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
|
package org.bouncycastle.crypto.engines;
import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.Wrapper;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.util.Arrays;
/**
* an implementation of the AES Key Wrapper from the NIST Key Wrap
* Specification as described in RFC 3394.
* <p>
* For further details see: <a href="http://www.ietf.org/rfc/rfc3394.txt">http://www.ietf.org/rfc/rfc3394.txt</a>
* and <a href="http://csrc.nist.gov/encryption/kms/key-wrap.pdf">http://csrc.nist.gov/encryption/kms/key-wrap.pdf</a>.
*/
public class RFC3394WrapEngine
implements Wrapper
{
private BlockCipher engine;
private KeyParameter param;
private boolean forWrapping;
private byte[] iv = {
(byte)0xa6, (byte)0xa6, (byte)0xa6, (byte)0xa6,
(byte)0xa6, (byte)0xa6, (byte)0xa6, (byte)0xa6 };
public RFC3394WrapEngine(BlockCipher engine)
{
this.engine = engine;
}
public void init(
boolean forWrapping,
CipherParameters param)
{
this.forWrapping = forWrapping;
if (param instanceof ParametersWithRandom)
{
param = ((ParametersWithRandom) param).getParameters();
}
if (param instanceof KeyParameter)
{
this.param = (KeyParameter)param;
}
else if (param instanceof ParametersWithIV)
{
this.iv = ((ParametersWithIV)param).getIV();
this.param = (KeyParameter)((ParametersWithIV) param).getParameters();
if (this.iv.length != 8)
{
throw new IllegalArgumentException("IV not equal to 8");
}
}
}
public String getAlgorithmName()
{
return engine.getAlgorithmName();
}
public byte[] wrap(
byte[] in,
int inOff,
int inLen)
{
if (!forWrapping)
{
throw new IllegalStateException("not set for wrapping");
}
int n = inLen / 8;
if ((n * 8) != inLen)
{
throw new DataLengthException("wrap data must be a multiple of 8 bytes");
}
byte[] block = new byte[inLen + iv.length];
byte[] buf = new byte[8 + iv.length];
System.arraycopy(iv, 0, block, 0, iv.length);
System.arraycopy(in, inOff, block, iv.length, inLen);
engine.init(true, param);
for (int j = 0; j != 6; j++)
{
for (int i = 1; i <= n; i++)
{
System.arraycopy(block, 0, buf, 0, iv.length);
System.arraycopy(block, 8 * i, buf, iv.length, 8);
engine.processBlock(buf, 0, buf, 0);
int t = n * j + i;
for (int k = 1; t != 0; k++)
{
byte v = (byte)t;
buf[iv.length - k] ^= v;
t >>>= 8;
}
System.arraycopy(buf, 0, block, 0, 8);
System.arraycopy(buf, 8, block, 8 * i, 8);
}
}
return block;
}
public byte[] unwrap(
byte[] in,
int inOff,
int inLen)
throws InvalidCipherTextException
{
if (forWrapping)
{
throw new IllegalStateException("not set for unwrapping");
}
int n = inLen / 8;
if ((n * 8) != inLen)
{
throw new InvalidCipherTextException("unwrap data must be a multiple of 8 bytes");
}
byte[] block = new byte[inLen - iv.length];
byte[] a = new byte[iv.length];
byte[] buf = new byte[8 + iv.length];
System.arraycopy(in, inOff, a, 0, iv.length);
System.arraycopy(in, inOff + iv.length, block, 0, inLen - iv.length);
engine.init(false, param);
n = n - 1;
for (int j = 5; j >= 0; j--)
{
for (int i = n; i >= 1; i--)
{
System.arraycopy(a, 0, buf, 0, iv.length);
System.arraycopy(block, 8 * (i - 1), buf, iv.length, 8);
int t = n * j + i;
for (int k = 1; t != 0; k++)
{
byte v = (byte)t;
buf[iv.length - k] ^= v;
t >>>= 8;
}
engine.processBlock(buf, 0, buf, 0);
System.arraycopy(buf, 0, a, 0, 8);
System.arraycopy(buf, 8, block, 8 * (i - 1), 8);
}
}
if (!Arrays.constantTimeAreEqual(a, iv))
{
throw new InvalidCipherTextException("checksum failed");
}
return block;
}
}
|