1#!/usr/local/bin/perl
2
3# define for pentium pro friendly version
4$ppro=1;
5
6push(@INC,"perlasm","../../perlasm");
7require "x86asm.pl";
8require "cbc.pl";
9
10&asm_init($ARGV[0],"cast-586.pl",$ARGV[$#ARGV] eq "386");
11
12$CAST_ROUNDS=16;
13$L="edi";
14$R="esi";
15$K="ebp";
16$tmp1="ecx";
17$tmp2="ebx";
18$tmp3="eax";
19$tmp4="edx";
20$S1="CAST_S_table0";
21$S2="CAST_S_table1";
22$S3="CAST_S_table2";
23$S4="CAST_S_table3";
24
25@F1=("add","xor","sub");
26@F2=("xor","sub","add");
27@F3=("sub","add","xor");
28
29&CAST_encrypt("CAST_encrypt",1);
30&CAST_encrypt("CAST_decrypt",0);
31&cbc("CAST_cbc_encrypt","CAST_encrypt","CAST_decrypt",1,4,5,3,-1,-1);
32
33&asm_finish();
34
35sub CAST_encrypt {
36    local($name,$enc)=@_;
37
38    local($win_ex)=<<"EOF";
39EXTERN	_CAST_S_table0:DWORD
40EXTERN	_CAST_S_table1:DWORD
41EXTERN	_CAST_S_table2:DWORD
42EXTERN	_CAST_S_table3:DWORD
43EOF
44    &main::external_label(
45			  "CAST_S_table0",
46			  "CAST_S_table1",
47			  "CAST_S_table2",
48			  "CAST_S_table3",
49			  );
50
51    &function_begin_B($name,$win_ex);
52
53    &comment("");
54
55    &push("ebp");
56    &push("ebx");
57    &mov($tmp2,&wparam(0));
58    &mov($K,&wparam(1));
59    &push("esi");
60    &push("edi");
61
62    &comment("Load the 2 words");
63    &mov($L,&DWP(0,$tmp2,"",0));
64    &mov($R,&DWP(4,$tmp2,"",0));
65
66    &comment('Get short key flag');
67    &mov($tmp3,&DWP(128,$K,"",0));
68    if($enc) {
69	&push($tmp3);
70    } else {
71	&or($tmp3,$tmp3);
72	&jnz(&label('cast_dec_skip'));
73    }
74
75    &xor($tmp3,	$tmp3);
76
77    # encrypting part
78
79    if ($enc) {
80	&E_CAST( 0,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
81	&E_CAST( 1,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
82	&E_CAST( 2,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
83	&E_CAST( 3,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
84	&E_CAST( 4,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
85	&E_CAST( 5,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
86	&E_CAST( 6,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
87	&E_CAST( 7,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
88	&E_CAST( 8,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
89	&E_CAST( 9,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
90	&E_CAST(10,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
91	&E_CAST(11,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
92	&comment('test short key flag');
93	&pop($tmp4);
94	&or($tmp4,$tmp4);
95	&jnz(&label('cast_enc_done'));
96	&E_CAST(12,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
97	&E_CAST(13,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
98	&E_CAST(14,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
99	&E_CAST(15,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
100    } else {
101	&E_CAST(15,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
102	&E_CAST(14,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
103	&E_CAST(13,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
104	&E_CAST(12,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
105	&set_label('cast_dec_skip');
106	&E_CAST(11,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
107	&E_CAST(10,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
108	&E_CAST( 9,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
109	&E_CAST( 8,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
110	&E_CAST( 7,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
111	&E_CAST( 6,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
112	&E_CAST( 5,$S,$L,$R,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
113	&E_CAST( 4,$S,$R,$L,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
114	&E_CAST( 3,$S,$L,$R,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
115	&E_CAST( 2,$S,$R,$L,$K,@F3,$tmp1,$tmp2,$tmp3,$tmp4);
116	&E_CAST( 1,$S,$L,$R,$K,@F2,$tmp1,$tmp2,$tmp3,$tmp4);
117	&E_CAST( 0,$S,$R,$L,$K,@F1,$tmp1,$tmp2,$tmp3,$tmp4);
118    }
119
120    &set_label('cast_enc_done') if $enc;
121# Why the nop? - Ben 17/1/99
122    &nop();
123    &mov($tmp3,&wparam(0));
124    &mov(&DWP(4,$tmp3,"",0),$L);
125    &mov(&DWP(0,$tmp3,"",0),$R);
126    &function_end($name);
127}
128
129sub E_CAST {
130    local($i,$S,$L,$R,$K,$OP1,$OP2,$OP3,$tmp1,$tmp2,$tmp3,$tmp4)=@_;
131    # Ri needs to have 16 pre added.
132
133    &comment("round $i");
134    &mov(	$tmp4,		&DWP($i*8,$K,"",1));
135
136    &mov(	$tmp1,		&DWP($i*8+4,$K,"",1));
137    &$OP1(	$tmp4,		$R);
138
139    &rotl(	$tmp4,		&LB($tmp1));
140
141    if ($ppro) {
142	&mov(	$tmp2,		$tmp4);		# B
143	&xor(	$tmp1,		$tmp1);
144
145	&movb(	&LB($tmp1),	&HB($tmp4));	# A
146	&and(	$tmp2,		0xff);
147
148	&shr(	$tmp4,		16); 		#
149	&xor(	$tmp3,		$tmp3);
150    } else {
151	&mov(	$tmp2,		$tmp4);		# B
152	&movb(	&LB($tmp1),	&HB($tmp4));	# A	# BAD BAD BAD
153
154	&shr(	$tmp4,		16); 		#
155	&and(	$tmp2,		0xff);
156    }
157
158    &movb(	&LB($tmp3),	&HB($tmp4));	# C	# BAD BAD BAD
159    &and(	$tmp4,		0xff);		# D
160
161    &mov(	$tmp1,		&DWP($S1,"",$tmp1,4));
162    &mov(	$tmp2,		&DWP($S2,"",$tmp2,4));
163
164    &$OP2(	$tmp1,		$tmp2);
165    &mov(	$tmp2,		&DWP($S3,"",$tmp3,4));
166
167    &$OP3(	$tmp1,		$tmp2);
168    &mov(	$tmp2,		&DWP($S4,"",$tmp4,4));
169
170    &$OP1(	$tmp1,		$tmp2);
171    # XXX
172
173    &xor(	$L,		$tmp1);
174    # XXX
175}
176
177