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
|
using System;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Utilities;
namespace Org.BouncyCastle.Crypto.Engines
{
/**
* A Noekeon engine, using direct-key mode.
*/
public class NoekeonEngine
: IBlockCipher
{
private const int GenericSize = 16; // Block and key size, as well as the amount of rounds.
private static readonly uint[] nullVector =
{
0x00, 0x00, 0x00, 0x00 // Used in decryption
};
private static readonly uint[] roundConstants =
{
0x80, 0x1b, 0x36, 0x6c,
0xd8, 0xab, 0x4d, 0x9a,
0x2f, 0x5e, 0xbc, 0x63,
0xc6, 0x97, 0x35, 0x6a,
0xd4
};
private uint[] state = new uint[4], // a
subKeys = new uint[4], // k
decryptKeys = new uint[4];
private bool _initialised, _forEncryption;
/**
* Create an instance of the Noekeon encryption algorithm
* and set some defaults
*/
public NoekeonEngine()
{
_initialised = false;
}
public virtual string AlgorithmName
{
get { return "Noekeon"; }
}
public virtual bool IsPartialBlockOkay
{
get { return false; }
}
public virtual int GetBlockSize()
{
return GenericSize;
}
/**
* initialise
*
* @param forEncryption whether or not we are for encryption.
* @param params the parameters required to set up the cipher.
* @exception ArgumentException if the params argument is
* inappropriate.
*/
public virtual void Init(
bool forEncryption,
ICipherParameters parameters)
{
if (!(parameters is KeyParameter))
throw new ArgumentException("Invalid parameters passed to Noekeon init - "
+ Platform.GetTypeName(parameters), "parameters");
_forEncryption = forEncryption;
_initialised = true;
KeyParameter p = (KeyParameter) parameters;
setKey(p.GetKey());
}
public virtual int ProcessBlock(
byte[] input,
int inOff,
byte[] output,
int outOff)
{
if (!_initialised)
throw new InvalidOperationException(AlgorithmName + " not initialised");
Check.DataLength(input, inOff, GenericSize, "input buffer too short");
Check.OutputLength(output, outOff, GenericSize, "output buffer too short");
return _forEncryption
? encryptBlock(input, inOff, output, outOff)
: decryptBlock(input, inOff, output, outOff);
}
public virtual void Reset()
{
// TODO This should do something in case the encryption is aborted
}
/**
* Re-key the cipher.
*
* @param key the key to be used
*/
private void setKey(byte[] key)
{
subKeys[0] = Pack.BE_To_UInt32(key, 0);
subKeys[1] = Pack.BE_To_UInt32(key, 4);
subKeys[2] = Pack.BE_To_UInt32(key, 8);
subKeys[3] = Pack.BE_To_UInt32(key, 12);
}
private int encryptBlock(
byte[] input,
int inOff,
byte[] output,
int outOff)
{
state[0] = Pack.BE_To_UInt32(input, inOff);
state[1] = Pack.BE_To_UInt32(input, inOff+4);
state[2] = Pack.BE_To_UInt32(input, inOff+8);
state[3] = Pack.BE_To_UInt32(input, inOff+12);
int i;
for (i = 0; i < GenericSize; i++)
{
state[0] ^= roundConstants[i];
theta(state, subKeys);
pi1(state);
gamma(state);
pi2(state);
}
state[0] ^= roundConstants[i];
theta(state, subKeys);
Pack.UInt32_To_BE(state[0], output, outOff);
Pack.UInt32_To_BE(state[1], output, outOff+4);
Pack.UInt32_To_BE(state[2], output, outOff+8);
Pack.UInt32_To_BE(state[3], output, outOff+12);
return GenericSize;
}
private int decryptBlock(
byte[] input,
int inOff,
byte[] output,
int outOff)
{
state[0] = Pack.BE_To_UInt32(input, inOff);
state[1] = Pack.BE_To_UInt32(input, inOff+4);
state[2] = Pack.BE_To_UInt32(input, inOff+8);
state[3] = Pack.BE_To_UInt32(input, inOff+12);
Array.Copy(subKeys, 0, decryptKeys, 0, subKeys.Length);
theta(decryptKeys, nullVector);
int i;
for (i = GenericSize; i > 0; i--)
{
theta(state, decryptKeys);
state[0] ^= roundConstants[i];
pi1(state);
gamma(state);
pi2(state);
}
theta(state, decryptKeys);
state[0] ^= roundConstants[i];
Pack.UInt32_To_BE(state[0], output, outOff);
Pack.UInt32_To_BE(state[1], output, outOff+4);
Pack.UInt32_To_BE(state[2], output, outOff+8);
Pack.UInt32_To_BE(state[3], output, outOff+12);
return GenericSize;
}
private void gamma(uint[] a)
{
a[1] ^= ~a[3] & ~a[2];
a[0] ^= a[2] & a[1];
uint tmp = a[3];
a[3] = a[0];
a[0] = tmp;
a[2] ^= a[0]^a[1]^a[3];
a[1] ^= ~a[3] & ~a[2];
a[0] ^= a[2] & a[1];
}
private void theta(uint[] a, uint[] k)
{
uint tmp;
tmp = a[0]^a[2];
tmp ^= rotl(tmp,8)^rotl(tmp,24);
a[1] ^= tmp;
a[3] ^= tmp;
for (int i = 0; i < 4; i++)
{
a[i] ^= k[i];
}
tmp = a[1]^a[3];
tmp ^= rotl(tmp,8)^rotl(tmp,24);
a[0] ^= tmp;
a[2] ^= tmp;
}
private void pi1(uint[] a)
{
a[1] = rotl(a[1], 1);
a[2] = rotl(a[2], 5);
a[3] = rotl(a[3], 2);
}
private void pi2(uint[] a)
{
a[1] = rotl(a[1], 31);
a[2] = rotl(a[2], 27);
a[3] = rotl(a[3], 30);
}
// Helpers
private uint rotl(uint x, int y)
{
return (x << y) | (x >> (32-y));
}
}
}
|
