/
cast.cpp
296 lines (258 loc) · 11 KB
/
cast.cpp
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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
// cast.cpp - written and placed in the public domain by Wei Dai and Leonard Janke
// based on Steve Reid's public domain cast.c
#include "pch.h"
#include "cast.h"
#include "misc.h"
NAMESPACE_BEGIN(CryptoPP)
/* Macros to access 8-bit bytes out of a 32-bit word */
#define U8a(x) GETBYTE(x,3)
#define U8b(x) GETBYTE(x,2)
#define U8c(x) GETBYTE(x,1)
#define U8d(x) GETBYTE(x,0)
/* CAST uses three different round functions */
#define f1(l, r, km, kr) \
t = rotlVariable(km + r, kr); \
l ^= ((S[0][U8a(t)] ^ S[1][U8b(t)]) - \
S[2][U8c(t)]) + S[3][U8d(t)];
#define f2(l, r, km, kr) \
t = rotlVariable(km ^ r, kr); \
l ^= ((S[0][U8a(t)] - S[1][U8b(t)]) + \
S[2][U8c(t)]) ^ S[3][U8d(t)];
#define f3(l, r, km, kr) \
t = rotlVariable(km - r, kr); \
l ^= ((S[0][U8a(t)] + S[1][U8b(t)]) ^ \
S[2][U8c(t)]) - S[3][U8d(t)];
#define F1(l, r, i, j) f1(l, r, K[i], K[i+j])
#define F2(l, r, i, j) f2(l, r, K[i], K[i+j])
#define F3(l, r, i, j) f3(l, r, K[i], K[i+j])
typedef BlockGetAndPut<word32, BigEndian> Block;
void CAST128::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 t, l, r;
/* Get inblock into l,r */
Block::Get(inBlock)(l)(r);
/* Do the work */
F1(l, r, 0, 16);
F2(r, l, 1, 16);
F3(l, r, 2, 16);
F1(r, l, 3, 16);
F2(l, r, 4, 16);
F3(r, l, 5, 16);
F1(l, r, 6, 16);
F2(r, l, 7, 16);
F3(l, r, 8, 16);
F1(r, l, 9, 16);
F2(l, r, 10, 16);
F3(r, l, 11, 16);
/* Only do full 16 rounds if key length > 80 bits */
if (!reduced) {
F1(l, r, 12, 16);
F2(r, l, 13, 16);
F3(l, r, 14, 16);
F1(r, l, 15, 16);
}
/* Put l,r into outblock */
Block::Put(xorBlock, outBlock)(r)(l);
}
void CAST128::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 t, l, r;
/* Get inblock into l,r */
Block::Get(inBlock)(r)(l);
/* Only do full 16 rounds if key length > 80 bits */
if (!reduced) {
F1(r, l, 15, 16);
F3(l, r, 14, 16);
F2(r, l, 13, 16);
F1(l, r, 12, 16);
}
F3(r, l, 11, 16);
F2(l, r, 10, 16);
F1(r, l, 9, 16);
F3(l, r, 8, 16);
F2(r, l, 7, 16);
F1(l, r, 6, 16);
F3(r, l, 5, 16);
F2(l, r, 4, 16);
F1(r, l, 3, 16);
F3(l, r, 2, 16);
F2(r, l, 1, 16);
F1(l, r, 0, 16);
/* Put l,r into outblock */
Block::Put(xorBlock, outBlock)(l)(r);
/* Wipe clean */
t = l = r = 0;
}
void CAST128::Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &)
{
AssertValidKeyLength(keylength);
reduced = (keylength <= 10);
word32 X[4], Z[4];
GetUserKey(BIG_ENDIAN_ORDER, X, 4, userKey, keylength);
#define x(i) GETBYTE(X[i/4], 3-i%4)
#define z(i) GETBYTE(Z[i/4], 3-i%4)
unsigned int i;
