#!/usr/local/bin/perl
#
# The inner loop instruction sequence and the IP/FP modifications are from
# Svend Olaf Mikkelsen <svolaf@inet.uni-c.dk>
#
push(@INC,"perlasm","../../perlasm");
require "x86asm.pl";
require "cbc.pl";
require "desboth.pl";
# base code is in microsft
# op dest, source
# format.
#
&asm_init($ARGV[0],"des-586.pl");
$L="edi";
$R="esi";
&external_label("DES_SPtrans");
&DES_encrypt("DES_encrypt1",1);
&DES_encrypt("DES_encrypt2",0);
&DES_encrypt3("DES_encrypt3",1);
&DES_encrypt3("DES_decrypt3",0);
&cbc("DES_ncbc_encrypt","DES_encrypt1","DES_encrypt1",0,4,5,3,5,-1);
&cbc("DES_ede3_cbc_encrypt","DES_encrypt3","DES_decrypt3",0,6,7,3,4,5);
&asm_finish();
sub DES_encrypt
{
local($name,$do_ip)=@_;
&function_begin_B($name,"EXTRN _DES_SPtrans:DWORD");
&push("esi");
&push("edi");
&comment("");
&comment("Load the 2 words");
$trans="ebp";
if ($do_ip)
{
&mov($R,&wparam(0));
&xor( "ecx", "ecx" );
&push("ebx");
&push("ebp");
&mov("eax",&DWP(0,$R,"",0));
&mov("ebx",&wparam(2)); # get encrypt flag
&mov($L,&DWP(4,$R,"",0));
&comment("");
&comment("IP");
&IP_new("eax",$L,$R,3);
}
else
{
&mov("eax",&wparam(0));
&xor( "ecx", "ecx" );
&push("ebx");
&push("ebp");
&mov($R,&DWP(0,"eax","",0));
&mov("ebx",&wparam(2)); # get encrypt flag
&rotl($R,3);
&mov($L,&DWP(4,"eax","",0));
&rotl($L,3);
}
# PIC-ification:-)
&picmeup($trans,"DES_SPtrans");
#if ($cpp) { &picmeup($trans,"DES_SPtrans"); }
#else { &lea($trans,&DWP("DES_SPtrans")); }
&mov( "ecx", &wparam(1) );
&cmp("ebx","0");
&je(&label("start_decrypt"));
for ($i=0; $i<16; $i+=2)
{
&comment("");
&comment("Round $i");
&D_ENCRYPT($i,$L,$R,$i*2,$trans,"eax","ebx","ecx","edx");
&comment("");
&comment("Round ".sprintf("%d",$i+1));
&D_ENCRYPT($i+1,$R,$L,($i+1)*2,$trans,"eax","ebx","ecx","edx");
}
&jmp(&label("end"));
&set_label("start_decrypt");
for ($i=15; $i>0; $i-=2)
{
&comment("");
&comment("Round $i");
&D_ENCRYPT(15-$i,$L,$R,$i*2,$trans,"eax","ebx","ecx","edx");
&comment("");
&comment("Round ".sprintf("%d",$i-1));
&D_ENCRYPT(15-$i+1,$R,$L,($i-1)*2,$trans,"eax","ebx","ecx","edx");
}
&set_label("end");
if ($do_ip)
{
&comment("");
&comment("FP");
&mov("edx",&wparam(0));
&FP_new($L,$R,"eax",3);
&mov(&DWP(0,"edx","",0),"eax");
&mov(&DWP(4,"edx","",0),$R);
}
else
{
&comment("");
&comment("Fixup");
&rotr($L,3); # r
&mov("eax",&wparam(0));
&rotr($R,3); # l
&mov(&DWP(0,"eax","",0),$L);
