast Software
# Polynomial Multiplication on ARM Processors using the NEON Engine.
#
# http://conradoplg.cryptoland.net/files/2010/12/mocrysen13.pdf
# ====================================================================
# Note about "528B" variant. In ARM case it makes lesser sense to
# implement it for following reasons:
#
# - performance improvement won't be anywhere near 50%, because 128-
# bit shift operation is neatly fused with 128-bit xor here, and
# "538B" variant would eliminate only 4-5 instructions out of 32
# in the inner loop (meaning that estimated improvement is ~15%);
# - ARM-based systems are often embedded ones and extra memory
# consumption might be unappreciated (for so little improvement);
#
# Byte order [in]dependence. =========================================
#
# Caller is expected to maintain specific *dword* order in Htable,
# namely with *least* significant dword of 128-bit value at *lower*
# address. This differs completely from C code and has everything to
# do with ldm instruction and order in which dwords are "consumed" by
# algorithm. *Byte* order within these dwords in turn is whatever
# *native* byte order on current platform. See gcm128.c for working
# example...
$flavour = shift;
if ($flavour=~/\w[\w\-]*\.\w+$/) { $output=$flavour; undef $flavour; }
else { while (($output=shift) && ($output!~/\w[\w\-]*\.\w+$/)) {} }
if ($flavour && $flavour ne "void") {
$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
( $xlate="${dir}arm-xlate.pl" and -f $xlate ) or
( $xlate="${dir}../../perlasm/arm-xlate.pl" and -f $xlate) or
die "can't locate arm-xlate.pl";
open STDOUT,"| \"$^X\" $xlate $flavour $output";
} else {
open STDOUT,">$output";
}
$Xi="r0"; # argument block
$Htbl="r1";
$inp="r2";
$len="r3";
$Zll="r4"; # variables
$Zlh="r5";
$Zhl="r6";
$Zhh="r7";
$Tll="r8";
$Tlh="r9";
$Thl="r10";
$Thh="r11";
$nlo="r12";
################# r13 is stack pointer
$nhi="r14";
################# r15 is program counter
$rem_4bit=$inp; # used in gcm_gmult_4bit
$cnt=$len;
sub Zsmash() {
my $i=12;
my @args=@_;
for ($Zll,$Zlh,$Zhl,$Zhh) {
$code.=<<___;
#if __ARM_ARCH__>=7 && defined(__ARMEL__)
rev $_,$_
str $_,[$Xi,#$i]
#elif defined(__ARMEB__)
str $_,[$Xi,#$i]
#else
mov $Tlh,$_,lsr#8
strb $_,[$Xi,#$i+3]
mov $Thl,$_,lsr#16
strb $Tlh,[$Xi,#$i+2]
mov $Thh,$_,lsr#24
strb $Thl,[$Xi,#$i+1]
strb $Thh,[$Xi,#$i]
#endif
___
$code.="\t".shift(@args)."\n";
$i-=4;
}
}
$code=<<___;
#include "arm_arch.h"
.text
#if defined(__thumb2__) || defined(__clang__)
.syntax unified
#define ldrplb ldrbpl
#define ldrneb ldrbne
#endif
#if defined(__thumb2__)
.thumb
#else
.code 32
#endif
.type rem_4bit,%object
.align 5
rem_4bit:
.short 0x0000,0x1C20,0x3840,0x2460
.short 0x7080,0x6CA0,0x48C0,0x54E0
.short 0xE100,0xFD20,0xD940,0xC560
.short 0x9180,0x8DA0,0xA9C0,0xB5E0
.size rem_4bit,.-rem_4bit
.type rem_4bit_get,%function
rem_4bit_get:
#if defined(__thumb2__)
adr $rem_4bit,rem_4bit
#else
sub $rem_4bit,pc,#8+32 @ &rem_4bit
#endif
b .Lrem_4bit_got
nop
nop
.size rem_4bit_get,.-rem_4bit_get
.global gcm_ghash_4bit
.type gcm_ghash_4bit,%function
.align 4
gcm_ghash_4bit:
#if defined(__thumb2__)
adr r12,rem_4bit
#else
sub r12,pc,#8+48 @ &rem_4bit
#endif
add $len,$inp,$len @ $len to point at the end
stmdb sp!,{r3-r11,lr} @ save $len/end too
ldmia r12,{r4-r11} @ copy rem_4bit ...