for (i=0; i<=16; i+=16)
{
// this part is copied directly from RFC 2144 (with some search and replace) by Wei Dai
Z[0] = X[0] ^ S[4][x(0xD)] ^ S[5][x(0xF)] ^ S[6][x(0xC)] ^ S[7][x(0xE)] ^ S[6][x(0x8)];
Z[1] = X[2] ^ S[4][z(0x0)] ^ S[5][z(0x2)] ^ S[6][z(0x1)] ^ S[7][z(0x3)] ^ S[7][x(0xA)];
Z[2] = X[3] ^ S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[4][x(0x9)];
Z[3] = X[1] ^ S[4][z(0xA)] ^ S[5][z(0x9)] ^ S[6][z(0xB)] ^ S[7][z(0x8)] ^ S[5][x(0xB)];
K[i+0] = S[4][z(0x8)] ^ S[5][z(0x9)] ^ S[6][z(0x7)] ^ S[7][z(0x6)] ^ S[4][z(0x2)];
K[i+1] = S[4][z(0xA)] ^ S[5][z(0xB)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[5][z(0x6)];
K[i+2] = S[4][z(0xC)] ^ S[5][z(0xD)] ^ S[6][z(0x3)] ^ S[7][z(0x2)] ^ S[6][z(0x9)];
K[i+3] = S[4][z(0xE)] ^ S[5][z(0xF)] ^ S[6][z(0x1)] ^ S[7][z(0x0)] ^ S[7][z(0xC)];
X[0] = Z[2] ^ S[4][z(0x5)] ^ S[5][z(0x7)] ^ S[6][z(0x4)] ^ S[7][z(0x6)] ^ S[6][z(0x0)];
X[1] = Z[0] ^ S[4][x(0x0)] ^ S[5][x(0x2)] ^ S[6][x(0x1)] ^ S[7][x(0x3)] ^ S[7][z(0x2)];
X[2] = Z[1] ^ S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[4][z(0x1)];
X[3] = Z[3] ^ S[4][x(0xA)] ^ S[5][x(0x9)] ^ S[6][x(0xB)] ^ S[7][x(0x8)] ^ S[5][z(0x3)];
K[i+4] = S[4][x(0x3)] ^ S[5][x(0x2)] ^ S[6][x(0xC)] ^ S[7][x(0xD)] ^ S[4][x(0x8)];
K[i+5] = S[4][x(0x1)] ^ S[5][x(0x0)] ^ S[6][x(0xE)] ^ S[7][x(0xF)] ^ S[5][x(0xD)];
K[i+6] = S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x8)] ^ S[7][x(0x9)] ^ S[6][x(0x3)];
K[i+7] = S[4][x(0x5)] ^ S[5][x(0x4)] ^ S[6][x(0xA)] ^ S[7][x(0xB)] ^ S[7][x(0x7)];
Z[0] = X[0] ^ S[4][x(0xD)] ^ S[5][x(0xF)] ^ S[6][x(0xC)] ^ S[7][x(0xE)] ^ S[6][x(0x8)];
Z[1] = X[2] ^ S[4][z(0x0)] ^ S[5][z(0x2)] ^ S[6][z(0x1)] ^ S[7][z(0x3)] ^ S[7][x(0xA)];
Z[2] = X[3] ^ S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[4][x(0x9)];
Z[3] = X[1] ^ S[4][z(0xA)] ^ S[5][z(0x9)] ^ S[6][z(0xB)] ^ S[7][z(0x8)] ^ S[5][x(0xB)];
K[i+8] = S[4][z(0x3)] ^ S[5][z(0x2)] ^ S[6][z(0xC)] ^ S[7][z(0xD)] ^ S[4][z(0x9)];
K[i+9] = S[4][z(0x1)] ^ S[5][z(0x0)] ^ S[6][z(0xE)] ^ S[7][z(0xF)] ^ S[5][z(0xC)];
K[i+10] = S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x8)] ^ S[7][z(0x9)] ^ S[6][z(0x2)];
K[i+11] = S[4][z(0x5)] ^ S[5][z(0x4)] ^ S[6][z(0xA)] ^ S[7][z(0xB)] ^ S[7][z(0x6)];
X[0] = Z[2] ^ S[4][z(0x5)] ^ S[5][z(0x7)] ^ S[6][z(0x4)] ^ S[7][z(0x6)] ^ S[6][z(0x0)];
X[1] = Z[0] ^ S[4][x(0x0)] ^ S[5][x(0x2)] ^ S[6][x(0x1)] ^ S[7][x(0x3)] ^ S[7][z(0x2)];
X[2] = Z[1] ^ S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[4][z(0x1)];
X[3] = Z[3] ^ S[4][x(0xA)] ^ S[5][x(0x9)] ^ S[6][x(0xB)] ^ S[7][x(0x8)] ^ S[5][z(0x3)];
K[i+12] = S[4][x(0x8)] ^ S[5][x(0x9)] ^ S[6][x(0x7)] ^ S[7][x(0x6)] ^ S[4][x(0x3)];