&mov(&DWP(4,"eax","",0),$R);
}
&pop("ebp");
&pop("ebx");
&pop("edi");
&pop("esi");
&ret();
&function_end_B($name);
}
sub D_ENCRYPT
{
local($r,$L,$R,$S,$trans,$u,$tmp1,$tmp2,$t)=@_;
&mov( $u, &DWP(&n2a($S*4),$tmp2,"",0));
&xor( $tmp1, $tmp1);
&mov( $t, &DWP(&n2a(($S+1)*4),$tmp2,"",0));
&xor( $u, $R);
&xor( $tmp2, $tmp2);
&xor( $t, $R);
&and( $u, "0xfcfcfcfc" );
&and( $t, "0xcfcfcfcf" );
&movb( &LB($tmp1), &LB($u) );
&movb( &LB($tmp2), &HB($u) );
&rotr( $t, 4 );
&xor( $L, &DWP(" ",$trans,$tmp1,0));
&movb( &LB($tmp1), &LB($t) );
&xor( $L, &DWP("0x200",$trans,$tmp2,0));
&movb( &LB($tmp2), &HB($t) );
&shr( $u, 16);
&xor( $L, &DWP("0x100",$trans,$tmp1,0));
&movb( &LB($tmp1), &HB($u) );
&shr( $t, 16);
&xor( $L, &DWP("0x300",$trans,$tmp2,0));
&movb( &LB($tmp2), &HB($t) );
&and( $u, "0xff" );
&and( $t, "0xff" );
&xor( $L, &DWP("0x600",$trans,$tmp1,0));
&xor( $L, &DWP("0x700",$trans,$tmp2,0));
&mov( $tmp2, &wparam(1) );
&xor( $L, &DWP("0x400",$trans,$u,0));
&xor( $L, &DWP("0x500",$trans,$t,0));
}
sub n2a
{
sprintf("%d",$_[0]);
}
# now has a side affect of rotating $a by $shift
sub R_PERM_OP
{
local($a,$b,$tt,$shift,$mask,$last)=@_;
&rotl( $a, $shift ) if ($shift != 0);
&mov( $tt, $a );
&xor( $a, $b );
&and( $a, $mask );
# This can never succeed, and besides it is difficult to see what the
# idea was - Ben 13 Feb 99
if (!$last eq $b)
{
&xor( $b, $a );
&xor( $tt, $a );
}
else
{
&xor( $tt, $a );
&xor( $b, $a );
}
&comment("");
}
sub IP_new
{
local($l,$r,$tt,$lr)=@_;
&R_PERM_OP($l,$r,$tt, 4,"0xf0f0f0f0",$l);
&R_PERM_OP($r,$tt,$l,20,"0xfff0000f",$l);
&R_PERM_OP($l,$tt,$r,14,"0x33333333",$r);
&R_PERM_OP($tt,$r,$l,22,"0x03fc03fc",$r);
&R_PERM_OP($l,$r,$tt, 9,"0xaaaaaaaa",$r);
if ($lr != 3)
{
if (($lr-3) < 0)
{ &rotr($tt, 3-$lr); }
else { &rotl($tt, $lr-3); }
}
if ($lr != 2)
{
if (($lr-2) < 0)
{ &rotr($r, 2-$lr); }
else { &rotl($r, $lr-2); }
}
}
sub FP_new
{
local($l,$r,$tt,$lr)=@_;
if ($lr != 2)
{
if (($lr-2) < 0)
{ &rotl($r, 2-$lr); }
else { &rotr($r, $lr-2); }
}
if ($lr != 3)
{
if (($lr-3) < 0)
{ &rotl($l, 3-$lr); }
else { &rotr($l, $lr-3); }
}
&R_PERM_OP($l,$r,$tt, 0,"0xaaaaaaaa",$r);
&R_PERM_OP($tt,$r,$l,23,"0x03fc03fc",$r);
&R_PERM_OP($l,$r,$tt,10,"0x33333333",$l);
&R_PERM_OP($r,$tt,$l,18,"0xfff0000f",$l);
&R_PERM_OP($l,$tt,$r,12,"0xf0f0f0f0",$r);
&rotr($tt , 4);
}
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