stmdb sp!,{r4-r11} @ ... to stack
ldrb $nlo,[$inp,#15]
ldrb $nhi,[$Xi,#15]
.Louter:
eor $nlo,$nlo,$nhi
and $nhi,$nlo,#0xf0
and $nlo,$nlo,#0x0f
mov $cnt,#14
add $Zhh,$Htbl,$nlo,lsl#4
ldmia $Zhh,{$Zll-$Zhh} @ load Htbl[nlo]
add $Thh,$Htbl,$nhi
ldrb $nlo,[$inp,#14]
and $nhi,$Zll,#0xf @ rem
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nhi]
add $nhi,$nhi,$nhi
eor $Zll,$Tll,$Zll,lsr#4
ldrh $Tll,[sp,$nhi] @ rem_4bit[rem]
eor $Zll,$Zll,$Zlh,lsl#28
ldrb $nhi,[$Xi,#14]
eor $Zlh,$Tlh,$Zlh,lsr#4
eor $Zlh,$Zlh,$Zhl,lsl#28
eor $Zhl,$Thl,$Zhl,lsr#4
eor $Zhl,$Zhl,$Zhh,lsl#28
eor $Zhh,$Thh,$Zhh,lsr#4
eor $nlo,$nlo,$nhi
and $nhi,$nlo,#0xf0
and $nlo,$nlo,#0x0f
eor $Zhh,$Zhh,$Tll,lsl#16
.Linner:
add $Thh,$Htbl,$nlo,lsl#4
and $nlo,$Zll,#0xf @ rem
subs $cnt,$cnt,#1
add $nlo,$nlo,$nlo
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nlo]
eor $Zll,$Tll,$Zll,lsr#4
eor $Zll,$Zll,$Zlh,lsl#28
eor $Zlh,$Tlh,$Zlh,lsr#4
eor $Zlh,$Zlh,$Zhl,lsl#28
ldrh $Tll,[sp,$nlo] @ rem_4bit[rem]
eor $Zhl,$Thl,$Zhl,lsr#4
#ifdef __thumb2__
it pl
#endif
ldrplb $nlo,[$inp,$cnt]
eor $Zhl,$Zhl,$Zhh,lsl#28
eor $Zhh,$Thh,$Zhh,lsr#4
add $Thh,$Htbl,$nhi
and $nhi,$Zll,#0xf @ rem
eor $Zhh,$Zhh,$Tll,lsl#16 @ ^= rem_4bit[rem]
add $nhi,$nhi,$nhi
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nhi]
eor $Zll,$Tll,$Zll,lsr#4
#ifdef __thumb2__
it pl
#endif
ldrplb $Tll,[$Xi,$cnt]
eor $Zll,$Zll,$Zlh,lsl#28
eor $Zlh,$Tlh,$Zlh,lsr#4
ldrh $Tlh,[sp,$nhi]
eor $Zlh,$Zlh,$Zhl,lsl#28
eor $Zhl,$Thl,$Zhl,lsr#4
eor $Zhl,$Zhl,$Zhh,lsl#28
#ifdef __thumb2__
it pl
#endif
eorpl $nlo,$nlo,$Tll
eor $Zhh,$Thh,$Zhh,lsr#4
#ifdef __thumb2__
itt pl
#endif
andpl $nhi,$nlo,#0xf0
andpl $nlo,$nlo,#0x0f
eor $Zhh,$Zhh,$Tlh,lsl#16 @ ^= rem_4bit[rem]
bpl .Linner
ldr $len,[sp,#32] @ re-load $len/end
add $inp,$inp,#16
mov $nhi,$Zll
___
&Zsmash("cmp\t$inp,$len","\n".
"#ifdef __thumb2__\n".
" it ne\n".
"#endif\n".