K[i+13] = S[4][x(0xA)] ^ S[5][x(0xB)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[5][x(0x7)];
K[i+14] = S[4][x(0xC)] ^ S[5][x(0xD)] ^ S[6][x(0x3)] ^ S[7][x(0x2)] ^ S[6][x(0x8)];
K[i+15] = S[4][x(0xE)] ^ S[5][x(0xF)] ^ S[6][x(0x1)] ^ S[7][x(0x0)] ^ S[7][x(0xD)];
}
for (i=16; i<32; i++)
K[i] &= 0x1f;
}
// The following CAST-256 implementation was contributed by Leonard Janke
const word32 CAST256::Base::t_m[8][24]={
{ 0x5a827999, 0xd151d6a1, 0x482133a9, 0xbef090b1, 0x35bfedb9, 0xac8f4ac1,
0x235ea7c9, 0x9a2e04d1, 0x10fd61d9, 0x87ccbee1, 0xfe9c1be9, 0x756b78f1,
0xec3ad5f9, 0x630a3301, 0xd9d99009, 0x50a8ed11, 0xc7784a19, 0x3e47a721,
0xb5170429, 0x2be66131, 0xa2b5be39, 0x19851b41, 0x90547849, 0x0723d551},
{ 0xc95c653a, 0x402bc242, 0xb6fb1f4a, 0x2dca7c52, 0xa499d95a, 0x1b693662,
0x9238936a, 0x0907f072, 0x7fd74d7a, 0xf6a6aa82, 0x6d76078a, 0xe4456492,
0x5b14c19a, 0xd1e41ea2, 0x48b37baa, 0xbf82d8b2, 0x365235ba, 0xad2192c2,
0x23f0efca, 0x9ac04cd2, 0x118fa9da, 0x885f06e2, 0xff2e63ea, 0x75fdc0f2},
{ 0x383650db, 0xaf05ade3, 0x25d50aeb, 0x9ca467f3, 0x1373c4fb, 0x8a432203,
0x01127f0b, 0x77e1dc13, 0xeeb1391b, 0x65809623, 0xdc4ff32b, 0x531f5033,
0xc9eead3b, 0x40be0a43, 0xb78d674b, 0x2e5cc453, 0xa52c215b, 0x1bfb7e63,
0x92cadb6b, 0x099a3873, 0x8069957b, 0xf738f283, 0x6e084f8b, 0xe4d7ac93},
{ 0xa7103c7c, 0x1ddf9984, 0x94aef68c, 0x0b7e5394, 0x824db09c, 0xf91d0da4,
0x6fec6aac, 0xe6bbc7b4, 0x5d8b24bc, 0xd45a81c4, 0x4b29decc, 0xc1f93bd4,
0x38c898dc, 0xaf97f5e4, 0x266752ec, 0x9d36aff4, 0x14060cfc, 0x8ad56a04,
0x01a4c70c, 0x78742414, 0xef43811c, 0x6612de24, 0xdce23b2c, 0x53b19834},
{ 0x15ea281d, 0x8cb98525, 0x0388e22d, 0x7a583f35, 0xf1279c3d, 0x67f6f945,
0xdec6564d, 0x5595b355, 0xcc65105d, 0x43346d65, 0xba03ca6d, 0x30d32775,
0xa7a2847d, 0x1e71e185, 0x95413e8d, 0x0c109b95, 0x82dff89d, 0xf9af55a5,
0x707eb2ad, 0xe74e0fb5, 0x5e1d6cbd, 0xd4ecc9c5, 0x4bbc26cd, 0xc28b83d5},
{ 0x84c413be, 0xfb9370c6, 0x7262cdce, 0xe9322ad6, 0x600187de, 0xd6d0e4e6,
0x4da041ee, 0xc46f9ef6, 0x3b3efbfe, 0xb20e5906, 0x28ddb60e, 0x9fad1316,
0x167c701e, 0x8d4bcd26, 0x041b2a2e, 0x7aea8736, 0xf1b9e43e, 0x68894146,
0xdf589e4e, 0x5627fb56, 0xccf7585e, 0x43c6b566, 0xba96126e, 0x31656f76},
{ 0xf39dff5f, 0x6a6d5c67, 0xe13cb96f, 0x580c1677, 0xcedb737f, 0x45aad087,
0xbc7a2d8f, 0x33498a97, 0xaa18e79f, 0x20e844a7, 0x97b7a1af, 0x0e86feb7,
0x85565bbf, 0xfc25b8c7, 0x72f515cf, 0xe9c472d7, 0x6093cfdf, 0xd7632ce7,
0x4e3289ef, 0xc501e6f7, 0x3bd143ff, 0xb2a0a107, 0x296ffe0f, 0xa03f5b17},
{ 0x6277eb00, 0xd9474808, 0x5016a510, 0xc6e60218, 0x3db55f20, 0xb484bc28,
