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
|
package org.bouncycastle.crypto.macs;
import java.util.Hashtable;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.ExtendedDigest;
import org.bouncycastle.crypto.Mac;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.util.Integers;
import org.bouncycastle.util.Memoable;
/**
* HMAC implementation based on RFC2104
*
* H(K XOR opad, H(K XOR ipad, text))
*/
public class HMac
implements Mac
{
private final static byte IPAD = (byte)0x36;
private final static byte OPAD = (byte)0x5C;
private Digest digest;
private int digestSize;
private int blockLength;
private Memoable ipadState;
private Memoable opadState;
private byte[] inputPad;
private byte[] outputBuf;
private static Hashtable blockLengths;
static
{
blockLengths = new Hashtable();
blockLengths.put("GOST3411", Integers.valueOf(32));
blockLengths.put("MD2", Integers.valueOf(16));
blockLengths.put("MD4", Integers.valueOf(64));
blockLengths.put("MD5", Integers.valueOf(64));
blockLengths.put("RIPEMD128", Integers.valueOf(64));
blockLengths.put("RIPEMD160", Integers.valueOf(64));
blockLengths.put("SHA-1", Integers.valueOf(64));
blockLengths.put("SHA-224", Integers.valueOf(64));
blockLengths.put("SHA-256", Integers.valueOf(64));
blockLengths.put("SHA-384", Integers.valueOf(128));
blockLengths.put("SHA-512", Integers.valueOf(128));
blockLengths.put("Tiger", Integers.valueOf(64));
blockLengths.put("Whirlpool", Integers.valueOf(64));
}
private static int getByteLength(
Digest digest)
{
if (digest instanceof ExtendedDigest)
{
return ((ExtendedDigest)digest).getByteLength();
}
Integer b = (Integer)blockLengths.get(digest.getAlgorithmName());
if (b == null)
{
throw new IllegalArgumentException("unknown digest passed: " + digest.getAlgorithmName());
}
return b.intValue();
}
/**
* Base constructor for one of the standard digest algorithms that the
* byteLength of the algorithm is know for.
*
* @param digest the digest.
*/
public HMac(
Digest digest)
{
this(digest, getByteLength(digest));
}
private HMac(
Digest digest,
int byteLength)
{
this.digest = digest;
this.digestSize = digest.getDigestSize();
this.blockLength = byteLength;
this.inputPad = new byte[blockLength];
this.outputBuf = new byte[blockLength + digestSize];
}
public String getAlgorithmName()
{
return digest.getAlgorithmName() + "/HMAC";
}
public Digest getUnderlyingDigest()
{
return digest;
}
public void init(
CipherParameters params)
{
digest.reset();
byte[] key = ((KeyParameter)params).getKey();
int keyLength = key.length;
if (keyLength > blockLength)
{
digest.update(key, 0, keyLength);
digest.doFinal(inputPad, 0);
keyLength = digestSize;
}
else
{
System.arraycopy(key, 0, inputPad, 0, keyLength);
}
for (int i = keyLength; i < inputPad.length; i++)
{
inputPad[i] = 0;
}
System.arraycopy(inputPad, 0, outputBuf, 0, blockLength);
xorPad(inputPad, blockLength, IPAD);
xorPad(outputBuf, blockLength, OPAD);
if (digest instanceof Memoable)
{
opadState = ((Memoable)digest).copy();
((Digest)opadState).update(outputBuf, 0, blockLength);
}
digest.update(inputPad, 0, inputPad.length);
if (digest instanceof Memoable)
{
ipadState = ((Memoable)digest).copy();
}
}
public int getMacSize()
{
return digestSize;
}
public void update(
byte in)
{
digest.update(in);
}
public void update(
byte[] in,
int inOff,
int len)
{
digest.update(in, inOff, len);
}
public int doFinal(
byte[] out,
int outOff)
{
digest.doFinal(outputBuf, blockLength);
if (opadState != null)
{
((Memoable)digest).reset(opadState);
digest.update(outputBuf, blockLength, digest.getDigestSize());
}
else
{
digest.update(outputBuf, 0, outputBuf.length);
}
int len = digest.doFinal(out, outOff);
for (int i = blockLength; i < outputBuf.length; i++)
{
outputBuf[i] = 0;
}
if (ipadState != null)
{
((Memoable)digest).reset(ipadState);
}
else
{
digest.update(inputPad, 0, inputPad.length);
}
return len;
}
/**
* Reset the mac generator.
*/
public void reset()
{
/*
* reset the underlying digest.
*/
digest.reset();
/*
* reinitialize the digest.
*/
digest.update(inputPad, 0, inputPad.length);
}
private static void xorPad(byte[] pad, int len, byte n)
{
for (int i = 0; i < len; ++i)
{
pad[i] ^= n;
}
}
}
|