" ldrneb $nlo,[$inp,#15]");
$code.=<<___;
bne .Louter
add sp,sp,#36
#if __ARM_ARCH__>=5
ldmia sp!,{r4-r11,pc}
#else
ldmia sp!,{r4-r11,lr}
tst lr,#1
moveq pc,lr @ be binary compatible with V4, yet
bx lr @ interoperable with Thumb ISA:-)
#endif
.size gcm_ghash_4bit,.-gcm_ghash_4bit
.global gcm_gmult_4bit
.type gcm_gmult_4bit,%function
gcm_gmult_4bit:
stmdb sp!,{r4-r11,lr}
ldrb $nlo,[$Xi,#15]
b rem_4bit_get
.Lrem_4bit_got:
and $nhi,$nlo,#0xf0
and $nlo,$nlo,#0x0f
mov $cnt,#14
add $Zhh,$Htbl,$nlo,lsl#4
ldmia $Zhh,{$Zll-$Zhh} @ load Htbl[nlo]
ldrb $nlo,[$Xi,#14]
add $Thh,$Htbl,$nhi
and $nhi,$Zll,#0xf @ rem
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nhi]
add $nhi,$nhi,$nhi
eor $Zll,$Tll,$Zll,lsr#4
ldrh $Tll,[$rem_4bit,$nhi] @ rem_4bit[rem]
eor $Zll,$Zll,$Zlh,lsl#28
eor $Zlh,$Tlh,$Zlh,lsr#4
eor $Zlh,$Zlh,$Zhl,lsl#28
eor $Zhl,$Thl,$Zhl,lsr#4
eor $Zhl,$Zhl,$Zhh,lsl#28
eor $Zhh,$Thh,$Zhh,lsr#4
and $nhi,$nlo,#0xf0
eor $Zhh,$Zhh,$Tll,lsl#16
and $nlo,$nlo,#0x0f
.Loop:
add $Thh,$Htbl,$nlo,lsl#4
and $nlo,$Zll,#0xf @ rem
subs $cnt,$cnt,#1
add $nlo,$nlo,$nlo
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nlo]
eor $Zll,$Tll,$Zll,lsr#4
eor $Zll,$Zll,$Zlh,lsl#28
eor $Zlh,$Tlh,$Zlh,lsr#4
eor $Zlh,$Zlh,$Zhl,lsl#28
ldrh $Tll,[$rem_4bit,$nlo] @ rem_4bit[rem]
eor $Zhl,$Thl,$Zhl,lsr#4
#ifdef __thumb2__
it pl
#endif
ldrplb $nlo,[$Xi,$cnt]
eor $Zhl,$Zhl,$Zhh,lsl#28
eor $Zhh,$Thh,$Zhh,lsr#4
add $Thh,$Htbl,$nhi
and $nhi,$Zll,#0xf @ rem
eor $Zhh,$Zhh,$Tll,lsl#16 @ ^= rem_4bit[rem]
add $nhi,$nhi,$nhi
ldmia $Thh,{$Tll-$Thh} @ load Htbl[nhi]
eor $Zll,$Tll,$Zll,lsr#4
eor $Zll,$Zll,$Zlh,lsl#28
eor $Zlh,$Tlh,$Zlh,lsr#4
ldrh $Tll,[$rem_4bit,$nhi] @ rem_4bit[rem]
eor $Zlh,$Zlh,$Zhl,lsl#28
eor $Zhl,$Thl,$Zhl,lsr#4
eor $Zhl,$Zhl,$Zhh,lsl#28
eor $Zhh,$Thh,$Zhh,lsr#4
#ifdef __thumb2__
itt pl
#endif
andpl $nhi,$nlo,#0xf0
andpl $nlo,$nlo,#0x0f
eor $Zhh,$Zhh,$Tll,lsl#16 @ ^= rem_4bit[rem]
bpl .Loop
___
&Zsmash();
$code.=<<___;
#if __ARM_ARCH__>=5
ldmia sp!,{r4-r11,pc}
#else
ldmia sp!,{r4-r11,lr}
tst lr,#1
moveq pc,lr @ be binary compatible with V4, yet
