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
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1335 USA.
*/
/* based on Wei Dai's arc4.cpp from CryptoPP */
#include "runtime.hpp"
#include "arc4.hpp"
#if defined(TAOCRYPT_X86ASM_AVAILABLE) && defined(TAO_ASM)
#define DO_ARC4_ASM
#endif
namespace TaoCrypt {
void ARC4::SetKey(const byte* key, word32 length)
{
x_ = 1;
y_ = 0;
word32 i;
for (i = 0; i < STATE_SIZE; i++)
state_[i] = i;
word32 keyIndex = 0, stateIndex = 0;
for (i = 0; i < STATE_SIZE; i++) {
word32 a = state_[i];
stateIndex += key[keyIndex] + a;
stateIndex &= 0xFF;
state_[i] = state_[stateIndex];
state_[stateIndex] = a;
if (++keyIndex >= length)
keyIndex = 0;
}
}
// local
namespace {
inline unsigned int MakeByte(word32& x, word32& y, byte* s)
{
word32 a = s[x];
y = (y+a) & 0xff;
word32 b = s[y];
s[x] = b;
s[y] = a;
x = (x+1) & 0xff;
return s[(a+b) & 0xff];
}
} // namespace
void ARC4::Process(byte* out, const byte* in, word32 length)
{
if (length == 0) return;
#ifdef DO_ARC4_ASM
if (isMMX) {
AsmProcess(out, in, length);
return;
}
#endif
byte *const s = state_;
word32 x = x_;
word32 y = y_;
if (in == out)
while (length--)
*out++ ^= MakeByte(x, y, s);
else
while(length--)
*out++ = *in++ ^ MakeByte(x, y, s);
x_ = x;
y_ = y;
}
#ifdef DO_ARC4_ASM
#ifdef _MSC_VER
__declspec(naked)
#else
__attribute__ ((noinline))
#endif
void ARC4::AsmProcess(byte* out, const byte* in, word32 length)
{
#ifdef __GNUC__
#define AS1(x) #x ";"
#define AS2(x, y) #x ", " #y ";"
#define PROLOG() \
__asm__ __volatile__ \
( \
".intel_syntax noprefix;" \
"push ebx;" \
"push ebp;" \
"mov ebp, eax;"
#define EPILOG() \
"pop ebp;" \
"pop ebx;" \
"emms;" \
".att_syntax;" \
: \
: "c" (this), "D" (out), "S" (in), "a" (length) \
: "%edx", "memory", "cc" \
);
#else
#define AS1(x) __asm x
#define AS2(x, y) __asm x, y
#define PROLOG() \
AS1( push ebp ) \
AS2( mov ebp, esp ) \
AS2( movd mm3, edi ) \
AS2( movd mm4, ebx ) \
AS2( movd mm5, esi ) \
AS2( movd mm6, ebp ) \
AS2( mov edi, DWORD PTR [ebp + 8] ) \
AS2( mov esi, DWORD PTR [ebp + 12] ) \
AS2( mov ebp, DWORD PTR [ebp + 16] )
#define EPILOG() \
AS2( movd ebp, mm6 ) \
AS2( movd esi, mm5 ) \
AS2( movd ebx, mm4 ) \
AS2( movd edi, mm3 ) \
AS2( mov esp, ebp ) \
AS1( pop ebp ) \
AS1( emms ) \
AS1( ret 12 )
#endif
PROLOG()
AS2( sub esp, 4 ) // make room
AS2( cmp ebp, 0 )
AS1( jz nothing )
AS2( mov [esp], ebp ) // length
AS2( movzx edx, BYTE PTR [ecx + 1] ) // y
AS2( lea ebp, [ecx + 2] ) // state_
AS2( movzx ecx, BYTE PTR [ecx] ) // x
// setup loop
// a = s[x];
AS2( movzx eax, BYTE PTR [ebp + ecx] )
#ifdef _MSC_VER
AS1( loopStart: ) // loopStart
#else
AS1( 0: ) // loopStart for some gas (need numeric for jump back
#endif
// y = (y+a) & 0xff;
AS2( add edx, eax )
AS2( and edx, 255 )
// b = s[y];
AS2( movzx ebx, BYTE PTR [ebp + edx] )
// s[x] = b;
AS2( mov [ebp + ecx], bl )
// s[y] = a;
AS2( mov [ebp + edx], al )
// x = (x+1) & 0xff;
AS1( inc ecx )
AS2( and ecx, 255 )
//return s[(a+b) & 0xff];
AS2( add eax, ebx )
AS2( and eax, 255 )
AS2( movzx ebx, BYTE PTR [ebp + eax] )
// a = s[x]; for next round
AS2( movzx eax, BYTE PTR [ebp + ecx] )
// xOr w/ inByte
AS2( xor bl, BYTE PTR [esi] )
AS1( inc esi )
// write to outByte
AS2( mov [edi], bl )
AS1( inc edi )
AS1( dec DWORD PTR [esp] )
#ifdef _MSC_VER
AS1( jnz loopStart ) // loopStart
#else
AS1( jnz 0b ) // loopStart
#endif
// write back to x_ and y_
AS2( mov [ebp - 2], cl )
AS2( mov [ebp - 1], dl )
AS1( nothing: )
// inline adjust
AS2( add esp, 4 ) // fix room on stack
EPILOG()
}
#endif // DO_ARC4_ASM
} // namespace
|
