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
|
/*
KeePass Password Safe - The Open-Source Password Manager
Copyright (C) 2003-2017 Dominik Reichl <dominik.reichl@t-online.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Security;
using System.Diagnostics;
#if !KeePassUAP
using System.Security.Cryptography;
#endif
using KeePassLib.Resources;
namespace KeePassLib.Cryptography.Cipher
{
/// <summary>
/// Standard AES cipher implementation.
/// </summary>
public sealed class StandardAesEngine : ICipherEngine
{
#if !KeePassUAP
private const CipherMode m_rCipherMode = CipherMode.CBC;
private const PaddingMode m_rCipherPadding = PaddingMode.PKCS7;
#endif
private static PwUuid g_uuidAes = null;
/// <summary>
/// UUID of the cipher engine. This ID uniquely identifies the
/// AES engine. Must not be used by other ciphers.
/// </summary>
public static PwUuid AesUuid
{
get
{
PwUuid pu = g_uuidAes;
if(pu == null)
{
pu = new PwUuid(new byte[] {
0x31, 0xC1, 0xF2, 0xE6, 0xBF, 0x71, 0x43, 0x50,
0xBE, 0x58, 0x05, 0x21, 0x6A, 0xFC, 0x5A, 0xFF });
g_uuidAes = pu;
}
return pu;
}
}
/// <summary>
/// Get the UUID of this cipher engine as <c>PwUuid</c> object.
/// </summary>
public PwUuid CipherUuid
{
get { return StandardAesEngine.AesUuid; }
}
/// <summary>
/// Get a displayable name describing this cipher engine.
/// </summary>
public string DisplayName
{
get
{
return ("AES/Rijndael (" + KLRes.KeyBits.Replace(@"{PARAM}",
"256") + ", FIPS 197)");
}
}
private static void ValidateArguments(Stream stream, bool bEncrypt, byte[] pbKey, byte[] pbIV)
{
Debug.Assert(stream != null); if(stream == null) throw new ArgumentNullException("stream");
Debug.Assert(pbKey != null); if(pbKey == null) throw new ArgumentNullException("pbKey");
Debug.Assert(pbKey.Length == 32);
if(pbKey.Length != 32) throw new ArgumentException("Key must be 256 bits wide!");
Debug.Assert(pbIV != null); if(pbIV == null) throw new ArgumentNullException("pbIV");
Debug.Assert(pbIV.Length == 16);
if(pbIV.Length != 16) throw new ArgumentException("Initialization vector must be 128 bits wide!");
if(bEncrypt)
{
Debug.Assert(stream.CanWrite);
if(!stream.CanWrite) throw new ArgumentException("Stream must be writable!");
}
else // Decrypt
{
Debug.Assert(stream.CanRead);
if(!stream.CanRead) throw new ArgumentException("Encrypted stream must be readable!");
}
}
private static Stream CreateStream(Stream s, bool bEncrypt, byte[] pbKey, byte[] pbIV)
{
StandardAesEngine.ValidateArguments(s, bEncrypt, pbKey, pbIV);
byte[] pbLocalIV = new byte[16];
Array.Copy(pbIV, pbLocalIV, 16);
byte[] pbLocalKey = new byte[32];
Array.Copy(pbKey, pbLocalKey, 32);
#if KeePassUAP
return StandardAesEngineExt.CreateStream(s, bEncrypt, pbLocalKey, pbLocalIV);
#else
RijndaelManaged r = new RijndaelManaged();
if(r.BlockSize != 128) // AES block size
{
Debug.Assert(false);
r.BlockSize = 128;
}
r.IV = pbLocalIV;
r.KeySize = 256;
r.Key = pbLocalKey;
r.Mode = m_rCipherMode;
r.Padding = m_rCipherPadding;
ICryptoTransform iTransform = (bEncrypt ? r.CreateEncryptor() : r.CreateDecryptor());
Debug.Assert(iTransform != null);
if(iTransform == null) throw new SecurityException("Unable to create Rijndael transform!");
return new CryptoStream(s, iTransform, bEncrypt ? CryptoStreamMode.Write :
CryptoStreamMode.Read);
#endif
}
public Stream EncryptStream(Stream sPlainText, byte[] pbKey, byte[] pbIV)
{
return StandardAesEngine.CreateStream(sPlainText, true, pbKey, pbIV);
}
public Stream DecryptStream(Stream sEncrypted, byte[] pbKey, byte[] pbIV)
{
return StandardAesEngine.CreateStream(sEncrypted, false, pbKey, pbIV);
}
}
}
|
