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
|
// sosemanuk.cpp - written and placed in the public domain by Jeffrey Walton
// based on public domain code by Martin Boesgaard, Mette Vesterager,
// Thomas Pedersen, Jesper Christiansen and Ove Scavenius.
#include "pch.h"
#include "config.h"
#include "rabbit.h"
#include "secblock.h"
#include "misc.h"
ANONYMOUS_NAMESPACE_BEGIN
using CryptoPP::word32;
using CryptoPP::rotlConstant;
#define ROTL32(x, y) rotlConstant<y>(x)
#define U32V(x) static_cast<word32>(x)
word32 G_func(word32 x)
{
/* Temporary variables */
word32 a, b, h, l;
/* Construct high and low argument for squaring */
a = x & 0xFFFF;
b = x >> 16;
/* Calculate high and low result of squaring */
h = (((U32V(a*a) >> 17U) + U32V(a*b)) >> 15U) + b*b;
l = x*x;
/* Return high XOR low */
return U32V(h^l);
}
word32 NextState(word32 c[8], word32 x[8], word32 carry)
{
/* Temporary variables */
word32 g[8], c_old[8], i;
/* Save old counter values */
for (i = 0; i<8; i++)
c_old[i] = c[i];
/* Calculate new counter values */
c[0] = U32V(c[0] + 0x4D34D34D + carry);
c[1] = U32V(c[1] + 0xD34D34D3 + (c[0] < c_old[0]));
c[2] = U32V(c[2] + 0x34D34D34 + (c[1] < c_old[1]));
c[3] = U32V(c[3] + 0x4D34D34D + (c[2] < c_old[2]));
c[4] = U32V(c[4] + 0xD34D34D3 + (c[3] < c_old[3]));
c[5] = U32V(c[5] + 0x34D34D34 + (c[4] < c_old[4]));
c[6] = U32V(c[6] + 0x4D34D34D + (c[5] < c_old[5]));
c[7] = U32V(c[7] + 0xD34D34D3 + (c[6] < c_old[6]));
carry = (c[7] < c_old[7]);
/* Calculate the g-values */
for (i = 0; i<8; i++)
g[i] = G_func(U32V(x[i] + c[i]));
/* Calculate new state values */
x[0] = U32V(g[0] + ROTL32(g[7], 16) + ROTL32(g[6], 16));
x[1] = U32V(g[1] + ROTL32(g[0], 8) + g[7]);
x[2] = U32V(g[2] + ROTL32(g[1], 16) + ROTL32(g[0], 16));
x[3] = U32V(g[3] + ROTL32(g[2], 8) + g[1]);
x[4] = U32V(g[4] + ROTL32(g[3], 16) + ROTL32(g[2], 16));
x[5] = U32V(g[5] + ROTL32(g[4], 8) + g[3]);
x[6] = U32V(g[6] + ROTL32(g[5], 16) + ROTL32(g[4], 16));
x[7] = U32V(g[7] + ROTL32(g[6], 8) + g[5]);
return carry;
}
ANONYMOUS_NAMESPACE_END
NAMESPACE_BEGIN(CryptoPP)
void RabbitPolicy::CipherSetKey(const NameValuePairs ¶ms, const byte *userKey, size_t keylen)
{
/* Generate four subkeys */
CRYPTOPP_UNUSED(params);
GetUserKey(LITTLE_ENDIAN_ORDER, m_t.begin(), 4, userKey, keylen);
/* Generate initial state variables */
m_mx[0] = m_t[0];
m_mx[2] = m_t[1];
m_mx[4] = m_t[2];
m_mx[6] = m_t[3];
m_mx[1] = U32V(m_t[3] << 16) | (m_t[2] >> 16);
m_mx[3] = U32V(m_t[0] << 16) | (m_t[3] >> 16);
m_mx[5] = U32V(m_t[1] << 16) | (m_t[0] >> 16);
m_mx[7] = U32V(m_t[2] << 16) | (m_t[1] >> 16);
/* Generate initial counter values */
m_mc[0] = ROTL32(m_t[2], 16);
m_mc[2] = ROTL32(m_t[3], 16);
m_mc[4] = ROTL32(m_t[0], 16);
m_mc[6] = ROTL32(m_t[1], 16);
m_mc[1] = (m_t[0] & 0xFFFF0000) | (m_t[1] & 0xFFFF);
m_mc[3] = (m_t[1] & 0xFFFF0000) | (m_t[2] & 0xFFFF);
m_mc[5] = (m_t[2] & 0xFFFF0000) | (m_t[3] & 0xFFFF);
m_mc[7] = (m_t[3] & 0xFFFF0000) | (m_t[0] & 0xFFFF);
/* Clear carry bit */
m_mcy = 0;
/* Iterate the system four times */
for (unsigned int i = 0; i<4; i++)
m_mcy = NextState(m_mc, m_mx, m_mcy);
/* Modify the counters */
for (unsigned int i = 0; i<8; i++)
m_mc[i] ^= m_mx[(i + 4) & 0x7];
/* Copy master instance to work instance */
for (unsigned int i = 0; i<8; i++)
{
m_wx[i] = m_mx[i];
m_wc[i] = m_mc[i];
}
m_wcy = m_mcy;
}
void RabbitPolicy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
{
// Rabbit's bufferByteSize in AdditiveCipherTemplate
const unsigned int BUFFER_SIZE = 16;
for (unsigned int i = 0; i<iterationCount; ++i)
{
/* Iterate the system */
m_wcy = NextState(m_wc, m_wx, m_wcy);
/* Encrypt/decrypt 16 bytes of data */
PutWord(false, LITTLE_ENDIAN_ORDER, output + 0, m_wx[0] ^ (m_wx[5] >> 16) ^ (m_wx[3] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 4, m_wx[2] ^ (m_wx[7] >> 16) ^ (m_wx[5] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 8, m_wx[4] ^ (m_wx[1] >> 16) ^ (m_wx[7] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 12, m_wx[6] ^ (m_wx[3] >> 16) ^ (m_wx[1] << 16));
// If AdditiveCipherTemplate does not have an acculated keystream
// then it will ask OperateKeystream to XOR the plaintext with
// the keystream and write it to the ciphertext buffer.
