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#!/usr/local/bin/perl
push(@INC,"perlasm","../../perlasm");
require "x86asm.pl";
require "cbc.pl";
&asm_init($ARGV[0],"rc5-586.pl");
$RC5_MAX_ROUNDS=16;
$RC5_32_OFF=($RC5_MAX_ROUNDS+2)*4;
$A="edi";
$B="esi";
$S="ebp";
$tmp1="eax";
$r="ebx";
$tmpc="ecx";
$tmp4="edx";
&RC5_32_encrypt("RC5_32_encrypt",1);
&RC5_32_encrypt("RC5_32_decrypt",0);
&cbc("RC5_32_cbc_encrypt","RC5_32_encrypt","RC5_32_decrypt",0,4,5,3,-1,-1);
&asm_finish();
sub RC5_32_encrypt
{
local($name,$enc)=@_;
&function_begin_B($name,"");
&comment("");
&push("ebp");
&push("esi");
&push("edi");
&mov($tmp4,&wparam(0));
&mov($S,&wparam(1));
&comment("Load the 2 words");
&mov($A,&DWP(0,$tmp4,"",0));
&mov($B,&DWP(4,$tmp4,"",0));
&push($r);
&mov($r, &DWP(0,$S,"",0));
# encrypting part
if ($enc)
{
&add($A, &DWP(4+0,$S,"",0));
&add($B, &DWP(4+4,$S,"",0));
for ($i=0; $i<$RC5_MAX_ROUNDS; $i++)
{
&xor($A, $B);
&mov($tmp1, &DWP(12+$i*8,$S,"",0));
&mov($tmpc, $B);
&rotl($A, &LB("ecx"));
&add($A, $tmp1);
&xor($B, $A);
&mov($tmp1, &DWP(16+$i*8,$S,"",0));
&mov($tmpc, $A);
&rotl($B, &LB("ecx"));
&add($B, $tmp1);
if (($i == 7) || ($i == 11))
{
&cmp($r, $i+1);
&je(&label("rc5_exit"));
}
}
}
else
{
&cmp($r, 12);
&je(&label("rc5_dec_12"));
&cmp($r, 8);
&je(&label("rc5_dec_8"));
for ($i=$RC5_MAX_ROUNDS; $i > 0; $i--)
{
&set_label("rc5_dec_$i") if ($i == 12) || ($i == 8);
&mov($tmp1, &DWP($i*8+8,$S,"",0));
&sub($B, $tmp1);
&mov($tmpc, $A);
&rotr($B, &LB("ecx"));
&xor($B, $A);
&mov($tmp1, &DWP($i*8+4,$S,"",0));
&sub($A, $tmp1);
&mov($tmpc, $B);
&rotr($A, &LB("ecx"));
&xor($A, $B);
}
&sub($B, &DWP(4+4,$S,"",0));
&sub($A, &DWP(4+0,$S,"",0));
}
&set_label("rc5_exit");
&mov(&DWP(0,$tmp4,"",0),$A);
&mov(&DWP(4,$tmp4,"",0),$B);
&pop("ebx");
&pop("edi");
&pop("esi");
&pop("ebp");
&ret();
&function_end_B($name);
}
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