1#!/usr/local/bin/perl
2
3push(@INC,"perlasm","../../perlasm");
4require "x86asm.pl";
5require "cbc.pl";
6
7&asm_init($ARGV[0],"rc5-586.pl");
8
9$RC5_MAX_ROUNDS=16;
10$RC5_32_OFF=($RC5_MAX_ROUNDS+2)*4;
11$A="edi";
12$B="esi";
13$S="ebp";
14$tmp1="eax";
15$r="ebx";
16$tmpc="ecx";
17$tmp4="edx";
18
19&RC5_32_encrypt("RC5_32_encrypt",1);
20&RC5_32_encrypt("RC5_32_decrypt",0);
21&cbc("RC5_32_cbc_encrypt","RC5_32_encrypt","RC5_32_decrypt",0,4,5,3,-1,-1);
22&asm_finish();
23
24sub RC5_32_encrypt
25	{
26	local($name,$enc)=@_;
27
28	&function_begin_B($name,"");
29
30	&comment("");
31
32	&push("ebp");
33	 &push("esi");
34	&push("edi");
35	 &mov($tmp4,&wparam(0));
36	&mov($S,&wparam(1));
37
38	&comment("Load the 2 words");
39	 &mov($A,&DWP(0,$tmp4,"",0));
40	&mov($B,&DWP(4,$tmp4,"",0));
41
42	&push($r);
43	 &mov($r,	&DWP(0,$S,"",0));
44
45	# encrypting part
46
47	if ($enc)
48		{
49		 &add($A,	&DWP(4+0,$S,"",0));
50		&add($B,	&DWP(4+4,$S,"",0));
51
52		for ($i=0; $i<$RC5_MAX_ROUNDS; $i++)
53			{
54			 &xor($A,	$B);
55			&mov($tmp1,	&DWP(12+$i*8,$S,"",0));
56			 &mov($tmpc,	$B);
57			&rotl($A,	&LB("ecx"));
58			&add($A,	$tmp1);
59
60			 &xor($B,	$A);
61			&mov($tmp1,	&DWP(16+$i*8,$S,"",0));
62			 &mov($tmpc,	$A);
63			&rotl($B,	&LB("ecx"));
64			&add($B,	$tmp1);
65			if (($i == 7) || ($i == 11))
66				{
67			 &cmp($r,	$i+1);
68			&je(&label("rc5_exit"));
69				}
70			}
71		}
72	else
73		{
74		 &cmp($r,	12);
75		&je(&label("rc5_dec_12"));
76		 &cmp($r,	8);
77		&je(&label("rc5_dec_8"));
78		for ($i=$RC5_MAX_ROUNDS; $i > 0; $i--)
79			{
80			&set_label("rc5_dec_$i") if ($i == 12) || ($i == 8);
81			 &mov($tmp1,	&DWP($i*8+8,$S,"",0));
82			&sub($B,	$tmp1);
83			 &mov($tmpc,	$A);
84			&rotr($B,	&LB("ecx"));
85			&xor($B,	$A);
86
87			 &mov($tmp1,	&DWP($i*8+4,$S,"",0));
88			&sub($A,	$tmp1);
89			 &mov($tmpc,	$B);
90			&rotr($A,	&LB("ecx"));
91			&xor($A,	$B);
92			}
93		 &sub($B,	&DWP(4+4,$S,"",0));
94		&sub($A,	&DWP(4+0,$S,"",0));
95		}
96
97	&set_label("rc5_exit");
98	 &mov(&DWP(0,$tmp4,"",0),$A);
99	&mov(&DWP(4,$tmp4,"",0),$B);
100
101	 &pop("ebx");
102	&pop("edi");
103	 &pop("esi");
104	&pop("ebp");
105	 &ret();
106	&function_end_B($name);
107	}
108
109
110