bx lr @ interoperable with Thumb ISA:-)
#endif
.size gcm_gmult_4bit,.-gcm_gmult_4bit
___
{
my ($Xl,$Xm,$Xh,$IN)=map("q$_",(0..3));
my ($t0,$t1,$t2,$t3)=map("q$_",(8..12));
my ($Hlo,$Hhi,$Hhl,$k48,$k32,$k16)=map("d$_",(26..31));
sub clmul64x64 {
my ($r,$a,$b)=@_;
$code.=<<___;
vext.8 $t0#lo, $a, $a, #1 @ A1
vmull.p8 $t0, $t0#lo, $b @ F = A1*B
vext.8 $r#lo, $b, $b, #1 @ B1
vmull.p8 $r, $a, $r#lo @ E = A*B1
vext.8 $t1#lo, $a, $a, #2 @ A2
vmull.p8 $t1, $t1#lo, $b @ H = A2*B
vext.8 $t3#lo, $b, $b, #2 @ B2
vmull.p8 $t3, $a, $t3#lo @ G = A*B2
vext.8 $t2#lo, $a, $a, #3 @ A3
veor $t0, $t0, $r @ L = E + F
vmull.p8 $t2, $t2#lo, $b @ J = A3*B
vext.8 $r#lo, $b, $b, #3 @ B3
veor $t1, $t1, $t3 @ M = G + H
vmull.p8 $r, $a, $r#lo @ I = A*B3
veor $t0#lo, $t0#lo, $t0#hi @ t0 = (L) (P0 + P1) << 8
vand $t0#hi, $t0#hi, $k48
vext.8 $t3#lo, $b, $b, #4 @ B4
veor $t1#lo, $t1#lo, $t1#hi @ t1 = (M) (P2 + P3) << 16
vand $t1#hi, $t1#hi, $k32
vmull.p8 $t3, $a, $t3#lo @ K = A*B4
veor $t2, $t2, $r @ N = I + J
veor $t0#lo, $t0#lo, $t0#hi
veor $t1#lo, $t1#lo, $t1#hi
veor $t2#lo, $t2#lo, $t2#hi @ t2 = (N) (P4 + P5) << 24
vand $t2#hi, $t2#hi, $k16
vext.8 $t0, $t0, $t0, #15
veor $t3#lo, $t3#lo, $t3#hi @ t3 = (K) (P6 + P7) << 32
vmov.i64 $t3#hi, #0
vext.8 $t1, $t1, $t1, #14
veor $t2#lo, $t2#lo, $t2#hi
vmull.p8 $r, $a, $b @ D = A*B
vext.8 $t3, $t3, $t3, #12
vext.8 $t2, $t2, $t2, #13
veor $t0, $t0, $t1
veor $t2, $t2, $t3
veor $r, $r, $t0
veor $r, $r, $t2
___
}
$code.=<<___;
#if __ARM_MAX_ARCH__>=7
.arch armv7-a
.fpu neon
.global gcm_init_neon
.type gcm_init_neon,%function
.align 4
gcm_init_neon:
vld1.64 $IN#hi,[r1]! @ load H
vmov.i8 $t0,#0xe1
vld1.64 $IN#lo,[r1]
vshl.i64 $t0#hi,#57
vshr.u64 $t0#lo,#63 @ t0=0xc2....01
vdup.8 $t1,$IN#hi[7]
vshr.u64 $Hlo,$IN#lo,#63
vshr.s8 $t1,#7 @ broadcast carry bit
vshl.i64 $IN,$IN,#1
vand $t0,$t0,$t1
vorr $IN#hi,$Hlo @ H<<<=1
veor $IN,$IN,$t0 @ twisted H
vstmia r0,{$IN}
ret @ bx lr
.size gcm_init_neon,.-gcm_init_neon
.global gcm_gmult_neon
.type gcm_gmult_neon,%function
.align 4
gcm_gmult_neon:
vld1.64 $IN#hi,[$Xi]! @ load Xi
vld1.64 $IN#lo,[$Xi]!
