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
|
using System;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
namespace Org.BouncyCastle.Crypto.Generators
{
/**
* Generator for PBE derived keys and ivs as usd by OpenSSL.
* <p>
* The scheme is a simple extension of PKCS 5 V2.0 Scheme 1 using MD5 with an
* iteration count of 1.
* </p>
*/
public class OpenSslPbeParametersGenerator
: PbeParametersGenerator
{
private readonly IDigest digest = new MD5Digest();
/**
* Construct a OpenSSL Parameters generator.
*/
public OpenSslPbeParametersGenerator()
{
}
public override void Init(
byte[] password,
byte[] salt,
int iterationCount)
{
// Ignore the provided iterationCount
base.Init(password, salt, 1);
}
/**
* Initialise - note the iteration count for this algorithm is fixed at 1.
*
* @param password password to use.
* @param salt salt to use.
*/
public virtual void Init(
byte[] password,
byte[] salt)
{
base.Init(password, salt, 1);
}
/**
* the derived key function, the ith hash of the password and the salt.
*/
private byte[] GenerateDerivedKey(
int bytesNeeded)
{
byte[] buf = new byte[digest.GetDigestSize()];
byte[] key = new byte[bytesNeeded];
int offset = 0;
for (;;)
{
digest.BlockUpdate(mPassword, 0, mPassword.Length);
digest.BlockUpdate(mSalt, 0, mSalt.Length);
digest.DoFinal(buf, 0);
int len = (bytesNeeded > buf.Length) ? buf.Length : bytesNeeded;
Array.Copy(buf, 0, key, offset, len);
offset += len;
// check if we need any more
bytesNeeded -= len;
if (bytesNeeded == 0)
{
break;
}
// do another round
digest.Reset();
digest.BlockUpdate(buf, 0, buf.Length);
}
return key;
}
/**
* Generate a key parameter derived from the password, salt, and iteration
* count we are currently initialised with.
*
* @param keySize the size of the key we want (in bits)
* @return a KeyParameter object.
* @exception ArgumentException if the key length larger than the base hash size.
*/
[Obsolete("Use version with 'algorithm' parameter")]
public override ICipherParameters GenerateDerivedParameters(
int keySize)
{
return GenerateDerivedMacParameters(keySize);
}
public override ICipherParameters GenerateDerivedParameters(
string algorithm,
int keySize)
{
keySize /= 8;
byte[] dKey = GenerateDerivedKey(keySize);
return ParameterUtilities.CreateKeyParameter(algorithm, dKey, 0, keySize);
}
/**
* Generate a key with initialisation vector parameter derived from
* the password, salt, and iteration count we are currently initialised
* with.
*
* @param keySize the size of the key we want (in bits)
* @param ivSize the size of the iv we want (in bits)
* @return a ParametersWithIV object.
* @exception ArgumentException if keySize + ivSize is larger than the base hash size.
*/
[Obsolete("Use version with 'algorithm' parameter")]
public override ICipherParameters GenerateDerivedParameters(
int keySize,
int ivSize)
{
keySize = keySize / 8;
ivSize = ivSize / 8;
byte[] dKey = GenerateDerivedKey(keySize + ivSize);
return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize);
}
public override ICipherParameters GenerateDerivedParameters(
string algorithm,
int keySize,
int ivSize)
{
keySize /= 8;
ivSize /= 8;
byte[] dKey = GenerateDerivedKey(keySize + ivSize);
KeyParameter key = ParameterUtilities.CreateKeyParameter(algorithm, dKey, 0, keySize);
return new ParametersWithIV(key, dKey, keySize, ivSize);
}
/**
* Generate a key parameter for use with a MAC derived from the password,
* salt, and iteration count we are currently initialised with.
*
* @param keySize the size of the key we want (in bits)
* @return a KeyParameter object.
* @exception ArgumentException if the key length larger than the base hash size.
*/
public override ICipherParameters GenerateDerivedMacParameters(
int keySize)
{
keySize = keySize / 8;
byte[] dKey = GenerateDerivedKey(keySize);
return new KeyParameter(dKey, 0, keySize);
}
}
}
|
