CipherFactory
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Kisa;
using Org.BouncyCastle.Asn1.Misc;
using Org.BouncyCastle.Asn1.Nist;
using Org.BouncyCastle.Asn1.Ntt;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
using System;
namespace Org.BouncyCastle.Crypto.Utilities
{
public class CipherFactory
{
private static readonly byte[] RC2Ekb = new byte[256] {
93,
190,
155,
139,
17,
153,
110,
77,
89,
243,
133,
166,
63,
183,
131,
197,
228,
115,
107,
58,
104,
90,
192,
71,
160,
100,
52,
12,
241,
208,
82,
165,
185,
30,
150,
67,
65,
216,
212,
44,
219,
248,
7,
119,
42,
202,
235,
239,
16,
28,
22,
13,
56,
114,
47,
137,
193,
249,
128,
196,
109,
174,
48,
61,
206,
32,
99,
254,
230,
26,
199,
184,
80,
232,
36,
23,
252,
37,
111,
187,
106,
163,
68,
83,
217,
162,
1,
171,
188,
182,
31,
152,
238,
154,
167,
45,
79,
158,
142,
172,
224,
198,
73,
70,
41,
244,
148,
138,
175,
225,
91,
195,
179,
123,
87,
209,
124,
156,
237,
135,
64,
140,
226,
203,
147,
20,
201,
97,
46,
229,
204,
246,
94,
168,
92,
214,
117,
141,
98,
149,
88,
105,
118,
161,
74,
181,
85,
9,
120,
51,
130,
215,
221,
121,
245,
27,
11,
222,
38,
33,
40,
116,
4,
151,
86,
223,
60,
240,
55,
57,
220,
byte.MaxValue,
6,
164,
234,
66,
8,
218,
180,
113,
176,
207,
18,
122,
78,
250,
108,
29,
132,
0,
200,
127,
145,
69,
170,
43,
194,
177,
143,
213,
186,
242,
173,
25,
178,
103,
54,
247,
15,
10,
146,
125,
227,
157,
233,
144,
62,
35,
39,
102,
19,
236,
129,
21,
189,
34,
191,
159,
126,
169,
81,
75,
76,
251,
2,
211,
112,
134,
49,
231,
59,
5,
3,
84,
96,
72,
101,
24,
210,
205,
95,
50,
136,
14,
53,
253
};
private CipherFactory()
{
}
private static int GetRC2EffectiveKeyBits(RC2CbcParameter rc2CbcParameter)
{
DerInteger rC2ParameterVersionData = rc2CbcParameter.RC2ParameterVersionData;
if (rC2ParameterVersionData == null)
return 32;
int intPositiveValueExact = rC2ParameterVersionData.IntPositiveValueExact;
if (intPositiveValueExact >= 256)
return intPositiveValueExact;
return RC2Ekb[intPositiveValueExact];
}
public static object CreateContentCipher(bool forEncryption, ICipherParameters encKey, AlgorithmIdentifier encryptionAlgID)
{
DerObjectIdentifier algorithm = encryptionAlgID.Algorithm;
if (algorithm.Equals(PkcsObjectIdentifiers.rc4)) {
RC4Engine rC4Engine = new RC4Engine();
rC4Engine.Init(forEncryption, encKey);
return rC4Engine;
}
BufferedBlockCipher bufferedBlockCipher = CreateCipher(encryptionAlgID.Algorithm);
Asn1Object asn1Object = encryptionAlgID.Parameters.ToAsn1Object();
if (asn1Object != null && !(asn1Object is DerNull)) {
if (algorithm.Equals(PkcsObjectIdentifiers.DesEde3Cbc) || algorithm.Equals(AlgorithmIdentifierFactory.IDEA_CBC) || algorithm.Equals(NistObjectIdentifiers.IdAes128Cbc) || algorithm.Equals(NistObjectIdentifiers.IdAes192Cbc) || algorithm.Equals(NistObjectIdentifiers.IdAes256Cbc) || algorithm.Equals(NttObjectIdentifiers.IdCamellia128Cbc) || algorithm.Equals(NttObjectIdentifiers.IdCamellia192Cbc) || algorithm.Equals(NttObjectIdentifiers.IdCamellia256Cbc) || algorithm.Equals(KisaObjectIdentifiers.IdSeedCbc) || algorithm.Equals(OiwObjectIdentifiers.DesCbc))
bufferedBlockCipher.Init(forEncryption, new ParametersWithIV(encKey, Asn1OctetString.GetInstance(asn1Object).GetOctets()));
else if (algorithm.Equals(AlgorithmIdentifierFactory.CAST5_CBC)) {
Cast5CbcParameters instance = Cast5CbcParameters.GetInstance(asn1Object);
bufferedBlockCipher.Init(forEncryption, new ParametersWithIV(encKey, instance.GetIV()));
} else {
if (!algorithm.Equals(PkcsObjectIdentifiers.RC2Cbc))
throw new InvalidOperationException("cannot match parameters");
RC2CbcParameter instance2 = RC2CbcParameter.GetInstance(asn1Object);
RC2Parameters parameters = new RC2Parameters(((KeyParameter)encKey).GetKey(), GetRC2EffectiveKeyBits(instance2));
bufferedBlockCipher.Init(forEncryption, new ParametersWithIV(parameters, instance2.IV.GetOctets()));
}
} else if (algorithm.Equals(PkcsObjectIdentifiers.DesEde3Cbc) || algorithm.Equals(AlgorithmIdentifierFactory.IDEA_CBC) || algorithm.Equals(AlgorithmIdentifierFactory.CAST5_CBC)) {
bufferedBlockCipher.Init(forEncryption, new ParametersWithIV(encKey, new byte[8]));
} else {
bufferedBlockCipher.Init(forEncryption, encKey);
}
return bufferedBlockCipher;
}
private static BufferedBlockCipher CreateCipher(DerObjectIdentifier algorithm)
{
IBlockCipherMode cipherMode;
if (NistObjectIdentifiers.IdAes128Cbc.Equals(algorithm) || NistObjectIdentifiers.IdAes192Cbc.Equals(algorithm) || NistObjectIdentifiers.IdAes256Cbc.Equals(algorithm))
cipherMode = new CbcBlockCipher(AesUtilities.CreateEngine());
else if (PkcsObjectIdentifiers.DesEde3Cbc.Equals(algorithm)) {
cipherMode = new CbcBlockCipher(new DesEdeEngine());
} else if (OiwObjectIdentifiers.DesCbc.Equals(algorithm)) {
cipherMode = new CbcBlockCipher(new DesEngine());
} else if (PkcsObjectIdentifiers.RC2Cbc.Equals(algorithm)) {
cipherMode = new CbcBlockCipher(new RC2Engine());
} else {
if (!MiscObjectIdentifiers.cast5CBC.Equals(algorithm))
throw new InvalidOperationException("cannot recognise cipher: " + algorithm?.ToString());
cipherMode = new CbcBlockCipher(new Cast5Engine());
}
return new PaddedBufferedBlockCipher(cipherMode, new Pkcs7Padding());
}
}
}