vmov.i64 $k48,#0x0000ffffffffffff
vldmia $Htbl,{$Hlo-$Hhi} @ load twisted H
vmov.i64 $k32,#0x00000000ffffffff
#ifdef __ARMEL__
vrev64.8 $IN,$IN
#endif
vmov.i64 $k16,#0x000000000000ffff
veor $Hhl,$Hlo,$Hhi @ Karatsuba pre-processing
mov $len,#16
b .Lgmult_neon
.size gcm_gmult_neon,.-gcm_gmult_neon
.global gcm_ghash_neon
.type gcm_ghash_neon,%function
.align 4
gcm_ghash_neon:
vld1.64 $Xl#hi,[$Xi]! @ load Xi
vld1.64 $Xl#lo,[$Xi]!
vmov.i64 $k48,#0x0000ffffffffffff
vldmia $Htbl,{$Hlo-$Hhi} @ load twisted H
vmov.i64 $k32,#0x00000000ffffffff
#ifdef __ARMEL__
vrev64.8 $Xl,$Xl
#endif
vmov.i64 $k16,#0x000000000000ffff
veor $Hhl,$Hlo,$Hhi @ Karatsuba pre-processing
.Loop_neon:
vld1.64 $IN#hi,[$inp]! @ load inp
vld1.64 $IN#lo,[$inp]!
#ifdef __ARMEL__
vrev64.8 $IN,$IN
#endif
veor $IN,$Xl @ inp^=Xi
.Lgmult_neon:
___
&clmul64x64 ($Xl,$Hlo,"$IN#lo"); # H.lo·Xi.lo
$code.=<<___;
veor $IN#lo,$IN#lo,$IN#hi @ Karatsuba pre-processing
___
&clmul64x64 ($Xm,$Hhl,"$IN#lo"); # (H.lo+H.hi)·(Xi.lo+Xi.hi)
&clmul64x64 ($Xh,$Hhi,"$IN#hi"); # H.hi·Xi.hi
$code.=<<___;
veor $Xm,$Xm,$Xl @ Karatsuba post-processing
veor $Xm,$Xm,$Xh
veor $Xl#hi,$Xl#hi,$Xm#lo
veor $Xh#lo,$Xh#lo,$Xm#hi @ Xh|Xl - 256-bit result
@ equivalent of reduction_avx from ghash-x86_64.pl
vshl.i64 $t1,$Xl,#57 @ 1st phase
vshl.i64 $t2,$Xl,#62
veor $t2,$t2,$t1 @
vshl.i64 $t1,$Xl,#63
veor $t2, $t2, $t1 @
veor $Xl#hi,$Xl#hi,$t2#lo @
veor $Xh#lo,$Xh#lo,$t2#hi
vshr.u64 $t2,$Xl,#1 @ 2nd phase
veor $Xh,$Xh,$Xl
veor $Xl,$Xl,$t2 @
vshr.u64 $t2,$t2,#6
vshr.u64 $Xl,$Xl,#1 @
veor $Xl,$Xl,$Xh @
veor $Xl,$Xl,$t2 @
subs $len,#16
bne .Loop_neon
#ifdef __ARMEL__
vrev64.8 $Xl,$Xl
#endif
sub $Xi,#16
vst1.64 $Xl#hi,[$Xi]! @ write out Xi
vst1.64 $Xl#lo,[$Xi]
ret @ bx lr
.size gcm_ghash_neon,.-gcm_ghash_neon
#endif
___
}
$code.=<<___;
.asciz "GHASH for ARMv4/NEON, CRYPTOGAMS by <appro\@openssl.org>"
.align 2
___
foreach (split("\n",$code)) {
s/\`([^\`]*)\`/eval $1/geo;
s/\bq([0-9]+)#(lo|hi)/sprintf "d%d",2*$1+($2 eq "hi")/geo or
s/\bret\b/bx lr/go or
s/\bbx\s+lr\b/.word\t0xe12fff1e/go; # make it possible to compile with -march=armv4
print $_,"\n";
}
close STDOUT or die "error closing STDOUT: $!"; # enforce flush
