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|
#!/usr/local/bin/perl
# define for pentium pro friendly version
$ppro=1;
push(@INC,"perlasm","../../perlasm");
require "x86asm.pl";
require "cbc.pl";
&asm_init($ARGV[0],"cast-586.pl",$ARGV[$#ARGV] eq "386");
$CAST_ROUNDS=16;
$L="edi";
$R="esi";
$K="ebp";
$tmp1="ecx";
$tmp2="ebx";
$tmp3="eax";
$tmp4="edx";
$S1="CAST_S_table0";
$S2="CAST_S_table1";
$S3="CAST_S_table2";
$S4="CAST_S_table3";
@F1=("add","xor","sub");
@F2=("xor","sub","add");
@F3=("sub","add","xor");
&CAST_encrypt("CAST_encrypt",1);
&CAST_encrypt("CAST_decrypt",0);
&cbc("CAST_cbc_encrypt","CAST_encrypt","CAST_decrypt",1,4,5,3,-1,-1);
&asm_finish();
sub CAST_encrypt {
local($name,$enc)=@_;
local($win_ex)=<<"EOF";
EXTERN _CAST_S_table0:DWORD
EXTERN _CAST_S_table1:DWORD
EXTERN _CAST_S_table2:DWORD
EXTERN _CAST_S_table3:DWORD
EOF
&main::external_label(
"CAST_S_table0",
"CAST_S_table1",
"CAST_S_table2",
"CAST_S_table3",
);
&function_begin_B($name,$win_ex);
&comment("");
&push("ebp");
&push("ebx");
&mov($tmp2,&wparam(0));
&mov($K,&wparam(1));
&push("esi");
&push("edi");
&comment("Load the 2 words");
&mov($L,&DWP(0,$tmp2,"",0));
&mov($R,&DWP(4,$tmp2,"",0));
&comment('Get short key flag');
&mov($tmp3,&DWP(128,$K,"",0));
if($enc) {
&push($tmp3);
} else {
&or($tmp3,$tmp3);
&jnz(&label('cast_dec_skip'));
}
&xor($tmp3, $tmp3);
# encrypting part
if ($enc) {
&E_CAST( 0,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 1,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 2,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 3,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 4,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 5,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 6,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 7,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 8,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 9,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(10,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(11,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&comment('test short key flag');
&pop($tmp4);
&or($tmp4,$tmp4);
&jnz(&label('cast_enc_done'));
&E_CAST(12,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(13,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(14,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(15,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
} else {
&E_CAST(15,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(14,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(13,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(12,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&set_label('cast_dec_skip');
&E_CAST(11,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST(10,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 9,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 8,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 7,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 6,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 5,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 4,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 3,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 2,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 1,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
&E_CAST( 0,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
}
&set_label('cast_enc_done') if $enc;
# Why the nop? - Ben 17/1/99
&nop();
&mov($tmp3,&wparam(0));
&mov(&DWP(4,$tmp3,"",0),$L);
&mov(&DWP(0,$tmp3,"",0),$R);
&function_end($name);
}
sub E_CAST {
local($i,$S,$L,$R,$K,$OP1,$OP2,$OP3,$tmp1,$tmp2,$tmp3,$tmp4)=@_;
# Ri needs to have 16 pre added.
&comment("round $i");
&mov( $tmp4, &DWP($i*8,$K,"",1));
&mov( $tmp1, &DWP($i*8+4,$K,"",1));
&$OP1( $tmp4, $R);
&rotl( $tmp4, &LB($tmp1));
if ($ppro) {
&mov( $tmp2, $tmp4); # B
&xor( $tmp1, $tmp1);
&movb( &LB($tmp1), &HB($tmp4)); # A
&and( $tmp2, 0xff);
&shr( $tmp4, 16); #
&xor( $tmp3, $tmp3);
} else {
&mov( $tmp2, $tmp4); # B
&movb( &LB($tmp1), &HB($tmp4)); # A # BAD BAD BAD
&shr( $tmp4, 16); #
&and( $tmp2, 0xff);
}
&movb( &LB($tmp3), &HB($tmp4)); # C # BAD BAD BAD
&and( $tmp4, 0xff); # D
&mov( $tmp1, &DWP($S1,"",$tmp1,4));
&mov( $tmp2, &DWP($S2,"",$tmp2,4));
&$OP2( $tmp1, $tmp2);
&mov( $tmp2, &DWP($S3,"",$tmp3,4));
&$OP3( $tmp1, $tmp2);
&mov( $tmp2, &DWP($S4,"",$tmp4,4));
&$OP1( $tmp1, $tmp2);
# XXX
&xor( $L, $tmp1);
# XXX
}
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