0x2b541930, 0xa2237638, 0x18f2d340, 0x8fc23048, 0x06918d50, 0x7d60ea58,
0xf4304760, 0x6affa468, 0xe1cf0170, 0x589e5e78, 0xcf6dbb80, 0x463d1888,
0xbd0c7590, 0x33dbd298, 0xaaab2fa0, 0x217a8ca8, 0x9849e9b0, 0x0f1946b8}
};
const unsigned int CAST256::Base::t_r[8][24]={
{19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11},
{4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28},
{21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13},
{6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30},
{23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15},
{8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0},
{25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17},
{10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2}
};
#define Q(i) \
F1(block[2],block[3],8*i+4,-4); \
F2(block[1],block[2],8*i+5,-4); \
F3(block[0],block[1],8*i+6,-4); \
F1(block[3],block[0],8*i+7,-4);
#define QBar(i) \
F1(block[3],block[0],8*i+7,-4); \
F3(block[0],block[1],8*i+6,-4); \
F2(block[1],block[2],8*i+5,-4); \
F1(block[2],block[3],8*i+4,-4);
/* CAST256's encrypt/decrypt functions are identical except for the order that
the keys are used */
void CAST256::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 t, block[4];
Block::Get(inBlock)(block[0])(block[1])(block[2])(block[3]);
// Perform 6 forward quad rounds
Q(0);
Q(1);
Q(2);
Q(3);
Q(4);
Q(5);
// Perform 6 reverse quad rounds
QBar(6);
QBar(7);
QBar(8);
QBar(9);
QBar(10);
QBar(11);
Block::Put(xorBlock, outBlock)(block[0])(block[1])(block[2])(block[3]);
}
/* Set up a CAST-256 key */
void CAST256::Base::Omega(int i, word32 kappa[8])
{
word32 t;
f1(kappa[6],kappa[7],t_m[0][i],t_r[0][i]);
f2(kappa[5],kappa[6],t_m[1][i],t_r[1][i]);
f3(kappa[4],kappa[5],t_m[2][i],t_r[2][i]);
f1(kappa[3],kappa[4],t_m[3][i],t_r[3][i]);
f2(kappa[2],kappa[3],t_m[4][i],t_r[4][i]);
f3(kappa[1],kappa[2],t_m[5][i],t_r[5][i]);
f1(kappa[0],kappa[1],t_m[6][i],t_r[6][i]);
f2(kappa[7],kappa[0],t_m[7][i],t_r[7][i]);
}
void CAST256::Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &)
{
AssertValidKeyLength(keylength);
word32 kappa[8];
GetUserKey(BIG_ENDIAN_ORDER, kappa, 8, userKey, keylength);
for(int i=0; i<12; ++i)
{
Omega(2*i,kappa);
Omega(2*i+1,kappa);
K[8*i]=kappa[0] & 31;
K[8*i+1]=kappa[2] & 31;
K[8*i+2]=kappa[4] & 31;
K[8*i+3]=kappa[6] & 31;
K[8*i+4]=kappa[7];
K[8*i+5]=kappa[5];
K[8*i+6]=kappa[3];
K[8*i+7]=kappa[1];
}
if (!IsForwardTransformation())
{
for(int j=0; j<6; ++j)
{
for(int i=0; i<4; ++i)
{
int i1=8*j+i;
int i2=8*(11-j)+i;
assert(i1<i2);
std::swap(K[i1],K[i2]);
std::swap(K[i1+4],K[i2+4]);
}
}
}
memset(kappa, 0, sizeof(kappa));
}
NAMESPACE_END