if ((operation & INPUT_NULL) != INPUT_NULL)
xorbuf(output, input, BUFFER_SIZE);
/* Increment pointers to input and output data */
input += BUFFER_SIZE;
output += BUFFER_SIZE;
}
}
void RabbitWithIVPolicy::CipherSetKey(const NameValuePairs ¶ms, const byte *userKey, size_t keylen)
{
/* Generate four subkeys */
CRYPTOPP_UNUSED(params);
GetUserKey(LITTLE_ENDIAN_ORDER, m_t.begin(), 4, userKey, keylen);
/* Generate initial state variables */
m_mx[0] = m_t[0];
m_mx[2] = m_t[1];
m_mx[4] = m_t[2];
m_mx[6] = m_t[3];
m_mx[1] = U32V(m_t[3] << 16) | (m_t[2] >> 16);
m_mx[3] = U32V(m_t[0] << 16) | (m_t[3] >> 16);
m_mx[5] = U32V(m_t[1] << 16) | (m_t[0] >> 16);
m_mx[7] = U32V(m_t[2] << 16) | (m_t[1] >> 16);
/* Generate initial counter values */
m_mc[0] = ROTL32(m_t[2], 16);
m_mc[2] = ROTL32(m_t[3], 16);
m_mc[4] = ROTL32(m_t[0], 16);
m_mc[6] = ROTL32(m_t[1], 16);
m_mc[1] = (m_t[0] & 0xFFFF0000) | (m_t[1] & 0xFFFF);
m_mc[3] = (m_t[1] & 0xFFFF0000) | (m_t[2] & 0xFFFF);
m_mc[5] = (m_t[2] & 0xFFFF0000) | (m_t[3] & 0xFFFF);
m_mc[7] = (m_t[3] & 0xFFFF0000) | (m_t[0] & 0xFFFF);
/* Clear carry bit */
m_mcy = 0;
/* Iterate the system four times */
for (unsigned int i = 0; i<4; i++)
m_mcy = NextState(m_mc, m_mx, m_mcy);
/* Modify the counters */
for (unsigned int i = 0; i<8; i++)
m_mc[i] ^= m_mx[(i + 4) & 0x7];
/* Copy master instance to work instance */
for (unsigned int i = 0; i<8; i++)
{
m_wx[i] = m_mx[i];
m_wc[i] = m_mc[i];
}
m_wcy = m_mcy;
}
void RabbitWithIVPolicy::CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)
{
CRYPTOPP_UNUSED(keystreamBuffer);
CRYPTOPP_ASSERT(length == 8);
/* Generate four subvectors */
GetBlock<word32, LittleEndian> v(iv); v(m_t[0])(m_t[2]);
m_t[1] = (m_t[0] >> 16) | (m_t[2] & 0xFFFF0000);
m_t[3] = (m_t[2] << 16) | (m_t[0] & 0x0000FFFF);
/* Modify counter values */
m_wc[0] = m_mc[0] ^ m_t[0];
m_wc[1] = m_mc[1] ^ m_t[1];
m_wc[2] = m_mc[2] ^ m_t[2];
m_wc[3] = m_mc[3] ^ m_t[3];
m_wc[4] = m_mc[4] ^ m_t[0];
m_wc[5] = m_mc[5] ^ m_t[1];
m_wc[6] = m_mc[6] ^ m_t[2];
m_wc[7] = m_mc[7] ^ m_t[3];
/* Copy state variables */
for (unsigned int i = 0; i<8; i++)
m_wx[i] = m_mx[i];
m_wcy = m_mcy;
/* Iterate the system four times */
for (unsigned int i = 0; i<4; i++)
m_wcy = NextState(m_wc, m_wx, m_wcy);
}
void RabbitWithIVPolicy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
{
// Rabbit's bufferByteSize in AdditiveCipherTemplate
const unsigned int BUFFER_SIZE = 16;
for (unsigned int i = 0; i<iterationCount; ++i)
{
/* Iterate the system */
m_wcy = NextState(m_wc, m_wx, m_wcy);
/* Encrypt/decrypt 16 bytes of data */
PutWord(false, LITTLE_ENDIAN_ORDER, output + 0, m_wx[0] ^ (m_wx[5] >> 16) ^ (m_wx[3] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 4, m_wx[2] ^ (m_wx[7] >> 16) ^ (m_wx[5] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 8, m_wx[4] ^ (m_wx[1] >> 16) ^ (m_wx[7] << 16));
PutWord(false, LITTLE_ENDIAN_ORDER, output + 12, m_wx[6] ^ (m_wx[3] >> 16) ^ (m_wx[1] << 16));
// If AdditiveCipherTemplate does not have an acculated keystream
// then it will ask OperateKeystream to XOR the plaintext with
// the keystream and write it to the ciphertext buffer.
if ((operation & INPUT_NULL) != INPUT_NULL)
xorbuf(output, input, BUFFER_SIZE);
/* Increment pointers to input and output data */
input += BUFFER_SIZE;
output += BUFFER_SIZE;
}
}
NAMESPACE_END
|
