1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
#!/usr/local/bin/perl
# At some point it became apparent that the original SSLeay RC4
# assembler implementation performs suboptimaly on latest IA-32
# microarchitectures. After re-tuning performance has changed as
# following:
#
# Pentium +0%
# Pentium III +17%
# AMD +52%(*)
# P4 +180%(**)
#
# (*) This number is actually a trade-off:-) It's possible to
# achieve +72%, but at the cost of -48% off PIII performance.
# In other words code performing further 13% faster on AMD
# would perform almost 2 times slower on Intel PIII...
# For reference! This code delivers ~80% of rc4-amd64.pl
# performance on the same Opteron machine.
# (**) This number requires compressed key schedule set up by
# RC4_set_key and therefore doesn't apply to 0.9.7 [option for
# compressed key schedule is implemented in 0.9.8 and later,
# see commentary section in rc4_skey.c for further details].
#
# <appro@fy.chalmers.se>
push(@INC,"perlasm","../../perlasm");
require "x86asm.pl";
&asm_init($ARGV[0],"rc4-586.pl");
$x="eax";
$y="ebx";
$tx="ecx";
$ty="edx";
$in="esi";
$out="edi";
$d="ebp";
&RC4("RC4");
&asm_finish();
sub RC4_loop
{
local($n,$p,$char)=@_;
&comment("Round $n");
if ($char)
{
if ($p >= 0)
{
&mov($ty, &swtmp(2));
&cmp($ty, $in);
&jbe(&label("finished"));
&inc($in);
}
else
{
&add($ty, 8);
&inc($in);
&cmp($ty, $in);
&jb(&label("finished"));
&mov(&swtmp(2), $ty);
}
}
# Moved out
# &mov( $tx, &DWP(0,$d,$x,4)) if $p < 0;
&add( &LB($y), &LB($tx));
&mov( $ty, &DWP(0,$d,$y,4));
# XXX
&mov( &DWP(0,$d,$x,4),$ty);
&add( $ty, $tx);
&mov( &DWP(0,$d,$y,4),$tx);
&and( $ty, 0xff);
&inc( &LB($x)); # NEXT ROUND
&mov( $tx, &DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND
&mov( $ty, &DWP(0,$d,$ty,4));
if (!$char)
{
#moved up into last round
if ($p >= 1)
{
&add( $out, 8)
}
&movb( &BP($n,"esp","",0), &LB($ty));
}
else
{
# Note in+=8 has occured
&movb( &HB($ty), &BP(-1,$in,"",0));
# XXX
&xorb(&LB($ty), &HB($ty));
# XXX
&movb(&BP($n,$out,"",0),&LB($ty));
}
}
sub RC4
{
local($name)=@_;
&function_begin_B($name,"");
&mov($ty,&wparam(1)); # len
&cmp($ty,0);
&jne(&label("proceed"));
&ret();
&set_label("proceed");
&comment("");
&push("ebp");
&push("ebx");
&push("esi");
&xor( $x, $x); # avoid partial register stalls
&push("edi");
&xor( $y, $y); # avoid partial register stalls
&mov( $d, &wparam(0)); # key
&mov( $in, &wparam(2));
&movb( &LB($x), &BP(0,$d,"",1));
&movb( &LB($y), &BP(4,$d,"",1));
&mov( $out, &wparam(3));
&inc( &LB($x));
&stack_push(3); # 3 temp variables
&add( $d, 8);
# detect compressed schedule, see commentary section in rc4_skey.c...
# in 0.9.7 context ~50 bytes below RC4_CHAR label remain redundant,
# as compressed key schedule is set up in 0.9.8 and later.
&cmp(&DWP(256,$d),-1);
&je(&label("RC4_CHAR"));
&lea( $ty, &DWP(-8,$ty,$in));
# check for 0 length input
&mov( &swtmp(2), $ty); # this is now address to exit at
&mov( $tx, &DWP(0,$d,$x,4));
&cmp( $ty, $in);
&jb( &label("end")); # less than 8 bytes
&set_label("start");
# filling DELAY SLOT
&add( $in, 8);
&RC4_loop(0,-1,0);
&RC4_loop(1,0,0);
&RC4_loop(2,0,0);
&RC4_loop(3,0,0);
&RC4_loop(4,0,0);
&RC4_loop(5,0,0);
&RC4_loop(6,0,0);
&RC4_loop(7,1,0);
&comment("apply the cipher text");
# xor the cipher data with input
#&add( $out, 8); #moved up into last round
&mov( $tx, &swtmp(0));
&mov( $ty, &DWP(-8,$in,"",0));
&xor( $tx, $ty);
&mov( $ty, &DWP(-4,$in,"",0));
&mov( &DWP(-8,$out,"",0), $tx);
&mov( $tx, &swtmp(1));
&xor( $tx, $ty);
&mov( $ty, &swtmp(2)); # load end ptr;
&mov( &DWP(-4,$out,"",0), $tx);
&mov( $tx, &DWP(0,$d,$x,4));
&cmp($in, $ty);
&jbe(&label("start"));
&set_label("end");
# There is quite a bit of extra crap in RC4_loop() for this
# first round
&RC4_loop(0,-1,1);
&RC4_loop(1,0,1);
&RC4_loop(2,0,1);
&RC4_loop(3,0,1);
&RC4_loop(4,0,1);
&RC4_loop(5,0,1);
&RC4_loop(6,1,1);
&jmp(&label("finished"));
&align(16);
# this is essentially Intel P4 specific codepath, see rc4_skey.c,
# and is engaged in 0.9.8 and later context...
&set_label("RC4_CHAR");
&lea ($ty,&DWP(0,$in,$ty));
&mov (&swtmp(2),$ty);
&movz ($tx,&BP(0,$d,$x));
# strangely enough unrolled loop performs over 20% slower...
&set_label("RC4_CHAR_loop");
&add (&LB($y),&LB($tx));
&movz ($ty,&BP(0,$d,$y));
&movb (&BP(0,$d,$y),&LB($tx));
&movb (&BP(0,$d,$x),&LB($ty));
&add (&LB($ty),&LB($tx));
&movz ($ty,&BP(0,$d,$ty));
&add (&LB($x),1);
&xorb (&LB($ty),&BP(0,$in));
&lea ($in,&BP(1,$in));
&movz ($tx,&BP(0,$d,$x));
&cmp ($in,&swtmp(2));
&movb (&BP(0,$out),&LB($ty));
&lea ($out,&BP(1,$out));
&jb (&label("RC4_CHAR_loop"));
&set_label("finished");
&dec( $x);
&stack_pop(3);
&movb( &BP(-4,$d,"",0),&LB($y));
&movb( &BP(-8,$d,"",0),&LB($x));
&function_end($name);
}
|